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| author | nfenwick <nfenwick@pglaf.org> | 2025-01-22 17:01:56 -0800 |
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| committer | nfenwick <nfenwick@pglaf.org> | 2025-01-22 17:01:56 -0800 |
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diff --git a/.gitattributes b/.gitattributes new file mode 100644 index 0000000..d7b82bc --- /dev/null +++ b/.gitattributes @@ -0,0 +1,4 @@ +*.txt text eol=lf +*.htm text eol=lf +*.html text eol=lf +*.md text eol=lf diff --git a/LICENSE.txt b/LICENSE.txt new file mode 100644 index 0000000..6312041 --- /dev/null +++ b/LICENSE.txt @@ -0,0 +1,11 @@ +This eBook, including all associated images, markup, improvements, +metadata, and any other content or labor, has been confirmed to be +in the PUBLIC DOMAIN IN THE UNITED STATES. + +Procedures for determining public domain status are described in +the "Copyright How-To" at https://www.gutenberg.org. + +No investigation has been made concerning possible copyrights in +jurisdictions other than the United States. Anyone seeking to utilize +this eBook outside of the United States should confirm copyright +status under the laws that apply to them. diff --git a/README.md b/README.md new file mode 100644 index 0000000..b58e93d --- /dev/null +++ b/README.md @@ -0,0 +1,2 @@ +Project Gutenberg (https://www.gutenberg.org) public repository for +eBook #66306 (https://www.gutenberg.org/ebooks/66306) diff --git a/old/66306-0.txt b/old/66306-0.txt deleted file mode 100644 index c6929b3..0000000 --- a/old/66306-0.txt +++ /dev/null @@ -1,5449 +0,0 @@ -The Project Gutenberg eBook of Stray Feathers From a Bird Man's Desk, by -Austin L. Rand - -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online at -www.gutenberg.org. If you are not located in the United States, you -will have to check the laws of the country where you are located before -using this eBook. - -Title: Stray Feathers From a Bird Man's Desk - -Author: Austin L. Rand - -Release Date: September 14, 2021 [eBook #66306] - -Language: English - -Character set encoding: UTF-8 - -Produced by: Tim Lindell, Tom Cosmas and the Online Distributed - Proofreading Team at https://www.pgdp.net (This book was - produced from images made available by the HathiTrust Digital - Library.) - -*** START OF THE PROJECT GUTENBERG EBOOK STRAY FEATHERS FROM A BIRD MAN'S -DESK *** - - - - -Transcriber Note - -Text emphasis denoted as _Italic_. - - - - - STRAY FEATHERS - FROM A BIRD MAN'S DESK - - - - - STRAY - FEATHERS - FROM - A BIRD MAN'S - DESK - - By Austin L. Rand - - CURATOR OF BIRDS, - CHICAGO NATURAL HISTORY MUSEUM - - WITH CARTOONS BY RUTH JOHNSON - - DOUBLEDAY & COMPANY, INC., GARDEN CITY, N.Y., 1955 - - - - - _Library of Congress Catalog Card Number 55-5254_ - - _Copyright, 1955, by Austin L. Rand_ © - _All Rights Reserved_ - _Printed in the United States_ - _At the Country Life Press, Garden City, N.Y._ - _First Edition_ - - - - -CONTENTS - - - PAGE - Introduction 9 - Birds Using Tools 15 - Birds as Brigands 19 - Birds Bathing 22 - How Birds Anoint Their Feathers 25 - Traveling Birds' Nests 28 - Maladaptation in Birds 31 - Feathered Baby Sitters and Co-op Nursery Nests 35 - Birds' Nests and Their Soup 38 - Walled Wives of Hornbills 42 - Buried Eggs and Young 45 - The Snowy Owl as a Trade Index 48 - Monkey Birds 51 - Bird-Made Incubators 54 - Cormorant Fishing 57 - The Shrike's Larder 60 - Bird Flavors 63 - How Many Feathers Has a Bird? 66 - Last Year's Birds' Nests 69 - Symbiosis--Animals Living in Mixed Households 73 - Bird Apartment Houses 77 - Bird Helpers at Nesting Time 81 - A Name for a Boat 84 - Weavers and Tailors in the Bird World 88 - Social Parasites among Birds 91 - Fish Eats Bird! 95 - Crows Are Smarter Than "Wise" Owls 98 - Tame Wild Birds 101 - Birds as Pilferers 104 - Hibernation in Birds 108 - Snakeskins in Birds' Nests 111 - Co-operation by Birds 117 - Watchdogs at the Nest 121 - Bird Guides to Honey 124 - Oxpeckers 127 - Wings in Feeding 130 - Instrumental Music of Birds 133 - Conditioning in Birds 136 - Poisonous Birds 140 - Kingfishers on the Telephone 143 - On Identifying Sea Serpents 147 - Conservation over the Telephone 151 - Birds Washing Food 154 - How Animal Voices Sound to Foreign Ears 157 - Sight Identification 160 - Green Hunting Jays Turn Blue 164 - How Birds Use Cows as Hunting Dogs 167 - Early Bird Listing 171 - Battle of the Sexes and Its Evolutionary Significance 173 - Water in the Desert 177 - Bird Graveyards 180 - Animal Gardens 183 - Dropping Things 186 - Learning by Birds 189 - Can Birds Count? 192 - Courtship Feeding 195 - They Turned the Tables 198 - Survival of the Unfit 201 - Dust and Snow Bathing 204 - Decoration in the Home 207 - Curiosity in Birds 210 - References 213 - Index 221 - - - - - -INTRODUCTION - - -In looking back over the preparation of these sketches I feel as though -each evening I'd gathered up the bits and pieces left over from the -day's work and fashioned them into designs for my own amusement and the -edification of my family. Truly it's as though I'd used stray feathers, -fallen from the bird skins I'd handled, and fitted them together into -something of wider interest than the original. - -Much of my work now is museum research, working with bird specimens -and books. In fashioning a research paper I always amass a great deal -more material, that is to say, information and ideas, than I am able -to use in it. In place of a lumber room I have a set of files with -index headings that range from Abundance and Age, through such headings -as Beauty, Feathering of Feet, Fictitious, Hysteria, Pterylography, -Social, Song, Tail Feathers, Valentine's Day, to Zoogeography. Here -I put the information that is irrelevant at the moment but too -interesting to discard. Its source is varied. Some has been accumulated -while studying specimens from localities as geographically separated as -Alaska, El Salvador, Gabon, Tristan da Cunha, Nepal, Negros, and New -Guinea; and while writing papers that range from describing new species -to discussing secondary sexual characters and ecological competition. -Some have been recorded while in the field on expeditions, trips that -ranged from two years in Madagascar, three expeditions in New Guinea, -and a season in the Philippines to trips nearer home from the Yukon to -Nova Scotia, Florida, and Central America. - -Gradually information builds up under each heading, and new ones are -added. These items are too interesting to remain buried in the files. -They are things people want to know about. So I began to draft them -into articles for publication in the museum's monthly, _The Chicago -Natural History Museum Bulletin_. The response was gratifying. The -press picked them up and reprinted them. One was used in a Chicago -_Tribune_ editorial. Several were used in commercial radio programs. -Encouraged, I prepared more, soon overrunning the space available in -the bulletin. - -Most scientific papers are not written to be read for enjoyment. -Conciseness as well as clarity are striven for, conveying certain -information in a small compass. The correlations made are often obscure -ones, appreciated only by scientists. Yet the material they contain -is often intensely interesting, and if these papers were written in -a more leisurely style, with more general correlations pointed out, -they would provide both interesting and entertaining reading. In a few -cases my own research falls in this class, and I've rewritten some of -my own papers with this in mind (_see_ "Battle of the Sexes and Its -Evolutionary Significance"). - -This collection of articles, if it were a painting, could be called a -conversation piece. Or it might be compared to a well-filled whatnot. -Each of the sixty chapters is an independent unit, illustrating some -facet of birds, their behavior, or our study of them. Some of the facts -may seem unusual or bizarre, but most of them are well known and well -documented. The thing that is new, if there is anything new, is the -setting in which I've placed them, the manner in which I've looked at -them. Taken as a whole, they touch on many different birds from many -different places in their less widely known aspects, and with a human -interest slant. - -"But what will your professional colleagues say?" asked a friend as -he flipped through the cartoons. "These pictures don't approach the -subject in a very serious manner." Quite true. But a discipline must -be very lightly rooted indeed if it can't stand a few caricatures and -cartoons and perhaps be the better for them. - -The knowledge of most people about the hornbills of tropical Africa, -the gulls of Australia, the penguins of Antarctica, and the crocodile -birds of the Nile is probably pretty vague. To give a frame of -reference in a biological sense is impractical in the compass of one -slim volume. - -But a ready-made frame of reference already exists: the parallels in -bird and in human. These I have used. But in so doing I am not imputing -human motives and attributes to birds. The actions are similar. The -workings of the human mind I understand only vaguely; that of the -bird I can study only through the actions of the birds. One set of -behavior may be learned and rational, one rigidly innate, entirely -instinctive, and inherited, or at most modified by experience. Be that -as it may, the similarity in the end result in two such different -vertebrate animals as man and bird when faced with similar problems is -often close. Perhaps it is because the solutions are necessarily few; -perhaps, and I incline to this feeling, it helps illustrate one aspect -of the close relationship between all animate nature. - -This series of articles is intended to be interesting and entertaining. -I hope it will also make more people aware of the many ways birds -act, here and in far places, how they have solved their problems and -profited by their opportunities. - - - - -STRAY FEATHERS FROM A BIRD MAN'S DESK - - - - -BIRDS USING TOOLS - -[Illustration] - - -Man is the tool user pre-eminent in the animal world, but he does not -stand completely alone in this. Here and there, in quite different -groups of animals such as insects, mammals, and birds, a few kinds have -forged a little ahead of the rest of their near relatives and show the -very beginning of tool using. - -The song thrush of Europe is perhaps a borderline case. It feeds in -part on snails. To get the soft edible animal out of its shell, it -carries or drags the snail to a favorite rock, its anvil, and there -hits it against the anvil until the shell is broken and its contents -exposed. The question is, can this be considered as using a tool? If -the song thrush moved or prepared the rock, which it does not do, -there would be no question that it was a tool. The sea otter brings -a stone from the bottom of the ocean and places it on its floating -body to use as a similar anvil in cracking hard objects, and this -undoubtedly is the use of a tool. At the other extreme are many species -of birds that beat their prey on branch or ground, wherever they happen -to be. The song thrush is certainly an advance over that, and can, I -think, be considered as using a tool in a primitive way. - -A few other species, too, bring shellfish to special places. Gulls on -our coasts pick up mussels and clams and, flying over a rock or some -other hard surface, drop the shellfish, and follow it down. If the -shell is broken, the dish is ready for the gull; if the shell is not -broken the gull takes the shellfish up to a higher altitude and tries -again. In places where hard-surfaced roads are conveniently located -gulls have learned to use them as shell-breaking places, and such roads -become littered with shells. - -Crows of more than one species also use the same routine in breaking -open shellfish, and they, too, have learned to use special hard -surfaces, such as masonry walls, on which to drop the shellfish. - - -PAINTING A BOWER The satin bowerbird of Australia, a species known to -science as _Ptilonorhynchus violaceus_, has also been considered as a -case in point when discussing the use of tools. The birds are somewhat -larger than a robin, the male glossy blue-black, the female greenish. -The male of this species constructs an elaborate bower, presumably for -courtship purposes. It makes it of sticks and twigs, and decorates it -with bright and curious objects such as shells, feathers, bits of -bone, and fruits, as do several other species of bowerbirds. But the -satin bowerbird is unique in painting the inside of its bower. Fruit -is crushed in its bill, and the bird, using its bill as the tool or -paintbrush, smears the fruit juice on the sticks on the inside of the -bower. While this is a wonderfully strange habit, and apparently unique -in the bird world, it is doubtful if this behavior can be considered as -using a tool. If the satin bowerbird used a twig, or a wad of moss or -fiber, which it does not do, in spreading the paint, the case would be -clear. - -The clearest case is that of the woodpecker finch of the Galápagos -Islands. _Camarhynchus pallidus_ is its proper name. It is one of a -group of dull-colored finches restricted to the Galápagos Islands. -Before it became known that one species used a tool, the chief claim to -fame of the group was that it, along with some other Galápagos Island -animals, such as the giant tortoises, had a great influence on Darwin's -thinking which resulted in his working out the theory of evolution as -set forth in his _Origin of Species_. - -The woodpecker finch feeds largely on insects it gets by searching -and probing on the ground, and on the trunk and leaves of trees. In -searching crevices the woodpecker finch is handicapped by its rather -short, thick bill, and to offset this, it picks up a slender, short -length of stick, or the spine of a prickly pear, and with this in its -bill, pokes into crannies. The insects, disturbed or driven out, are -seized. Sometimes the woodpecker finch digs into the tree trunk and -then gets a stick to probe with; sometimes it carries its probe about -with it, poking in crannies until prey is disturbed. Then the stick is -dropped and the food seized. - -We have seen how several birds are perhaps borderline cases in -using tools. They use certain special aspects of their environment -in preparing their food, and use it time after time. It's probably -instinctive behavior, but learning is shown in the gulls and crows -coming to recognize and use a hard-surfaced road in breaking open their -shellfish. The use of a probe by the woodpecker finch is a clear and -unique case of tool using by a bird. - - - - -BIRDS AS BRIGANDS - -[Illustration] - - -Anti-social activities of humans such as those of brigands who plunder -their fellow men find their parallels in the bird world. - -The bald eagle is one of the best-known of the birds that practice -such brigandage. Fond of fish, and capable of capturing it himself -upon occasion, it is a common practice for the eagle to take fish from -the osprey, plunder the osprey has just caught from the water. The -osprey, with a fresh-caught fish, flies heavily. The watching eagle -quickly overtakes the smaller, heavily laden bird and forces it to -drop its catch, then dives down and usually catches the fish before it -can strike the land or water. Rarely does the osprey escape with its -food under such an attack. It is recorded that an eagle made several -dives at one fish-laden osprey and, when these were not successful in -making it lose its hold on the fish, the eagle dived under the smaller -bird, turned over on its back, and with talons outstretched, snatched -the fish from the grasp of the osprey and sailed away with it, as -successful a pirate as ever sailed the seas. - - -NEMESIS OF VULTURES Besides taking fresh-caught food from the osprey -the bald eagle has been seen pursuing vultures and making them disgorge -their meal of carrion. The eagle, if unsuccessful in catching the -disgorged food in the air, may land on the ground and eat it there. -We know also that the aerial flights the eagle uses to frighten the -vulture into relinquishing his food are not idle threats, for an eagle -has been seen to strike and kill a bird that refused to disgorge. - -Not only does our American eagle adopt such practices, but related -species in other parts of the world behave in similar ways. The New -Guinea sea eagle harries the osprey there, and on the west coast of -Africa a sea eagle robs pelicans and cormorants of their prey. - -Certain long-winged birds of the tropical seas, such as _Fregata -magnificens_, are known popularly as man-o'-war birds or frigate -birds, reflecting their well-known character as pirates and tyrannical -freebooters. The man-o'-war birds get part of their food from many -creatures which swarm at the surface of the sea, but they also get much -of their food by forcing terns, cormorants, boobies, and pelicans to -deliver up their catch. - -In a tropical bay a school of small fish comes to the surface, perhaps -driven by large fish below; from far and near terns gather, darting -down to seize the fish that jump into the air. Above them circle the -frigate birds, ready to dive down and chase and harry a successful tern -until it drops its fish and leaves its prey to the freebooter. - - -BOOBIES ARE VICTIMS Frigate birds may sail about, also, where a colony -of nesting brown boobies is located, waiting for the birds laden with -food to return home. When such a food-laden booby returns, the frigate -bird dashes down at it, buffets it with its wings, snaps at it with -its long, hooked bill, until the booby finally drops its fish for the -man-o'-war bird to enjoy. - -The skua, a big, dark relative of the gull, is also known as a pirate. -Its chief food is fish but it also eats many other foods from the -sea. It rarely takes the trouble to fish for itself but watches until -some other bird, perhaps a gull or a tern, has been successful in -its hunting and then gives chase, forcing the unfortunate hunter to -relinquish its food. Several of the skua's smaller relatives, the -jaegars, have similar habits. It is written of the pomarine jaegar off -our New England coast that they are notorious pirates and freebooters, -the highwaymen among birds that prey on their neighbors on the fishing -grounds and make them stand and deliver. The jaegar gives chase to a -tern that has caught a fish and follows it through every twist and turn -as if the two were yoked together. Finally the harassed tern drops its -fish and the jaeger swoops down and seizes it before it can strike the -water. - - - - -BIRDS BATHING - -[Illustration] - - -The toilet of most birds includes wetting their feathers in water and -shaking the feathers and preening them with the bill. This bathing -probably helps remove foreign matter from the birds' plumage and -helps keep it in good condition. In addition it is probable that in -summer the birds derive enjoyment from the coolness resulting from the -bathing. But birds bathe in cold weather as well as warm and have been -recorded doing so when the temperature of the air was only 10 or so -degrees above zero. - -The sparrows and robins that come about a birdbath usually hop right -into the water. They squat down, fluttering their wings, and duck their -heads into the water, splashing and rolling it over their backs. They -may become quite drenched. Then they fly to some perch to sit and preen -and dry their soaked feathers. - -But some birds take shower baths. During a shower in late summer I have -seen marsh hawks sitting in the rain with wings spread, apparently -enjoying the wetting the shower gives them, and a buzzard has been -recorded as deliberately flying to an open perch in a rainstorm and -sitting there with its wings spread and sometimes shaking them until -the shower was over, when it flew to a sheltered place. - - -SPRINKLERS A BOON The artificial showers of lawn sprinklers provide an -opportunity for birds about our gardens to take a shower bath in fine -weather. A robin or a flicker may hop into the shower and squat there -and indulge in bathing antics on the wet grass. Hummingbirds have been -seen to fly into the dense spray of a lawn sprinkler and hover there -for a moment, gradually assuming a vertical position and spreading the -tail, then slowly settling to the ground, and finally "sitting" on the -grass, body erect and tail spread out fanwise, the wings continuing to -vibrate slowly. In a few moments the bird may rise into the air and -repeat the whole performance. - -In wet tropical forest it is probable that many of the treetop birds -bathe in the water that collects on the surface of the leaves, pushing -their way through clusters of wet leaves and over wet surfaces of -others until they are as wet as if they had actually been bathing -in water. This is not restricted to tropical birds, for even in our -latitudes towhees have been recorded as bathing thus, and thrushes and -flickers have been seen to rub themselves over the wet grass and then -go through the actions of bathing followed by preening. - - -BATHING WHILE FLYING Watching swifts or swallows coursing low over the -surface of a lake and occasionally touching it leaves one with the -impression sometimes that the birds are bathing rather than picking up -insect food or drinking. With some other birds the habit of bathing -from the wing is more definite. Sometimes drongo shrikes that are -sitting up on a perch near the edge of a pool will fly out over the -water, drop directly into it with a little splash, and then rise and -fly back to their perch, where they either repeat the performance or -sit and preen their feathers. - - -POST-PRANDIAL ABLUTIONS Ospreys have been recorded as bathing while -on the wing in a rather striking manner. They have been seen flying -along just above the surface of the water, then descending into it, -adopting a sort of vertical American-eagle attitude while flapping the -wings, then rising a little, flying on, and repeating the process. It -has been suggested that the osprey is washing its feet in this manner -after finishing its meal. One observer makes this still more definite. -He says that the osprey finishes its meal of fish on a perch in a tree -and then flies low over the lake. Dropping both its legs, the osprey -drags them through the water, flapping its wings all the time. Then it -immerses its beak and head into the water while still flying along, -apparently washing off the scales and slime that it had gotten on -itself while making its meal of fish. - - - - -HOW BIRDS ANOINT THEIR FEATHERS - -[Illustration] - - -A bird's plumage receives a great deal of care from the bird that wears -it. The bill is the only implement for this grooming, and it is run -through and along the feathers it can reach, helping clean them and -making sure they lie in their proper place in the bird's dress. There -are parts of the plumage that the bird's bill obviously can't reach, -as that of the head, but ducks at least surmount this difficulty by -rubbing their head against their body. - -Many birds have oil glands (the only external glands that most birds -have), a pair of glands just above and in front of the root of the -tail, on the back. They contain an oily substance, and the usual -explanation of its use is that the secretion of these glands is used -in dressing the feathers. Certainly birds that have oil glands seem to -use them, nibbling at them as though to press out the oil, touching -them with the bill, and then rubbing the bill through the feathers, and -rubbing the head against the oil gland. - -The beautiful, soft, whitish bloom seen on some birds' feathers, such -as the pale gray of a male marsh hawk and filmy appearance of some -herons' plumage, is caused by specialized feathers called "powder -down." Sometimes this powder down is scattered through the plumage; -sometimes it is in patches, such as the particularly conspicuous ones -in the herons. The tips of the powder down are continually breaking off -and sifting over the rest of the plumage, giving it the bloom that with -handling quickly rubs off. - - -WALNUTS AS A COSMETIC But birds sometimes rub foreign substances over -their feathers--just why we don't know. Grackles have been known to use -the acid juice of green walnuts in preening. - -In Pennsylvania starlings have been seen to come to walnut trees when -the nuts were almost three-quarters grown, in June, and peck a hole in -the sticky hull of a nut, clip the bill into it, undoubtedly wetting -the bill against the pulpy interior, and then thrust the bill into -their plumage. - -They did this from June to August, especially on hot, dry summer days, -but some birds continued this even during light rain. Some years before -the above was recorded, when this sort of thing was less known, Edward -Howe Forbush, noted ornithologist, cautiously used a similar record in -his classical _Birds of Massachusetts and Other New England States_. He -writes that his colleague, J. N. Baskett, says he saw a bluejay lift -its wing and rub pungent walnut leaves repeatedly into the feathers -beneath. - - -BEER AND MOTH BALLS Since then such things have been recorded a number -of times, including a catbird that anointed its feathers with a leaf -and a grackle that found a moth ball and, holding this in its bill, -rubbed it against the underside of its spread wing and the side of its -body. After several applications the grackle dropped the moth ball and -preened its feathers; then again it picked up the moth ball and treated -the other wing as well as its belly. - -Recent experiments with tame song sparrows have shown that they may use -beer, orange juice, vinegar, and other things made available to them in -dressing their plumage, and it appears that this may be correlated with -a little-understood type of activity known as anting, in which live -ants are placed on the feathers. - - - - -TRAVELING BIRDS' NESTS - -[Illustration] - - -In spring and fall many of our birds make long journeys under their own -power, some of the most publicized being the migration of the Arctic -tern, a bird that may spend the northern summer north of the Arctic -Circle and, before returning there next season, may have visited south -of the Antarctic Circle. The golden plover that makes a nonstop flight -to Hawaii is another famous traveler, and many of our smaller songbirds -are no mean travelers either. The barn swallow that nests about an -Illinois farm in the summer may spend the winter in Argentina. The tiny -hummingbirds' feat of crossing the Gulf of Mexico nonstop is worthy of -mention too. Such travels have become commonplace through familiarity. -We have come to accept even the possibility of occasional transatlantic -passages of small perching birds, helped by transatlantic vessels, and -of such birds as starlings, making their way from place to place by -boxcar. - -But when it is time for birds to make their nests and rear their family -we expect them to give up their traveling for a time and to settle down -in one place. We expect, with our songbirds, to have the male arrive -first, pick out a territory, and announce to his species that other -males are to keep out and that a mate is welcome. The female arrives -and chooses her mate or territory, and a nesting ensues. Many species -defend the area around the nest against others of their kind. So it -comes as a surprise to find nests built in such a situation that they -are not stationary but move back and forth, along with part of their -environment. - - -BY BOAT Tree swallows nest on the ferryboats that ply between -Ogdensburg, New York, and Prescott, Ontario, across the St. Lawrence -River where it is more than a mile wide. The nests are tucked into -suitable openings on the ferries, and the frequent trips back and -forth across this mile of water and the docking at different piers do -not seem to disturb the birds. They gather their nesting material of -feathers and straws and leaves from either shore, and when the young -are being fed, insects may be gathered about the Canadian or the United -States shore, depending on where the ferryboat is docked. - -Another example comes from Western Australia, also of a swallow, the -welcome swallow which is nearly like our barn swallow. A pair of these -birds nested on a boat used for visiting local coastal stations. If -there were eggs or young in the nest when the boat sailed, the old -birds would accompany it, once following her on a trip of thirty-five -miles and back. - - -BY TRAIN Barn swallows have been noted nesting on railway trains that -run across the two-mile portage between Atlin Lake and Lake Tagish in -British Columbia. In the summer the train makes the trip almost daily, -and for many years a pair, or a succession of pairs, has made its -nest and raised its young in one of the open baggage cars. Members of -the train crew took an interest in the birds and put up a cigar box -for a safe place for their nest. Here the family seemed to prosper, -undisturbed by the proximity of people and baggage and the clatter as -well as the movement of the train. - - - - -MALADAPTATION IN BIRDS - -[Illustration] - - -Through selection birds have become adapted to their environment. In -most cases this is successful adaptation. Occasionally, however, we -come across instances in which the adaptations do not work out. Such -cases, where the actions of the birds are not beneficial or are even -detrimental to it, come as surprises. - -Since the introduction of the Tartarian honeysuckle (_Lonicera -tatarica_) into the United States from Asia, its planting as an -ornamental shrub provides each autumn a display of juicy red fruit. -This fruit contains saponin, a substance that has the effect of an -anesthetic and muscle poison and may paralyze the greater nerve -centers (in sufficiently large doses saponin causes death by cardiac -paralysis). A condition of intoxication has been recorded for robins -feeding extensively on these honeysuckle berries: "... this drunkenness -has been seen in every shade of severity, from mild unsteadiness to a -degree of incoordination sufficient to cause the birds to fall to the -ground. It seems to make some of the birds utterly fearless and perhaps -a bit belligerent, for they become quite unafraid of passers-by and -interested spectators. A few dead robins have been found about these -honeysuckle bushes--presumably poisoned by the berry diet." Fortunately -the poisoning of birds by this honeysuckle seems to be uncommon. - -In the Philippines the local people gather the juice of the coconut -inflorescence in bamboo tubes placed in the crowns of the palms. This -juice ferments quickly and provides a refreshing, mildly intoxicating -drink. A little parrot of the Philippines, the hanging parakeet, has a -taste for this drink, comes and drinks from the containers, sometimes -becomes drunk, falls in, and drowns. - -The California woodpecker ordinarily differs from many birds because -it does not lead a hand-to-mouth existence but stores food. These -woodpeckers feed extensively on acorns, and one way they store them is -by drilling holes in the bark of a tree and fitting an acorn into each -hole. The whole trunk of a tree thus may be pitted with stored acorns. -When the acorn crop fails and the nuts are scarce the woodpecker -goes through the same storage activities but, being unable to find -sufficient acorns, it stores pebbles instead. These pebbles are, of -course, quite useless to the woodpecker, and this is an interesting -example of an instinct "gone wrong." - -Sometimes these woodpeckers have another method of storing their -acorns. This is by dropping them into cavities in tree trunks, but when -stored in such a way there seems to be no way for the birds to reach -them. Here again we have a blind impulse to store acting in such a way -that the bird gains nothing by the act. - -The raven is ordinarily and quite correctly considered one of the most -intelligent of birds, but a raven I kept in captivity and fed small -fish attempted to store some of them by pushing them through a knothole -in the back of its cage. The fish fell about fifteen inches below the -knothole, where the raven could not possibly reach them. After pushing -each fish through the raven peered through the knothole though it -could not see the fish. Here again we have the instinctive storing act -carried out in such a way that it produced no benefit to the bird. - -The late George Latimer Bates, noted ornithologist, studying the birds -of West Africa, found a most surprising thing in connection with one of -the honey-guides. As a group, these birds are noted for the habit of -attracting the attention of human beings and leading them to bee trees, -presumably so that they will break down the bee tree for the honey, and -the birds can feed on the scraps left over. Bates found that the West -African species is parasitic on other birds in its nesting habits and -its young have been found in the nesting hole of a little barbet. This -barbet was a much smaller bird than the honey-guide and the entrance -to the nest hole was so small that Bates doubted that the honey-guide -would have been able to get in to lay its egg. He suggested that the -egg may have been laid elsewhere and deposited in the nest by the -parent's bill. It is difficult to understand how the young honey-guide -would be able to get out, for when fully fledged it would have been far -too large to squeeze through the entrance that admitted the tiny body -of its foster parents, the barbets. This is an almost incredible story -and if true looks like a case of maladaptation. - - - - -FEATHERED BABY SITTERS AND CO-OP NURSERY NESTS - -[Illustration] - - -Co-operative nurseries, where a few parents look after the young -while the rest of the adults, temporarily freed of the care of their -offspring, can go about their other affairs, appear in the bird world. - -The wild turkey of our Eastern United States commonly steals away -singly to lay its eggs and incubate them in its nest on the ground. -But occasionally it happens, Audubon writes, that several hen turkeys -associate together and lay their eggs in one nest, and raise their -young together. With the turkey apparently there is little division of -labor, as Audubon writes of finding three hens sitting on forty-two -eggs, but he says that one of the hens is always on the watch at the -nest so that natural enemies have no chance to rob it. - - -A GREGARIOUS BIRD What is of only occasional occurrence in one -species may be the regular course of events in another, and in the -ani we find it customary for a number of birds to nest together. The -anis are moderate-sized cuckoos living in the tropical Americas. The -smooth-billed ani is perhaps the best known, for Dr. D. E. Davis, when -studying at Harvard for his doctor's degree, made a special trip to -Cuba to study them in the field. The smooth-billed ani goes in flocks -the year round. Usually there are about seven birds in the flock, but -there may be as many as twenty-four. The nest is a bulky structure -of twigs and fresh leaves. When nest building starts usually one -bird is most active, but as many as five birds were seen carrying in -sticks at one time. When the nest of sticks and leaves is finished -several females may lay their eggs in it. But apparently only one bird -incubates at a time, and the male takes his turn at incubating. When -the young hatch, after about thirteen days, most of the adults in the -colony help feed the young. - -Eider ducks may nest in dense colonies, but each bird has its own nest -in which it lays its own eggs, and in which the female alone incubates. -But after the young hatch and the mother leads them to the water, the -young may band into larger flocks, accompanied by a number of females, -and the young seem to be independent of their particular parent, but -attach themselves to and are tended by the nearest duck. - - -PENGUIN SOCIAL GROUPS A much more elaborate system for caring for -the young has been evolved by certain penguins. The sexes alternate -in their care of the young in the early stages. But when the young -are partly grown the family unity breaks up for a communistic type -of social organization. The young are now grouped into bands of up -to twenty or more birds and are left under the care of a few old -birds, while the rest of the adults go to the water, which may be -some distance away. Periodically they return with food for the young. -Apparently the individual young is not recognized by the parent, which -goes to the particular group of which its young is a part, and there -may feed any one of the "child groups." - -Here we have two definite cases of a social organization that has -resulted in division of labor: in the incubation of the ani, and in the -care of young penguins. In addition we have two less specialized cases -of the same thing, showing the sort of raw material on which evolution -can operate to produce new behavior patterns. - - - - -BIRDS' NESTS AND THEIR SOUP - -[Illustration] - - -In caves near the ocean in the Far East nest myriads of tiny swiftlets -whose chief impact on the civilized world is that their nests provide -an edible article of commerce. "Birds' nest soup" at once comes to the -mind of the Occidental, few of whom have ever eaten of the nests, or -even seen the birds to know them. For those who would like to see the -nests, some museums have them on exhibition, such as in the Chicago -Natural History Museum, where two nests are placed in their natural -setting, and beside them is a quantity of the material of commerce in -its raw state. - -The birds themselves are dusky-colored swifts only a few inches -long, and belong to a group of swifts that represents perhaps the -most puzzling problems of species identification in the bird world. -As yet we do not know even how many species there are. The genus is -called _Collocalia_. Only some of its members make the edible nests; -others mix so much moss into the nest that it is useless for soup. One -species has the scientific name of _esculenta_, given in reference to -the supposed edible nature of the nest, but through error the name was -applied to a species whose nests are not edible. In habits all these -swiftlets seem very similar, flying about with a rather weak flight for -a swift, catching their insect food on the wing. - -A number of swifts, including our chimney swift, use the secretion of -their salivary glands as a glue to stick together their nest, and to -stick it to the wall of a cave, the inside of a hollow tree, or the -inside of a chimney. But some of the edible-nest swifts go further -and make their nest entirely of this secretion from their enormously -enlarged salivary glands. This material, as it comes from the mouth -of the bird, resembles a saturated solution of gum arabic and is very -viscid. If one draws out a strand from the mouth of the bird and sticks -it on a rod, by rotating the rod and winding up on it the thread of -saliva one can empty the salivary glands of the bird. This material -dries quickly, and is the material of which the nest is made. When -the bird makes its nest, which it does in large colonies in caves, -it flies up to the rock wall, applies the saliva to the rock in a -semicircle or horseshoe. Gradually a little shelf is built out, and in -the finished nest one can see the many little strands that have gone -into the structure. It may take the birds as long as three months to -make this nest, even if undisturbed. The birds lay their two eggs in -the nest, and raise their naked, helpless hatchlings into facsimiles of -themselves in it. - -But in the Orient, especially in China, the nests are highly prized by -epicures as a delicacy. As the supply is limited the price is high. A -note with some material we saw stated that the price was $12 to $36 a -pound in Siam. - -The climbing for and collecting of these nests requires daring, skill -and is not without danger. The nests may be far back and high up in -the cave. Ropes and poles may have to be fixed in place to aid the -climber, who has a flaming torch in one hand and carries a sack or -basket for the nests. In Siam, at least, the collecting of these nests -was hereditary, father training son. The rights to collect nests are -valuable. In Siam, where the rights to collecting the nests were vested -in the state, revenue of as high as £20,000 has been received from the -rights for this collection. - -The nests are said to be of highly nitrogenous material, and contain -about 50 per cent of protein and 7½ per cent of mineral matter. Their -use as food is an Oriental custom, but an Occidental opinion of their -flavor is that it is bland, and an appreciation of it needs to be -cultivated. The price of these nests is so great that unscrupulous -persons have manufactured spurious nests. These nests are made from -agar-agar, the jelly made by boiling down certain seaweed, and are so -cleverly flavored that only connoisseurs can detect the fraud. - -We usually think of these nests in connection with birds'-nest soup, -which may be made with chicken or beef broth and then the cleaned -material of the nest added like tapioca or vermicelli. Sometimes a -sweet soup is made. Sometimes lotus seeds, sugar, and the nest material -are used in the preparation of the dish. But in the Orient, at least -formerly, they're considered to have medicinal qualities, too. It is -said that when combined with ginseng they are capable of restoring life -to a person on the point of death. In Northern China where the winter -is bitterly cold, it is a general belief that the blood congeals and -can only be thawed out by drinking a soup made of these nests. The -list of further benefits, such as against tuberculosis, as a tonic, -stimulant, and a pacifier of the stomach, recall advertisements of -patent medicines. - - - - -WALLED WIVES OF HORNBILLS - -[Illustration] - - -For long it has been written that the male hornbill walled up his mate -in her nest in a hole in a tree at nesting time, and one author even -wrote that the male plucked out the female's feathers at this time. -The facts underlying these statements have different interpretations, -but the nesting of the hornbill is still one of the most extraordinary -of animal habits. Travelers and naturalists in Africa had brought back -tantalizing bits of information, to add piecemeal to our knowledge of -these birds. Now all this is synthesized and corrected by R. E. Moreau, -onetime resident in East Africa, who made a study of certain species, -raised young birds by hand, and gave us a comparative study of their -behavior. Even this study must be considered preliminary, for, of the -twenty-six African species, we have breeding data on only sixteen of -them. - -First we must not generalize too far as to "the hornbills," for there -are Asiatic and Malayan species as well as African, and African species -differ among themselves, the ground hornbill being especially aberrant -in its habits. - -It is quite true that in many African species the female is walled up -in her nest, and the period when she is enclosed may last three to -four months. But it cannot be interpreted as an imprisonment forced on -her by the male, and presumably she could, if she wanted to, open the -entrance at any time, as she does finally on emerging. - -Among the African species the details vary, but the nest is usually -located in a hole in a tree, and except in the case of the ground -hornbill the entrance is plastered up so that only a narrow slit is -left, about wide enough for the passage of the bird's bill. The female -takes an active part in the walling up of the opening, and might be -said to wall herself in. When the opening to be filled in is wide, the -male may bring earth, which he mixes with saliva in his gullet, and -presents to the female, who does the actual plastering. In some species -the walling up of the entrance may take months. - -The female may wall herself in some days before she lays her first egg. -Throughout incubation she remains there. Depending on the species, she -may peck her way out, or burst out when the young are partly grown, or -she may stay until the young are ready to fly. - -During the time the female is walled in the male brings food for her, -and later for the young, also. That he is a good provider is indicated -by the fatness of the female and her young. This is proverbial with the -natives of Africa. The method of feeding varies with the species. The -male may bring a bit of food in its bill, pass it in to the female, -and then go for another, or in other species we might think more -intelligent, the male carries a quantity of berries in its gullet, and -these are regurgitated one by one and passed to the waiting female; -such species make trips to the nest less frequently. - -Apparently shortly after the female goes into the retirement of her -walled-in nest, she molts all her flight feathers, so that she is -flightless, and then begins to grow them again. - -When the female bursts out of the nest with the young only partly -grown, the young that remain in a still very undeveloped state in the -nest, using material in the nest such as remains of food and rotten -wood, replaster the hole! The young, perhaps only halfway through their -fledgling period, wall themselves in! The female then helps the male -care for the young. - -Such is an outline of what some of the African hornbills do at nesting -time. The habit is unique in the bird world. One species appears not to -wall up its nest. In an Asiatic species it is said that if the male is -killed other hornbills help to feed the female in retirement. The whole -procedure is an amazing behavior pattern, and one for the development -of which it is difficult to find a functional explanation. - - - - -BURIED EGGS AND YOUNG - -[Illustration] - - -The crocodile bird, or Egyptian plover, has enjoyed a dubious publicity -because of its reputed habit of entering, and coming out of, crocodile -mouths. As Herodotus put it, the crocodile's mouth is infested with -leeches, and when the crocodile comes out of the water it lies with its -mouth open facing the western breeze. Then the crocodile bird goes into -the crocodile's mouth and devours the leeches, to the gratification of -the crocodile, who is careful not to harm the bird. Though there are -some more recent observations corroborating this, modern observers who -have had abundant opportunity have watched for this behavior and have -not seen it. - -As one authority on African birds puts it, it is evidently not an -everyday occurrence. - -But the crocodile bird has other habits that are just as bizarre and -interesting. It lives along the sandy shores of African rivers, and -when it lays its clutch of two to four eggs these are buried in the -sand so there is no sign of them aboveground. The bird sits on top of -this spot. A. L. Butler, who studied this bird in the Sudan, thought -that the sand might be scraped away from the eggs and the eggs brooded -in normal fashion by night. The young birds are very precocial, and -feed themselves on tiny insects, but they follow the parent. When -danger threatens the young squat motionless in some depression. The toe -mark of a hippopotamus is a favorite place. Then the old bird, with her -bill, throws sand over the young until they may be completely covered. -Not only does this happen when the birds are very small, but continues -up until the time the birds can fly. Dr. W. Serle in Sierra Leone once -saw a crocodile bird burying something and found the disturbed spot -fairly easily, as recent rain had beaten the sand beach smooth and -hard; a fully fledged young was unearthed. It squatted motionless until -prodded from behind, then it ran swiftly, rose, and flew away strongly. - -The burying is not only protection from immediate enemies; A. L. Butler -believed it was normal for the young when not feeding to be buried for -safety or as protection from the burning sun. For a further protection -from the sun the parent moistens the sand by regurgitating water over -it. - -Butler on one occasion saw a crocodile bird drink at the water's edge, -run up onto a sand beach, regurgitate water, then settle to brood. -Butler marked the spot, went to it, and, scraping away the dampened -sand, found a tiny chick about one inch below the surface. - -This covering of the eggs by the parent is not unique in the bird -world. The pied-billed grebe of North America also does this. When -disturbed at the nest the incubating bird has been seen to use quick -pecking motions to draw material from the edge of the nest over the -eggs. Instead of leaving the eggs exposed the nest simply looks like a -heap of trash and may thus escape the attention of a predator. It used -to be thought that this grebe used to incubate only at night, leaving -the eggs covered during the day to be incubated by the heat from the -sun and from the decaying vegetation of the nest. However, recent -studies have shown this is not the case, and protection by concealment -seems to be the main advantage of this behavior. - -Yet another species of quite a different group, the eider duck, covers -its eggs on leaving them. The eider's nest is characterized by a -blanket of down, plucked from the breast of the bird, and when the -female has time, when she leaves the nest she pulls the edges of the -down blanket over the eggs, perhaps for concealment, perhaps for the -sake of the down's insulating properties, keeping the eggs warm in a -northern climate during the parent's absence. - -Here we have covering of eggs for what seems to be very different -purposes: to keep the eggs cool; to keep them warm; and to hide them -from view. - - - - -THE SNOWY OWL AS A TRADE INDEX - -[Illustration] - - -Angus Gavin was a fur trader at the Perry River post of the Hudson's -Bay Company on the edge of the Arctic Ocean. White foxes were the -chief fur brought in, and the Eskimos were the trappers. Sometimes it -was necessary to advance credit to an Eskimo, against the expectation -of a coming season's catch out of which the advance was to be repaid. -Gavin, who was a keen naturalist as well as trader, writes, "I used my -observation on Snowy Owl abundance to govern extension of credit...." -When snowy owls were abundant he could extend liberal credit to the -Eskimo with every assurance the white-fox catch would be good and that -the Eskimo would be able to liquidate his debt. When snowy owls were -scarce little credit would be extended, for the white-fox catch would -be small. - -In general we've accepted the value of birds to man, and are -appreciative of the complicated web of life in which one animal affects -many others. But this use of snowy-owl abundance as a guide in granting -credit strikes me as novel. Actually, of course, it is quite sound, for -it uses one part of the chain that links such diverse items as owls, -lemmings, foxes, Eskimo, fur trader, and finally of course milady in -her white-fox furs. - - -LEMMINGS IMPORTANT First of the factors involved is, of course, the -vegetation; the grasses, herbs, and tiny dwarf shrubs of the Arctic -barrens. The next are the lemmings, mouselike creatures of the Far -North that eat the vegetation. They are the first step in turning -grass into flesh and fur and feathers. One of the striking facts of -lemming biology is the fluctuation in their numbers. Some years they -swarm, lemmings are everywhere, and in places they erupt in vast -emigration, the tundra and the sea ice being covered with masses of -moving lemmings. We know this best from the accounts written about the -lemmings of Norway, but the same thing occurs in the American Arctic. -At other times they're scarce and it is difficult to find even one. -Strangely there's a periodicity in this, and periods of abundance and -scarcity tend to recur every four years. What happens or what causes it -we don't know. - -The Arctic fox, staple fur bearer of the Far North, and the snowy owl -both prey on lemmings. Lemmings are so important to them that when -lemmings are abundant the foxes and the owls prosper and multiply; when -the lemmings are scarce the foxes and the owls starve or migrate, in -any case where there are few lemmings there are few foxes or owls. - -Thus we see how it is that an abundance of snowy owls can indicate -that the Eskimo will make a good fox catch and the trader will do good -business. - - - - -MONKEY BIRDS - -[Illustration] - - -Birds get their everyday names in a variety of ways in the countries -where they live; from their looks, like the snake birds and the pond -scroggins; from their color, like the cardinal and the blackbird; -from their behavior, like the frigate bird and the creepers and the -boobies and king-birds; from what they eat, or are supposed to eat, -like the antbirds and plantain eaters and bee eaters; from what they -say, like the poor-will and the more-pork; from how they say it, like -the warblers and the screamers; from how often they say it, like the -brain-fever bird and the wideawake terns; from where they nest, like -the cliff swallow and the house martin and the chimney swift; and some -from their non-bird associates, like the cowbird, moose-bird, and the -monkey bird. - -It is the monkey birds that have taken our fancy at the moment. The -forests of Africa, the jungles of Borneo, and the forests of the -Philippine Islands each have a bird that associates so often with -monkeys that this habit became incorporated into its local name. The -birds are not at all closely related. One is a hornbill, one is a -drongo shrike, and one is the fairy bluebird. The hornbill goes in -parties of their own kind, but apparently the drongo, and certainly the -fairy bluebird prefer the society of monkeys to that of their own kind. - -The stories we have of them stress the utilitarian aspect of the -association; that the monkeys as they travel about through the trees -scare insects out of their hiding places and the birds, being on hand, -can snap up the insects more easily than if they had to search them out -for themselves. - -The monkey bird in Africa, which is a hornbill, follows, along below -the monkeys in the lower branches of the trees. It used to be thought -this was for the fruit the monkeys dropped, but then it was found the -hornbills were insectivorous. Instead of being scavengers the hornbills -are using the monkeys to beat out their game for them. - -Hamba Kerah, the slave of the monkeys, is what the Malays of Borneo -call the racket-tailed drongo. This is from its habit of stationing -itself behind a band of monkeys traveling through the forest. But Mr. -Ridley, who watched them, decided it was the other way around; the -monkeys, unwittingly of course, were working for the drongo, acting as -beaters to drive out the insects which the bird snapped up in the air. - -In the Philippines it is "the sentinel of the monkey" that is applied -to the fairy bluebird. The bluebird seldom associates with its own -kind, but is almost invariably associated with a band of crab-eating -macaques. But here again it seems the monkeys are acting as beaters for -the bird, driving out insects. - -This is a sort of unconscious co-operation one finds in the bird world. -One animal helps out another without being aware of it. Birds are ever -ready to profit by such behavior, and when it proves of enough benefit, -the habit can become usual for the species, as in the cowbird-cow -relationship, or indispensable as with the oxpecker-hoofed-animal -association. - - - - -BIRD-MADE INCUBATORS - -[Illustration] - - -Incubators as we know them on chicken farms are electrical gadgets with -thermostats to control the temperature, or at least with oil lamps -to supply the heat necessary for the young chick in the egg to grow. -Naturally we wouldn't expect anything so artificial as this in the bird -world, but there is one group of birds that does not brood its eggs but -has employed another method of incubating. - -The birds that do this are fowl-like birds of the Australasian area. -They are variously called "mound builders" from the nest mound they -construct, "megapodes" from the large size of their scratching feet, or -bush turkeys, presumably from their edible qualities. These birds bury -their eggs and leave them thus to hatch without any brooding by the -bird. The birds have adapted their habits to two different sources of -natural heat. On some of the Pacific islands there is local volcanism -making the sand warm. To such places the birds come to bury their eggs. - -But in many of the tropical forests there is not this convenient -natural heat. Another method is employed. The birds take advantage -of the heat generated by rotting vegetation. They scratch up the -surface litter of the forest floor into mounds--structures that may -be a yard or two high and five or six yards across. Some much larger -have been observed. It is into these the hens burrow and lay their -eggs. The temperatures in them have been recorded as 95° to 96° F., -which compares with normal bird temperatures of just over 100° (bird -temperatures are a few degrees higher than normal human temperature). - -The bush turkeys from Queensland have been bred in captivity, and have -given some extremely interesting data, according to an article by Mr. -Coles in the proceedings of the Zoological Society of London for 1937. -It was the male who did all the building of the mound. Though the -female started to cover the eggs laid singly in burrows in the mound, -the male finished this. And it was the male that looked after the nest -mound during the incubation period, continually scratching over the -surface layer. Both parents helped the young emerge, by digging burrows -into the mound which the emerging young, who had started to burrow out, -could use. - -The young are in a very advanced state and apparently are able to fly -and look after themselves upon emerging. On the day after hatching one -chick is reported as able to flutter up to a perch six feet high. -In the captive birds mentioned above, the parents, though they were -attending to the mound and helped the chick out, appeared to take no -further interest in the chick once it was out. - -There are a few other cases when birds cover or bury their eggs. With -the grebes it has been said they covered them and left them to be -incubated, but that is doubtful. Certainly the megapodes are the only -ones to present a dear case of "artificial" incubation. - -This burying of eggs by the megapodes of course brings to mind the way -some reptiles, such as turtles, bury their eggs. And considering that -from an evolutionary viewpoint birds are really only modified reptiles, -it is perhaps not surprising that they too have this habit. But that -it is really an ancestral trait retained by the megapodes is doubtful. -Rather I'm inclined to think it's another example of the many ways -birds have evolved, or changed their habits so as to utilize as much of -the environment as they can in as many ways as possible. - - - - -CORMORANT FISHING - -[Illustration] - - -In western Europe, when falconry was in favor for taking game on land -and in the air, there was a certain vogue for training cormorants to -take fish. Like the falcons, the cormorants were hooded and carried -on the wrist, but of course where the falcons flew to their game, the -cormorants swam to theirs. - -It was in China where cormorants were domesticated, "completely and -perfectly," as that eminent Sinologist Dr. Laufer says. Extensive -breeding establishments have been maintained. The eggs of the breeding -flock of cormorants are given to a hen to hatch, for cormorants as -mothers prove unsatisfactory under domestication. When the eggs hatch -the young cormorants must have special care; for, unlike the young of -ducks and geese, young cormorants at hatching are not down-covered -and able to run about, but are weak, helpless things sensitive to -cold. They are placed in cotton batting, artificial heat provided when -necessary, and they are fed by hand on a diet composed basically of -chopped eel. - -Finally the young are full grown and fully feathered. The training is -now started. First the young are tied to a stake at the water's edge. -A whistle signal is given and the young cormorant is pushed into the -water. Thus he learns to know and obey the signal to go into the water. -Then the trainer throws him little fish. These the cormorant catches -in its beak and when he does the trainer whistles another signal, to -bring the bird back to him with the fish. And the cord tied to the -bird is used to demonstrate what is meant and make sure its done. So -the training goes on until the bird has graduated to a class taught -from a boat. Sometimes a small float is attached to the cormorant by -a short cord, and it can be drawn in with a bamboo hook. If young -birds are trained in the company of trained birds, it takes but half -as long. Finally the training is complete and the fisherman sets out -with his birds. This is no sporting event; it is the serious business -of life, getting a living from fishing. On the sampan or the bamboo -raft there may be from two to a dozen birds; sometimes they may have -special perches built for them along each side of the boat. Sometimes -the cormorant has a cord or band around its neck. The reason for this -is disputed. Some say its a place to attach a cord; a place to get hold -of the bird; some say each man's cormorant is thus specially marked for -identification; some that it's to prevent the bird from swallowing -its prey. With well-trained cormorants it is sometimes dispensed with. -At a signal the cormorants go into the water, swim, and dive seeking -fish. The fisherman, by stamping his feet, by voice or whistle, and by -hitting the water with a bamboo directs and encourages the birds. When -the cormorant catches a fish it brings it back to the boat, and the -fisherman may use a net, or may lift up the cormorant onto the boat -on an oar or pole, and take the fish from the bird. If a bird is lazy -it's encouraged by beating the water near it with a bamboo pole. As -cormorants' plumage is only partly waterproof they cannot stay in the -water indefinitely, and this, as well as fatigue, probably determines -the rest periods when the birds are lifted aboard. Sometimes the -fisherman helps attract fish to the boat for the cormorants to catch by -scattering grains of rice in the water. - -When the day is finished the cormorants are collected, fed, and the -fisherman goes home with the sustenance for his family, gathered by a -bird. - -In Japan the cormorant is also used, but apparently somewhat -differently. There cormorant fishing may partake of the nature of a -sport. Sometimes the cormorants are "harnessed" into a team, each -attached by a cord to a single line, directed by one master. In China -the fishing is usually done during the day, but in Japan night fishing -is common, the scene being illuminated by fires in braziers or cressets -on the boat, or lanterns. - - - - -THE SHRIKE'S LARDER - -[Illustration] - - -Our northern shrike is a songbird which has developed feeding habits -along the lines of those of a hawk. Whereas most birds its size are -content with fruits, seeds, or insects of a size it can beat or bite -and then swallow whole, our northern shrike takes not only small -insects but prefers large ones, and mice and birds too big to be -swallowed whole. It is an opportunist and takes what is most abundant -and easily accessible. The shrike's strong hooked bill is a powerful -weapon, used with a nipping motion that is directed at the back of the -head or neck of mouse or bird. - -Now with the dead sparrow or mouse the shrike is at a disadvantage. -With a powerful bill hooked at the tip its feet are still those of a -songbird and are not strong enough to hold its large prey while pulling -it to pieces. Only small insects are held in one foot and pulled to -pieces. To meet this need for holding large dead prey the impaling -habit was evolved. The result of this is the so-called larders, which -form a fancied resemblance to meat hanging in a butcher shop, and have -given the birds their name of butcherbird. A thorn tree, a splintered -end of a branch, or even the barbs of wire fencing may serve. The -shrike flies to one of these, carrying the prey in its bill (rarely in -its feet), and with a pulling motion fixes the prey on a projection -point. Sometimes instead of impaling the mouse or bird it pulls it into -the fork of a branch, and so wedges it there. Now the food is firmly -held, and the shrike can use its bill effectively to pull off pieces -of flesh and swallow them. When the bird has fed, it leaves the rest -of the animal hanging where it was. It may return to this food and -make repeated meals of it if not spoiled, or dried up, until the whole -is devoured. But often parts of meals are left hanging and discarded. -If suitable thorn bushes are scarce the shrike may return time after -time to the same tree with its prey, and in time this tree may come -to be decked with many partly devoured carcasses. Such trees are the -so-called "larders." There is another aspect of shrike behavior that -adds to these larders. The shrike, even when replete, may seize any -prey that appears and impale it. The bird's organization is such that -the sight of a small moving animal may start the actions that end with -impalement even when the bird is not hungry. This food usually is not -eaten later. - -Thus the shrike's "butcher shop" is not primarily a store of food, -even though it sometimes serves as such when in times of scarcity -remains of old meals are eaten. It is not a gathering of food in time -of plenty and saving it for a later use. Rather the placing of many -items in one tree is the result of its being a favorable impaling -place. And the impaling is behavior developed to overcome the weakness -of the claws in a bird whose disposition and strong beak enable it to -prey habitually on larger animals which otherwise it could not tear to -pieces and eat. - - - - -BIRD FLAVORS - -[Illustration] - - -Particularly in the study of insects it has been shown that bright -or contrasting and conspicuous colors tend to be associated with -ill-flavor in the animals that wear them, while insects with a good -flavor tend to be so colored that they are difficult to see. The -first is a warning coloration--advertising to a predator that he will -not enjoy eating this insect and better leave it alone; the other -is concealing color, its function apparently to keep predators from -finding their prey. The tasters in the experiments that have been -used to work out the above generalizations were usually birds, but, -as checks, a variety of other animals were used, and the magpie moth -(_Abraxas grossulariata_), for instance, was found to be distasteful -to certain spiders, frogs, lizards, various birds, a bat, and finally -"the late Dr. Hans Gadow (one of the leading ornithologists of his -day), who made a practice of sampling caterpillars, remarked on trying -an _A. grossulariata_ that it was quite one of the worst he had ever -eaten!" Apparently ideas in taste are similar throughout large sections -of the predatory animal world. Reversing the usual role, and using -insects (hornets) as tasters of bird flesh, the celebrated British -naturalist, Dr. H. B. Cott, has recently studied the question of -the palatability in birds and their coloration. Naturally Dr. Cott, -with his customary thoroughness, compared hornets as tasters with -other animals, including cats and men, and found a surprisingly close -agreement in the results. - -The experimental procedure was to expose the flesh of two different -birds (without feathers) at the same time, and see which the wasps ate -first. Thus a graded series was built up of the 38 species of birds -tested, with a palatability rating of from 1 to 38. The wryneck and the -crested lark stood at the top of the list, and the pied kingfisher and -the white-rumped black chat, as the least palatable, at the bottom with -Numbers 37 and 38. - -Then, surveying the coloration of the birds, and their habits, Dr. Cott -made the important correlation that in general the birds whose flesh -was most edible were protectively colored, and those whose flesh was -least palatable tended to be conspicuous in color and behavior! - -To relate it to the theory of evolution Cott concludes that selective -pressure by predators seems to have forced vulnerable species along -two divergent lines of specialization: leading in those which are -relatively palatable toward concealment, and in those which are -relatively distasteful toward advertisement. - - - - -HOW MANY FEATHERS HAS A BIRD? - -[Illustration] - - -The question as to the number of feathers on a bird seems a simple -one without complication. Dr. Wetmore, the well-known ornithologist -who was secretary of the Smithsonian Institute, has given us some -data. The number varies with the species, of course: the smallest -bird, a hummingbird from Cuba, had the fewest, 940 feathers; larger -birds had more, the robin 2587, and the mourning dove 2635 feathers. A -glaucous-winged gull had 6540; a mallard 11,903 feathers; a Plymouth -Rock chicken was said to have 8325 feathers; and a later investigator -reported 25,216 feathers on a swan. - -But as one thinks of it, more questions arise, as in any -investigation. The answer to one question poses two more. The first -question is, do not the birds in winter need a wanner plumage to keep -out the cold than they do in summer, when it is warm? Do they have more -feathers then? This was definitely true in the case of the goldfinch: -a bird in summer dress had only 1439 feathers, while one in winter -plumage had 2368 feathers, obviously an adaptation for cold weather. - -The next question is more abstruse, but eminently practical: the -smaller a body, the larger exposed surface for its weight it presents. -That is, for its weight a small bird has a proportionately much greater -surface from which heat is lost than does a larger one. With equal -heat-producing mechanism and metabolism, a small bird would need -more insulation than a large one. Reduced to its simplest: one would -expect small birds to have relatively more feathers than large ones: -more feathers per gram of weight. Is this true? Two members of the -Department of Poultry Husbandry at Cornell University, Dr. F. B. Hutt -and Lelah Ball, supplied the answer. Small birds do have more feathers -per gram of body weight than do larger ones. A hummingbird weighing 2.8 -grams had 940 feathers or 335 feathers per gram; a nighthawk weighing -67.9 grams had 2034 feathers or 29 feathers per gram; while a swan -weighing 6123 grams had 25,216 feathers or 4 feathers per gram of body -weight. - -Presumably there are still other relations: Do the birds that live in -the tropics where it is warm have fewer feathers than species of the -same size of arctic climates, as one would expect? Are certain types of -feathers such as those of aquatic birds better insulated than those of -land birds, so that the bird requires fewer of them to keep warm? Does -a dense coat of down reduce the number of feathers needed to keep warm? -Do the loose feathers of ostriches, lacking barbules, necessitate some -adjustment in numbers? The things we've learned point the way to other -questions to be investigated. - - - - -LAST YEAR'S BIRDS' NESTS - -[Illustration] - - -The wisdom of our fathers is sometimes embodied in what we call old -saws, to wit, "Many hands make light work," to which the iconoclast -retorts, "Too many cooks spoil the broth." And when we come to the -phrase, "As useless as a last year's bird's nest," we must reply, -"Circumstances alter cases." For many a bird's nest of yesteryear still -has its use; some a biological use to other birds; some to feed and -clothe man. - - -SUBLEASES The snug, secure cavity that a woodpecker chisels in some -tree trunk for its nest will last for many years, a shelter in which -tree swallows, house wrens, screech owls, bluebirds, or wood mice -may make headquarters and use as a nursery. In the strange forests of -saguaro, a giant cactus of southern Arizona, the nest cavities of the -gila woodpeckers and the gilded flickers in the cactus trunks seem -necessary for the presence of many nesting birds. Without them the -birds would have to go elsewhere for cavities in which to nest. In old -woodpecker nest cavities the elf owl, pigmy owl, screech owl, sparrow -hawk, ash-throated flycatcher, martin, and crested flycatcher commonly -nest, and cactus wrens and even Lucy's warbler may use them. Their use -is not confined to birds alone, for scaly lizards, snakes, rats, and -mice have been found in them. In the Argentine there is a woodhewer -that appears to depend on the domed mud nest of the red oven-bird for -its nesting sites. It takes over a recently vacated or an old nest of -the oven-bird and lines it with grass and feathers for its own use. In -Africa and Madagascar the great domed nest of the hammerkop stork may -find a secondary use in sheltering barn owls. - - -SANDPIPERS AND EAGLES But it is not only burrows and domed nests that -when deserted by their original occupants are used by other birds. The -solitary sandpiper of our northlands belongs to a group in which nest -building is reduced to a minimum, usually little more than a hollow -in the ground with a few bits of material added. But the solitary -sandpiper, and the green sandpiper of the Old World have broken with -tradition and customarily lay their eggs in the abandoned nest of some -thrush. Our great homed owl is another bird that may use the discarded -nest of a crow or hawk for its eggs and young. And age in the eagle's -nest means little to the eagle. Frances Herrick, the noted chronicler -of the life of the American bald eagle, writes of one nest in the -crotch of a lofty tree that had been in use for thirty-six years. Each -year more material was added until the nest became 12 feet high, 8½ -feet across the top, and was estimated to weigh 2 tons. - -Man has found, among others, the following two direct uses for two -kinds of birds' nests: one he uses for food; of another he makes -covering for himself. - -The swift's nests used for food have been discussed in another chapter, -"Birds' Nests and Their Soup," so here I will only tell of the use of -birds' nests as human covering. - - -EIDER-DOWN BLANKETS An eider-down has come to mean a comforter, a -sleeping bag, or even a padded jacket. But to an ornithologist eider -down still has its older meaning: the down of an eider duck. It is this -material gathered from the eider ducks' nests which forms the article -of commerce. The eider's nest may contain grass, seaweed, and sticks, -but it is notable for the blanket of down on which the eggs rest, and -with which the female covers the eggs when she leaves them. This down -is plucked from the breast of the female. If it is taken from the nest -she replaces it with more, and it is on this principle that harvesting -of the down is carried out. On islands and islets in the northern part -of the North Atlantic eiders nest in great numbers in dense colonies. -Some of these are jealously guarded by the local inhabitants, who -gather the first blanket of down from the eggs, and later, after the -eggs have hatched, gather the second crop of down with which the female -has replaced the first to guard her eggs against the inclement weather -of those boreal latitudes. Each nest may yield an ounce or so of the -precious down, which is carefully cleaned and sent to market. It is -this material, extremely light, extremely elastic, and one of the best -non-conductors of heat, which finally becomes the important part of -real eider-down comforters, sleeping bags, and padded jackets. - - - - -SYMBIOSIS--ANIMALS LIVING IN MIXED HOUSEHOLDS - -[Illustration] - - -Symbiosis, a term from the Greek, is what the biologist uses for the -living together of two dissimilar organisms. In a broad sense it -includes such diverse relations as the lice living on man and rats in -his house, the union of an alga and a fungus to form a lichen, and the -cross-pollination of flowers by hummingbirds. - -The story of the burrowing owls of our Western plains living in amity -with prairie dogs and rattlesnakes as one happy family comes to mind -as an example. But "foolish nonsense" is how the noted biographer of -North American birds, A. C. Bent, characterizes such stories. He then -goes on to quote evidence as to what actually happens, and one can see -how the story originated. The prairie dogs, which are really plump, -dumpy, ground squirrels and not dogs at all, dig their burrows close -to each other on the prairie in colonies which have come to be called -prairie-dog towns, or dog towns or simply "towns." Burrowing owls also -take up their residence in these towns, probably because they find -burrows ready made and do not have to dig their own as they are quite -able to do. - - -MODERATELY PREDATORY The owls may make an occasional meal of a young -prairie dog, and a prairie dog may perhaps dine occasionally on owl -eggs, but on the whole owls and dogs get along on terms of easy -familiarity. Sometimes when alarmed, both may scuttle into the same -burrow for safety, but each has its own burrow. With the rattlesnake -it is different. The rattlesnake may live in burrows in the dog town, -but when it is hungry it eats owl or dog as occasion offers. While -the picture of a happy family of owl, dog, and snake is a myth, the -symbiosis of owl and dog, at least in the same colony, is striking. - -In Africa there is a tiny falcon only about eight inches long which is -called a pygmy falcon because of its small size. When Dr. Friedmann was -studying the social weavers in South Africa, birds which nest in large -colonies under a common roof they make in a savanna tree, he found -these falcons occupying nest chambers in thriving weaver colonies. -There was no friction between the weaverbirds and the falcons, and they -were sometimes seen to sit side by side. When Friedmann collected three -of these falcons he found bird remains in their stomachs but they were -not remains of the social weavers. Apparently the falcons were feeding -largely on small birds, but they did not molest the weaverbirds which -had made the nests the falcons were using. - - -PARROT-DUCK-OPOSSUM MÉNAGE We occasionally find a mallard nesting in a -tree, on an old crow or hawk nest, and there are ducks like the wood -duck and the golden-eye, which usually nest in holes in trees, but a -South American duck called the tree teal habitually nests in a parrot's -nest. The parrots, called monk parakeets, make their nests in compact -colonies in the branches of trees, so close together that they form -a single mass. The tree teal's usual manner of nesting is to lay its -eggs in one of the chambers in this apartment-house colony. At first -the eggs are laid on the rough twig floor of the nest, but as the eggs -increase in number a lining of down, plucked from the breast of the -bird, is added until it may even extend out the entrance of the nest. -Apparently parrot and duck both get along amicably in their pendant -treetop cradles. An opossum sometimes also finds these parrot nests -to its liking, though one wonders if it may not have a meal of young -parrot or duck in mind. But be that as it may, in different chambers -of a single communal nest of these parrots, parrots, a duck, and an -opossum have been found. - -On islets off the New Zealand coast lives a rather large-sized lizard -called _Sphenodon_. It's rather well known by name, at least, for it -is one of those relics of a formerly more widespread group which are -called living fossils. It is also noted for its remarkable development -of a pineal eye, the remnant of an important sense organ in ancestral -forms, and formerly an organ some philosophers supposed to be the seat -of the soul. But here we are interested in the fact that petrels swarm -to these same islands to dig their burrows and lay their eggs in them, -and it is in these same burrows that _Sphenodon_ spends its daylight -hours. Apparently the insect-eating _Sphenodon_ and the oceanic-feeding -petrels share the burrows amicably, adding still another example of a -rather long list of dissimilar organisms whose lives are associated. - - - - -BIRD APARTMENT HOUSES - -[Illustration] - - -Every now and then in our press appear blasts against crowded living -conditions in our cities, and the tenements where people are crowded -together. Often there is the implication that this type of thing is -unnatural and abnormal. And yet when we look about us in the bird world -we see that gregariousness is a common trait. We have only to remember -the great flocks of starlings and blackbirds in the autumn, or the -massed flights of water fowl. Not only in traveling and in feeding, but -also at nesting time birds may gather together, and some birds nest in -such close association that the term "apartment houses" or "tenement" -is really applicable. - -The martins' house on our lawn with perhaps dozens of closely spaced -rooms (some houses have as many as two hundred rooms) is a case in -point. The neat martin house, made of boards, is a man-made thing, -but even before the white man came to this continent, and before the -Choctaw Indians hung up groups of hollow gourds for the martin colonies -to use, the martins nested in colonies. Even in recent years certain -colonies we might consider unprogressive have been reported as using -such diverse nesting situations as among the boulders of a lake shore -in Minnesota, and the closely spaced woodpecker holes which riddled -a dead pine in Florida. And probably it was always thus. The martins -liked company at nesting. - - -CLIFF DWELLERS, TOO Perhaps it would not be proper to consider a colony -of bank swallows, each with a separate burrow in the same small cut -bank and roofed with the same few square yards of turf of mother earth, -as a real apartment house of cliff dwellers. But the term has been used -in connection with a West Indian woodpecker, where a dozen pairs were -nesting in a single dead tree, and "the trunk was a veritable apartment -house." A similar situation exists with the naked-faced barbet of West -Africa. This bird too makes a hole in a dead tree for its nest, like a -woodpecker, and colonies of thirty to fifty birds may be found nesting -in a single dead tree, while other dead trees nearby, apparently -equally suitable, are untenanted. Colonies of hundreds of nests of -cliff swallows, the nests touching and overlapping, may be under the -eaves of a single barn, or as they used to be and some still are, on -the sheltered side of a cliff. But as these birds had nothing to do -with the making of the roof, perhaps these too do not deserve to be -rated as apartment houses. - -In southern South America there is a monk parakeet that makes a real -tenement. It nests colonially in treetops, and the nests of sticks are -placed so close together that they merge and form a single mass, up to -nine feet across, in which each parakeet has its own nest. Similar to -this is the palm chat. This West Indian bird is small and thrush-sized, -dull in color, brownish with a streaked breast, nothing remarkable to -look at, but it carries amazingly large sticks, little thinner than a -lead pencil and as much as two feet and more long up to the top of a -palm tree, and there it makes its bulky community nest. - - -BUILD NESTS CO-OPERATIVELY These stick nests, which may be four feet -and more across, are conspicuous and regular features of the landscape -in Hispaniola. The colony consists of four to eight pairs of birds, -and each has its own apartment in the bulky structure, and its own -passageway to the outside. But in the parts of the community nests that -hold the individual nests together and cover them there are roughly -defined passages running through the interlacing twigs of the top of -the nest so that the birds can creep about under cover. Apparently some -of the work is carried on in common, for as many as half a dozen birds -may be working close together, pulling and twisting twigs more firmly -into place. - -The social weaver is the most advanced apartment builder. It, like the -palm chat, has little of distinction in its appearance, being mostly -dull brownish with a black face. But in its home country, the savannas -of Rhodesia in southeastern Africa, its huge community nests in the -savanna trees may be seen from afar. The largest Friedmann saw when he -was studying the bird there was about 25 feet by 15 feet, by 5 feet -high, and contained about 95 nests. And this might have been still -bigger, for part of it had broken the branch on which it rested and -fallen to the ground. Sir Andrew Smith, the early ornithologist of -South Africa, has written that when these birds start a colony they -first of all make a roof of coarse grass. The group to which the social -weaver belongs gets its name from the remarkable ability some of them -have of weaving their nesting materials. But the social weaver neither -plaits nor weaves its roof. It puts the roof together in the form of a -well-made hayrick with a fairly definite thatching arrangement so that -the water runs off. This is a community effort. Under this roof each -individual pair makes its own separate nest. These apartment houses are -used year after year, but last year's chambers are not used, new ones -being made under the roof each year, and so it grows bigger and bigger -until the weight of the mass may break the branches and cause a part or -the whole to fall to the ground. - - - - -BIRD HELPERS AT NESTING TIME - -[Illustration] - - -In many a well-run American home the children have definite -responsibilities, the older children may help look after the younger, -and even grown-up relatives may stay as part of the family group. As in -so many cases there may be found parallels to this in the bird world. - -The ani, the curious tropical American cuckoo that makes communal -nests, is gregarious and the young of the first brood become part of -the parent flock. Two more broods may be raised during one season -in Cuba, and the young of the earlier brood may feed their younger -brothers and sisters of the later brood. The same has been recorded -for many other species in the wild: in eastern bluebirds, mountain -bluebirds, wheatears, long-tailed titmice, barn swallows, coots, rails, -and gallinules young have been recorded as feeding still younger birds. -In captivity this habit has been seen a number of times. Young birds -hardly able to feed themselves may help feed still younger individuals -of the same or other species, and a nestling crowned hornbill has been -seen to offer food to its nestmates. This tendency to feed nestmates -evidently appears very early in the life of the bird, as Dr. C. O. -Whitman, who worked intensively with pigeons at the University of -Chicago, recorded a hybrid dove only twelve days old that fed its -nestmate. - - -FIVE JAYS AT A NEST It was rather generally known that occasionally -more than the two parent birds attended a nest, but until 1935, when -Alexander Skutch, the authority on the biology of Central American -birds, published his paper "Helpers at the Nest," few of us realized -how widespread this was. Since most birds of a species are difficult to -identify individually, one must actually see the extra, unmated helpers -at the nest along with the parents to be sure they are there. In the -brown jays of Central America that Skutch studied closely the colors of -the soft parts, bill, feet, and eye rings were variable and he was able -to recognize many individual birds. At five nests he watched he found -at least one helper at each nest, and at one there were five helpers, -all bringing food. Sometimes, if between an incoming, food-laden bird -and the young, they would take the food and pass it on to the nestling. -At one nest the unmated helper was more zealous in guarding the nest -than were the rightful parents. Sometimes, perhaps, these helpers were -unmated young of the parents' previous year's brood, but this could -hardly have been the case where there were five helpers, for the brown -jay ordinarily raises no more than three young a year. A black-eared -bush tit of Central America seems to have a great preponderance of -males and at one nest in addition to the parents there were three other -males bringing food to the young. - - -MATERNAL PENGUINS Perhaps the most striking example among birds is -the emperor penguin. These birds breed in the dark and cold of the -antarctic winter, on the edge of the ice shelf. The single egg is -carried on the feet of the brooding bird; indeed one wonders what other -adaptation for holding the egg would be possible in this land of ice, -snow, and water. Only a few of the adults in each colony lay eggs any -year, perhaps one in five, or one in twelve. But all the adults in -the colony have the urge to incubate and brood. Thus many old birds, -rather than merely the two parents, may take turns caring for each egg -or chick, leaving the rest ample time to feed. So strong is the urge -to brood that struggles may take place over a chick and it may be very -roughly handled. Indeed the chicks may so resent this that they may -creep away into ice crevices and freeze to death. Another strange turn -this behavior may take is that frozen eggs, dead chicks, and even bumps -of ice of suitable size are carried on the feet and covered with the -birds' feathers by their "would-be fathers and mothers." - - - - -A NAME FOR A BOAT - -[Illustration] - - -A request for the name of a sea bird, a name to be used for a boat, -came to me at my desk in the museum one day. My memory was quickly -exhausted with sea gull, sea swallow, and albatross. But I keep within -reach the handy guide, _Birds of the Ocean_, by W. B. Alexander. In -the index I found twenty pages of names, two columns to a page. They -started with _aalge, Uria_, and went on down through the alphabet to -_yelkouan, Puffinus_, and to _zimmermanni, Sterna_. - - -EUPHONY NEEDED A name should be short, pleasant-sounding, and easy -to remember and to say, so obviously such words as _Macronectes_, -_Brachyramphus_, _Aptenodytes_, and _Coprotheres_ are ruled out among -the scientific names. But further, when choosing a name for a boat -from among those of water birds, one should consider the kind of a -boat. There should be some appropriateness; some points of resemblance -between the boat and the bird, or between the boat owner and the bird. -Albatross seems right for a seagoing sailing ship, sailing to southern -oceans; tern (or sea swallow) appropriate for light, dainty coastal -sailing craft; puffin or auk or murre for power craft, for these birds -spend most of their time stolidly on the water and when they fly have a -direct buzzing flight. Loon and dabchick would do well for fresh-water -boats. But one objection to both them and the various auks for a name -is that these birds spend much time swimming underwater. They might -better give their names to submarines. The big, stocky sea ducks, -called scoters and eiders might suit some stout craft that ply to -arctic waters. - - -SCIENTIFIC NAMES AVAILABLE I reviewed the host of other names. -Scientific names need not be ignored either. What is nicer than -_Gygis_, the name of the white, fairy, or love tern of the South Seas -for a small summer sail boat? Then going farther afield into austral -waters for far traveling craft there's _Diomedea_, the name of the -albatross, and _Daption_, the medium-sized petrel that also is called -pintado for the same reason a white-splashed horse is called a pinto, -and _Prion_, the tiny whalebirds of the antarctic whose blue-gray back -is near the ideal ocean-camouflage color. _Larus_, a good honest name -without frills, belonging to the gulls that haunt our harbors, coasts, -and lakes, would do for a plain, everyday sort of boat. Kittiwake is -another gull that spends more time at sea. Gannets are boldly black and -white, strong-flying birds of the North Atlantic, and one could use -that, or its scientific equivalent, _Moris_, for a boat. - -Penguin and pelican I'm doubtful about; I can't imagine a boat for -either. Skua or jaeger would, of course, be a lovely symbol for a -pirate vessel, as would frigate bird; both are birds that practice -the stand-and-deliver method of getting food from weaker fisherfolk. -The petrels called shearwaters are among the hardiest seagoing birds, -but the name has little association for most people beyond wondering -if they feed around breakwaters. Petrel itself isn't a bad name, -though one might think of the storm petrels, which are also called -Mother Carey's chickens, and have been considered the souls of drowned -sailors, though their name perhaps refers to Peter, and his attempt to -walk on the water, as these birds are continually trying to do. - -Phalaropes are snipes of sorts that have taken up a periodic seagoing -habit, and their name might often be appropriate. Even their habit of -spinning quickly about as they sit on the water might still agree. A -Chicago man named his Chris-Craft _Sandpiper_, after, as he said, the -bird that goes hopping along the beach before the waves. - -_Sula_ is a good sort of a word, and the name of birds that are strong, -swift fliers of the tropics. But in English they're usually called -booby, which is an English word meaning simpleton (which name the birds -got from stupidly perching on ships). _Alle_ for the little auk or -dovekie would do for a tiny boat in northern waters, and I knew of one -boat called the _Alca_, after the razor-billed auk, while _Cepphus_, -the name of the black guillemots, is equally good, as is both _Lunda_ -and its equivalent puffin. - -Some names have a stark simplicity that would attract few, like shag, -used for the cormorant, and muttonbird for a petrel. The cahow people -might shy from because for many years we were not sure whether this -West Indian petrel was extinct or not. - -Myself, there are two names I rather like and I've been saving for the -last: for a small sailboat I'd say the _Wideawake_, as the sooty tern -is called in its tropical home, and the other, for a larger seagoing -boat, is the _Mollymawk_, a sailor's name for the albatross. - - - - -WEAVERS AND TAILORS IN THE BIRD WORLD - -[Illustration] - - -One can imagine the consternation in trade-union circles when it -becomes known that there are, among birds, those who weave and those -who sew. Their products are entirely for home consumption and there -are no minimum wage, no maximum hours, or any fair-trade or quality -agreements. None of the Audubon societies have even touched on the -matter. - - -WEAVING The sewing and the weaving is done entirely in the construction -of nests. To take up the weavers first, we can point to the Baltimore -oriole, which makes a sac-shaped, pendant nest, often hung from the -trailing tips of elm branches. The walls of this sac are formed of -fibers pushed and pulled back and forth with the birds' bills in a -seeming haphazard way so that a roughly woven or stitched fabric -results. But the finest weavers belong to that group of birds known -as weaverbirds. One might expect that to be an expert weaver a bird -would have to have a slender bill. But no, their bills are short, -stout, clumsy-looking, and sparrowlike. And yet these are the birds -that weave elaborate pendant nests of fibers and straws. The finest -are in shape like an inverted retort, with the nest proper in an oval -chamber, fastened to a branch by a special strand of fibers, and with -a tube or funnel for an entrance. The walls of these fine weaverbirds' -nests are amazingly strongly and neatly woven. In captivity one of the -weaverbirds, the red-billed weaver, was studied at its nest building -and it was found that the strong, intricate, and beautiful weaving of -this species actually included knots of several sorts. - - -TAILORING The tailoring is done by birds of quite another group. They -are Old World warblers of several sorts, some in southern Asia and -some in Africa. The tailoring consists of sewing the edges of leaves -together to form a place for their tiny nests. The Indian tailorbird is -perhaps the best known. When these tiny olive-green and gray birds set -about nest building the female punctures the margins of the leaves with -her bill. Then she brings cobwebs and pushes them through the punctures -in the edges of the leaves, and winds them around, and draws the edges -of the leaves together. Strands of cotton are used too for this. -Sometimes a single leaf is used; its two edges being drawn together -to form a funnel. Sometimes a number of leaves are joined. Sometimes -it is claimed knots are used, but this seems not to be the case. What -are mistaken for knots seem made in this way: The cotton used is soft -and frays easily, so that the part of it forced through a tiny aperture -issues as a fluffy knob, which looks like a knot. "The bird makes no -knots; she merely forces a portion of the cotton strand through a -puncture," and the edges of the puncture catch and hold it, according -to Casey Wood, who studied the birds in India. The lining of the nest -is of soft material and this the bird anchors by making a puncture in -the leaf, grasping a strand of this material, and pulling it out; the -cotton outside then expands into a minute button which helps hold the -nest and contents in place as though riveted. One nest is recorded as -having been so riveted in seventy-five places. - -The camouflage of the tailorbirds' nests is very good; it is usually -built in thick foliage, the leaves are little deranged, the punctures -do not cause the leaf to die; and the leaves being the same as the -others, there is little for the eye to pick up as indicating a bird's -nest. - - - - -SOCIAL PARASITES AMONG BIRDS - -[Illustration] - - -The mother who would leave her infant on a stranger's doorstep, to be -brought up an orphan, not even knowing its own parents, is a despicable -character in human society. But when we leave the man-made society we -must leave man-made rules of behavior and man-made prejudices behind. -Morals are human. The rest of the animal world is not immoral, it is -amoral. It cannot afford criteria beyond survival and reproduction. So -while we call certain birds "social parasites," we attach no stigma to -them. They represent several groups: the cowbirds, the weavers, the -cuckoos, the honey-guides, and the ducks. - -Carelessness in egg laying is common even in birds that ordinarily -lay their eggs in their own nest and care for them themselves, as for -instance the robins' eggs that you may find on your lawn (which of -course are wasted; addling and rotting). Perhaps the fate of the eggs -of pheasants and ruffed grouse which are found in the same nest may -be more happy. Ducks usually make their own nests, but many species -occasionally lay eggs in the nest of another species, and one South -American duck no longer makes any nest of its own, but is a social -parasite, not only on other kinds of ducks, but also on coots and some -other birds. - -The small, well-marked family of honey-guides of Africa, notable in -other ways, also is remarkable for being social parasites. Their -favorite host species, chosen to look after the eggs and young, are -their close relatives, the barbets (which themselves are most closely -related to our woodpeckers). - -The nesting of certain African weaverbirds was long a puzzle to -ornithologists until it was found they too were social parasites, on -other weaverbirds. - - -VARIED NESTING HABITS The cowbirds, of several species in North and -South America, belong to a family notable for the variation in its -nesting habits. Their nests vary from the elaborate purse-shaped -structures of the oropendola and orioles to the dome-shaped nest on the -ground of the meadow lark, the simple cup of the bobolink and redwing; -the cowbird makes none. The cowbird lays its eggs in the nests of a -wide variety of other species to be cared for by them. Here those who -discuss the relative importance of heredity versus environment can -profit by considering these social parasites. The young cowbird, -hatched and brought up by, say, a yellow warbler, remains a cowbird. -As soon as it no longer needs its foster parents' care it flocks with -other cowbirds, with all their mannerisms and characteristics, and next -season it mates with another cowbird. There is nothing left of its -early environment. - -The cuckoos of the New World and some of those of the Old make their -own nests in normal avian fashion. But a number of Old World species -are social parasites, and their behavior has long been a subject of -study and discussion. Specializations indicate that here perhaps we -have the highest stages of social parasitism. Whereas the cowbird may -grow up with nestmates that are the young of the foster parent, unless -perchance it crowds them out or starves them if it is larger, the young -cuckoo gets the rightful occupants of the nest on its back and throws -them out of the nest to perish. - - -EGGS LOOK ALIKE Another refinement in social parasitism by the European -cuckoo is that apparently certain individuals, and apparently certain -strains, lay their eggs only in the nests of certain host species. -And these cuckoos' eggs resemble those of the particular species in -whose nest the cuckoos' eggs are laid. For example, if certain cuckoos -lay their eggs only in the nests of meadow pipits these cuckoos' eggs -would resemble those of meadow pipits, while another group of cuckoos -specializing in hedge-sparrows would have eggs resembling those of -hedge-sparrows. Another oriental cuckoo has a color adaptation in -the young. In southern Asia these cuckoos parasitize crows, and the -nestling cuckoos have black feathers like the young crows; in the -Australian area where the same species of cuckoo occurs it parasitizes -grayish-brown honey eaters and the young are brown, more like the -rightful nestlings. Both these resemblances apparently reduce the -chances of the cuckoos' offspring being rejected by the foster parents. - - - - -FISH EATS BIRD! - -[Illustration] - - -It has become commonplace to hear about birds eating fish. The -government gets out reports on the relation of fish-eating birds to -fish abundance. The cries of commercial fisheries have caused inquiries -to be instituted into the food of cormorants that were supposed to be -eating the fish before they grew up enough for us to eat. The scarcity -of salmon in some of our Northeastern streams has caused the allocation -of biologists to study the predation of kingfisher and merganser on -salmon fry and fingerlings. - -But fish get some of their own back by eating birds. It's not as spot -news as the "man bites dog" angle, but it's certainly less widely -known. - -To one who has fished for large-mouth black bass among the cypress -trees and the bonnets of water hyacinth, and seen the bass strike -savagely at surface lures as soon as they hit the surface, it comes as -no surprise to find they strike at, and catch, such birds as Maryland -yellow-throats that flutter across close to the surface of the water. - -Young ducks, too, are good game to the large-mouth, and probably many -a young duck finds its way into the maw of a bass. On a pond where -bass had taken many young ducks I heard a story of a fisherman who -made a floating model of a mother duck, powered it with a propeller, -and attached to it by lines of various lengths several floating models -of downy ducklings. In each duckling was concealed a hook. The whole -flotilla was set afloat, and drifted across the pond. Mother steamed -ahead, with young following. Soon the bass, used to a duck diet, began -to grab the ducklings. When the model was retrieved several large bass -were taken. - -In Northern waters, where Northern pike, or jackfish, as they're called -in the North, abound in duck-nesting waters, pike are accused of eating -enough ducklings to affect the survival of the broods. Many a marshland -traveler has reported young ducks and young grebes diving, to be seen -no more. He's blamed the pike. Sometimes perhaps the young bird has -simply come up unobserved. But enough pike's stomachs have proved -to have young ducks in them to demonstrate pike do eat ducklings. -Strangely, in some areas, pike eat many ducklings; in others they do -not eat them. But it's not alone young birds or small birds that get -eaten by fish. - -A twenty-four-inch bass is recorded as having been caught while it -still had the legs of a full-grown coot projecting from its mouth. From -beak to tip of its outstretched legs the coot measured seventeen inches -and it weighed one and one quarter pounds. - -Angler fish weighing between forty and fifty pounds have been found -to have eaten birds. One had the band from a Manx shearwater in its -stomach, and another had an adult American merganser. In tropical and -subtropical seas the examination of birds seemed to indicate they had -been attacked by some fish and seized by the feet, but were able to -escape, and a white-winged black tern off Corsica has been seen to -disappear under the water, presumably dragged under by a fish. - - - - -CROWS ARE SMARTER THAN "WISE" OWLS - -[Illustration] - - -The owl has always been considered the symbol of wisdom. The old saying -has it that "fine feathers don't make fine birds," but I'm afraid that -the owl has taken in people with its appearance. The owl's reputation -for wisdom seems to be based on a staid, impressive appearance combined -with an inarticulate disposition. Though owls do at times make a great -deal of noise, hooting, shrieking, and whistling, much of the time the -owl sits quietly looking wise and saying nothing. But owls don't seem -to have much behind the front they put up. People who have studied -them find the young are very slow to learn to feed themselves, and one -saw-whet owl that was kept captive refused to eat liver put into its -cage, apparently not recognizing the meat as food. But when the liver -was stuffed into an empty mouse skin the owl at once ate it. One might -conclude that the owl was the original "stuffed shirt." - -The crows and their relative, the jays, are the birds that are really -intelligent. They are active and usually have little trouble getting -enough to eat. They have an abounding curiosity that leads them to -spend their time investigating things and getting new experiences. And -they seem to profit by these experiences, too. - -The following is how three ravens co-operated in getting a bone from a -dog, as written by B. J. Bretherton: - -"He was espied by a raven who flew down and tried to scare the dog by -loud cawing, in which he was shortly afterwards assisted by another, -both birds sidling up to the dogs head until they were barely out of -his reach. Just at this time a third raven appeared on the scene and -surveyed the situation from an adjacent fence, but soon flew down -behind the dog and advanced until within reach of his tail, which he -seized so roughly that the dog turned for an instant to snap at him, -and at the same moment the bone was snatched away by one of the ravens -at his head." - - -CROWS LEARN FROM OTHERS Crows have been recorded as profiting by -the experience of one of their numbers. In Washington, when almonds -were ripening in the almond orchards and crows were swarming there -threatening to destroy the nut crop, an estimated 30,000 crows were -involved and the destruction of an $800 crop was complete in two days. -Various methods of control were tried unsuccessfully. Finally some -almonds were slit open, poisoned, and scattered about in the orchards. -Very few crows were actually poisoned, not exceeding 1 per cent of the -flock. The first reaction of the crows when one of their number was -poisoned was one of extreme panic. There was tumultuous clamoring and -confusion. Then the flock abandoned the attempts to feed on almonds and -left the area completely. Here we have a case of superior intelligence, -birds profiting by the sight of a few of their numbers being poisoned -fleeing the area and so escaping being poisoned themselves. - - - - -TAME WILD BIRDS - -[Illustration] - - -We think of wild birds as being shy creatures by nature. For those -of us who have kept a feeding station for birds in the winter so as -to have the pleasure of association with the chickadee, nuthatches, -woodpeckers, and other visitors, one of the most attractive things is -that the wild birds become tame. Through association with persons they -gradually learn that human beings are not to be feared. The high point -of many a bird lover's experience is when a chickadee becomes so tame -that it will perch on his body and without fear will feed from his hand. - -It seems to be true that birds in wilderness areas are wilder and more -shy of men than those living about dwellings where they are protected. -This is notably true of the robin. In villages they hop around on the -ground unmindful of the near presence of humans. How different they are -in the wilderness, where the robins fly away apparently in great fear, -while the human intruder is still far distant. - -It comes as a considerable surprise to find that here and there over -the world there are instances of birds with so little fear of humans -that they come and perch on them. - - -PERCHING ON PEOPLE In the Galápagos Islands, where the general -fearlessness of birds is famous, one of these cases is recorded. David -Lack, who was studying the biology of the Galápagos Islands' birds, -found when walking through the woods on Indefatigable Island that a -flycatcher would sometimes try to settle on his head. Lack stood still -and found the bird's object was to pull out some of his hair. The bird, -having failed to detach any of the hair of his head, tried, apparently -with no better success, to pull out hair from his eyebrows and then -from his chest. This was at the height of the breeding season and -apparently the bird was trying to get nesting material. This seemed -to be a usual type of behavior there, and Lack correlated it with the -general tameness of the birds on the islands. - -There is a honey eater in Australia that includes in its pattern of -behavior perching on people's heads and shoulders and attempting to -pull out hair for use in its nest. A. H. Chisholm writes of going -to certain places and taking companions with him for the sake of -experiencing this, and the practice is so common with the species -that Australians refer to this honey eater as "the hair dresser." -In this case it is not tameness alone. The white-eared honey eater, -which indulges in this practice, is no more tame most of the time -than any of the other small local birds that live in that part of -Australia. Only at nesting time does it attempt to light on persons. -Chisholm correlates this hair-plucking trait with other habits of the -honey eater: he speaks of its gathering hair from such animals as rock -wallabies and gathering bristles from farmyard pigs and goats. - -Our familiar phoebe has been recorded as perching on deer hunters -in the fall and using them as a vantage point from which to conduct -its hunting. This was in North Carolina, and the weather being warm, -mosquitoes were notably in evidence. The bird showed no sign of fear or -nervousness, but perched on the hunter's gun, on top of his head, and -various parts of his body, and then flew out and picked up mosquitoes. -As the hunter's face seemed to be attracting more mosquitoes the phoebe -directed his attentions there. In picking mosquitoes off his face the -sharp points of the bird's bill were noticeably felt at every capture -and the irritation caused by a succession of these pricks caused the -hunter to decide that he could take care of the mosquito situation -better without the help of the phoebe. As H. H. Brimley, the hunter, -put it "... my face was beginning to feel somewhat inflamed from the -frequent pecks to which it had been subjected so I called it a day and -told the phoebe to stop pestering me." This took place in a wild part -of North Carolina and Brimley suggested that the phoebe's abnormal lack -of fear was caused by its having never seen a human being before. - - - - -BIRDS AS PILFERERS - -[Illustration] - - -Pilfering, or petty theft, is one of the less desirable but very human -attributes of our race. But it's also pretty widespread in the animal -kingdom. Theft as the usual thing is practiced by only a few birds. -But when it's a case of petty theft, happening now and then, it is -common enough in the bird world. It's not restricted to any group of -birds, but may crop up almost anywhere. There's no threat or fight -about it usually. The bird, which gets its food by means of the acuity -of its vision and the quick co-ordination of its movements with the -recognition of its food, sees the food in another bird's possession and -just goes up and takes it. Sometimes the food is taken from a larger -and stronger bird, an achievement accomplished by audacity, agility, -and quickness. A sparrow hawk, that inoffensive little rufous-red -falcon that spends most of its time catching grasshoppers, was sitting -on a telephone wire holding a small mammal it had caught, apparently -about to devour it, when a loggerhead shrike sitting nearby flew -straight to the hawk, seized its prey, and made off, leaving the hawk -sitting there, apparently dumfounded by the audacity and success of the -attack. A case in which the pilfering caused a mild fuss involved an -English kingfisher and a dipper. The kingfisher lit above a pool where -a dipper was feeding, obtaining food in the pool and bringing it ashore -to eat it. When the dipper next came ashore the kingfisher flew down, -there was a momentary scuffle, and the dipper departed, leaving its -food to the kingfisher, who promptly ate it. Despite this occurrence -the dipper allowed itself to lose its prey again before it left, and -the kingfisher presumably had to resume fishing for itself. - - -THEFT NOT RESENTED It is sometimes surprising that this pilfering, -when it occurs over and over again, is not actively resented, -particularly when the pilferer is a smaller bird. Some of the thrushes -are especially docile when they're victimized. Sometimes when American -robins are feeding on the ground, house sparrows hop along with them, -and when the robin finds a worm the sparrow hops up quietly and boldly -takes the worm from the robin with scarcely a protest from the victim. -One robin is reported to have been robbed six times, of six worms, one -right after the other by a small flock of sparrows while the robin -continued to hunt for worms. - -The starling, an aggressive Old World species introduced and very -successful here, also victimizes the American robin. In one case a -starling made four successful raids in five minutes, the robin not -attempting to fight or defend its food, but simply moving off a little -way and continuing to hunt for worms while the starling waited nearby. - -This is not a new trait of the starling, for in its Old World home, in -Britain, it has been seen to victimize blackbirds and song thrushes -(relatives of our robin). This happened when a blackbird pulled up -a worm, a starling flew to the spot, and the blackbird moved away, -leaving the worm to the starling. This method of obtaining worms was -sometimes used by all the starlings on a lawn where both species were -feeding, much to the hindrance in the feeding of both blackbirds and -song thrushes. - -Gulls have been recorded as snatching fish from mergansers that had -caught fish by underwater dives and brought them to the surface to eat. -Gulls also follow pelicans, and just after the pelican has completed -its plunge and before it can swallow the fish protruding from its bill, -a gull may flutter in, alight on the water or even on the pelican's -head, and seize the fish. The pelican does not attempt to do anything -about it, but accepts the pilfering with stoic calm. - -Grackles victimizing ibises seems perhaps the strangest of the whole -series of reports. The ibis often attempts to elude the grackles but -without success. About Lake Okeechobee, Florida, where ibis are common, -they feed largely on crayfish, which they secure by probing the holes -made by these creatures. Grackles swarm there, and, on occasion, no -sooner does an ibis seize a crayfish than one to four grackles try -to secure it. The ibis may take flight and attempt to escape with its -prey, but one of the grackles usually gets the crayfish away from it. - -Possibly some of these birds are on their way to becoming habitual -pilferers, in which such social parasitism is a fixed mode of life. -With evolution, if this thieving benefits the species that snatch -the food, it may become a usual habit. For habits, like structures, -are subject to variations, to selection, and thus to change and -elaboration. - - - - -HIBERNATION IN BIRDS - -[Illustration] - - -Not until 1948 did the scientific world have satisfactory evidence that -any bird hibernated. True, it was an established fact that sometimes in -cold weather some birds, notably swifts and hummingbirds, might become -torpid for a short time, but this was not hibernation. - -The early literature, of more than a century ago, contained many -accounts, some claiming to be firsthand, of birds hibernating. Swallows -in particular were reported as seen to submerge in ponds in the autumn. -Numbers of them were said to have been found hanging to submerged -willow branches apparently sleeping the winter away. When ponds were -drained in winter, sometimes swallows were said to have been found -buried in the mud, revived, and upon occasion kept alive indoors -until the spring. Sometimes slime-covered swallows, evidently just -out of hibernation, were reported found in the spring. Swallows were -the most commonly recorded, but other species, too, were mentioned as -hibernating, such as the cuckoo that shed its feathers and crept into a -crevice to sleep away the winter. - -Such accounts gradually disappeared from the literature. We can accept -none of them. The old records of underwater and also the featherless -hibernation of birds must be discarded. The occasional torpidity, in -cold weather, of swallows, swifts, and hummingbirds is another matter, -and appears to be of sporadic though not common occurrence. - - -FROGS MISTAKEN FOR BIRDS It is interesting to speculate as to how -the old "firsthand" accounts originated. They had certain basis of -fact. The first was that swallows were seen flying about in summer. -They disappeared in winter. Aristotle claimed they hibernated, in a -featherless condition, so there was nothing unusual in seeing them -that way. Observation was less critical, and it is probable that frogs -from the mud of ponds were mistaken for naked swallows, and perhaps -bats, which do hibernate, taken from caves or hollow trees, were also -mistaken for swallows. - - -AN AUTHENTIC RECORD In 1948, and again in 1949, Edmund C. Jaeger, of -California, published accounts of a poor-will he found hibernating. -This was the first acceptable evidence that such a thing occurs. In a -little cavity in the wall of a canyon in the Chuckawalla Mountains of -the Colorado desert in California, Jaeger found a poor-will in a state -of profound torpidity in December, 1946. He could pick out the bird in -his hand, examine it and put it back in the little cavity it occupied -without eliciting more than a slight movement of its eyelids. On a -later occasion handling it revived it somewhat. - -The next winter Jaeger found a poor-will, perhaps the same bird, -hibernating in the same niche. Over a period of eighty days, from -November 26, 1947, to February 14, 1948, he visited it periodically, -examined it, and took its temperature. The body temperature was low, -64°-68° F., compared with more than 100° F. of an active bird; with -a medical stethoscope he could detect no heartbeat, and a cold metal -mirror held directly in front of its nostrils collected no moisture -from its breathing. The body processes were evidently very low. The -bird was banded for identification, and in the third winter the same -bird wearing the same band was found to have returned to hibernate -again in the same rock niche. But on subsequent visits it was -missing--perhaps having lived out its allotted span, perhaps the prey -of some predator. - - - - -SNAKESKINS IN BIRDS' NESTS - -[Illustration] - - -There are occasionally discovered behavior patterns of birds that are -so unusual as to make one stop and wonder. They are unusual for birds -generally, but in a species here and there they are the regular thing. -Such is the placing of a shed snakeskin in their nests by some birds. - -A bird like the English sparrow, or the road runner, which uses a -variety of material coarse or fine, would be expected to use shed -snakeskins occasionally, as it came across them. But there are a number -of species that seem to use snakeskins regularly in their nests. -It would seem that the birds deliberately sought out the skins for -this purpose, as though they were as much a part of the nest as the -mud in the bottom of a robin's nest or the fresh green grass heads -ornamenting the entrance to some weaverbirds' nests. - - -SOME HABITS BAFFLING I have long since given up thinking that every -aspect of a bird's life must serve a useful purpose. Indeed I have -already pointed out some definite maladaptations. But usually every -type of behavior has a logical origin. By considering its occurrence in -various species and against the background of the bird's everyday life -some correlations usually can be found. - -The list of birds habitually using snakeskins in their nests is short, -as follows: - -1. Great-crested flycatcher--belonging to the New World flycatchers, -breeding in Eastern North America and nesting in holes. - -2. Arizona crested flycatcher--a relative of the great-crested variety, -with similar habits. - -3. Blue grosbeak--an American member of the sparrow family, making an -open nest in bushes. - -4. Black-crested titmouse--a member of the chickadee family, living in -Western North America and nesting in holes. - -5. Bank mynah--a starling, living in southern Asia and nesting in holes -in banks. - -6. Rifle bird--an Australian bird of paradise, making a cup-shaped nest -in trees. - -7. Madagascar bulbul--making a cup-shaped nest in trees. - - -LIKE A DECORATION Twenty or more other species of birds have been -recorded as using snakeskins more or less commonly, or occasionally -perhaps on the basis of availability or of chance. But with the above -they're an essential part of the nest. In some of the species the -snakeskins are arranged as a rim around the edge of the nest almost as -a decoration; sometimes the snakeskins may make up most of the nest. - -Now as to possible correlations. The species are not closely related. -Except for the two flycatchers the other five represent five different -families. The distribution over the world is wide, too: America, Asia, -Madagascar, Australia. Various explanations for the behavior have -been advanced. It has been suggested that it's correlated with hole -nesting, but three of the seven do not nest in holes. The most common -theory is that it's to frighten away possible predators by making them -think there is a snake in the nest. However, this is not very likely, -and, too, one wonders why the birds that use the snakeskins are not -frightened themselves. Indeed, one writer, surely not seriously, has -suggested that the fright in early life of crested flycatchers at -finding a snakeskin in the nest accounts for the upstanding crest in -this species! - - -"BURGLAR ALARM" THEORY Another suggestion is that the snakeskin, by -the rustling noise it makes when touched, acts as an alarm bell or -a burglar alarm to warn the rightful occupants of the nest when an -intruder approaches. This also seems a rather weak explanation. - -We are left, then, with the fact that this curious habit has been -developed in a few birds, not closely related, that live in various -parts of the world and that have very different habits. It is usual -with them. A number of others occasionally have this habit. - -My first clue as to the proper background against which to solve this -habit came when, unpacking a bird collection made in Borneo by curator -of anatomy D. Dwight Davis, I took out a bulbul's nest. In its outer -edge were flat, weathered leaves that resembled snakeskins. Later, when -we received a bird collection from Dr. D. S. Rabor of the Philippines -there was a nest of another species of bulbul and this too had flat, -dead, weathered leaves in it that looked like snakeskin. When I was -in Madagascar, in 1929-31, I had found three nests of the Madagascar -bulbul with a snakeskin used in each. Here was a clue. I decided to -investigate the nests of the other species of bulbuls of southern -Asia and Africa where the family is represented by many species. By -considering the snakeskin-using species against the background of the -nesting of the other species some correlation might appear. - - -BOOKWORK This became a library problem at once. I had to look up -the earlier reviews of the problem in the ornithological journals, -_The Auk_ and the _Ornithologische Monatsberichte_, then in Strong's -_Bibliography of Birds_, to make sure that no important papers were -missing from my own subject file. Stuart Baker's _Fauna of British -India, Birds_ had a large part of one volume devoted to bulbuls, and -gave excellent summaries of the nidification of each species occurring -there. Bannerman's _Birds of Tropical West Africa_ covered the western -part of that continent, and Jackson's and Sclater's _Birds of Kenya -Colony_ did the same for the eastern part. For collateral material I -looked in Mathews' _Birds of Australia_, Volume 12, Forbush's _Birds -of Massachusetts_, and Mrs. F. M. Bailey's _Birds of New Mexico_, and a -dozen minor publications. - -But it was worth it. - -Perhaps my earlier thinking was dominated by the thought that the shed -snakeskins had been parts of animals toward which many birds show an -antipathy. But it's extremely probable a bird does not recognize the -snakeskin as such. Rather to it the shed snakeskin is a strip of thin, -flexible material. Obviously it would be used, by chance, by many bird -species, such as the house wren, which, in addition to using such -natural materials as twigs, grass, and hair, has been recorded as using -lead pencils, paper, nails, safety pins, and snakeskins in its nest. - -As to the regular users of snakeskin, the snakeskin-using Madagascar -bulbul did fit into a pattern. Bulbuls in general make characteristic -simple cup nests. Some species use almost any available material. But -quite a few species had specific choices of materials: one species' -nest had tendrils of vines in its base; another a lining of grass heads -of a certain color; another pine needles; another red dead leaves; and -the Madagascar bulbul snakeskins. - - -A SOLUTION There seems to be a tendency for many species to make -distinctive nests. They often accomplish this by a choice of material -used by few or no other species. What more natural than that one -species, being in a country where snakes are common, should hit on shed -snakeskins! - -To show that the choice of snakeskin as nesting material is an -expression of a tendency for each species of bird to make a different -kind of nest may not be much of an answer. But it is to an extent. -No longer do we say, "Why are certain birds' nests characterized by -snakeskins?" Rather we have the broader, more general question, "Why -does each kind of bird tend to build a nest different from that of -every other kind?" Thus, little by little, we clear away small, vexing -questions and resolve them into larger, more general questions. For -answers to these we sometimes plan extended work involving field -studies, studies of specimens, and books. And sometimes, as we examine -a specimen, read a paper, or unpack a shipment, an answer, or at least -a clue, springs to our mind. - - - - -CO-OPERATION BY BIRDS - -[Illustration] - - -The importance of co-operation, contrasted with competition, has -assumed increased importance in discussions of evolution, as it has -in discussions of human social progress. Co-operation in nature is of -various kinds; from the manner in which a forest shelters the squirrel -to the manner in which two or more individuals of one species work -together for a common object. The working together of two birds to rear -a family is so well known an affair that one forgets that it is an -example of co-operation, not only in building the nest and brooding and -feeding the young, but also in defending the nest and the young. - -Sometimes more than one species will join in ousting an enemy. For -example, when a cat caught a young robin, recently out of the nest, -the parents, in their frantic effort to make the cat release the bird, -attracted the attention of another robin and a pair of cardinals -nesting nearby in a honeysuckle. All five birds dived at the cat, -screaming and pecking it so vigorously that it released the young robin -and fled. - - -EAGLES JOIN EFFORTS More spectacular are some of the co-operative -activities of birds in food getting. Bald eagles sometimes feed on -ducks. Frequently two eagles may combine their efforts. The two birds -may work together to force a black duck from the air onto the water, -and when they are trying to catch a diving duck, they much more quickly -exhaust their prey by swooping at it in turn. Bald eagles sometimes -take water birds too large for them to carry, and then they must flap -along dragging their prey on the surface of the water to the nearest -shore. On one occasion an eagle dragging a large cormorant ashore was -joined by two other birds, and all three took turns in dragging it. -When they got it ashore, all three shared it. - -Several fish-eating birds co-operate in capturing their prey. "The -merganser is primarily a fishing duck ... very skillful and a voracious -feeder. It pursues underwater and catches successfully the swiftest -fish. Often a party of sheldrakes may be seen fishing together, driving -the panic-stricken fish into the shallows or into some small pool where -they may be more easily caught," according to A. C. Bent. - -When a school of fish approached a flock of white pelicans, the birds -suddenly assumed a circular position, surrounding the school. All the -pelicans moved slowly but cautiously toward the center of the circle, -their heads near the surface of the water or partly submerged and their -necks slightly extended. The birds moved in perfect unison, making the -circle progressively smaller, ready to engulf their helpless victims at -the first opportunity. When all the pelicans were close to the fish, -the birds made rapid jabs at the fish and apparently consumed a large -number of them. It appeared that every bird got from one to several -fish. - - -13,000 BAND TOGETHER Avocets and, to a lesser extent, the black-necked -stilts also band together for co-operative drives on small fry and -aquatic insects. Such drives are made in water of wading depth. -Instead of forming circles the birds present compact spearhead and -wedge formations and sweep the bottom muck with the characteristic -back-and-forth side movements of their long bills. As many as 13,000 -avocets have been observed taking part in such co-operative feeding -projects. - -Another striking example is furnished by black vultures observed by -E. A. McIlhenny. A three-quarters-grown skunk was wandering across a -field. A vulture alighted near the skunk which immediately stopped -and raised its tail. Other nearby vultures joined the one nearby the -skunk, and when six or eight of them had gathered one suddenly attacked -it. The skunk immediately discharged its defensive scent, but without -effect, for the vultures attacked in a mass and other vultures circling -above joined in until there were probably twenty-five or more around -the skunk. With much flapping and croaking, the vultures pulled it -about until it was dead, and then devoured it. - -On another occasion a black vulture came from high in the air to -alight near two full-grown opossums following a narrow cattle trail. -The first vulture was almost at once joined by many others until there -were probably between seventy-five and one hundred black vultures -following the opossums. Suddenly three or four of the vultures attacked -and the others joined in. Quickly both opossums were covered with a -swarm of hissing, flapping birds, and within fifteen minutes there was -nothing left of them but the larger bones and the hides, and these were -stripped of every vestige of flesh. - - - - -WATCHDOGS AT THE NEST - -[Illustration] - - -A savage watchdog outside his master's house helps to protect it. If an -intruder comes, the watchdog, if it's the right kind, simply bites him -without preliminaries. There's a parallel to this in the bird world. -Some birds often have their nests close to wasps' or bees' nests, or in -trees inhabited by biting ants. The birds and the ants, wasps, or bees -get along without disturbing each other. But when intruders come along -the insects swarm out, biting or stinging and driving the intruder -away. The insects are protecting their own homes, but one of the -results, the protecting of the birds' homes, is just as satisfactory to -the birds as if they did it on purpose. This building of birds' nests -close to wasps' nests is a common practice with certain sunbirds and -weaverbirds, especially in Africa. It occurs too often to be chance. -The question naturally arises as to how much the birds understand of -it all--do they actually seek out the association? That's difficult to -say, but the facts of the association are still there. - -Though some of these associations are evidently fairly common and -chosen deliberately by the birds--and one can easily visualize how the -protection works--field observations as to the natural enemies against -which they are effective, and how effective they are, are largely -lacking. Usually the records are something like those of Van Rossem for -the Giraud's flycatcher in El Salvador, in which he points out that -this bird usually nests in certain mimosa trees armed with numerous -heavy, curved thorns. These thorns are hollowed out and inhabited by -swarms of small but extremely hostile antlike insects, so that the nest -is well protected. However, the effectiveness of ant and bee protection -against human predation can be seen in the following. - -Take the case of Mr. M. E. W. North, who arranged a rope to climb to a -fish eagle's nest in East Africa. He had gotten about fifty feet up and -was considering going out on the big limb on which the nest was, when -he noticed a wild bee on his sleeve. Realizing that he was disturbing -a wild-bee hive, and knowing that the sting of these vicious bees can -be dangerous, fatalities having been reported, he came down his rope -at express speed, crashing through projecting branches and brambles. -Reaching the ground, he freed himself from the rope and fled to a safe -distance, considering himself lucky to have received only three stings. - -On another occasion, again in East Africa, Mrs. R. E. Moreau attempted -to reach a hawk's nest to measure the eggs, but when she was up in the -tree, savage, biting red ants drove her out. - - - - -BIRD GUIDES TO HONEY - -[Illustration] - - -In Africa there are birds which lead men to honey. They are called -honey-guides and their family name, Indicatoridae, has the same idea -incorporated into it. Though there are several species of these small, -dull-colored birds, which are related on the one hand to woodpeckers -and on the other to barbets, it is only one species, the common or -black-throated honey-guide that is well known as a guide to honey. - -The traveler in the country may find one of these birds chattering and -flying ahead of him. The natives, who know this bird well and favorably -will tell the traveler to follow; it will lead to a bee tree. The -native, as he follows this guide, gives occasional whistles, as if to -encourage the bird. The bird continues, flying from perch to perch, -ahead, and chattering noisily. Sometimes it may return to see if the -men are following; sometimes it remains chattering on its perch until -the followers catch up. Finally the bird will go no farther. It flies -about aimlessly and allows one to approach closely. This is the spot. -In a hole in the tree trunk, or in the ground nearby the bees' nest is -to be found. - -When the beehive is opened, and the honey taken, the honey-guide will -eat the comb that is left, and apparently it is for this that the -complicated behavior of leading of man to the beehive is developed. - -Wax of the honeycomb is a usual food of this species, judging by -stomach examinations, and one wonders how they get it when man is -not about to open the bee trees for them. The birds have no special -adaptation for getting into the hives; indeed their only apparent -adaptation for this habit is a thick skin, perhaps a protection against -bee stings. Perhaps, as has been suggested, other animals, squirrels, -monkeys, or honey badgers may unwittingly aid them by opening up bee -trees for their own purposes and allow the honey-guides to snatch food -for themselves. - -An amusing side of the picture is that sometimes the honey-guides may -lead the honey hunter to a beehive owned by a native. - -There are also records of the honey-guide leading men to big game: -leopard or lions. That this occurs is amply documented, but one wonders -whether or not this was accidental; the honey-guide leading the way -to honey perhaps by accident leads the way past the resting place of -one of these big cats so that the man stumbles over the big game and -perhaps gets the impression he was led to the animal. - - - - -OXPECKERS - -[Illustration] - - -The lives of oxpeckers are so linked to those of large, hoofed game -or domestic cattle that in West Africa where game is scarce the birds -depend on cattle, and their range is restricted accordingly. There the -cattle are confined to the higher and more northern areas, free of -tsetse flies, from Senegal to Northern Cameroon. Thus tsetse flies help -to determine the limits of the oxpeckers' range. - -Except for their nesting, which is in holes in trees, and their -sleeping, most of their time is spent on the bodies of the larger -herbivores. There they run about over the hides and legs of the beasts, -like woodpeckers on a tree. They stay remarkably close to the animals, -and even ride on them as they travel. The oxpeckers' food is largely -ticks, which it gets from the hide of the animal by working over it -with the side of its bill, shearing off the ticks with a scissorlike -action of its mandibles. But when an animal has sores or cuts or -scratches the oxpecker may peck into them, and eat flesh and blood of -its host. - -Correlated with this unusual and close relationship, a modification -in the oxpeckers has taken place. There are only two species, both -African, and they are dull-colored, modified starlings. The legs are -stout, with curved, very sharp claws for clinging to the hides of -animals, and the bill, very sharp at the tip, with the cutting edge of -the mandible very sharp to aid in scissoring off ticks. - -All the larger herbivores are attended by oxpeckers except the elephant -and the hippo, but the favorite seems to be the rhino, and for this -he's sometimes called the rhino bird as well as tickbird and oxpecker. -The rhino gives the bird its food, and in return the bird provides a -service of a value difficult to evaluate. It acts as a sentinel and -may warn the rhino of the approach of hunters, for which habit it is -execrated by sportsmen. - -It would seem that such relationships could have developed only where -the supply of big game was large. With the introduction of cattle -and other domestic animals it was natural the oxpecker should turn -its attention to them. Here the question arose as to the attentions -of the oxpeckers being harmful or otherwise to the herds. Mr. R. E. -Moreau, formerly of the East African Research Station at Amani, has -investigated the problem. He finds that white men who own herds tend -to consider the oxpecker a nuisance; Africans tend to consider it -beneficial and some African cattle owners object to having the birds -killed; the beasts themselves tolerate the birds. - -There is the possibility on the one hand of oxpeckers spreading certain -cattle diseases that are mechanically transmitted, and on the other -hand they may help reduce disease by eating ticks, the vectors of -certain diseases. Of course dipping the cattle takes care of ticks on -them, and here we see another indirect effect of civilization on bird -life. When cattle have been dipped the oxpeckers disappear from the -herd. Perhaps it is because there is no longer food for them there; -perhaps they get enough of the poison dip left on the beasts' hair to -be lethal. - - - - -WINGS IN FEEDING - -[Illustration] - - -The obvious adaptation of a bird's wings is for locomotion; to fly in -the air. It is true that some few birds are flightless, and some like -the penguins use their wings for underwater swimming, but this does not -spoil the generalization. - -Secondary uses, some with special adaptations, occur: the owl at bay -spreads its wings wide, with the effect of increasing its apparent size -and being more terrifying to a predator. The young bird, begging to be -fed, flutters its wings in a characteristic way, and the female, in -some of her mating behavior, may also flutter her wings like those of a -young bird. - -In courtship the wings may play an important part in display. In the -Australian rifle bird they are held out, fully spread on each side of -the bird like a velvet curtain against which the vivid iridescence -of the throat patch stands out more vividly. The argus pheasant has -the inner secondaries greatly elongated and ornamented in a fashion -recalling the decoration of a peacock's tail and these he spreads to -show in his courtship, while the ruffed grouse uses his wings to make -instrumental music, his drumming. - -Wings in geese and swans may be used in fighting, and tame birds may -severely buffet humans who take too close an interest in their young. -In the related screamers of South America the bend of the wing is -equipped with long, very sharp spurs, which undoubtedly make formidable -weapons in fighting. - -In addition wings are used in at least three different ways in feeding. -The red-tailed hawk may spread its wings as it sits on its prey, -perhaps a behavior adapted to help the bird maintain its balance when -dealing with struggling prey, perhaps to help smother the struggles of -its prey. - -The secretary bird of Africa is said to feed on snakes, poisonous and -non-poisonous ones, and is said to use its huge wings as shields for -its body in attacking them. - -But the strangest use of wings in feeding is that practiced by a -blackish African heron. In feeding in shallow water it takes a few -rapid steps, apparently to bring it within reach of fish it has -sighted, then spreads its wings, bringing them forward until they -meet, and with the tips of the quills in the water. The head is in -the canopy formed by the wings, and apparently it is here under this -canopy that the fish on which it feeds are caught. The suggestion as -to the correlation that presents itself is that the dark canopy thrown -over the fish confuses them and makes them easier to catch. - - - - -INSTRUMENTAL MUSIC OF BIRDS - -[Illustration] - - -Vocal music bulks large in our avian springtime chorus, but don't -overlook the instrumental music that accompanies it. The drumming of -the downy woodpecker on the dead limb of a maple near my bedroom window -is as much a part of my spring as is the cheery cheerup of our robin. -It's not that woodpeckers are voiceless that they drum. The flicker -can be called in with his particularly rich repertoire to repudiate it -vociferously. All day the downy woodpecker goes about pounding his head -against tree trunks, with his bill chiseling out wood-boring insects -to eat. What more natural when springtime comes and he wants to tell -the world, and especially other woodpeckers about it, to select a -dead limb with a nice tone in my maple tree and hammer out a rolling -tattoo--his love song and his challenge. - - -A DRUMMER The gray-brown ruffed grouse of a wood lot we used to have -in the Chicago area is a drummer I miss. "Thump-thump ..." he started -slowly, and then quickened to a roll that filled the forest with hollow -sound and you wondered whence it came, unless you happened to know, as -I did, that an old log in the patch of gray birch was the old cock's -favorite performing stand. There he came to roll out his invitation to -the demure hen grouse. A drummer, I've called him, yet he has no drum. -It's his wings, striking the air, that thump and build up into a roll, -its volume testifying to his great breast muscles as well as does the -whir of wings as he hurtles away through the air when I come too close. - -The snipe of a nearby marsh makes music with feathers and wind, music -that is more enthralling to me than the song of the yellowthroat or -the vocal imitation of stake driving by the bittern. Circling high, -then with a change of pace, his "winnowing" or "bleating" spring song -comes drifting down. There is still room for argument, but probably -it's air rushing past the outer tail feathers that makes the sound. One -year a short-eared owl nested in the nearby meadow. Owls generally are -vocalists, even if we don't rate very high their hoots or yelps, but -the short-eared owl also has an instrumental performance. Sometimes, -when giving his mating song on the wing, a series of "toots," he -interrupted this by a dive in which he brought his wings together under -his body, with a clapping sound. It's part of the performance, but -not, as might be said, the owl applauding his own show. - -Over our public school each evening in early summer a nighthawk booms. -He has a voice, and he uses it, calling "beep" as he circles high. But -the climax of his performance is instrumental, wind on feathers. He -heads down, wings high, toward the flat gravel roof on which his mate -is sitting. As he approaches the roof he moves his wings down; the air -rushing past the quills gives a tearing boom as he comes out of the -dive and mounts skyward again. - -At dusk, at a damp corner of our old wood lot, in the spring, I -listened for the woodcock's flight song, a twittering of wing music as -he circles up, and sweet music, too, for a wild fowler's ears, is the -whistling of the wings of a passing pair of black ducks on their way in -the early darkness. - - - - -CONDITIONING IN BIRDS - -[Illustration] - - -The classical experiment in conditioning and reflexes is that of -Pavlov. It consisted of sounding a bell each time food was given to -a dog. Finally the salivary response resulted even when the bell -was rung, without the food being given to the dog. The dog was -_conditioned_ to the bell. First it had responded to the food, then -to the food and the bell, and finally to the bell alone, by a flow of -saliva. The beauty of this experiment is in its simplicity, dealing as -it does with a single reflex. - -Though much behavior is more complex, experiments have been worked out -to show how the environment, in a broad sense, can influence inherited -behavior. An illuminating example of this is the one I made dealing -with young loggerhead shrikes and the duration of their infantile -behavior. Young shrikes, as with young passerine birds in general, -while in the nest are fed directly by the parents, who place food in -their mouths. One of the earliest behavior patterns these young birds -perform is to stretch up with widely opened mouth, fluttering wings, -and buzzing calls, in anticipation of being fed. This we call begging. -Though typically infantile behavior, it may reappear in courtship, but -this latter we will not consider here. - -Ordinarily this infantile begging behavior is discontinued shortly -after the young birds leave the nest and become able to feed -themselves. Observations indicate that in a state of nature this change -is probably hastened in part by the young birds themselves, who come to -avoid having food thrust down their gullets, and prefer to pick up the -food for themselves, and in part by the waning interest of the parents -in the young, which confers an advantage on the young who early become -self-supporting. - - -CASE OF RETARDED DEVELOPMENT Certain observations made from time to -time have indicated that though the age at which young birds changed -from infantile begging for food to self-supporting independence was a -fixed thing, started by instinct, certain external factors, notably the -amount of care the young received, could affect the age at which this -change occurred. Indeed there was a record of a young cedar waxwing -raised by hand who never learned to feed itself. - -When I secured a brood of four young loggerhead shrikes, or -butcherbirds, the material was available to conduct a controlled -experiment. The young birds were raised together by hand to the stage -where they were ready to begin to pick up things, to feed themselves, -and to begin to abandon their infantile behavior of begging for food. -This was when they were twenty-one days old. They were then divided -into two lots and housed separately. One couple had a supply of food -kept in front of them, and hand feeding was gradually discontinued and -stopped as soon as possible. At the age of twenty-eight days they fed -themselves well, though they still begged freely when I approached. By -the time they were thirty-nine days old they begged rarely, and after -the age of forty-five days they were not seen to beg. - -The other couple had no free food available at any time, and they were -fed completely by hand, the food being placed in their mouths. At the -age of twenty-eight days they had made no effort to feed themselves. -By the time they were fifty-three days old they made efforts to feed -themselves, trying to peck the food from the fingers instead of having -it thrust into their mouths, and evidently would have changed quickly -to independent self-feeding and abandoned their infantile begging -behavior. But hand feeding was continued. At the age of seven and -a half months, when the experiment was discontinued, though these -birds were capable of feeding themselves, as was seen when food was -accidentally dropped on the floor of their cage, they still begged for -food from their human foster parent. - - -OBJECT LESSON FOR PARENTS These four birds used in this experiment -were nestmates, and had similar heredity and early environment. The -birds in the lot which received only enough care to ensure proper -development became self-feeding, independent, and lost their infantile -begging behavior when they were about a month and a half old. The other -lot, which received an excessive amount of care in the latter part -of infancy, and were hand fed without being allowed to develop the -behavior that would have made them independent, retained the infantile -behavior pattern of begging to be fed until the end of the experiment. -They were then seven and a half months old, and their nestmates, under -a different set of conditions, had lost their infantile behavior six -months earlier. - -With some birds it appears excessive care can be a conditioning factor. -It can delay the loss of infantile behavior and the acquiring of the -normal independence. Though instinctively the young shrikes tried to -develop their independent behavior, when this was not possible they -continued their dependent, conditioned behavior. - - - - -POISONOUS BIRDS - -[Illustration] - - -Poison we know perhaps best in the plant world, whence comes, for -example, strychnine. The deadly nightshade, a common weed, is another -well-known poison plant. In the animal world we know poison best as -something that is injected into the body by stings of bees, bites -of spiders, the bites of insects, and even bites of shrews. In -addition some animals having irritating, bad-tasting, or poisonous -secretions which presumably protect the possessor from predators. -This has received most attention in the insect world, the bad-tasting -grasshoppers being examples. Toads have an acrid secretion from their -skins which deters many would-be toad eaters, and pickerel frogs have -somewhat the same thing. - -The following three birds, which are recorded as having poisonous -flesh, are, strangely enough, all members of groups ordinarily -considered good table birds. Further, it seems the poisonous properties -of their flesh are not constant, but apparently depend on what they -have been eating. - -The ruffed grouse of the United States is regarded by many as the -finest of upland game birds and favored by the epicure. However, -Mr. E. H. Forbush, in his monumental _Birds of Massachusetts and -Other New England States_, gives accounts to show that in winter the -ruffed grouse is known to eat leaves of laurel, which have poisonous -properties, and that there are stories of serious poisoning resulting -from eating the flesh of the birds. Such poisoning, Forbush points out, -seems to have taken place only long ago and only by winter-taken birds. -Perhaps now that it is illegal to shoot grouse in the winter when they -may have been feeding on laurel, such poisoning does not occur. This -seems an additional reason for obeying the game laws. - -Pigeons in the tropics are abundant both as to individuals and as to -species and many are favored as food. However, Messrs. D. L. Serventy -and H. M. Mitchell, in their recent volume on the birds of Western -Australia, report that bronze-wing pigeons of two species are given to -feeding on the seeds of the box-poison plant, and when they have been -feeding on these seeds their entrails and bones, but not the flesh, are -poisonous to dogs and cats. The effects of eating this poison seems to -be that the dogs and cats have fits, become mad, bite at anyone within -reach, and finally die in convulsions. - -During Colonel Meinertzhagen's study of the birds of Mauritius he found -that one of the pigeons there had a bad reputation from a culinary -point of view. Reports have it that some of the people who have eaten -the flesh of this pigeon suffered from extreme lassitude, while others -reported the effects as convulsions. Strangely some of the people who -reported sickness from eating this pigeon say it tastes well, while -others who have eaten it without ill effects say that the flesh is -bitter. - - - - -KINGFISHERS ON THE TELEPHONE - -[Illustration] - - -"What color is the kingfisher? Not the American one, but the European -and Asiatic one? My husband is painting one and needs to know the -colors," a lady's voice came over the telephone. I thought quickly. -"Will it help if I explain the various kinds and colors of kingfishers -and where they live? But no, lessons on taxonomy and zoogeography -fall too flat most of the time." The lady's voice had a Central -European quality. To her "the kingfisher" probably meant the little -sparrow-sized kingfisher of the Old World scientists know as _Alcedo -atthis_. So I'd better start with that. I described the cobalt-blue -back, with darker wings, and dark bars on the crown; an earth-brown -stripe through the side of the head, paling to whitish posteriorly, -and with ocherous underparts. - -"What color is the eye?" - -"Brown." - -"And the feet?" - -"Red." - -"And the nails?" - -"Black." - -She thanked me prettily. I tried to tell her about some of the other -kingfishers, but she said no, she had enough, and hung up. - -I sighed and thought regretfully of all the other things I had ready to -tell her. - -In the United States we think of the kingfisher as the belted -kingfisher, larger than a jay, with a tousled crest and a voice like -a watchman's rattle. But there are other species farther south in -the Americas, and in the Old World there are still more. The tropics -are their home. Only one species reaches Northern United States, and -only one reaches Britain. But in New Guinea, for instance, there are -about twenty-four of the ninety or so known kinds of kingfishers; the -smallest tiny as a warbler, the largest nearly crow size. - -Kingfishers, we call them, but many live on the dry land, and instead -of catching fish catch insects or other tiny animals from the ground. -One large species, with a broad shovel-like bill, is even reputed to -dig in the earth to get its food of earthworms. - -They all look much alike in shape. Once you overcome your surprise at -seeing a kingfisher as big as a crow, or smaller than a sparrow, you -recognize one anywhere--big-headed, large-billed birds with tiny feet -that sit up quietly much of the time. Blue is a common color, but not -all are blue. Some are generally reddish in color, some patterned with -browns, grays, and whites tinged with blue. Many are decorated with -crests, and a few species have elongated spatulate-tipped central tail -feathers that have earned the species the name paradise kingfishers. - -Its voice has given one species its name: the laughing jackass, the -jackass kingfisher, or the kookaburra of Australia. "Ha ha huh huh ho -ha ha huk" in a deafening chorus has been given as a description of its -call. A. H. S. Lucas and W. H. D. Le Souëf, no doubt with tongue in -cheek, record that "_on dit_ that the jackass has been heard to laugh -while a cicada [it had eaten whole] has been skirring inside him." - - -CLASSICAL ALLUSIONS Halcyon, Alcyone, and Ceyx appear in the scientific -names of kingfishers. Scientific names make the layman shudder. Latin, -he says, and if he's told they're not Latin, but rather Greek, it -doesn't help any. But once you know the story of Halcyon (or Alcyone) -and Ceyx, the names stick in your mind. In ancient times Halcyon was -the daughter of Aeolus. And in grief for her drowned husband, Ceyx, she -threw herself into the sea. The gods, out of compassion, changed both -into kingfishers. Halcyon was also used by the Greeks as a name for the -kingfisher and it was fabled to make its nest on the sea, and to quiet -the waves for its incubation period. Poets still use Halcyon for the -kingfishers in reference to calm, happy, peaceful days, Halcyon days; -the sort of days in which the kingfishers can nest on the quiet waves. - -The lady had not waited for all this. She had gone. I would have liked -to see the picture her husband was painting when it was finished. - - - - -ON IDENTIFYING SEA SERPENTS - -[Illustration] - - -The lock ness monster reappears periodically in the newspapers. This -monster seems to belong in the general category of "sea serpent." As a -museum zoologist I've had little to do with such things. The stock in -trade of a museum is specimens and if someone sends us a "sea serpent" -(and I don't mean a water snake or a sea snake), we'll identify it. -If it doesn't have a name we'll give it one and make a place for -it in our classification. Until then we are aloof. We've had some -little experience at times with "sea serpents" and the following will -illustrate the sort of investigation and the results that we've had. - -Years ago Sir Frederick Jackson was an administrator in East Africa. -In addition to his official duties he was an enthusiastic and an able -naturalist. So when a "sea serpent" was reported there he investigated. - - -IN KENYA The sea serpent was said to frequent Lake Naivasha in the Rift -Valley of Kenya Colony. Up until 1909 there were many rumors of it, and -Europeans had seen it with their own eyes. It always appeared on the -lake about the same time each day, about five o'clock in the afternoon, -always about the same distance from the shore, and was always traveling -in the same direction, from north to south. All descriptions agreed -that it was long, black, and reptilelike, and that it kept appearing -and disappearing on the surface of the water at short intervals. - -Sir Frederick kept watch with one of the people who had reported it. -And, sure enough, what appeared like a long black reptile appearing and -disappearing, or like a school of porpoises, rising and disappearing, -came into view. But Sir Frederick had binoculars and was able to make -out that what to other people had been a long black reptile was in -reality a long line of white-breasted cormorants in flight, on their -way to their roosting quarters. As they flapped steadily along they -were plainly evident, to the naked eye, as a moving black line; as they -paused in their flapping and sailed on motionless wings they became -invisible to the naked eye, though, of course, still visible through -the binoculars. - - -IN NEW GUINEA Once, for a few startled moments, I thought I had a sea -serpent before my very eyes. It was on the middle Fly River in south -New Guinea. We were camped on a bamboo-covered bluff overlooking the -river. Though about one hundred miles from the mouth, the tide made -itself strongly felt here, and there was an abundance of driftwood. -This driftwood, varying from freshly uprooted trees that had fallen -into the river to waterlogged timber that had been long in the river, -went up and down on the tide until it got out in the main channel and -so on to the sea. One day at lunch, sitting in front of my tent, I -was idly watching the driftwood. One piece in particular caught my -fancy. Apparently it was the root of a partly submerged log, projecting -about three feet above the water, and curved at the end so that it -looked like the neck and head of a reptile with a casque on its head. -Knowing it was a waterworn root, in fancy I even saw its eye. I called -my companion's attention to it, as here was as close as we were ever -likely to get to a sea serpent. Then, the "head" turned. It was alive. -For a few startled moments it was a sea serpent. You can imagine our -amazement at having a piece of driftwood that we had in fancy turned -into a sea serpent come to life. Investigation became the order of the -day. The binoculars that were constantly at hand were trained on it. -The reality came as a further surprise. Our sea serpent was the head -and shoulders of a cassowary which was swimming the river. Later I -found that these large, ostrichlike birds, which have a large casque on -their heads, are well known to swim, but I didn't then. - -This seemed an ideal opportunity to collect a specimen. These birds may -weigh up to 150 pounds. When shot in the forest there is the question -of lugging them perhaps miles to camp. Here was one swimming up to our -door. - -We sat quietly waiting for it. But our native boys had seen it too, for -next I saw them rowing the dinghy to it. An oar was brought into play -to stun it. And then both the boys and ourselves found out something -else. Dead cassowaries sink. When the bird was stunned by a blow of an -oar, it disappeared below the surface and was never seen again. - - - - -CONSERVATION OVER THE TELEPHONE - -[Illustration] - - -Richard Orr, the _Tribune_ reporter, called me one day about bronze -grackles. It seems that the Chicago _Tribune_, in their "Day by Day -on the Farm," had told about the grackles on the _Tribune_ farm. A -_Tribune_ reader wrote in, expressing surprise that grackles were -permitted on the _Tribune_ farm and gave details of destruction by -grackles of other birds, personally observed. What were the facts of -the case? Should grackles be tolerated? Or should they be eliminated? -Orr wanted to know. - -This is the sort of question that is difficult. It is important, -too, for it involves basic conservation issues. And there is no -sharp, clear-cut yes-or-no answer. The question as to the grackle's -character reminds me of the character of Moses, as explained when I -was in school by a professor of the Bible: The black was there and -the white was there; Moses was a character sketch in gray. And so -with most creatures. They're both good and bad from our standpoint. -Grackles certainly do kill other birds at times, and interrupt the -nesting of some of our favorite songbirds. And yet, liking birds as I -do, I tolerate them in my garden. On a trumpet vine on our garage in -Chesterton, Indiana, one year we had a grackle build its nest on top of -a domed English-sparrow nest. The young of both sparrows and grackles -hatched about the same time, and the two families, within six inches -of each other, were successfully raised without friction between the -parents. - -Quite evidently grackles are not always killers of other birds. As to -robins or grackles being the "better" birds, if we had a robin's nest -that we prized, and the grackle killed the young in it, the grackle -would be "bad." But if we were an inquiring farmer, and had to weigh -the grackle against the robin, we might find the grackle "good" and the -robin "bad." The grackle feeds its young vast quantities of insects -harmful to the gardener; the robin sometimes seems to specialize in -earthworms. Earthworms are beneficial to man, passing through the -earth, making air and water more accessible, and, by passing earth and -vegetable matter through their intestines, enrich the soil. - -The house wren that warned the _Tribune_ reader when the grackles -were about is often prized as a garden bird; it is bold, saucy in -appearance, and a vigorous songster. But it is also well known as a -quarrelsome bird, prone to punch holes in the eggs of its neighbors, -and it also may fill up with sticks nesting boxes so that other birds -cannot use them. - -The above was the gist of what I told Orr, and appeared in the May 5, -1950, _Tribune_. - -Thinking of it afterwards, as is usual, I thought of many other things -I could have said, and perhaps made more clear that no bird is all good -or all bad, from our human point of view. Their relationships with -the rest of the landscape are complex. I like to see butterflies flit -about my garden. But butterflies are caterpillars at one stage. And -caterpillars may eat some of the things in my garden. But some birds -feed on caterpillars. If I eliminate the caterpillars because they -eat the plants I like, at one stroke I eliminate the source of the -butterflies I like, and food for some birds I also like. - -Perhaps the partial answer, if answer there be in this imperfect -world, is summed up by moderation: I can have some butterflies, some -caterpillars, some plants, and some birds in my garden. If one becomes -too abundant and interferes with the others, I prune it. Maintaining -some sort of a balance, we can have some of each. - - - - -BIRDS WASHING FOOD - -[Illustration] - - -We not only wash ourselves and our clothes, but certain items of our -food are regularly washed, as spinach, to get the sand out of it. -Washing has been so important in our society that we've coined the term -"Cleanliness is next to godliness." Possibly we've the snobbish idea -it's a strictly human trait. Among other animals we don't expect to -find water used for such cleanliness, and the raccoon, who does wash -his food, is considered a sort of biological oddity. - -But when we come to birds we find a surprising number of them that wash -their food. - -The dipper of our Western mountains in Oregon has been seen to wash -insects and grubs before feeding them to the young birds. The parents -held the food crosswise in the bill and the head was twisted rapidly -from side to side in the water. Not until then was the food taken to -the nest for the young. - -The scene shifts to Africa. Four buff-backed herons were feeding on -a flooded lawn at Gezira, Egypt. One of the birds captured a large -insect, apparently a large black beetle. Holding the insect in the tip -of its bill, the bird walked to the water, immersed the beetle three -times, shaking and fumbling with it the while, and then swallowing it. - -Then in Britain came a whole host of records, after an observation -in Holland in 1946 of curlew sandpipers washing food. The birds were -probing the dry mud at the edge of a little creek. When one of the -birds got a small sand worm, it at once ran with quick steps to the -creek and stepped into the shallow water, where it dipped the worm a -few times into the water before swallowing it. Then it trotted away -for more. The editor of _British Birds_, the journal in which this was -published, suggested that this might be a more common habit than the -scanty published records would indicate, and invited observations. - -A spate of records resulted in the succeeding numbers of the journal: -a whimbrel washing crabs; a snipe, earthworms; godwits washing their -food; with curlews it was reported to be normal; dunlins, greenshanks, -redshanks, ringed plover, and oyster catchers were all reported doing -this until it appears that with the group of birds we call shore -birds--sandpipers, snipes, plovers, and their relatives--it may indeed -be normal. The details of the observations strongly suggest that the -reason for the washing, in many cases at least, is the same one that -underlies our washing spinach; to get the sand and mud out of it. - - - - -HOW ANIMAL VOICES SOUND TO FOREIGN EARS - -[Illustration] - - -When in El Salvador in 1951, I found that the common barnyard animals -had much the same voices as the ones with which I was familiar in -the United States. But when I saw their utterances written down it -was another matter. The voices written in Spanish sometimes looked -as different as the names of the animals written in Spanish. Take -the donkey, for example (or _burro_, as they call it in Spanish). In -English we call its "song" "Heehaw!" In Spanish they wrote it for me, -"Aja! Aja! Ija! Ija!" There were a number of German scientists at the -Instituto Tropical de Investigaciones Científicas, where I was working, -and for comparison I asked them to write for me what the same animals -said in German. The burro (_Esel_, they call it in German) says, -"_Ihå! Ihå!_" in German. Despite the difference in the appearance of -these words, when they were pronounced by the various nationalities -they sounded very similar. Compared with the original assinine -pronunciation, the Spanish version was awarded the prize for being the -best rendition of the beast's voice. - -The cat's "_Miau, miau, miau_" in Spanish, "_Miau, miau_" in German, -and "Meow" in English were all very similar in appearance as well as -sound. The duck's voice came out differently. In Spanish it was "_Cuá, -cuá, cuá_," in German "_Wack, wack_," and in English the initial "Cu" -or "Q" sound of the Spanish, and the final "k" sound of the German -are united into "quack." The hoot owl came out much the same in -pronunciation, though it looked different in the Spanish "_Ju_," in -German "_Hu_," and in English "Who." - -The cow's, the pig's, and the frog's voices were also rather similar -in the three languages: the cow's in Spanish being "_Meu, meu, -muuu_," in German "_Mŭh, mŭh_," and in English "Moo"; the pig's -"_Grup-grup, wink_," "_Óŭik, Óŭik_," and "Grunt, oink"; and the frog's -"_Cruac, croac, croac_" "_Quak, quak_," and "Croak." The barnyard -rooster has a difficult voice to transcribe in letters. In Spanish -it was "_Quiquiriguiiii_," in German "_Kickeriki_," and in English -"Cock-a-doodle-do." After listening to the various renditions by the -various nations I could see how each rendition came into being, but as -for deciding which was closest to the original I hesitated to choose. - -When it came to the dog, the discrepancy was surprising: in Spanish -it was "_Guán, guán, guán_," in German "_Waŭ, waŭ_," and in English -"Bowwow." The German and the English are close enough. But though I -went outside and listened to the dogs in Salvador, never did they seem -to say, "_Guán, guán, guán_," though I must admit that neither did they -seem to say, "Bowwow." - - - - -SIGHT IDENTIFICATION - -[Illustration] - - -Sometimes when I'm trying to decide whether the birds of the Cameroon -Mountains of West Africa are the result of one invasion and variation -_in situ_, or of two invasions, or whether the Himalayan red-billed -choughs of Ladak are different from those of Nepal, or how the molt of -the cassowary resembles that of penguins, I am called to the telephone -to identify a bird someone has seen. - -The chances are it's a starling. I've not kept a record, but I fancy -half the questions are on identification of starlings. In the distance -starlings are black, and people know them. But close up, where details -can be seen, they puzzle people with their variety. The young may be -dull brownish; the adults may be speckled in the winter; in the spring -the speckled tips of the feathers wear off and they're all black. But -the black is iridescent, and in sunshine glitters purple or greenish. -And the bill color changes too: it becomes yellow in the spring. - -Sometimes it's surprising how you can spot a bird from a brief -description. Take this one: a bird that sits with its stomach on -the ground, and has a big mouth, and long whiskers; a whippoorwill -obviously. Or take this one: a bill like a chicken and with flat feet -at the back; obviously a pied-billed grebe. - -There was one that absolutely stumped me for a day. The lady said -it had a bill like an eagle, and a tail that stuck up. For the rest -she was vague. Often habits, actions, or habitat are a help to me in -placing a bird, but I could get nothing to help--not even where she had -seen it. I admitted I couldn't help her. The next day someone brought -in a picture puzzle out of a newspaper, and there, right in the center, -was my bird. It was a dodo! We don't mind helping people learn things, -indeed we consider it part of our job, but to help them work puzzles is -too much! - - -MY LESSON Sight identifications of most students probably contain -errors. On common species it's not important, as quantitatively -they cancel out. But when a bird tripper, anxious to make a new -record, wants me to help him decide he saw an exotic tern, I'm very -careful--I've had experience. Rarities have to be checked on all -points, not identified by elimination or on a few key characters. One -of the best lessons of caution I had in New Guinea. It was in the -mountains. Each morning I hunted in a forest where I'd found a new -genus of bowerbird. Anything might occur, I thought. Then I saw flying -through the treetops what could only be a magpie. A long-tailed, black -and white bird, its pattern was unmistakable. There was nothing like it -known from New Guinea. It would be an extension of range from Asia. Or -it was a new and unknown species. Anyway I needed it as a specimen. But -it was shy and eluded me. Morning after morning I haunted the forest. -Finally I got the bird. And it turned out to be a partly albinistic -specimen of a common, black, long-tailed bird of paradise. The abnormal -white areas in its plumage had fooled me completely. But it helped -teach me caution as to sight identifications. - -One of my Gary friends, Mr. Raymond Grow, who is a keen bird student, -has the proper approach, as his identification of a winter duck showed. -There were a number of unusual winter birds that season (1951-52): -brown-headed chickadees, pine and evening grosbeaks, and red-breasted -nuthatches, all from the North, were present. It was the sort of winter -one expects other rarities from the North. - - -DUCK CAUSES CONFUSION Mr. Grow had seen at the edge of Lake Michigan a -duck he didn't know; it was boldly patterned in black and white, a big -duck. An immature male eider seemed the only possibility. He came into -the museum and we went over specimens, noting the difference in the -shape of the head between the king and the common eider. He studied the -descriptions and the plates. Nothing quite fitted. Unsatisfied, he went -back to Michigan City, found the duck again, and suddenly realized -it was a muscovy duck, partly albinistic, and escaped from someone's -barnyard. - -It's not the first time a muscovy has caused confusion. Only a -year or so ago we had a duck sent us from the Philippines that our -correspondent wrote was shot swimming in a river with a Philippine -mallard and surely represented a new species. But it turned out to -be a muscovy whose original home is tropical American but has become -domesticated and transported by man to far parts of the globe. -Occasionally birds escape and take to the wild, even as this Philippine -bird had done. - - - - -GREEN HUNTING JAYS TURN BLUE - -[Illustration] - - -Sometimes in "working out" a bird collection things get dull. In -identifying the specimens, and writing down why they are this species, -or that species, or subspecies, it seems routine; as though it were -simply routine putting things in the categories ready for them. - -Such was my feeling one day as I worked over Himalayan jays and magpies -from Nepal. I'd done the yellow-billed blue magpie, and the red-billed -blue magpie, which both fell into their places smoothly. Then I got -out the literature, the pertinent keys, and descriptions for the next -species, the green hunting jay. It's a beautiful, pale, apple-green -bird, with a green crest, and set off by dark red wings. It checked -with the descriptions, and I wrote _Kitta chinensis_, its scientific -name, on the label. Then, to check the species' identification and to -determine the subspecies, I turned to the collection, to the birds from -India, Siam, and north Indochina, which should all be the same. - -I pulled out the drawer--and blinked at the jays, rows of them; all -pale blue with brown wings. I looked at the name on the case, on the -tray, and the name on each specimen. They all said the same, _Kitta -chinensis chinensis_, and it was the bird described as green, like my -new specimen. It was uncanny. The new green specimens and the old blue -ones were identical in size, in structure of bill, crest, feet, tail; -they must be the same. And they were. The book, I found, described -how the colors changed with age, and in John Gould's magnificently -illustrated folio, _Birds of Asia_, published in 1861, he had the -green hunting jay depicted both as a green bird with red wings and, in -the background, a "blue" green hunting jay like our museum specimens. -When alive, and when freshly killed, the birds are green. But with the -passing of time the green changes to pale blue, and the red wings to -brown wings. Probably my new specimen, now a year old, is less green -than it was when fresh. And when twenty years old, like our museum -skins, it will be blue too. - -The riddle was solved, and it fits into a well-known phenomenon, -"museum age" or post-mortem change. "Foxing," we call it for short. We -see it in the male American merganser, where the lovely rich salmon -color of the fresh bird becomes plain white. The emerald cuckoo of -Africa has vivid rich yellow under parts when fresh, and this too -becomes dingy white. Gray Canada jays become more brownish. Birds that -are olive or other shades of green tend to become more olive; brown -birds tend to become more russet or foxy (hence the term "foxing"). We -keep all our specimens in dustproof, lightproof metal cases. The change -is not caused by fading. Apparently it's a change in the pigment, -perhaps from oxidation. - -Taxonomists, the men who classify and name birds, have been fooled by -it. Old skins used to represent the birds of an area may give a quite -different idea of what they are like than do fresh skins, and when -skins of different age are compared, the conclusions may be wrong. - -Foxing is one of the pitfalls for the unwary taxonomist, and something -he has to guard against. - - - - -HOW BIRDS USE COWS AS HUNTING DOGS - -[Illustration] - - -The sportsman out for quail or woodcock uses dogs to drive out the -birds for him. Starlings and cowbirds about Chicago use the same -principle in hunting grasshoppers. Instead of dogs they use cows, -though of course the cows are intent on something else and presumably -unconscious of the fact that they're helping the birds. - -As the cow grazes slowly across a meadow, it scares up grasshoppers -close in front of it. The cowbirds and starlings take advantage of -this. Instead of covering the meadow on foot, constantly alert for a -sitting grasshopper, or to chase one they flush, the birds keep with a -grazing cow. They take up a position by the head, or a foot, and catch -the insects the cow disturbs. The cow is so much larger than the bird -that it is likely to flush more insects. The grasshoppers on the wing -are much easier to see than when at rest in the concealing grass, and -some fly directly toward the bird. Too, the grasshoppers fleeing a cow -are less likely to be alert to other dangers. - - -CONFIRMED BY OBSERVATION The advantages of this to the bird are -obvious. But we've just assumed they were, and we had no data on the -relative efficiency of the two methods of hunting. A few years ago, -however, while in El Salvador, I was able to get quantitative data -proving that using a cow as a beater was advantageous, as we suspected, -and showing how much more effective it was, something we did not know. - -The bird concerned was not the starling, which does not occur there, -or a cowbird, which occurs but consorts little with cows, but was -the grove-billed ani, a black cuckoo about twelve inches long of -the tropics of Central and South America. Like our starling and our -cowbird, it kept with cows, catching the grasshoppers and other insects -that flew up. Both anis and cows were common in the grassy fields about -our headquarters in San Salvador. We decided, my son Stanley and I, -to watch anis with cows for a few hours, and then without cows for a -few hours; thus getting the average rate for each type of feeding. We -quickly found it wasn't as easy as that. Something always happened; -even on the levelest and most open fields the birds were constantly -disappearing behind a tuft of grass, or in a hollow, or, if nothing -else, behind the cow's head or feet. Then, too, the ani we elected -to watch wouldn't pay attention to the job in hand. It would wander -off, or go to sleep. And sometimes, when we were about to discontinue -watching a somnolent bird, it would snap up an insect. Perhaps it -had been watching all the time. Finally we found we had to record -observations of many short periods, of from three to fourteen minutes -each, and add them together. - -By dint of much patient watching we got our data. In the dry season -when insects were scarce and the grass short, it took an ani, hunting -alone, two minutes on the average to find an insect. In the same length -of time hunting with a cow the catch averaged three insects. Thus -hunting with a cow as a beater was three times as effective as hunting -alone. - -The effect of the change of the season in abundance of food for the ani -was very striking. In the wet season the grass began to grow fast, and -insects became common. Then the anis had an easy time. Without a cow -an ani averaged between three and four insects a minute, more than six -times as much as in the dry times. There was less incentive to use a -cow as a beater, with food so abundant, but when the ani did so, its -rate of finding insects was still higher: between four and five insects -per minute. In a table it looks like this: - - -_Average Number of Insects Per Minute Found by Ani Feeding_ - - WITHOUT COW WITH COW - - Dry Season .5 1.5 - Wet Season 3.4 4.7 - -But the three-times-greater-results in a given time in the dry season -do not tell the whole story as to the effectiveness of using a -beater. When an ani was hunting by itself it walked about, covering a -surprisingly large amount of ground. When using a cow as a beater, not -only did it catch more insects in a given length of time, but it also -walked about much less, saving a great deal of energy. - -This is not true co-operation between cow and bird, for they're not -working together toward a common end. It's not exploitation of the cow -by the birds, for the cows lose nothing. It is closer to a form of -harmless parasitism, for the ani profits from the activities of the -cow without either harming or helping the cow. It also illustrates -how sharp birds are--ready to take advantage of any factor in their -environment that will help them get their food. - - - - -EARLY BIRD LISTING - -[Illustration] - - -I wonder how many of the people who go out making lists of spring birds -know that bird listing goes back to ancient times. It's a modern sport, -but earlier bird watching was serious, and a competitive listing of -birds played a part in as important an event as the selection of the -site of the city of Rome. - -The story, as Plutarch tells it, is that Romulus wanted the city on -what became known as Roma Quadrata; Remus wanted it on the Aventine -Mount. As was the custom in those days, they concluded at last to -decide by a divination from a flight of birds. The twins placed -themselves apart at some distance and watched. Remus, they say, saw -six vultures, a truly notable flight; Romulus saw twelve and from this -rare and unusual occurrence Romulus' choice of the site for the city -was accepted. - - -VULTURES HIGHLY REGARDED Partly from this the vulture became chiefly -regarded by the Romans in their divinations from birds. But even before -this the vulture was highly regarded. Hercules, it was said, was always -very joyful when a vulture appeared to him upon any occasion. He -considered it the least harmful of creatures; not pernicious to corn, -fruit tree, or cattle, it never killed or hurt any living thing. It -was also thought not to eat other birds, a weighty point in its favor, -as Plutarch quotes from Aeschylus, "What bird is clean that preys on -fellow bird?" And apparently its deciding claim to esteem was its -rarity and infrequency, which gave rise to the opinion in some that it -came from another world, an opinion foisted by the soothsayers of the -day. - -Earlier yet, birds played a part in Rome's history. Plutarch warns -that some give you mere fables of the origin of Rome, but it is -widely current that Remus and Romulus, fathered by Mars, the God of -War, were exposed in a remote place to perish. This would have taken -place, but for a she-wolf that nursed them, and birds of various sorts -that brought little morsels of food which they put into their mouths. -Some, however, hold the belief that not birds of various sorts but a -woodpecker was the bird that constantly fed and watched the twins, and -even in Plutarch's time the Romans still worshiped and honored the -woodpecker for this service to the founder of the city. - - - - -BATTLE OF THE SEXES AND ITS EVOLUTIONARY SIGNIFICANCE - -[Illustration] - - -I used to think that the battle of the sexes so ably portrayed by James -Thurber was artificial, a man- and/or woman-made thing. But recently -I've come to see it as old--probably as old as sex itself in the animal -world. - -Under the severe tide, "Secondary Sexual Characters and Ecological -Competition," in a paper from the Bird Division of the Chicago Museum, -I've outlined the possibility of competition for food, between -the sexes, being a factor in evolution, responsible in part for -characteristics of structure and traits that distinguish them. - -In circles that discuss evolution the idea is current that food -competition is important between species. It may even be stated as a -rule: two species with the same food habits cannot live in the same -place. Competition drives one out, unless they have different food -habits. These differences seem especially evident when you look at -closely related species, and they are accomplished in a variety of -ways. A habitat difference is very common. The long-eared owl hunts in -the woods--its cousin, the short-eared owl, hunts the meadows; the song -sparrow favors the drier shrubbery while its cousin, the swamp sparrow, -lives in wetter shrubbery. - - -THE SIZE FACTOR Sometimes the difference is accomplished by size; take -the downy and hairy woodpeckers of our wood lots, very similar except -that one is larger and is adapted for larger prey, the other smaller -and adapted for smaller food items. Sometimes they feed differently, -as the Baltimore oriole, which picks flowers and pecks through their -sides, while the orchard oriole probes into flowers as they hang on the -branches. Thus more individuals of several species live in an area. - -When a pair of birds "sets up housekeeping" and starts "raising a -family" they can no longer drift about, looking for easy living and -places where food is plentiful. Their wanderings are restricted by -having a fixed point, the nest, as their center of interest. Two -individuals must draw on the food supply from an area about the nest. -Competition would be extreme, and, if there were a scarcity, perhaps -critical. - -We know how different the sexes may be; how different the rooster is -from the hen in our domestic fowl, or the drake and the duck in the -mallard, or the red male and the green female of the scarlet tanager. -These sexual differences have mostly correlated with display and -mating. But logically there should be differences in feeding behavior -and adaptations between the sexes. - -The basic idea is contained in the old nursery rhyme: - - Jack Sprat could eat no fat, - His wife could eat no lean; - And so between them both, - They licked the platter clean. - -The two birds of a mated pair, limited to a single area, could be -expected to have different food preferences or adaptations for getting -it. And we find that there are cases of this. The most striking is -that of the huia from New Zealand, of which I've written in a Chicago -Museum bulletin. Both sexes have similar food preferences, especially -wood-inhabiting insects, but they get them in different ways. The male -has a short, straight, stout bill for digging out the wood-boring -grubs, woodpecker fashion; the female has a much longer, slender, and -curved bill for probing into holes for them, creeper fashion. The -female may get grubs in wood too hard for the male to chisel. They -supplement each other. - - -DIET VARIATION BY SEX It is possible that further study may show more -sexual differences to have a feeding advantage; the larger size of -female hawks fitting them to take larger prey; the smaller size of -certain female songbirds fitting them for smaller prey, the smaller -bills of female hornbills, the straight bill of the male western grebe, -and the upturned bill of the female. Perhaps all are of advantage to -the species in giving each sex slightly different advantages in getting -food. - -Selection could have its effect in the populations with most sexual -difference in feeding habits being most successful in raising and -leaving progeny. Thus, slowly, differences between the sexes would -accumulate. However, it must be kept in mind that this sort of -evolution would be limited. The drifting apart of the sexes would be -checked by the necessity for their coming together periodically for at -least a short period, at nesting time. - - - - -WATER IN THE DESERT - -[Illustration] - - -Water is a precious thing in the desert. Without it no life is -possible. When rains come plants spring into vigorous growth. During -the long stretches without rain they rest, some as seed, while some -plants store water in root systems, or in large trunks. Animals have -developed a number of ways of surviving long dry spells in arid country. - -Among mammals the kangaroo rat of our Southwestern desert seems able to -get along without water. This is caused by an arrangement within the -body whereby the necessary water is manufactured within the animal from -other foodstuffs: metabolic water. - -The accessibility of drinking water in a desert may be the determining -factor in whether or not some birds can survive there. The nests of -Gambel's quail must be close enough to drinking water for the newly -hatched young to walk there, else they perish of thirst. It has -been said that newly hatched chicks of the related valley quail of -California cannot travel more than a few hundred yards from their -hatching places without water. Broods hatched farther away are doomed -to die. - -Sand grouse, relatives of the pigeons that have adopted the general -appearance and habits of quail, live in the Old World, primarily in -arid or even desert areas. Where they occur their daily traveling to -water is a well-marked phenomenon. Their flight is swift and powerful, -and though they may traverse long distances of barren, inhospitable -country to watering places, their punctuality in arriving at water, -morning and evening in some species, is remarkable. - -But what of the young of these desert dwellers that need water? A most -unusual situation exists; indeed it seems to be unique. The old birds -bring water to the young! This has long been recorded, but as recently -as 1921 it has been questioned. However, Mr. Meade-Waldo's observations -on birds in captivity seem to definitely establish the custom, and its -methods. - - -PARENTS CARRY WATER Both birds incubate the eggs, the male by night, -the female by day, and both parents care for the young. But it is the -male only that brings water to the young. He rubs his breast violently -up and down on the ground, and then, his feathers awry, he gets into -his drinking water and saturates the feathers of his under parts. -Then, in captivity, he would run to the hen, make a demonstration, -whereupon the young would run out from under her, get under him, and -suck the water from his feathers. This they did by passing the feathers -through their bills, continuing and changing about until the supply was -exhausted. It was found that until the young can fly they take water in -no other way. - -This was in captivity. Presumably in the wild the process is the same, -the adult flying with wet under parts from the water hole to the -resting place where the young are under the care of the female. - -The similarity of the young sucking water from the feathers to young -mammals suckling their mother has been pointed out. But another and a -truer similarity exists: that of the young sand grouse getting water -from the feathers, and young quail getting water from dew-wet leaves in -areas where dew is heavy and there is but little surface water. - - - - -BIRD GRAVEYARDS - -[Illustration] - - -The best-known stories of animal graveyards are those of elephants. -But when I asked the curator of mammals about them the answer I got -was little better than a snort. Apparently the evidence for them is so -vague that it's little better than a myth. - -But in birds we have a few bits of evidence from far-scattered places -that occasionally such things as graveyards exist. - -In the antarctic Dr. Robert Cushman Murphy found on the island of South -Georgia a place where Johnny penguins went to die. It was in a lake -in a coastal range of hills. The lake bottom was thickly strewn with -scores of penguin bodies, all of which had apparently died a natural -death. The icy water, Murphy thought, might preserve them for years. -The hills, away from the sea, seem a surprising place for the graveyard -of such aquatic birds as the penguins, but it correlates with another -peculiarity of their mental makeup. They like to nest on high land, or -at least far from the sea. The blind instinctiveness of much penguin -behavior is well shown by these birds when there is no high land on -their nesting island. Then they may nest so far from the beach on which -they land that they are close to the water on the other side. Yet they -always returned to the sea by the long route, never taking the shorter -route. - -Another aspect of this preference for land distant from the sea is -shown by their behavior when threatened with danger from man or dog. -They flee away from the sea, back onto the land, when safety for them -actually lies in the sea. Presumably this fixed behavior dates back to -the time when the seal that is called the sea leopard was the penguin's -main enemy. Then the sea held their only danger. With man's arrival the -situation changed, but only after considerable experience with man do -the birds change this behavior. - -Apparently, when the time came for the penguins in this South Georgia -graveyard to die, they followed their age-old pattern, climbing to the -high country and away from the sea. - - -IN A HOLLOW TREE In a hole about eighteen inches in diameter and twelve -feet deep in the trunk of a wych elm in Hants, England, Ursula M. -Grigg reports finding the bones of at least ninety jackdaws, thirteen -starlings, six green woodpeckers, and twenty-five stock doves. All the -remains were clean, and not much broken or decomposed. The idea that -these bones were the remains of owls' or other predators' feasts was -discarded for a number of reasons; as was the idea that this had been -a natural trap, the birds entering to roost or nest and being unable -to escape. The most tenable idea seems to be that this was a favorite -roosting place in winter, and that during the severe weather old and -weakened birds, roosting there, succumbed and added their bodies to -this communal grave. - - -ON AN ISLAND Another instance comes from the little Cape Verde Isle of -Cima in the South Atlantic. A photograph in the _National Geographic_ -magazine for 1927, Vol. 52, P. 27, has the caption that this island is -unique and uninhabited and covered with the tiny bones of millions of -petrels which in ages past have come here to die. Certainly the plate -shows an amazing litter of bird bones on the tiny plateau of this islet. - -Petrels are mostly pelagic birds, coming to the land only to nest on -isolated islets. Can this "graveyard" be merely the normal accumulation -of the bones of the nesting season mortality, or can it be that the -birds actually come here to die? - - - - -ANIMAL GARDENS - -[Illustration] - - -Best known of the "gardens" and "animal husbandry" of the lower animals -are those of the ants; the aphis kept by the ants for the sake of a -sweetish secretion, and the underground fungus garden of the ants. In -the vertebrates I know nothing comparable to this, but we do get a -number of cases where there is a definite relation between the animals -and the growth of vegetation. - -It has been said that in the antarctic the nesting colonies of some -penguins are detrimental to the vegetation. The constant passing -and standing of the birds on the limited areas of soil preclude the -growing of vegetation over sufficiently large areas to be an important -factor in hindering plant growth. But the reverse is true of the -Johnny penguin in the Falklands, where it is sometimes known as the -best farmer in the country. The Falkland Islands, off southern South -America, are cold, wet, and windy. Sheep raising is one of the main -industries. And the Johnny penguin helps to provide better pasture -for the sheep. The birds nest in colonies and their droppings help -to enrich the land so that the grass grows taller and richer. Rather -than using the same area for their breeding colony each year the birds -select a new, clean area at the beginning of each breeding season, so -that they improve the ground over a larger area. - -From the arctic comes another example of a relationship between bird -and plant. On the arctic barrens, here and there, are large boulders, -erratics left by the glacier that covered the land in times past. And -on these boulders, and here only, one finds patches of bright yellow -or reddish lichen known to scientists as _Xantheria_ or _Xanthoria_. -Apparently its presence is owed to the fact that these boulders are -the lookout places of snowy owls, hawks, and other birds. Their -droppings, falling on the rocks, provide the nutrient layer necessary -for the growth of the lichens. It is probable that these lichens are -transported from place to place by the birds carrying the soredia on -their feet. In recognition of the close relationship between these -lichens and birds an ecologist has coined the rather formidable term -"ornithocoprophilous" to express the relationship. - -Also in the arctic are the arctic-fox gardens. The arctic fox often -makes its burrows in sandy places, and about the entrance to the -burrow accumulate remains of former meals, fox droppings, and suchlike -animal debris. This in time enriches the soil and the vegetation -there grows taller and more lush than elsewhere on the barrens. This -lush vegetation attracts the small, mouselike arctic rodents, the -lemmings, that feed on green, succulent vegetation. There is of course -one further step in this chain. One of the important foods of the -arctic fox is the lemming, which he thus brings to his door by the -richer vegetation he unwittingly causes to occur there. A charming -arrangement, one of the old naturalists called it. - - - - -DROPPING THINGS - -[Illustration] - - -The story is well known, being recorded by Pliny, of how the poet -Aeschylus came to his death through a bird mistaking his bald head -for a rock and dropping a turtle on it. The bird was evidently the -lammergeier or "lamb vulture," one of the largest and most magnificent -of the Old World birds of prey; nearly four feet long. In the Atlas -Mountains of North Africa its normal food is turtles, and these it -cracks open, so that it can get at the meat, by carrying them up into -the air and dropping them on a rock. Now it lives in the Himalayas -and in Africa, having been almost if not completely exterminated from -Europe because of its alleged predation on sheep. Not only turtles but -bones are treated in the same manner, to get at the marrow. Though -the habit is well known, it is surprising how difficult it is to find -a firsthand description of it. So far I know of only one description -written by an eyewitness. And yet, in East Africa recently a stony -mountaintop was found littered with broken bones that seemed to be the -result of the lammergeier's habit. - - -GULLS DO IT As I have mentioned, gulls open clams and mussels in this -way; and crows, which are among the most intelligent of birds, do it -also. They pick up the mussels left exposed by the falling tide, fly up -above a hard stretch of beach, a big rock, or a stretch of nearby paved -road, and drop the shellfish there. While in general this practice is -restricted to a few groups of birds, it is practiced by them in many -far parts of the world. The Pacific gull of Australia, widely separated -from its near relatives, has the same maneuver for opening shellfish as -has our herring gull. - -It's hard to understand just how this habit came about. One can imagine -that some birds found it out by accident when flying about with a -stubborn "nut" they were unable to crack. Or perhaps it was in play -they found it. The raven is known to fly about carrying and dropping -things in play. - - -SPARROWS DO IT TOO Often, to find a background if not an explanation of -a habit, we look about to see if it's used in some other connection. -I've already mentioned the play of some of the crows. Only one other -"dropping" habit has come to my attention, and that is a single -record for the very common house sparrow. Edmund Jaeger writes that -in Nebraska, and again in Riverside, California, he saw house sparrows -on gravel roofs, dropping small stones over the edge. The pebbles, or -small bits of crushed stone, were carried to the edge of the building -by the sparrows, dropped, and as each pebble was dropped the sparrow -turned its head, apparently the better to watch or listen to the pebble -fall and strike. No obvious utility appeared in these actions. It, too, -looked like pastime. Perhaps there was no better reason behind them -than that behind small children dropping stones down a well. - - - - -LEARNING BY BIRDS - -[Illustration] - - -Of course birds can learn. Indeed there's a trite saying that no animal -has been discovered so low that it cannot learn. One of the simplest -cases of learning is shown by parts of some experiments I carried out -years ago on the curve-billed thrasher. I had raised a number of these -thrashers by hand, and in connection with finding out about their -tasting abilities I first fed them on the white of egg, hard-boiled and -cut into little squares. They liked it. Then I soaked more squares of -boiled egg white in evil tasting (to me) formalin. The birds came to -the dish, and also ate them. But after that for a week they refused to -eat such egg white. They had quickly learned to avoid the ill-tasting -food. - - -BAD-TASTING FOOD Once I hand-raised a barred owl from a nestling to -adulthood. Sometimes getting food for it was a problem, and upon -occasion I fed it frogs, which it seemed to like well enough. But then -came a day when I fed it a toad. The owl seized the toad at once. -Now toad skin, presumably as a defense weapon of the toad, secretes -a substance irritating to the mucous membranes of some animals. And -this was evidently irritating to the owl, for it did not hold the toad -long in its bill. It spat it out, and the owl's face gave evidence of -disgust. After that the owl not only refused to take toads, but it also -refused to take frogs such as it had found palatable before. Evidently -frogs looked too much like toads. The learning was effective, and -extended not only to the original object, but also to other, similar -objects. - - -BUCKET-DRAWING When in Florida with the Archbold Expeditions I was -studying blue jays. A very simple but amusing thing that chickadees -learn is to sit on a perch and pull up a little container of food that -dangles far below the perch on a string. Jays, along with crows, are -among the most clever of birds, as I've said before, and I gave two -jays in one cage a chance to learn the trick. In three days one of -the jays was regularly and quickly pulling up the little bucketlike -container and getting its food from it. The process was simple: the -jay reached down, seized the string in its beak, secured the slack -under its foot, and reached down again for another pull. Sometimes five -separate pulls were needed to raise the food bucket the eight inches to -the perch. - -The jays were regularly fed in this manner. Soon I noticed that only -one of the two birds pulled up the bucket, though the other also fed -from it. In effect one was depending on the work of the other. After -this had gone on for a month, I wondered if the second jay, which had -never done any of the work, would be able to pull up the bucket if left -alone. Certainly it had had lots of opportunity to learn by seeing -its cage mate go through the motion. So I left it alone in the cage. -This second jay, despite its chances to learn by observation, took -one day longer to learn how to pull up the bucket of food than had -the first jay. The jays certainly learned the trick quickly through a -trial-and-error process, but simply watching the process seemed to be -of little help in learning it. - - - - -CAN BIRDS COUNT? - -[Illustration] - - -If birds can count, it's a rather rudimentary thing--perhaps no more -than impressions of the size of groups. The widely known example -showing that birds don't seem to distinguish between one and two -persons is the ruse used by bird photographers and students of birds -who are using blinds from which to watch the birds at close range. - -The hide, or blind, is a little hut built perhaps a few feet from the -nest to be photographed. If the photographer enters the blind in the -sight of the parent birds, and conceals himself there, the birds who -saw him go in will be a long time in coming to the nest and in resuming -their normal activities. But if the photographer takes a companion -with him, both go into the blind and conceal themselves, and then -one of them goes away leaving the other concealed, the bird quickly -disregards the intrusion and goes about its activities as though no one -were left in the blind. This subterfuge has long been used and is very -successful. Apparently the bird is unable to distinguish between the -two people that arrive at the nest and the one only that leaves, and -behaves as if both had gone away. - -In my duck-hunting days a duck hunter who used wooden decoys told me -he was sure that there was a certain number of decoys necessary before -they were effective. - -The decoys were wooden blocks, carved and painted to resemble -life-sized ducks, weighted to float like them, and anchored in shallow -water in a flock within gunshot range of the blind in which the duck -shooter sat. The idea was that ducks flying by would see the flock on -the water, assume that here was a safe resting place, and fly in and -light, or attempt to light among them, giving the wild-fowl gunner an -opportunity to shoot the wild birds. - -The duck shooter claimed that if less than twenty-five or thirty decoys -were put out in the flock, the setup was much less effective than if -more than twenty-five to thirty decoys were used. He thought that the -ducks could distinguish between less than twenty-five or thirty and -more than twenty-five to thirty, and favored the latter. Though this is -distinguishing between greater and lesser amounts, it hardly comes in -the category of counting. - - -DISTINGUISH "MORE" FROM "LESS" However, a series of experiments -summarized on Page 121 in the periodical _Bird Banding_ for 1940 seem -to indicate that birds can distinguish between different numbers of -things, such as peas and numbers of dots. The birds, including pigeons, -parakeets, and jackdaws, were trained either to choose a certain -number of objects under certain circumstances, or to choose between -two quantities of objects with reward and punishment motivation. It -was found that these birds were able to distinguish up to a maximum -of six. That this is really counting in the human sense of the term, -which is linked with speech or written symbols, is improbable, but it -does indicate, as one would expect, that birds do at times distinguish -between different quantities, and sometimes with considerable -precision. - - - - -COURTSHIP FEEDING - -[Illustration] - - -A young man, giving his best girl a box of chocolates, and a bird, -giving his prospective mate a worm or a berry, have this in common: -they are both practicing courtship feeding. Further, humans and birds -are the only vertebrate animals that do this. - -With birds, during courtship, the female often begs to be fed by acting -like a young bird--with fluttering wings and widely gaping mouth. The -male normally places the food he has collected directly in the open -mouth of the female. - -The significance of this courtship feeding has been discussed -especially by David Lack, in the scientific journal, the _Auk_. It -seems that in courtship feeding the food as such is not of primary -importance. The female does not need the food she is begging for; -indeed she may have had a full meal since her mate, whom she is -soliciting, had last eaten. Perhaps it is of help in maintaining the -bond between the pair during the period that exists before they have a -nest and young to look after. In this connection it is interesting that -with waxwings during courtship feeding the fruit that the male gives -the female may be "handed" back (by beak) and the food exchanged back -and forth. - -In looking for significance and correlations in courtship feeding we -find that some species practice courtship feeding and some do not. And -the birds that do practice it are usually those in which both sexes -care for the young. It might be considered an early, useless appearance -of a habit that later becomes useful when the male feeds the incubating -female and helps feed the young. - -This type of behavior, in which an act used elsewhere is introduced -into courtship, is sometimes called "symbolic." Other such symbolic -acts are the preening that sometimes takes place between a pair of -mating birds, and the passing or the manipulation of nesting material -long before there is a nest to be built. - -Some species during courtship go through actions that resemble -courtship feeding except that no food is passed; the bill touching of -the mourning dove and of the waxwing falls in this category. Perhaps -it is incipient courtship feeding on its way in the long course of -evolution, either upward, to include food, or downward, away from -courtship feeding. - -Their functions seem to be to give something for the pair to do; -something they can share. It helps fill up the pair's day and keep them -together. It is something that helps strengthen the bond between them, -against the day when both will be working together raising a brood. - - - - -THEY TURNED THE TABLES - -[Illustration] - - -Most birds prey on animals enough weaker than themselves to be in no -danger from their prey; their hunting is more like that of the gunner -after rabbits than that of the hunter after lions. But there are -exceptions. - -The great blue heron, armed with a spearheadlike bill, lives largely -on fish. These it spears in the water, stalking about after them on -its long legs, or waiting like a bird on a Japanese screen, as patient -as any fisherman, for its prey to come within striking distance. The -heron's size and its great bill render it safe from most enemies. But -it sometimes overestimates its ability. Audubon recorded one on the -Florida coast that, standing in deep water, up to its belly, struck a -fish too large for it. The fish dragged the bird for several yards, now -on the surface, now underwater. Finally, after a severe struggle, the -heron freed itself. It was exhausted, and stood near the shore, head -turned away from the sea. As if, Audubon said, it was afraid to make -another attempt at fish catching. - -A more serious encounter for the bird was recorded in _Field and -Stream_ magazine. The heron had caught a shad about a foot long. -He tried to swallow it, but it was too big to go down. He tried to -disgorge it, but the fins of the fish, acting as barbs, kept it from -slipping backwards and out. The result was death for both bird and fish. - - -CAUGHT BY A CLAM The oyster catcher, a large black and white relative -of the sandpiper, feeds on, among other things, shellfish. Mussels and -oysters look like hard nuts to crack, even with a stout, wedgelike bill -such as that of the oyster catchers. The oyster catcher's favorite -feeding times are when the tide has fallen and the shellfish are -first exposed to the air and before they have closed up their shells, -and again when the tide is rising and the shells are just beginning -to open. The oyster catcher stabs into the shell, and with its bill -cuts the strong adductor muscles that hold the shells of the bivalves -together. The rest is easy. But a danger lurks here: what about -stabbing into too big a shellfish, or making an inept stab? And this -very thing has happened. On the South Carolina coast Mr. W. P. Baldwin -found a trapped, drowned bird. It was held, with the tip of its bill -caught in the shell of a hard-shell clam, as if in a trap. Apparently -the rising tide had flooded and drowned the bird. - -The raven eats most anything, living or dead, and except for man -has little to fear in the northern forests where it lives. Yet from -Wisconsin comes a record of one that met his death through a porcupine. -The porcupine's quills are a dreadfully prickly covering that one -would think would protect it from most encounters. Yet one animal, the -fisher, kills and eats it as a matter of course, and wolves and bears -sometimes eat them without too many ill-effects from the spines. The -slow-moving porcupine has little regard for automobiles, and many are -run over on country roads. A porcupine is too big and tough for a raven -to kill and the Wisconsin raven had probably fed on a dead porcupine. -Stuck through its gizzard was a quill, and another, which had -apparently caused its death, was stuck in its heart, having apparently -worked there from the digestive tract. - -Many small insectivorous birds eat spiders as well as insects. This -they do almost with impunity in temperate latitudes, where only -occasionally do spiders make webs strong enough to trap a bird. But -in the tropics, where there are more large spiders, their webs must -be a greater hazard to birds. That the hazard exists in both climes, -however, is shown by a goldfinch reported caught in a spider's web in -Cape Cod, Massachusetts, and a dusky flycatcher caught in a spider's -web in Cameroons, West Africa. - - - - -SURVIVAL OF THE UNFIT - -[Illustration] - - -To care for the weak, the unfit, and the cripple is usually considered -an extremely highly developed altruism in our society. As our society -progresses, more and more provisions are made for the unfit. - -In nature the unfit usually is soon weeded out. If an animal is -unable to feed itself it is doomed; or if it is less successful than -its fellows it has less chance of leaving progeny. That is natural -selection. - -Hence on both counts it comes as a surprise to find two -well-authenticated cases of crippled birds, unable to search for food -for themselves, surviving for long periods. - -The first is T. R. Peale's record in 1848 of a brown booby on Enderby -Island in the Pacific. An adult bird whose plumage indicated it was -several years old was found on the island, and it had only one wing, -the other having been lost by some accident and the wound completely -healed. The bird was unable to go to sea and get its own food, and was -being fed by its fellows. - -The second was a frigate bird, found on the Revillagigedo Islands, -reported by A. W. Anthony in 1898. This bird, too, was fat, and had one -wing withered and useless, evidently from hatching. It had never flown. -Frigate birds are masters of the air that snatch their food on the wing -from the surface of the water, and a flightless frigate bird would be -as badly off as a flightless swallow. The cripple had been fed all its -life by its neighbors. - -At first the uncritical might think, What altruism, what charity, for -the healthy to feed these two cripples. But an explanation involving -less advanced principles, principles more in keeping with what we know -about bird behavior, is possible. Remember that young birds that are -unable to begin feeding themselves at the proper time may continue to -beg for food, and be dependent for a long time, as I have shown with -young shrikes under the chapter, "Conditioning in Birds." Remember that -a young bird begging for food may be fed by adults, not its parents, -and even by other young birds (shown in "Bird Helpers at Nesting -Time"); and we have the clue. - -The cripples, hungry, begged for food; the healthy birds responded by -feeding, as they might do to other begging young, and owing to the -unusual circumstances both were continued. - -These certainly are cases where the unfit survived. Natural selection -has not operated. But such cases are rare exceptions. - - - - -DUST AND SNOW BATHING - -[Illustration] - - -The taxidermist preparing a bird specimen for the museum sometimes has -to deal with one whose plumage is soiled or stained. He may have to -wash it with water. Then, to dry the plumage, fluff it, and help in -arranging the plumage so it will lie smooth and natural, he may use a -powder: corn meal, sawdust, plaster, or plaster and potato starch may -be worked into the feathers, then dusted out again. It is interesting -that birds themselves use and have used long before taxidermists a -similar method of using dust in dressing their feathers, a fact that -anyone who has watched domestic hens for any length of time must be -aware. - - -A DIRTY BATH Recently I watched a house sparrow dusting by the railway -track in the city of Chicago. The dust may have been in part "clean" -earth, but in part it was soot, city dust, and soft-coal debris. The -sparrows here were dingy, all had their plumage heavily impregnated -with city grime, and looked very different from the sparrows in the -country. And this sparrow I was watching when it had finished dusting -was the worst of the lot. These city sparrows, even when they bathe in -water, seem never to get much of the grime out of their feathers. - -This reminded me that Oscar Heinroth once wrote that birds do not bathe -to get themselves clean, but bathe as an aid in bringing their feathers -into order and making them lie smoothly. Perhaps he is right. Certainly -my sparrow did nothing to clean himself. - -It is in arid countries, plains and deserts especially, where many of -the birds take only dust baths. In more humid regions water bathing -is the rule. But some birds do both, like our flicker and our house -sparrow, bathing now in water, now in sand. - -In northern climates, when the land is held in the grip of winter, -the water frozen over, and the earth covered with snow, neither dust -nor water bathing is possible. Then, it has been recorded, some birds -find a substitute in snow. Among other cases, in Alaska the hawk owl -has been seen to perch in the snow on the tops of telephone poles, -and go through the motions of bathing; in England a rook was recorded -as bathing "in crisp powdery snow as if it were taking a bath in dust -or water"; and in New England in midwinter juncos have been recorded -bathing "in light dry snow, just as other sparrows take dust baths in -hot weather." - -The snow evidently is used as a substitute for dust in these northern -latitudes. - - - - -DECORATION IN THE HOME - -[Illustration] - - -To use a bunch of flowers or a spray of leaves in decorating a room -in a house is a refinement of civilization. As the flowers fade, or -the leaves wilt, they are replaced with fresh ones. Sometimes a winter -bouquet is used that will serve for months. - -There are several birds that habitually deck their nests with green -vegetation, and when it is wilted, it is renewed with fresh. The reason -is not clear. It has been suggested it is to supply humidity and, by -evaporation, coolness; it has also been suggested that its use serves a -sanitary purpose. But whatever the reason in birds' eyes, it looks like -decoration to human eyes. - -This habit is common with a number of different hawks: for example, -the red-tailed hawk is reported sometimes to have its nest, a bulky -flat, basin-shaped structure in the crotch of a tree, "profusely and -beautifully lined with fresh green sprigs of white pine, which are -frequently renewed during incubation and during the earlier stages in -the growth of the young." The golden eagle is said to add green grass, -or green leaves often attached to the twigs from time to time to the -lining of the nest, especially after the young are hatched; and the -broad-winged hawk is said to add green leaves to the lining of its -nest. In quite another group of birds the same thing also occurs. A -carrion crow's nest in England was visited periodically from March to -August. Strangely no eggs were laid during this whole period, but the -birds remained in attendance. When found, fresh sprigs of oak leaves -were interwoven around the rim of the nest. On subsequent visits the -oak leaves were found to have been replaced with fresh ones, and the -leaves were kept fresh until late August. - -The purple martin supplies another example. The nest boxes we put up -for them supply their main breeding places in some areas. "The parents -have a habit of collecting many green leaves and placing them in the -nest, a practice which may tend by evaporation to reduce the heat" in -the next box. "Where large colonies are breeding they sometimes injure -pear trees by stripping certain branches of their leaves," according to -E. H. Forbush. - -A Madagascar weaverbird provides an example of decorating the nest -entrance of a quite different type of nest; in this case the nest is in -the shape of an inverted retort, with the entrance through the spout. -The entrance is decorated with green grass heads or with green leaves, -and the males keep adding fresh green decorations even when the eggs -are being incubated by the female. - -It seems hard to believe that this is really decoration, that it is not -for some purpose--either connected with the raising of the young, or -more probably a leisure or substitute activity--something to keep the -bird busy and strengthen the bond between bird and nest when it is not -otherwise directly occupied with nesting activities. - - - - -CURIOSITY IN BIRDS - -[Illustration] - - -Being unable to ask birds questions that will receive answers, we -have to judge their motives from appearances. And from the way some -birds act curiosity seems a strong motivation at times. They show a -disposition to inquire into things, especially strange things. - -Young blue jays that I've raised and studied are among the most prying, -investigating, inquisitive birds I've known. When well fed they devoted -much time to examining things. Humans, of course, would examine objects -by picking them up in their hands, looking at and feeling them, perhaps -tasting them. The jays, with more limited equipment, would examine them -with bill and eye. When the jays were very young their toes interested -them. They pecked at and twisted their own and their neighbor's toes. -Pencils and crayons on my desk appeared to interest them particularly. -These they were continually pulling about and pecking at. They went -about picking at lines on paper, knotholes in the walls of their -cage, the red letters printed on a bottle label, and the buttons on -our clothes. Cigarettes they liked to investigate by pulling them to -pieces. It looked as if the jays were interested in finding out about -the things around them by touch and taste as much as they could. - - -LURED INTO DANGER Compared with jays, ducks seem rather stolid -creatures, but they have curiosity too. This was well known to the -old-time duck hunters who capitalized on it in duck shooting. The -technique is known as "tolling" and I've used two variations of it in -museum collecting. - -Once on a little mountain lake in New Guinea I found a pair of ducks of -a rare species I especially needed for our collection. I stalked them -to the farthest bit of cover I could reach, a tussock of grass on the -lake margin, behind which I lay concealed. But the ducks were still too -far away for me to reach, and their feeding did not seem to be drawing -them nearer. I remembered the gunners' trick of tolling, and tried it. -I took out my white handkerchief, held it above the tussock of grass -while I kept well hidden, and waved the handkerchief back and forth. -The response was surprisingly prompt and gratifying. The two ducks -turned at once and swam right in to me so that I secured them without -any trouble. - -Once on a lake in central New York State there was a flock of scaup -ducks swimming well offshore. It looked as if they never would come in -near the bank. Quite by accident a setter dog that accompanied us began -to cavort along the beach. Again the ducks turned and the whole flock -came swimming in. Only then did I remember that among old-time gunners -there was the practice of using a dog thus, a dog that was even trained -for the purpose, to jump high and run about very conspicuously while -the ducks were far out, and as the ducks came swimming in, to keep -lower and frisk about partly concealed so that the ducks would have to -come close to satisfy their curiosity. - - - - -REFERENCES - - -Is it true? Did it really happen? The implications and correlations are -my own, and some of the accounts on the previous pages are based on my -experiences. But many of the facts come from the writings of others. -Where the incidents are well known no documentation is given. But when -the behavior described is little known or only recently discovered -I've given a reference so that the source can be consulted. These are -arranged under the appropriate chapter headings. - - -BIRDS USING TOOLS - - Edna Fisher, _Jour. Mammalogy_, Vol. 20, p. 21 (sea otter). P. - A. Gilbert, 1939, _Emu_, Vol. 39, pp. 18-22 (satin bower bird). - D. Lack, 1947, _Darwin's Finches_, p. 59 (woodpecker finch). D. - Morris, 1954, _British Birds_, Vol. 47, p. 33 (song thrush). A. C. - Bent, 1921, _U. S. Natl. Mus. Bull._ 113, p. 111 (gull and crow). - - -BIRDS AS BRIGANDS - - A. L. Rand, 1954, _Fieldiana-Zoology_ (Chicago), Vol. 36, p. 35 - (eagle, skua, frigate bird). - - -BIRDS BATHING - - F. N. Bassett, 1922, _Condor_, Vol. 24, p. 63 (hummingbirds). A. C. - Bent, 1937, _U. S. Natl. Mus. Bull._, 167, p. 370 (osprey). - - -HOW BIRDS ANOINT THEIR FEATHERS - - W. L. McAtee, 1938, _Auk_, Vol. 55, p. 98 (review). - - -TRAVELING BIRDS' NESTS - - H. S. Swarth, 1935, _Condor_, Vol. 37, p. 84 (barn swallows). M. A. - Common, 1942, _Auk_, Vol. 59, p. 43 (tree swallow). D. L. Serventy - and H. M. Whittell, 1948, _Birds of Western Australia_, p. 243 - (welcome swallow). - - -MALADAPTATION IN BIRDS - - J. Grinnell, 1926, _Condor_, Vol. 28, p. 97 (robin). W. H. - Bergtold, 1930, _Auk_, Vol. 47, p. 571 (robin). H. W. Henshaw, - 1921, _Condor_, Vol. 23, p. 109 (California woodpecker). D. - Bannerman, 1933, _Birds Tropical West Africa_, Vol. 3, p. 415 - (thick-billed honey-guide). - - -FEATHERED BABY SITTERS AND CO-OP NURSERY NESTS - - D. Davis, 1940, _Auk_, Vol. 57, p. 179 (ani). A. C. Bent, 1925, _U. - S. Natl. Mus. Bull._, 130, p. 85 (eider duck). R. C. Murphy, 1936, - _Oceanic Birds of South America_, Vol. 1, p. 398 (penguins). - - -BIRDS' NESTS AND THEIR SOUP - - Gibson-Hill, 1948, _Malay. Nat. Jour._, Vol. 3, p. 190; F. H. - Giles, 1935, _Jour. Siam Soc. Nat. Hist. Suppl._, Vol. 10, p. 137; - and Jabouille, 1931, _L'Oiseau et Rev. Franc. d'Ornith._, Vol. 1, - n.s., p. 219 (swiftlets). - - -WALLED WIVES OF HORNBILLS - - R. E. Moreau, 1937, _Proc. Zool. Soc._ London, 1937, p. 331 - (hornbills). - - -BURIED EGGS AND YOUNG - - A. Newton, 1893, _Dictionary of Birds_, p. 733; and D. Bannerman, - 1931, _Birds Trop. West Africa_, Vol. II, p. 205 (crocodile bird). - Deusing, 1939, _Auk_, Vol. 56, p. 367 (grebe). Bent, 1925, _U. S. - Natl. Mus. Bull._, 130, p. 98 (eider duck). - - -THE SNOWY OWL AS A TRADE INDEX - - A. Gavin, 1947, _Wilson Bull._, Vol. 59, p. 202 (snowy owl). - - -MONKEY BIRDS - - A. L. Rand, 1954, _Fieldiana-Zoology_ (Chicago), Vol. 36, p. 23 - (various "monkey-birds"). - - -BIRD-MADE INCUBATORS - - C. G. Sibley, 1946, _Condor_, Vol. 48, p. 92; Coles, 1937, _Proc. - Zool. Soc. London_, 1937, pp. 261-73; Fleay, 1937, _Emu_, Vol. 36, - pp. 153-63 (mound builders). - - -CORMORANT FISHING - - B. Laufer, 1931, _Publ. Field Mus. Nat. Hist. (Anthr. Ser.)_, 18, - pp. 201-62; Gudger, 1926, Amer. Nat., 60, p. 5 (cormorant fishing). - - -THE SHRIKE'S LARDER - - A. C. Bent, 1950, _U. S. Natl. Mus. Bull._ 197, p. 120 (shrike's - larder). - - -BIRD FLAVORS - - H. B. Cott, 1946, _Proc. Zool. Soc. London_, Vol. 116, pp. 371-524 - (bird flavors). - - -HOW MANY FEATHERS HAS A BIRD? - - A. Wetmore, 1936, _Auk_, Vol. 53, p. 159; F. B. Hutt and L. Ball, - 1938, _Auk_, 55, p. 651 (number of feathers). - - -LAST YEAR'S BIRDS' NESTS - - A. C. Bent, 1925, _U. S. Natl. Mus. Bull._ 130, pp. 91, 92; H. F. - Lewis, 1938, _Bird-Lore_, Vol. 40, p. 239 (eider down). - - -SYMBIOSIS--ANIMALS LIVING IN MIXED HOUSEHOLDS - - A. C. Bent, 1938, _U. S. Natl. Mus. Bull._ 170, pp. 384-86, 398 - (burrowing owl). H. Friedmann, 1930, _Natural History_, Vol. 30, p. - 205 (social weaver). W. H. Hudson, 1920, _Birds of La Plata_, Vol. - 2, p. 31 (monk parrot). W. R. B. Oliver, 1930, New Zealand Birds, - p. 118 (_Sphenodon_). - - -BIRD APARTMENT HOUSES - - A. C. Bent, 1942, _U. S. Natl. Mus. Bull._ 179, p. 490 (purple - martin). A. Wetmore and F. C. Lincoln, 1933, _Proc. U. S. Nat. - Mus._, Vol. 82, art. 25, p. 44 (West Indian woodpecker). D. - Bannerman, 1933, _Birds of Tropical West Africa_, Vol. 3, p. - 381 (barbets). J. T. Emlen, 1954, _Auk_, Vol. 71, p. 16 (cliff - swallows). W. H. Hudson, 1920, _Birds of La Plata_, Vol. 2, p. - 31 (monk parrot). A. Wetmore and B. H. Swales, _U. S. Natl. Mus. - Bull._ 155, p. 346 (palm chat); H. Friedmann, 1930, _Nat. Hist._, - Vol. 30, p. 205 (social weaver). - - -BIRD HELPERS AT NESTING TIME - - A. Skutch, 1935, _Auk_, 52, p. 257 (helpers at nest). M. M. Nice, - 1943, _Trans. Linn. Soc._, Vol. 6, p. 79 (young feeding young). R. - C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. 360 - (emperor penguins). - - -WEAVERS AND TAILORS IN THE BIRD WORLD - - H. Friedmann, 1922, _Zoologica_, Vol. 2, p. 355 (weaverbird). C. A. - Wood, 1926, _Smithsonian Rept._, p. 349 (tailorbird). - - -SOCIAL PARASITES AMONG BIRDS - - A. H. Miller, 1946, _Sci. Monthly_, Vol. 62, p. 238 (social - parasites). - - -FISH EATS BIRD! - - W. E. Glegg, 1945, _Ibis_, p. 422 (fish eating birds). - - -CROWS ARE SMARTER THAN "WISE" OWLS - - A. L. Rand, 1943, _Canad. Field Nat._, Vol. 57, p. 35 (saw-whet - owl). A. L. Rand, 1942, _Bull. Amer. Mus. Nat. Hist._, 79, p. 518 - (blue jay). A. C. Bent, 1946, _U. S. Natl. Mus. Bull._ 191, p. 196 - (raven), p. 266 (crow). - - -TAME WILD BIRDS - - D. Lack, 1942, _Ibis_, p. 271 (flycatcher). A. H. Chisholm, 1943, - _Ibis_, p. 105 (honey eaters). H. H. Brimley, 1934, _Auk_, 51, p. - 237 (phoebe). - - -BIRDS AS PILFERERS - - A. L. Rand, 1954, _Fieldiana-Zoology_, Vol. 36, p. 31 (pilfering, - several species). - - -HIBERNATION IN BIRDS - - W. L. McAtee, 1947, _Amer. Midland. Nat._, 38, p. 191 (old records - on torpidity). E. C. Jaeger, 1949, _Condor_, 51, p. 105 (poor-will). - - -SNAKESKINS IN BIRDS' NESTS - - A. L. Rand, 1953, _Nat. Hist. Miscl._ (Chicago), No. 125 - (snakeskins in nests). - - -CO-OPERATION BY BIRDS - - A. L. Rand, 1954, _Fieldiana-Zool._ (Chicago), Vol. 36, pp. 10, 12 - (co-operation, various species). - - -WATCHDOGS AT THE NEST - - R. E. Moreau, 1942, _Ibis_, p. 240 (in Africa). D. R. Dickey and A. - J. van Rossem, 1938, _Publ. Field Mus. Nat. Hist._, _Zool. Ser._, - Vol. 23, p. 360 (in El Salvador). - - -BIRD GUIDES TO HONEY - - H. Friedmann, 1954, _Nat. Geog. Mag._, Vol. 105, p. 551 - (honey-guides). - - -OXPECKERS - - D. Bannerman, 1948, _Birds of Tropical West Africa_, Vol. 6, p. 105 - (oxpecker). - - -WINGS IN FEEDING - - J. Delacour, 1946, _Auk_, Vol. 63, p. 441 (black heron). - - -CONDITIONING IN BIRDS - - A. L. Rand, 1942, _Bull. Amer. Mus. Nat. Hist._, Vol. 79, p. 517 - (shrikes). - - -POISONOUS BIRDS - - E. H. Forbush, 1927, _Birds of Mass._, etc., Vol. 2, p. 34 (ruffed - grouse). D. L. Serventy and H. M. Whittell, 1948, _Birds of Western - Australia_, pp. 73, 74 (Australian pigeons). R. Meinertzhagen, - 1912, _Ibis_, p. 96 (Mauritius pigeon). - - -BIRDS WASHING FOOD - - F. G. Evenden, 1943, _Condor_, 45, p. 120 (dipper). For divers - records of washing food see _British Birds_ for 1946, 6 and 8. - - -HOW BIRDS USE COWS AS HUNTING DOGS - - A. L. Rand, 1953, _Auk_, 70, p. 26 (ani). - - -BATTLE OF THE SEXES AND ITS EVOLUTIONARY SIGNIFICANCE - - A. L. Rand, 1952, _Fieldiana-Zoology_ (Chicago), Vol. 34, p. 65. - - -WATER IN THE DESERT - - C. T. Vorhies, 1945, _Univ. Ariz. Agri. Exp. Sta. Tech. Bull._ 107 - (water need in desert). J. T. Emlen, Jr., and B. Blading, 1945, - _Univ. Calif. Coll. Agri. Bull._ 695, p. 34 (valley quail). E. G. - B. Meade-Waldo, 1922, _Bull. Brit. Orn. Cl._, Vol. 42, p. 69 (sand - grouse). - - -BIRD GRAVEYARDS - - R. C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. - 372 (penguins). U. M. Grigg, 1950, Brit. Birds, Vol. 43, pp. 11-13 - (graveyard in hollow tree). G. Simmons, 1927, _Nat. Geog. Mag._, - Vol. 52, p. 27 (petrel bones on Cima). - - -ANIMAL GARDENS - - R. C. Murphy, 1936, _Oceanic Birds of South America_, Vol. 1, p. - 374 (penguins). F. Harper, 1953, _Amer. Midland Nat._, Vol. 49, p. - 6 (birds and lichens). H. W. Feilden, 1877, _Zoologist_, Vol. 1, p. - 319 (arctic-fox gardens). - - -DROPPING THINGS - - M. E. W. North, 1948, _Ibis_, p. 138-41 (lammergeier). E. Jaeger, - 1951, _Condor_, 53, p. 207 (sparrow). - - -LEARNING BY BIRDS - - A. L. Rand, 1941, _Bull. Amer. Mus. Nat. Hist._, Vol. 78, p. 222 - (thrasher). A. L. Rand, 1942, _Bull. Amer. Mus. Nat. Hist._, Vol. - 79, p. 518 (blue jay). - - -CAN BIRDS COUNT? - - _Bird-banding_, 1940, Vol. 11, p. 121 (summary various experiments). - - -COURTSHIP FEEDING - - D. Lack, 1940, _Auk_, Vol. 57, p. 169 (courtship feeding). - - -THEY TURNED THE TABLES - - A. C. Bent, 1926, _U. S. Natl. Mus. Bull._ 135, p. 109 (great - blue heron). W. P. Baldwin, 1946, _Auk_, Vol. 63, p. 589 (oyster - catcher). G. Mackay, 1929, _Auk_, 46, p. 123 (goldfinch). D. - Bannerman, 1936, _Birds Tropical West Africa_, Vol. 4, p. 244 - (dusky flycatcher). - - -SURVIVAL OF THE UNFIT - - A. W. Anthony, 1898, _Auk_, Vol. 15, p. 314 (frigate bird). J. - Cassin, 1858, _United States exploring expedition ..., Mammals - and Birds_, Philadelphia, p. 364 (brown booby). - - -DECORATION IN THE HOME - - A. C. Bent, 1937, _U. S. Nat. Mus. Bull._ 167, p. 151 (red-tailed - hawk), p. 296 (golden eagle). M. R. Lieff and N. P. Jordan, 1950, - _British Birds_, Vol. 43, p. 56 (carrion crow). E. H. Forbush, - 1929, _Birds of Mass., etc._, Vol. 3, p. 141 (purple martin). A. L. - Rand, 1936, _Bull. Amer. Mus. Nat. Hist._, Vol. 72, pp. 487, 490 - (weaverbird). - - - - -INDEX - - - adaptation, 31 - Aeschylus, death of, 186 - Aeschylus on vultures, 172 - ani, feeding rates of, 168 - anointing feathers, 25 - anting, 27 - anvil, thrush's, 15 - apartment houses, 77 - Arctic fox and snowy owl, 49 - association of: burrowing owl, prairie dog, snake, 73 - lizard, petrel, 75 - parrot, duck, opossum, 75 - social weaver, falcon, 74 - - baby sitters, 35 - bad and good birds, 152 - bathing in dust, 204 - bathing in snow, 204 - bathing in water, 22, 205 - beehives, guiding to, 125 - beeswax as bird food, 125 - bird of paradise, 162 - boat names, 84 - booming of nighthawk, 135 - bower, painting of, 16 - brigands, birds as, 19 - brush turkey, 54 - bucket drawing by jay, 190 - buried eggs, 45 - buried young, 45 - - cassowaries swim, 149 - cattle disease and oxpeckers, 129 - _Chicago Tribune_ farm, 151 - cliff dwellers, 78 - colony, mixed, 73 - colony nesters, 77 - color, change in jay, 164 - color and palatability, 63 - communistic care of young, 37 - community nests, 35 - conditioning, 136 - conservation, 151 - co-operation, 117 - co-operation: birds and monkeys, 51-53 - cow and ani, 167 - in carrying prey, 118 - in fishing by pelican, 118 - in killing skunk, 119 - co-op nursery, 35 - cormorant: fishing with, 57 - training, 58 - cosmetics, various, 26 - counting, of photographers, 193 - distinguishing more from less, 193 - courtship feeding, 195 - function of, 197 - significance of, 195 - covering eggs: by eider duck, 47 - by grebe, 47 - cows, use as hunting dogs, 167 - credit and snowy owl, 48 - cripples, cared for, 201 - crocodile bird, 45 - crow, intelligence of, 98 - crows profit by experience, 99 - curiosity, 210 - - dangerous prey, 198 - death: caused by clam, 199 - by porcupine, 202 - by spiders, 200 - decoration: function of, 209 - in nests, 207 - snakeskin in, 113 - droppings things: 186 - by crows, 16 - by gulls, 16, 187 - by lammergeier, 186 - by sparrow, 187 - reason for, 188 - drumming: of grouse, 134 - of woodpecker, 133 - drunkenness, 32 - duck, muscovy, 162 - - ecological competition, 173 - eggs: buried, 55 - covered, 46, 47 - in other birds' nests, 91 - specializations, 93 - eider down, 71 - environment modifies heredity, 139 - Eskimo, credit to, 48 - experience: crows profit by, 99 - learning by, 189 - - feathers: and size of bird, 67 - and temperature, 67 - number of, 66 - feeding rates of ani, 168 - fish eats bird, 95 - fishing with cormorants, 57 - flavor of flesh, 63, 142 - flesh: flavor of, 63, 142 - poisonous, 141 - fluctuations in the Arctic, 48 - food: impaling of by shrike, 61 - storage of, 32, 61 - foster parents, 93 - foster young, specialization in, 93 - foxing, 166 - frogs mistaken for birds, 109 - - gardens: animal, 183 - ecological balance in, 153 - of Arctic fox, 185 - good and bad birds, 152 - grackles, character of, 152 - graveyards: 180 - in hollow tree, 181 - on island, 182 - penguins', 180 - green hunting jay, 164 - guarding birds' nests, by insects, 121 - guides to honey, 124 - - hair pulling, 102 - helpers at nesting time, 81 - heredity modified by environment, 139 - hibernation, 108 - honey guides: 124 - lead to big game, 125 - hornbills' nests, 42 - households, mixed, 73 - - identification: caution in making, 161 - errors in, 161 - over the telephone, 160 - sight, 161 - incubation, artificial, 56 - incubators, bird-made, 54 - infantile behavior modified, 137 - inquisitive birds, 210 - instrumental music, 133 - intelligence, comparative, 98 - intoxication, 32 - - jays: change of color in, 164 - helping at nest, 81 - - kingfisher: a painting of, 143 - classical allusions to, 145 - on the telephone, 143 - variation in, 144 - - lammergeier and Aeschylus, 186 - larder, shrike's, 60 - laughing jackass, voice of, 145 - learning, 189 - lemming and Arctic fox, 49 - lichens and birds, 184 - listing of birds, early, 171 - - maladaptation, 31 - megapode nesting, 54 - migration, 28 - mixed households, 73 - monkey birds: 51 - and birds, various, 52-53 - mound builder and nest, 54 - music, instrumental, 133 - - names: appropriateness, 51, 85 - available scientific, 85 - domestic and foreign, 157 - euphony needed, 84 - for boats, 84 - how given, 51 - natural selection not operating, 203 - nests: co-operative, 79 - decoration of, 207 - Guarded by insects, 121 - helpers at, 81 - in soup, 38, 48 - last year's, 69 - leaves in, 207 - megapodes, 54 - parasitism, 91 - secondhand, 69 - subleases on, 69 - transportation of, 28 - use by man, 71 - use of snakeskin in, 111 - walled, of hornbill, 42--44 - nest building, co-operative, 79 - nidification, reptile type, 56 - nursery, 35 - - oil glands, 25 - owl, and toad, 190 - owl, intelligence of, 98 - oxpecker: 127 - value to herds, 128 - - painting a kingfisher, 143 - painting of bower, 16 - palatability, 63 - penguins, maternal, 36 - people, birds perching on, 102 - pilfering: 104 - by grackle, 106 - by kingfisher, 105 - by shrike, 105 - by starling, 105 - poison fruit, 31 - poisonous birds, 140 - poor-will in hibernation, 109 - powder down, 26 - preening, 25 - probe, used by finch, 17 - - references, 213 - retarded development, 137 - rhino bird, 128 - robbery: by birds, 19,104 - by eagle, 19, 20 - by frigate bird, 20 - by raven, 99 - by skua, 21 - Rome, founding of, 171 - Romulus and Remus as bird watchers, 171 - - Salvador bird voices, 157 - sand grouse carrying water, 178 - sea serpents: identification of, 147 - in Kenya, 148 - in New Guinea, 148 - sentinel of the monkey, 53 - sewing nests, 89 - sexes: battle of, 173 - different diets of, 175 - sexual differences, ecological significance of, 173 - shrike's larder, 60 - shrike, young, infantile behavior prolonged, 137 - slave of the monkeys, 52 - snails, broken on anvil, 15 - snakeskins: in nests, 111 - as decorations, 112 - bibliographic work on use of, 114 - reasons for using, 115 - theories of use, 113 - snowy owl, as trade index, 49 - social parasites, 33, 91 - soothsayers use birds, 172 - sounds produced mechanically, 134 - soup, birds'-nest, 38 - storage: of acorns, 32 - of fish, 33 - survival of unfit, 201 - swifts' nests, 38-41 - symbiosis, 73 - - tables turned, 198 - tailorbirds, 89 - tameness, 101 - taste in birds, 189 - telephone: conversations on, 143, 151 - identification over, 160 - theft, petty, 104 - thrush, breaking snail's shell, 15 - tick bird, 128 - ticks, food of oxpecker, 128 - tolling of ducks, 211 - tool, use of, 15 - torpidity, 108 - trade index, snowy owls as, 49 - - unfit survive, 201 - - vegetation and penguins, 183 - - washing food: 154 - reasons for, 156 - watchdogs at nests, 121 - water: carried by birds, 46, 178 - flights to, 178 - need of, 177 - weaving nests, 88 - wing music of owl, 134 - wings: use of, 130 - in feeding, 131 - winnowing of snipe, 134 - wisdom, owl, symbol of, 98 - - young: buried, 45 - communistic care of, 37 - fed by other young, 81, 203 - honey-guide's, 33 - independent from hatching, 55 - - - * * * * * - - -Transcriber Note - -Minor typos corrected. - -*** END OF THE PROJECT GUTENBERG EBOOK STRAY FEATHERS FROM A BIRD MAN'S -DESK *** - 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Rand</div> - -<div style='display:block; margin:1em 0'> -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online -at <a href="https://www.gutenberg.org">www.gutenberg.org</a>. If you -are not located in the United States, you will have to check the laws of the -country where you are located before using this eBook. -</div> - -<p style='display:block; margin-top:1em; margin-bottom:1em; margin-left:2em; text-indent:-2em'>Title: Stray Feathers From a Bird Man's Desk</p> - -<div style='display:block; margin-top:1em; margin-bottom:1em; margin-left:2em; text-indent:-2em'>Author: Austin L. Rand</div> - -<div style='display:block; margin:1em 0'>Release Date: September 14, 2021 [eBook #66306]</div> - -<div style='display:block; margin:1em 0'>Language: English</div> - -<div style='display:block; margin:1em 0'>Character set encoding: UTF-8</div> - -<div style='display:block; margin-left:2em; text-indent:-2em'>Produced by: Tim Lindell, Tom Cosmas and the Online Distributed Proofreading Team at https://www.pgdp.net (This book was produced from images made available by the HathiTrust Digital Library.)</div> - -<div style='margin-top:2em; margin-bottom:4em'>*** START OF THE PROJECT GUTENBERG EBOOK STRAY FEATHERS FROM A BIRD MAN'S DESK ***</div> - - - - -<div class="figcenter" id="cover" style="width: 297px;"> - <img src="images/cover.png" width="297" height="439" alt="Stray Feathers from a Bird Man's Desk -- Austin L. Rand" /> -</div> - -<p class="pmt2 pmb2 hanging"><b>Transcriber Note</b>—The link [Ref] at Chapter headers -links to the corresponding listing in the <a href="#REFERENCES">References</a> section at the end of the book.</p> - -<p><span class="pagenum" id="Page_1">- 1 -</span></p> - - - -<h1>STRAY FEATHERS<br />FROM A BIRD MAN'S DESK</h1> - -<p><span class="pagenum" id="Page_2">- 2 -</span></p> - - -<p><span class="pagenum" id="Page_3">- 3 -</span></p> - - -<p class="big tdc">STRAY<br /> -FEATHERS<br /> -FROM<br /> -A BIRD MAN'S<br /> -DESK</p> - -<p class="tdc" style="font-size: 1.5em;">By Austin L. Rand<br /> -<span class="smaller">CURATOR OF BIRDS,<br /> -CHICAGO NATURAL HISTORY MUSEUM</span><br /> -<br /> -<br /> -WITH CARTOONS BY RUTH JOHNSON</p> - - -<p class="pmt4 pmb2 tdc">DOUBLEDAY & COMPANY, INC., GARDEN CITY, N.Y., 1955</p> - -<p><span class="pagenum" id="Page_4">- 4 -</span></p> - - -<p class="pmt4 pmb4 ind8em"> -<i>Library of Congress Catalog Card Number 55-5254</i><br /> -<br /> -<i>Copyright, 1955, by Austin L. Rand</i> ©<br /> -<i>All Rights Reserved</i><br /> -<i>Printed in the United States</i><br /> -<i>At the Country Life Press, Garden City, N.Y.</i><br /> -<i>First Edition</i><br /> -</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> - -<p><span class="pagenum" id="Page_5">- 5 -</span></p> - -<h2 class="nobreak" id="CONTENTS">CONTENTS</h2> -</div> - -<table class="tblcont" summary="TOC"> -<tr> - <td></td> - <td class="tdr smaller">PAGE</td> -</tr> -<tr> - <td class="tdl">Introduction</td> - <td class="tdr"><a href="#INTRODUCTION">9</a></td> -</tr> -<tr> - <td class="tdl">Birds Using Tools</td> - <td class="tdr"><a href="#BIRDS_USING_TOOLS">15</a></td> -</tr> -<tr> - <td class="tdl">Birds as Brigands</td> - <td class="tdr"><a href="#BIRDS_AS_BRIGANDS">19</a></td> -</tr> -<tr> - <td class="tdl">Birds Bathing</td> - <td class="tdr"><a href="#BIRDS_BATHING">22</a></td> -</tr> -<tr> - <td class="tdl">How Birds Anoint Their Feathers</td> - <td class="tdr"><a href="#HOW_BIRDS_ANOINT_THEIR_FEATHERS">25</a></td> -</tr> -<tr> - <td class="tdl">Traveling Birds' Nests</td> - <td class="tdr"><a href="#TRAVELING_BIRDS_NESTS">28</a></td> -</tr> -<tr> - <td class="tdl">Maladaptation in Birds</td> - <td class="tdr"><a href="#MALADAPTATION_IN_BIRDS">31</a></td> -</tr> -<tr> - <td class="tdl">Feathered Baby Sitters and Co-op Nursery Nests</td> - <td class="tdr"><a href="#FEATHERED_BABY_SITTERS_AND_CO-OP_NURSERY_NESTS">35</a></td> -</tr> -<tr> - <td class="tdl">Birds' Nests and Their Soup</td> - <td class="tdr"><a href="#BIRDS_NESTS_AND_THEIR_SOUP">38</a></td> -</tr> -<tr> - <td class="tdl">Walled Wives of Hornbills</td> - <td class="tdr"><a href="#WALLED_WIVES_OF_HORNBILLS">42</a></td> -</tr> -<tr> - <td class="tdl">Buried Eggs and Young</td> - <td class="tdr"><a href="#BURIED_EGGS_AND_YOUNG">45</a></td> -</tr> -<tr> - <td class="tdl">The Snowy Owl as a Trade Index</td> - <td class="tdr"><a href="#THE_SNOWY_OWL_AS_A_TRADE_INDEX">48</a></td> -</tr> -<tr> - <td class="tdl">Monkey Birds</td> - <td class="tdr"><a href="#MONKEY_BIRDS">51</a></td> -</tr> -<tr> - <td class="tdl">Bird-Made Incubators</td> - <td class="tdr"><a href="#BIRD-MADE_INCUBATORS">54</a></td> -</tr> -<tr> - <td class="tdl">Cormorant Fishing</td> - <td class="tdr"><a href="#CORMORANT_FISHING">57</a></td> -</tr> -<tr> - <td class="tdl">The Shrike's Larder</td> - <td class="tdr"><a href="#THE_SHRIKES_LARDER">60</a></td> -</tr> -<tr> - <td class="tdl">Bird Flavors</td> - <td class="tdr"><a href="#BIRD_FLAVORS">63</a></td> -</tr> -<tr> - <td class="tdl">How Many Feathers Has a Bird?</td> - <td class="tdr"><a href="#HOW_MANY_FEATHERS_HAS_A_BIRD">66</a></td> -</tr> -<tr> - <td class="tdl">Last Year's Birds' Nests</td> - <td class="tdr"><a href="#LAST_YEARS_BIRDS_NESTS">68</a></td> -</tr> -<tr> - <td class="tdl">Symbiosis—Animals Living in Mixed Households</td> - <td class="tdr"><a href="#SYMBIOSIS_ANIMALS_LIVING_IN_MIXED_HOUSEHOLDS">73</a></td> -</tr> -<tr> - <td class="tdl">Bird Apartment Houses</td> - <td class="tdr"><a href="#BIRD_APARTMENT_HOUSES">77</a></td> -</tr> -<tr> - <td class="tdl">Bird Helpers at Nesting Time - <span class="pagenum" id="Page_6">- 6 -</span></td> - <td class="tdr"><a href="#BIRD_HELPERS_AT_NESTING_TIME">81</a></td> -</tr> -<tr> - <td class="tdl">A Name for a Boat</td> - <td class="tdr"><a href="#A_NAME_FOR_A_BOAT">84</a></td> -</tr> -<tr> - <td class="tdl">Weavers and Tailors in the Bird World</td> - <td class="tdr"><a href="#WEAVERS_AND_TAILORS_IN_THE_BIRD_WORLD">88</a></td> -</tr> -<tr> - <td class="tdl">Social Parasites among Birds</td> - <td class="tdr"><a href="#SOCIAL_PARASITES_AMONG_BIRDS">91</a></td> -</tr> -<tr> - <td class="tdl">Fish Eats Bird!</td> - <td class="tdr"><a href="#FISH_EATS_BIRD">95</a></td> -</tr> -<tr> - <td class="tdl">Crows Are Smarter Than "Wise" Owls</td> - <td class="tdr"><a href="#CROWS_ARE_SMARTER_THAN_WISE_OWLS">98</a></td> -</tr> -<tr> - <td class="tdl">Tame Wild Birds</td> - <td class="tdr"><a href="#TAME_WILD_BIRDS">101</a></td> -</tr> -<tr> - <td class="tdl">Birds as Pilferers</td> - <td class="tdr"><a href="#BIRDS_AS_PILFERERS">104</a></td> -</tr> -<tr> - <td class="tdl">Hibernation in Birds</td> - <td class="tdr"><a href="#HIBERNATION_IN_BIRDS">108</a></td> -</tr> -<tr> - <td class="tdl">Snakeskins in Birds' Nests</td> - <td class="tdr"><a href="#SNAKESKINS_IN_BIRDS_NESTS">111</a></td> -</tr> -<tr> - <td class="tdl">Co-operation by Birds</td> - <td class="tdr"><a href="#CO-OPERATION_BY_BIRDS">117</a></td> -</tr> -<tr> - <td class="tdl">Watchdogs at the Nest</td> - <td class="tdr"><a href="#WATCHDOGS_AT_THE_NEST">121</a></td> -</tr> -<tr> - <td class="tdl">Bird Guides to Honey</td> - <td class="tdr"><a href="#BIRD_GUIDES_TO_HONEY">124</a></td> -</tr> -<tr> - <td class="tdl">Oxpeckers</td> - <td class="tdr"><a href="#OXPECKERS">127</a></td> -</tr> -<tr> - <td class="tdl">Wings in Feeding</td> - <td class="tdr"><a href="#WINGS_IN_FEEDING">130</a></td> -</tr> -<tr> - <td class="tdl">Instrumental Music of Birds</td> - <td class="tdr"><a href="#INSTRUMENTAL_MUSIC_OF_BIRDS">133</a></td> -</tr> -<tr> - <td class="tdl">Conditioning in Birds</td> - <td class="tdr"><a href="#CONDITIONING_IN_BIRDS">136</a></td> -</tr> -<tr> - <td class="tdl">Poisonous Birds</td> - <td class="tdr"><a href="#POISONOUS_BIRDS">140</a></td> -</tr> -<tr> - <td class="tdl">Kingfishers on the Telephone</td> - <td class="tdr"><a href="#KINGFISHERS_ON_THE_TELEPHONE">143</a></td> -</tr> -<tr> - <td class="tdl">On Identifying Sea Serpents</td> - <td class="tdr"><a href="#ON_IDENTIFYING_SEA_SERPENTS">147</a></td> -</tr> -<tr> - <td class="tdl">Conservation over the Telephone</td> - <td class="tdr"><a href="#CONSERVATION_OVER_THE_TELEPHONE">151</a></td> -</tr> -<tr> - <td class="tdl">Birds Washing Food</td> - <td class="tdr"><a href="#BIRDS_WASHING_FOOD">154</a></td> -</tr> -<tr> - <td class="tdl">How Animal Voices Sound to Foreign Ears</td> - <td class="tdr"><a href="#HOW_ANIMAL_VOICES_SOUND_TO_FOREIGN_EARS">157</a></td> -</tr> -<tr> - <td class="tdl">Sight Identification</td> - <td class="tdr"><a href="#SIGHT_IDENTIFICATION">160</a></td> -</tr> -<tr> - <td class="tdl">Green Hunting Jays Turn Blue</td> - <td class="tdr"><a href="#GREEN_HUNTING_JAYS_TURN_BLUE">164</a></td> -</tr> -<tr> - <td class="tdl">How Birds Use Cows as Hunting Dogs</td> - <td class="tdr"><a href="#HOW_BIRDS_USE_COWS_AS_HUNTING_DOGS">167</a></td> -</tr> -<tr> - <td class="tdl">Early Bird Listing</td> - <td class="tdr"><a href="#EARLY_BIRD_LISTING">171</a></td> -</tr> -<tr> - <td class="tdl">Battle of the Sexes and Its Evolutionary Significance - <span class="pagenum" id="Page_7">- 7 -</span></td> - <td class="tdr"><a href="#BATTLE_OF_THE_SEXES_AND_ITS_EVOLUTIONARY_SIGNIFICANCE">173</a></td> -</tr> -<tr> - <td class="tdl">Water in the Desert</td> - <td class="tdr"><a href="#WATER_IN_THE_DESERT">177</a></td> -</tr> -<tr> - <td class="tdl">Bird Graveyards</td> - <td class="tdr"><a href="#BIRD_GRAVEYARDS">180</a></td> -</tr> -<tr> - <td class="tdl">Animal Gardens</td> - <td class="tdr"><a href="#ANIMAL_GARDENS">183</a></td> -</tr> -<tr> - <td class="tdl">Dropping Things</td> - <td class="tdr"><a href="#DROPPING_THINGS">186</a></td> -</tr> -<tr> - <td class="tdl">Learning by Birds</td> - <td class="tdr"><a href="#LEARNING_BY_BIRDS">189</a></td> -</tr> -<tr> - <td class="tdl">Can Birds Count?</td> - <td class="tdr"><a href="#CAN_BIRDS_COUNT">192</a></td> -</tr> -<tr> - <td class="tdl">Courtship Feeding</td> - <td class="tdr"><a href="#COURTSHIP_FEEDING">195</a></td> -</tr> -<tr> - <td class="tdl">They Turned the Tables</td> - <td class="tdr"><a href="#THEY_TURNED_THE_TABLES">198</a></td> -</tr> -<tr> - <td class="tdl">Survival of the Unfit</td> - <td class="tdr"><a href="#SURVIVAL_OF_THE_UNFIT">201</a></td> -</tr> -<tr> - <td class="tdl">Dust and Snow Bathing</td> - <td class="tdr"><a href="#DUST_AND_SNOW_BATHING">204</a></td> -</tr> -<tr> - <td class="tdl">Decoration in the Home</td> - <td class="tdr"><a href="#DECORATION_IN_THE_HOME">207</a></td> -</tr> -<tr> - <td class="tdl">Curiosity in Birds</td> - <td class="tdr"><a href="#CURIOSITY_IN_BIRDS">210</a></td> -</tr> -<tr> - <td class="tdl">References</td> - <td class="tdr"><a href="#REFERENCES">213</a></td> -</tr> -<tr> - <td class="tdl">Index</td> - <td class="tdr"><a href="#INDEX">221</a></td> -</tr> -</table> - - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_9">- 9 -</span></p> - - -<h2 class="nobreak" id="INTRODUCTION">INTRODUCTION</h2> -</div> - - -<p>In looking back over the preparation of these sketches -I feel as though each evening I'd gathered up the bits and -pieces left over from the day's work and fashioned them -into designs for my own amusement and the edification -of my family. Truly it's as though I'd used stray feathers, -fallen from the bird skins I'd handled, and fitted them together -into something of wider interest than the original.</p> - -<p>Much of my work now is museum research, working -with bird specimens and books. In fashioning a research -paper I always amass a great deal more material, that is to -say, information and ideas, than I am able to use in it. In -place of a lumber room I have a set of files with index -headings that range from Abundance and Age, through -such headings as Beauty, Feathering of Feet, Fictitious, -Hysteria, Pterylography, Social, Song, Tail Feathers, -Valentine's Day, to Zoogeography. Here I put the information -that is irrelevant at the moment but too interesting to -discard. Its source is varied. Some has been accumulated -while studying specimens from localities as geographically -separated as Alaska, El Salvador, Gabon, Tristan da -Cunha, Nepal, Negros, and New Guinea; and while writing -papers that range from describing new species to discussing -secondary sexual characters and ecological competition. -Some have been recorded while in the field on -<span class="pagenum" id="Page_10">- 10 -</span> -expeditions, trips that ranged from two years in Madagascar, -three expeditions in New Guinea, and a season in -the Philippines to trips nearer home from the Yukon to -Nova Scotia, Florida, and Central America.</p> - -<p>Gradually information builds up under each heading, -and new ones are added. These items are too interesting -to remain buried in the files. They are things people want -to know about. So I began to draft them into articles for -publication in the museum's monthly, <i>The Chicago Natural -History Museum Bulletin</i>. The response was gratifying. -The press picked them up and reprinted them. One was -used in a Chicago <i>Tribune</i> editorial. Several were used in -commercial radio programs. Encouraged, I prepared more, -soon overrunning the space available in the bulletin.</p> - -<p>Most scientific papers are not written to be read for enjoyment. -Conciseness as well as clarity are striven for, -conveying certain information in a small compass. The -correlations made are often obscure ones, appreciated only -by scientists. Yet the material they contain is often intensely -interesting, and if these papers were written in a -more leisurely style, with more general correlations -pointed out, they would provide both interesting and entertaining -reading. In a few cases my own research falls in -this class, and I've rewritten some of my own papers with -this in mind (<i>see</i> "Battle of the Sexes and Its Evolutionary -Significance").</p> - -<p>This collection of articles, if it were a painting, could be -called a conversation piece. Or it might be compared to a -well-filled whatnot. Each of the sixty chapters is an independent -unit, illustrating some facet of birds, their behavior, -or our study of them. Some of the facts may seem -<span class="pagenum" id="Page_11">- 11 -</span> -unusual or bizarre, but most of them are well known and -well documented. The thing that is new, if there is anything -new, is the setting in which I've placed them, the -manner in which I've looked at them. Taken as a whole, -they touch on many different birds from many different -places in their less widely known aspects, and with a -human interest slant.</p> - -<p>"But what will your professional colleagues say?" asked -a friend as he flipped through the cartoons. "These pictures -don't approach the subject in a very serious manner." -Quite true. But a discipline must be very lightly rooted -indeed if it can't stand a few caricatures and cartoons and -perhaps be the better for them.</p> - -<p>The knowledge of most people about the hornbills of -tropical Africa, the gulls of Australia, the penguins of -Antarctica, and the crocodile birds of the Nile is probably -pretty vague. To give a frame of reference in a biological -sense is impractical in the compass of one slim volume.</p> - -<p>But a ready-made frame of reference already exists: -the parallels in bird and in human. These I have used. But -in so doing I am not imputing human motives and attributes -to birds. The actions are similar. The workings of -the human mind I understand only vaguely; that of the -bird I can study only through the actions of the birds. One -set of behavior may be learned and rational, one rigidly -innate, entirely instinctive, and inherited, or at most modified -by experience. Be that as it may, the similarity in the -end result in two such different vertebrate animals as man -and bird when faced with similar problems is often close. -Perhaps it is because the solutions are necessarily few; -perhaps, and I incline to this feeling, it helps illustrate one -<span class="pagenum" id="Page_12">- 12 -</span> -aspect of the close relationship between all animate nature.</p> - -<p>This series of articles is intended to be interesting and -entertaining. I hope it will also make more people aware -of the many ways birds act, here and in far places, how -they have solved their problems and profited by their opportunities.</p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_13">- 13 -</span></p> - -<h2 class="nobreak" id="STRAY_FEATHERS_FROM_A_BIRD_MANS_DESK">STRAY FEATHERS FROM A BIRD MAN'S DESK</h2> -</div> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_15">- 15 -</span></p> - -<h2 class="nobreak tdl2" id="BIRDS_USING_TOOLS">BIRDS USING TOOLS <span class="ref"><a href="#ref_1">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_15" style="width: 291px;"> - <img src="images/015.png" width="291" height="221" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">M</span>an is the tool user</span> pre-eminent in the animal world, -but he does not stand completely alone in this. Here and -there, in quite different groups of animals such as insects, -mammals, and birds, a few kinds have forged a little ahead -of the rest of their near relatives and show the very beginning -of tool using.</p> - -<p>The song thrush of Europe is perhaps a borderline case. -It feeds in part on snails. To get the soft edible animal out -of its shell, it carries or drags the snail to a favorite rock, -its anvil, and there hits it against the anvil until the shell -is broken and its contents exposed. The question is, can -this be considered as using a tool? If the song thrush -<span class="pagenum" id="Page_16">- 16 -</span> -moved or prepared the rock, which it does not do, there -would be no question that it was a tool. The sea otter -brings a stone from the bottom of the ocean and places it -on its floating body to use as a similar anvil in cracking -hard objects, and this undoubtedly is the use of a tool. At -the other extreme are many species of birds that beat their -prey on branch or ground, wherever they happen to be. -The song thrush is certainly an advance over that, and can, -I think, be considered as using a tool in a primitive way.</p> - -<p>A few other species, too, bring shellfish to special places. -Gulls on our coasts pick up mussels and clams and, flying -over a rock or some other hard surface, drop the shellfish, -and follow it down. If the shell is broken, the dish is ready -for the gull; if the shell is not broken the gull takes the -shellfish up to a higher altitude and tries again. In places -where hard-surfaced roads are conveniently located gulls -have learned to use them as shell-breaking places, and -such roads become littered with shells.</p> - -<p>Crows of more than one species also use the same -routine in breaking open shellfish, and they, too, have -learned to use special hard surfaces, such as masonry walls, -on which to drop the shellfish.</p> - - -<p class="pmt2"><span class="allsmcap">PAINTING A BOWER</span> The satin bowerbird of Australia, -a species known to science as <i>Ptilonorhynchus -violaceus</i>, has also been considered as a case in point when -discussing the use of tools. The birds are somewhat larger -than a robin, the male glossy blue-black, the female greenish. -The male of this species constructs an elaborate -bower, presumably for courtship purposes. It makes it of -sticks and twigs, and decorates it with bright and curious -<span class="pagenum" id="Page_17">- 17 -</span> -objects such as shells, feathers, bits of bone, and fruits, -as do several other species of bowerbirds. But the satin -bowerbird is unique in painting the inside of its bower. -Fruit is crushed in its bill, and the bird, using its bill as -the tool or paintbrush, smears the fruit juice on the sticks -on the inside of the bower. While this is a wonderfully -strange habit, and apparently unique in the bird world, it -is doubtful if this behavior can be considered as using a -tool. If the satin bowerbird used a twig, or a wad of moss -or fiber, which it does not do, in spreading the paint, the -case would be clear.</p> - -<p>The clearest case is that of the woodpecker finch of the -Galápagos Islands. <i>Camarhynchus pallidus</i> is its proper -name. It is one of a group of dull-colored finches restricted -to the Galápagos Islands. Before it became known that -one species used a tool, the chief claim to fame of the -group was that it, along with some other Galápagos Island -animals, such as the giant tortoises, had a great influence -on Darwin's thinking which resulted in his working out -the theory of evolution as set forth in his <i>Origin of Species</i>.</p> - -<p>The woodpecker finch feeds largely on insects it gets by -searching and probing on the ground, and on the trunk -and leaves of trees. In searching crevices the woodpecker -finch is handicapped by its rather short, thick bill, and to -offset this, it picks up a slender, short length of stick, or the -spine of a prickly pear, and with this in its bill, pokes into -crannies. The insects, disturbed or driven out, are seized. -Sometimes the woodpecker finch digs into the tree trunk -and then gets a stick to probe with; sometimes it carries -its probe about with it, poking in crannies until prey is -disturbed. Then the stick is dropped and the food seized.</p> - -<p><span class="pagenum" id="Page_18">- 18 -</span></p> - -<p>We have seen how several birds are perhaps borderline -cases in using tools. They use certain special aspects of -their environment in preparing their food, and use it time -after time. It's probably instinctive behavior, but learning -is shown in the gulls and crows coming to recognize and -use a hard-surfaced road in breaking open their shellfish. -The use of a probe by the woodpecker finch is a clear and -unique case of tool using by a bird.</p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_19">- 19 -</span></p> - -<h2 class="nobreak tdl2" id="BIRDS_AS_BRIGANDS">BIRDS AS BRIGANDS <span class="ref"><a href="#ref_2">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_19" style="width: 301px;"> - <img src="images/019.png" width="301" height="177" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">A</span>nti-social activities</span> of humans such as those of brigands -who plunder their fellow men find their parallels in -the bird world.</p> - -<p>The bald eagle is one of the best-known of the birds -that practice such brigandage. Fond of fish, and capable -of capturing it himself upon occasion, it is a common practice -for the eagle to take fish from the osprey, plunder the -osprey has just caught from the water. The osprey, with -a fresh-caught fish, flies heavily. The watching eagle -quickly overtakes the smaller, heavily laden bird and -forces it to drop its catch, then dives down and usually -catches the fish before it can strike the land or water. -<span class="pagenum" id="Page_20">- 20 -</span> -Rarely does the osprey escape with its food under such an -attack. It is recorded that an eagle made several dives at -one fish-laden osprey and, when these were not successful -in making it lose its hold on the fish, the eagle dived under -the smaller bird, turned over on its back, and with talons -outstretched, snatched the fish from the grasp of the -osprey and sailed away with it, as successful a pirate as -ever sailed the seas.</p> - - -<p class="pmt2"><span class="allsmcap">NEMESIS OF VULTURES</span> Besides taking fresh-caught -food from the osprey the bald eagle has been seen pursuing -vultures and making them disgorge their meal of -carrion. The eagle, if unsuccessful in catching the disgorged -food in the air, may land on the ground and eat it -there. We know also that the aerial flights the eagle uses -to frighten the vulture into relinquishing his food are not -idle threats, for an eagle has been seen to strike and kill -a bird that refused to disgorge.</p> - -<p>Not only does our American eagle adopt such practices, -but related species in other parts of the world behave in -similar ways. The New Guinea sea eagle harries the osprey -there, and on the west coast of Africa a sea eagle robs -pelicans and cormorants of their prey.</p> - -<p>Certain long-winged birds of the tropical seas, such as -<i>Fregata magnificens</i>, are known popularly as man-o'-war -birds or frigate birds, reflecting their well-known character -as pirates and tyrannical freebooters. The man-o'-war birds -get part of their food from many creatures which swarm -at the surface of the sea, but they also get much of their -food by forcing terns, cormorants, boobies, and pelicans to -deliver up their catch.</p> - -<p><span class="pagenum" id="Page_21">- 21 -</span></p> - -<p>In a tropical bay a school of small fish comes to the -surface, perhaps driven by large fish below; from far and -near terns gather, darting down to seize the fish that jump -into the air. Above them circle the frigate birds, ready to -dive down and chase and harry a successful tern until it -drops its fish and leaves its prey to the freebooter.</p> - - -<p class="pmt2"><span class="allsmcap">BOOBIES ARE VICTIMS</span> Frigate birds may sail about, -also, where a colony of nesting brown boobies is located, -waiting for the birds laden with food to return home. -When such a food-laden booby returns, the frigate bird -dashes down at it, buffets it with its wings, snaps at it with -its long, hooked bill, until the booby finally drops its fish -for the man-o'-war bird to enjoy.</p> - -<p>The skua, a big, dark relative of the gull, is also known -as a pirate. Its chief food is fish but it also eats many other -foods from the sea. It rarely takes the trouble to fish for -itself but watches until some other bird, perhaps a gull or -a tern, has been successful in its hunting and then gives -chase, forcing the unfortunate hunter to relinquish its -food. Several of the skua's smaller relatives, the jaegars, -have similar habits. It is written of the pomarine jaegar -off our New England coast that they are notorious pirates -and freebooters, the highwaymen among birds that prey -on their neighbors on the fishing grounds and make them -stand and deliver. The jaegar gives chase to a tern that has -caught a fish and follows it through every twist and turn -as if the two were yoked together. Finally the harassed -tern drops its fish and the jaeger swoops down and seizes it -before it can strike the water.</p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_22">- 22 -</span></p> - -<h2 class="nobreak tdl2" id="BIRDS_BATHING">BIRDS BATHING <span class="ref"><a href="#ref_3">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_22" style="width: 280px;"> - <img src="images/022.png" width="280" height="235" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he toilet</span> of most birds includes wetting their feathers -in water and shaking the feathers and preening them with -the bill. This bathing probably helps remove foreign matter -from the birds' plumage and helps keep it in good -condition. In addition it is probable that in summer the -birds derive enjoyment from the coolness resulting from -the bathing. But birds bathe in cold weather as well as -warm and have been recorded doing so when the temperature -of the air was only 10 or so degrees above zero.</p> - -<p>The sparrows and robins that come about a birdbath -usually hop right into the water. They squat down, fluttering -their wings, and duck their heads into the water, -<span class="pagenum" id="Page_23">- 23 -</span> -splashing and rolling it over their backs. They may become -quite drenched. Then they fly to some perch to sit and -preen and dry their soaked feathers.</p> - -<p>But some birds take shower baths. During a shower in -late summer I have seen marsh hawks sitting in the rain -with wings spread, apparently enjoying the wetting the -shower gives them, and a buzzard has been recorded as -deliberately flying to an open perch in a rainstorm and -sitting there with its wings spread and sometimes shaking -them until the shower was over, when it flew to a sheltered -place.</p> - - -<p class="pmt2"><span class="allsmcap">SPRINKLERS A BOON</span> The artificial showers of lawn -sprinklers provide an opportunity for birds about our -gardens to take a shower bath in fine weather. A robin -or a flicker may hop into the shower and squat there and -indulge in bathing antics on the wet grass. Hummingbirds -have been seen to fly into the dense spray of a lawn sprinkler -and hover there for a moment, gradually assuming a -vertical position and spreading the tail, then slowly settling -to the ground, and finally "sitting" on the grass, body -erect and tail spread out fanwise, the wings continuing -to vibrate slowly. In a few moments the bird may rise -into the air and repeat the whole performance.</p> - -<p>In wet tropical forest it is probable that many of the -treetop birds bathe in the water that collects on the surface -of the leaves, pushing their way through clusters of -wet leaves and over wet surfaces of others until they are -as wet as if they had actually been bathing in water. This -is not restricted to tropical birds, for even in our latitudes -towhees have been recorded as bathing thus, and thrushes -<span class="pagenum" id="Page_24">- 24 -</span> -and flickers have been seen to rub themselves over the wet -grass and then go through the actions of bathing followed -by preening.</p> - - -<p class="pmt2"><span class="allsmcap">BATHING WHILE FLYING</span> Watching swifts or swallows -coursing low over the surface of a lake and occasionally -touching it leaves one with the impression sometimes -that the birds are bathing rather than picking up insect -food or drinking. With some other birds the habit of bathing -from the wing is more definite. Sometimes drongo -shrikes that are sitting up on a perch near the edge of a -pool will fly out over the water, drop directly into it with -a little splash, and then rise and fly back to their perch, -where they either repeat the performance or sit and preen -their feathers.</p> - - -<p class="pmt2"><span class="allsmcap">POST-PRANDIAL ABLUTIONS</span> Ospreys have been -recorded as bathing while on the wing in a rather striking -manner. They have been seen flying along just above the -surface of the water, then descending into it, adopting a -sort of vertical American-eagle attitude while flapping the -wings, then rising a little, flying on, and repeating the -process. It has been suggested that the osprey is washing -its feet in this manner after finishing its meal. One observer -makes this still more definite. He says that the osprey -finishes its meal of fish on a perch in a tree and then flies -low over the lake. Dropping both its legs, the osprey drags -them through the water, flapping its wings all the time. -Then it immerses its beak and head into the water while -still flying along, apparently washing off the scales and -slime that it had gotten on itself while making its meal -of fish.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_25">- 25 -</span></p> - -<h2 class="nobreak tdl2" id="HOW_BIRDS_ANOINT_THEIR_FEATHERS">HOW BIRDS ANOINT THEIR FEATHERS <span class="ref"><a href="#ref_4">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_25" style="width: 267px;"> - <img src="images/025.png" width="267" height="223" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">A</span> bird's plumage</span> receives a great deal of care from the -bird that wears it. The bill is the only implement for this -grooming, and it is run through and along the feathers it -can reach, helping clean them and making sure they lie in -their proper place in the bird's dress. There are parts of the -plumage that the bird's bill obviously can't reach, as that -of the head, but ducks at least surmount this difficulty by -rubbing their head against their body.</p> - -<p>Many birds have oil glands (the only external glands -that most birds have), a pair of glands just above and in -front of the root of the tail, on the back. They contain an -oily substance, and the usual explanation of its use is that -<span class="pagenum" id="Page_26">- 26 -</span> -the secretion of these glands is used in dressing the -feathers. Certainly birds that have oil glands seem to use -them, nibbling at them as though to press out the oil, -touching them with the bill, and then rubbing the bill -through the feathers, and rubbing the head against the -oil gland.</p> - -<p>The beautiful, soft, whitish bloom seen on some birds' -feathers, such as the pale gray of a male marsh hawk and -filmy appearance of some herons' plumage, is caused by -specialized feathers called "powder down." Sometimes this -powder down is scattered through the plumage; sometimes -it is in patches, such as the particularly conspicuous ones -in the herons. The tips of the powder down are continually -breaking off and sifting over the rest of the plumage, -giving it the bloom that with handling quickly rubs off.</p> - - -<p class="pmt2"><span class="allsmcap">WALNUTS AS A COSMETIC</span> But birds sometimes rub -foreign substances over their feathers—just why we don't -know. Grackles have been known to use the acid juice of -green walnuts in preening.</p> - -<p>In Pennsylvania starlings have been seen to come to -walnut trees when the nuts were almost three-quarters -grown, in June, and peck a hole in the sticky hull of a nut, -clip the bill into it, undoubtedly wetting the bill against -the pulpy interior, and then thrust the bill into their -plumage.</p> - -<p>They did this from June to August, especially on hot, -dry summer days, but some birds continued this even during -light rain. Some years before the above was recorded, -when this sort of thing was less known, Edward Howe -Forbush, noted ornithologist, cautiously used a similar -<span class="pagenum" id="Page_27">- 27 -</span> -record in his classical <i>Birds of Massachusetts and Other -New England States</i>. He writes that his colleague, J. N. -Baskett, says he saw a bluejay lift its wing and rub -pungent walnut leaves repeatedly into the feathers beneath.</p> - - -<p class="pmt2"><span class="allsmcap">BEER AND MOTH BALLS</span> Since then such things have -been recorded a number of times, including a catbird that -anointed its feathers with a leaf and a grackle that found -a moth ball and, holding this in its bill, rubbed it against -the underside of its spread wing and the side of its body. -After several applications the grackle dropped the moth -ball and preened its feathers; then again it picked up the -moth ball and treated the other wing as well as its belly.</p> - -<p>Recent experiments with tame song sparrows have -shown that they may use beer, orange juice, vinegar, and -other things made available to them in dressing their -plumage, and it appears that this may be correlated with -a little-understood type of activity known as anting, in -which live ants are placed on the feathers.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_28">- 28 -</span></p> - -<h2 class="nobreak tdl2" id="TRAVELING_BIRDS_NESTS">TRAVELING BIRDS' NESTS <span class="ref"><a href="#ref_5">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_28" style="width: 280px;"> - <img src="images/028.png" width="280" height="221" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>n spring</span> and fall many of our birds make long journeys -under their own power, some of the most publicized being -the migration of the Arctic tern, a bird that may spend the -northern summer north of the Arctic Circle and, before -returning there next season, may have visited south of the -Antarctic Circle. The golden plover that makes a nonstop -flight to Hawaii is another famous traveler, and many of -our smaller songbirds are no mean travelers either. The -barn swallow that nests about an Illinois farm in the summer -may spend the winter in Argentina. The tiny hummingbirds' -feat of crossing the Gulf of Mexico nonstop is -worthy of mention too. Such travels have become -<span class="pagenum" id="Page_29">- 29 -</span> -commonplace through familiarity. We have come to accept -even the possibility of occasional transatlantic passages of -small perching birds, helped by transatlantic vessels, and -of such birds as starlings, making their way from place to -place by boxcar.</p> - -<p>But when it is time for birds to make their nests and -rear their family we expect them to give up their traveling -for a time and to settle down in one place. We expect, with -our songbirds, to have the male arrive first, pick out a -territory, and announce to his species that other males -are to keep out and that a mate is welcome. The female -arrives and chooses her mate or territory, and a nesting -ensues. Many species defend the area around the nest -against others of their kind. So it comes as a surprise to -find nests built in such a situation that they are not -stationary but move back and forth, along with part of -their environment.</p> - - -<p class="pmt2"><span class="allsmcap">BY BOAT</span> Tree swallows nest on the ferryboats that ply -between Ogdensburg, New York, and Prescott, Ontario, -across the St. Lawrence River where it is more than a mile -wide. The nests are tucked into suitable openings on the -ferries, and the frequent trips back and forth across this -mile of water and the docking at different piers do not -seem to disturb the birds. They gather their nesting material -of feathers and straws and leaves from either shore, -and when the young are being fed, insects may be gathered -about the Canadian or the United States shore, depending -on where the ferryboat is docked.</p> - -<p>Another example comes from Western Australia, also -of a swallow, the welcome swallow which is nearly like -<span class="pagenum" id="Page_30">- 30 -</span> -our barn swallow. A pair of these birds nested on a boat -used for visiting local coastal stations. If there were eggs -or young in the nest when the boat sailed, the old birds -would accompany it, once following her on a trip of thirty-five -miles and back.</p> - - -<p class="pmt2"><span class="allsmcap">BY TRAIN</span> Barn swallows have been noted nesting on -railway trains that run across the two-mile portage between -Atlin Lake and Lake Tagish in British Columbia. -In the summer the train makes the trip almost daily, and -for many years a pair, or a succession of pairs, has made its -nest and raised its young in one of the open baggage cars. -Members of the train crew took an interest in the birds -and put up a cigar box for a safe place for their nest. Here -the family seemed to prosper, undisturbed by the proximity -of people and baggage and the clatter as well as the -movement of the train.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_31">- 31 -</span></p> - -<h2 class="nobreak tdl2" id="MALADAPTATION_IN_BIRDS">MALADAPTATION IN BIRDS <span class="ref"><a href="#ref_6">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_31" style="width: 295px;"> - <img src="images/031.png" width="295" height="211" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>hrough selection</span> birds have become adapted to their -environment. In most cases this is successful adaptation. -Occasionally, however, we come across instances in which -the adaptations do not work out. Such cases, where the -actions of the birds are not beneficial or are even detrimental -to it, come as surprises.</p> - -<p>Since the introduction of the Tartarian honeysuckle -(<i>Lonicera tatarica</i>) into the United States from Asia, its -planting as an ornamental shrub provides each autumn a -display of juicy red fruit. This fruit contains saponin, a -substance that has the effect of an anesthetic and muscle -poison and may paralyze the greater nerve centers (in -<span class="pagenum" id="Page_32">- 32 -</span> -sufficiently large doses saponin causes death by cardiac -paralysis). A condition of intoxication has been recorded -for robins feeding extensively on these honeysuckle berries: -"... this drunkenness has been seen in every shade -of severity, from mild unsteadiness to a degree of incoordination -sufficient to cause the birds to fall to the ground. -It seems to make some of the birds utterly fearless and perhaps -a bit belligerent, for they become quite unafraid of -passers-by and interested spectators. A few dead robins -have been found about these honeysuckle bushes—presumably -poisoned by the berry diet." Fortunately the -poisoning of birds by this honeysuckle seems to be uncommon.</p> - -<p>In the Philippines the local people gather the juice of -the coconut inflorescence in bamboo tubes placed in the -crowns of the palms. This juice ferments quickly and provides -a refreshing, mildly intoxicating drink. A little parrot -of the Philippines, the hanging parakeet, has a taste for -this drink, comes and drinks from the containers, sometimes -becomes drunk, falls in, and drowns.</p> - -<p>The California woodpecker ordinarily differs from many -birds because it does not lead a hand-to-mouth existence -but stores food. These woodpeckers feed extensively on -acorns, and one way they store them is by drilling holes in -the bark of a tree and fitting an acorn into each hole. The -whole trunk of a tree thus may be pitted with stored -acorns. When the acorn crop fails and the nuts are scarce -the woodpecker goes through the same storage activities -but, being unable to find sufficient acorns, it stores pebbles -instead. These pebbles are, of course, quite useless to the -<span class="pagenum" id="Page_33">- 33 -</span> -woodpecker, and this is an interesting example of an instinct -"gone wrong."</p> - -<p>Sometimes these woodpeckers have another method of -storing their acorns. This is by dropping them into cavities -in tree trunks, but when stored in such a way there seems -to be no way for the birds to reach them. Here again we -have a blind impulse to store acting in such a way that -the bird gains nothing by the act.</p> - -<p>The raven is ordinarily and quite correctly considered -one of the most intelligent of birds, but a raven I kept in -captivity and fed small fish attempted to store some of -them by pushing them through a knothole in the back of -its cage. The fish fell about fifteen inches below the knothole, -where the raven could not possibly reach them. After -pushing each fish through the raven peered through the -knothole though it could not see the fish. Here again we -have the instinctive storing act carried out in such a way -that it produced no benefit to the bird.</p> - -<p>The late George Latimer Bates, noted ornithologist, -studying the birds of West Africa, found a most surprising -thing in connection with one of the honey-guides. As a -group, these birds are noted for the habit of attracting the -attention of human beings and leading them to bee trees, -presumably so that they will break down the bee tree for -the honey, and the birds can feed on the scraps left over. -Bates found that the West African species is parasitic on -other birds in its nesting habits and its young have been -found in the nesting hole of a little barbet. This barbet was -a much smaller bird than the honey-guide and the entrance -to the nest hole was so small that Bates doubted -that the honey-guide would have been able to get in to -<span class="pagenum" id="Page_34">- 34 -</span> -lay its egg. He suggested that the egg may have been laid -elsewhere and deposited in the nest by the parent's bill. It -is difficult to understand how the young honey-guide -would be able to get out, for when fully fledged it would -have been far too large to squeeze through the entrance -that admitted the tiny body of its foster parents, the -barbets. This is an almost incredible story and if true looks -like a case of maladaptation.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_35">- 35 -</span></p> - -<h2 class="nobreak tdl2" id="FEATHERED_BABY_SITTERS_AND_CO-OP_NURSERY_NESTS">FEATHERED BABY SITTERS AND CO-OP NURSERY NESTS <span class="ref"><a href="#ref_7">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_35" style="width: 291px;"> - <img src="images/035.png" width="291" height="209" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">C</span>o-operative nurseries</span>, where a few parents look after -the young while the rest of the adults, temporarily freed -of the care of their offspring, can go about their other -affairs, appear in the bird world.</p> - -<p>The wild turkey of our Eastern United States commonly -steals away singly to lay its eggs and incubate them in its -nest on the ground. But occasionally it happens, Audubon -writes, that several hen turkeys associate together and lay -their eggs in one nest, and raise their young together. With -the turkey apparently there is little division of labor, as -Audubon writes of finding three hens sitting on forty-two -eggs, but he says that one of the hens is always on the -<span class="pagenum" id="Page_36">- 36 -</span> -watch at the nest so that natural enemies have no chance -to rob it.</p> - - -<p class="pmt2"><span class="allsmcap">A GREGARIOUS BIRD</span> What is of only occasional occurrence -in one species may be the regular course of -events in another, and in the ani we find it customary for -a number of birds to nest together. The anis are moderate-sized -cuckoos living in the tropical Americas. The smooth-billed -ani is perhaps the best known, for Dr. D. E. Davis, -when studying at Harvard for his doctor's degree, made a -special trip to Cuba to study them in the field. The smooth-billed -ani goes in flocks the year round. Usually there are -about seven birds in the flock, but there may be as many -as twenty-four. The nest is a bulky structure of twigs and -fresh leaves. When nest building starts usually one bird is -most active, but as many as five birds were seen carrying -in sticks at one time. When the nest of sticks and leaves is -finished several females may lay their eggs in it. But apparently -only one bird incubates at a time, and the male -takes his turn at incubating. When the young hatch, after -about thirteen days, most of the adults in the colony help -feed the young.</p> - -<p>Eider ducks may nest in dense colonies, but each bird -has its own nest in which it lays its own eggs, and in which -the female alone incubates. But after the young hatch and -the mother leads them to the water, the young may band -into larger flocks, accompanied by a number of females, -and the young seem to be independent of their particular -parent, but attach themselves to and are tended by the -nearest duck.</p> - -<p><span class="pagenum" id="Page_37">- 37 -</span></p> - - -<p class="pmt2"><span class="allsmcap">PENGUIN SOCIAL GROUPS</span> A much more elaborate -system for caring for the young has been evolved by certain -penguins. The sexes alternate in their care of the -young in the early stages. But when the young are partly -grown the family unity breaks up for a communistic type -of social organization. The young are now grouped into -bands of up to twenty or more birds and are left under the -care of a few old birds, while the rest of the adults go to -the water, which may be some distance away. Periodically -they return with food for the young. Apparently the individual -young is not recognized by the parent, which goes -to the particular group of which its young is a part, and -there may feed any one of the "child groups."</p> - -<p>Here we have two definite cases of a social organization -that has resulted in division of labor: in the incubation of -the ani, and in the care of young penguins. In addition we -have two less specialized cases of the same thing, showing -the sort of raw material on which evolution can operate to -produce new behavior patterns.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_38">- 38 -</span></p> - -<h2 class="nobreak tdl2" id="BIRDS_NESTS_AND_THEIR_SOUP">BIRDS' NESTS AND THEIR SOUP <span class="ref"><a href="#ref_8">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_38" style="width: 271px;"> - <img src="images/038.png" width="271" height="224" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>n caves</span> near the ocean in the Far East nest myriads of -tiny swiftlets whose chief impact on the civilized world is -that their nests provide an edible article of commerce. -"Birds' nest soup" at once comes to the mind of the Occidental, -few of whom have ever eaten of the nests, or even -seen the birds to know them. For those who would like to -see the nests, some museums have them on exhibition, -such as in the Chicago Natural History Museum, where -two nests are placed in their natural setting, and beside -them is a quantity of the material of commerce in its raw -state.</p> - -<p>The birds themselves are dusky-colored swifts only a -<span class="pagenum" id="Page_39">- 39 -</span> -few inches long, and belong to a group of swifts that represents -perhaps the most puzzling problems of species -identification in the bird world. As yet we do not know -even how many species there are. The genus is called -<i>Collocalia</i>. Only some of its members make the edible -nests; others mix so much moss into the nest that it is useless -for soup. One species has the scientific name of <i>esculenta</i>, -given in reference to the supposed edible nature of -the nest, but through error the name was applied to a -species whose nests are not edible. In habits all these -swiftlets seem very similar, flying about with a rather weak -flight for a swift, catching their insect food on the wing.</p> - -<p>A number of swifts, including our chimney swift, use -the secretion of their salivary glands as a glue to stick together -their nest, and to stick it to the wall of a cave, the -inside of a hollow tree, or the inside of a chimney. But -some of the edible-nest swifts go further and make their -nest entirely of this secretion from their enormously enlarged -salivary glands. This material, as it comes from the -mouth of the bird, resembles a saturated solution of gum -arabic and is very viscid. If one draws out a strand from -the mouth of the bird and sticks it on a rod, by rotating the -rod and winding up on it the thread of saliva one can -empty the salivary glands of the bird. This material dries -quickly, and is the material of which the nest is made. -When the bird makes its nest, which it does in large -colonies in caves, it flies up to the rock wall, applies the -saliva to the rock in a semicircle or horseshoe. Gradually -a little shelf is built out, and in the finished nest one can -see the many little strands that have gone into the structure. -It may take the birds as long as three months to make -<span class="pagenum" id="Page_40">- 40 -</span> -this nest, even if undisturbed. The birds lay their two eggs -in the nest, and raise their naked, helpless hatchlings into -facsimiles of themselves in it.</p> - -<p>But in the Orient, especially in China, the nests are -highly prized by epicures as a delicacy. As the supply is -limited the price is high. A note with some material we -saw stated that the price was $12 to $36 a pound in Siam.</p> - -<p>The climbing for and collecting of these nests requires -daring, skill and is not without danger. The nests may be -far back and high up in the cave. Ropes and poles may -have to be fixed in place to aid the climber, who has a -flaming torch in one hand and carries a sack or basket for -the nests. In Siam, at least, the collecting of these nests -was hereditary, father training son. The rights to collect -nests are valuable. In Siam, where the rights to collecting -the nests were vested in the state, revenue of as high as -£20,000 has been received from the rights for this collection.</p> - -<p>The nests are said to be of highly nitrogenous material, -and contain about 50 per cent of protein and 7½ per cent -of mineral matter. Their use as food is an Oriental custom, -but an Occidental opinion of their flavor is that it is bland, -and an appreciation of it needs to be cultivated. The price -of these nests is so great that unscrupulous persons have -manufactured spurious nests. These nests are made from -agar-agar, the jelly made by boiling down certain seaweed, -and are so cleverly flavored that only connoisseurs can detect -the fraud.</p> - -<p>We usually think of these nests in connection with -birds'-nest soup, which may be made with chicken or beef -broth and then the cleaned material of the nest added like -<span class="pagenum" id="Page_41">- 41 -</span> -tapioca or vermicelli. Sometimes a sweet soup is made. -Sometimes lotus seeds, sugar, and the nest material are -used in the preparation of the dish. But in the Orient, at -least formerly, they're considered to have medicinal qualities, -too. It is said that when combined with ginseng they -are capable of restoring life to a person on the point of -death. In Northern China where the winter is bitterly -cold, it is a general belief that the blood congeals and can -only be thawed out by drinking a soup made of these nests. -The list of further benefits, such as against tuberculosis, as -a tonic, stimulant, and a pacifier of the stomach, recall -advertisements of patent medicines.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_42">- 42 -</span></p> - -<h2 class="nobreak tdl2" id="WALLED_WIVES_OF_HORNBILLS">WALLED WIVES OF HORNBILLS <span class="ref"><a href="#ref_9">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_42" style="width: 306px;"> - <img src="images/042.png" width="306" height="198" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">F</span>or long</span> it has been written that the male hornbill -walled up his mate in her nest in a hole in a tree at nesting -time, and one author even wrote that the male plucked -out the female's feathers at this time. The facts underlying -these statements have different interpretations, but the -nesting of the hornbill is still one of the most extraordinary -of animal habits. Travelers and naturalists in Africa had -brought back tantalizing bits of information, to add piecemeal -to our knowledge of these birds. Now all this is synthesized -and corrected by R. E. Moreau, onetime resident -in East Africa, who made a study of certain species, raised -young birds by hand, and gave us a comparative study of -<span class="pagenum" id="Page_43">- 43 -</span> -their behavior. Even this study must be considered preliminary, -for, of the twenty-six African species, we have -breeding data on only sixteen of them.</p> - -<p>First we must not generalize too far as to "the hornbills," -for there are Asiatic and Malayan species as well as -African, and African species differ among themselves, the -ground hornbill being especially aberrant in its habits.</p> - -<p>It is quite true that in many African species the female -is walled up in her nest, and the period when she is enclosed -may last three to four months. But it cannot be -interpreted as an imprisonment forced on her by the male, -and presumably she could, if she wanted to, open the entrance -at any time, as she does finally on emerging.</p> - -<p>Among the African species the details vary, but the nest -is usually located in a hole in a tree, and except in the case -of the ground hornbill the entrance is plastered up so that -only a narrow slit is left, about wide enough for the passage -of the bird's bill. The female takes an active part in -the walling up of the opening, and might be said to wall -herself in. When the opening to be filled in is wide, the -male may bring earth, which he mixes with saliva in his -gullet, and presents to the female, who does the actual -plastering. In some species the walling up of the entrance -may take months.</p> - -<p>The female may wall herself in some days before she -lays her first egg. Throughout incubation she remains -there. Depending on the species, she may peck her way -out, or burst out when the young are partly grown, or she -may stay until the young are ready to fly.</p> - -<p>During the time the female is walled in the male brings -food for her, and later for the young, also. That he is a good -<span class="pagenum" id="Page_44">- 44 -</span> -provider is indicated by the fatness of the female and her -young. This is proverbial with the natives of Africa. The -method of feeding varies with the species. The male may -bring a bit of food in its bill, pass it in to the female, and -then go for another, or in other species we might think -more intelligent, the male carries a quantity of berries in -its gullet, and these are regurgitated one by one and -passed to the waiting female; such species make trips to -the nest less frequently.</p> - -<p>Apparently shortly after the female goes into the retirement -of her walled-in nest, she molts all her flight feathers, -so that she is flightless, and then begins to grow them -again.</p> - -<p>When the female bursts out of the nest with the young -only partly grown, the young that remain in a still very -undeveloped state in the nest, using material in the nest -such as remains of food and rotten wood, replaster the -hole! The young, perhaps only halfway through their -fledgling period, wall themselves in! The female then -helps the male care for the young.</p> - -<p>Such is an outline of what some of the African hornbills -do at nesting time. The habit is unique in the bird world. -One species appears not to wall up its nest. In an Asiatic -species it is said that if the male is killed other hornbills -help to feed the female in retirement. The whole procedure -is an amazing behavior pattern, and one for the -development of which it is difficult to find a functional -explanation.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_45">- 45 -</span></p> - -<h2 class="nobreak tdl2" id="BURIED_EGGS_AND_YOUNG">BURIED EGGS AND YOUNG <span class="ref"><a href="#ref_10">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_45" style="width: 295px;"> - <img src="images/045.png" width="295" height="186" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he crocodile bird</span>, or Egyptian plover, has enjoyed a -dubious publicity because of its reputed habit of entering, -and coming out of, crocodile mouths. As Herodotus put it, -the crocodile's mouth is infested with leeches, and when -the crocodile comes out of the water it lies with its mouth -open facing the western breeze. Then the crocodile bird -goes into the crocodile's mouth and devours the leeches, to -the gratification of the crocodile, who is careful not to -harm the bird. Though there are some more recent observations -corroborating this, modern observers who have -had abundant opportunity have watched for this behavior -and have not seen it.</p> - -<p><span class="pagenum" id="Page_46">- 46 -</span></p> - -<p>As one authority on African birds puts it, it is evidently -not an everyday occurrence.</p> - -<p>But the crocodile bird has other habits that are just as -bizarre and interesting. It lives along the sandy shores of -African rivers, and when it lays its clutch of two to four -eggs these are buried in the sand so there is no sign of -them aboveground. The bird sits on top of this spot. -A. L. Butler, who studied this bird in the Sudan, thought -that the sand might be scraped away from the eggs and -the eggs brooded in normal fashion by night. The young -birds are very precocial, and feed themselves on tiny insects, -but they follow the parent. When danger threatens -the young squat motionless in some depression. The toe -mark of a hippopotamus is a favorite place. Then the old -bird, with her bill, throws sand over the young until they -may be completely covered. Not only does this happen -when the birds are very small, but continues up until the -time the birds can fly. Dr. W. Serle in Sierra Leone once -saw a crocodile bird burying something and found the disturbed -spot fairly easily, as recent rain had beaten the sand -beach smooth and hard; a fully fledged young was unearthed. -It squatted motionless until prodded from behind, -then it ran swiftly, rose, and flew away strongly.</p> - -<p>The burying is not only protection from immediate -enemies; A. L. Butler believed it was normal for the young -when not feeding to be buried for safety or as protection -from the burning sun. For a further protection from the -sun the parent moistens the sand by regurgitating water -over it.</p> - -<p>Butler on one occasion saw a crocodile bird drink at the -water's edge, run up onto a sand beach, regurgitate water, -<span class="pagenum" id="Page_47">- 47 -</span> -then settle to brood. Butler marked the spot, went to it, -and, scraping away the dampened sand, found a tiny chick -about one inch below the surface.</p> - -<p>This covering of the eggs by the parent is not unique in -the bird world. The pied-billed grebe of North America -also does this. When disturbed at the nest the incubating -bird has been seen to use quick pecking motions to draw -material from the edge of the nest over the eggs. Instead -of leaving the eggs exposed the nest simply looks like a -heap of trash and may thus escape the attention of a -predator. It used to be thought that this grebe used to -incubate only at night, leaving the eggs covered during -the day to be incubated by the heat from the sun and from -the decaying vegetation of the nest. However, recent -studies have shown this is not the case, and protection by -concealment seems to be the main advantage of this behavior.</p> - -<p>Yet another species of quite a different group, the eider -duck, covers its eggs on leaving them. The eider's nest is -characterized by a blanket of down, plucked from the -breast of the bird, and when the female has time, when -she leaves the nest she pulls the edges of the down blanket -over the eggs, perhaps for concealment, perhaps for the -sake of the down's insulating properties, keeping the eggs -warm in a northern climate during the parent's absence.</p> - -<p>Here we have covering of eggs for what seems to be very -different purposes: to keep the eggs cool; to keep them -warm; and to hide them from view.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_48">- 48 -</span></p> - -<h2 class="nobreak tdl2" id="THE_SNOWY_OWL_AS_A_TRADE_INDEX">THE SNOWY OWL AS A TRADE INDEX <span class="ref"><a href="#ref_11">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_48" style="width: 283px;"> - <img src="images/048.png" width="283" height="205" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">A</span>ngus Gavin</span> was a fur trader at the Perry River post of -the Hudson's Bay Company on the edge of the Arctic -Ocean. White foxes were the chief fur brought in, and the -Eskimos were the trappers. Sometimes it was necessary to -advance credit to an Eskimo, against the expectation of a -coming season's catch out of which the advance was to be -repaid. Gavin, who was a keen naturalist as well as trader, -writes, "I used my observation on Snowy Owl abundance -to govern extension of credit...." When snowy owls -were abundant he could extend liberal credit to the -Eskimo with every assurance the white-fox catch would be -good and that the Eskimo would be able to liquidate his -<span class="pagenum" id="Page_49">- 49 -</span> -debt. When snowy owls were scarce little credit would be -extended, for the white-fox catch would be small.</p> - -<p>In general we've accepted the value of birds to man, and -are appreciative of the complicated web of life in which -one animal affects many others. But this use of snowy-owl -abundance as a guide in granting credit strikes me as -novel. Actually, of course, it is quite sound, for it uses one -part of the chain that links such diverse items as owls, -lemmings, foxes, Eskimo, fur trader, and finally of course -milady in her white-fox furs.</p> - - -<p class="pmt2"><span class="allsmcap">LEMMINGS IMPORTANT</span> First of the factors involved -is, of course, the vegetation; the grasses, herbs, and -tiny dwarf shrubs of the Arctic barrens. The next are the -lemmings, mouselike creatures of the Far North that eat -the vegetation. They are the first step in turning grass into -flesh and fur and feathers. One of the striking facts of -lemming biology is the fluctuation in their numbers. Some -years they swarm, lemmings are everywhere, and in places -they erupt in vast emigration, the tundra and the sea ice -being covered with masses of moving lemmings. We know -this best from the accounts written about the lemmings of -Norway, but the same thing occurs in the American Arctic. -At other times they're scarce and it is difficult to find even -one. Strangely there's a periodicity in this, and periods of -abundance and scarcity tend to recur every four years. -What happens or what causes it we don't know.</p> - -<p>The Arctic fox, staple fur bearer of the Far North, and -the snowy owl both prey on lemmings. Lemmings are so -important to them that when lemmings are abundant the -foxes and the owls prosper and multiply; when the lemmings -<span class="pagenum" id="Page_50">- 50 -</span> -are scarce the foxes and the owls starve or migrate, -in any case where there are few lemmings there are few -foxes or owls.</p> - -<p>Thus we see how it is that an abundance of snowy owls -can indicate that the Eskimo will make a good fox catch -and the trader will do good business.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_51">- 51 -</span></p> - -<h2 class="nobreak tdl2" id="MONKEY_BIRDS">MONKEY BIRDS <span class="ref"><a href="#ref_12">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_51" style="width: 305px;"> - <img src="images/051.png" width="305" height="232" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">B</span>irds get</span> their everyday names in a variety of ways in the -countries where they live; from their looks, like the snake -birds and the pond scroggins; from their color, like the -cardinal and the blackbird; from their behavior, like the -frigate bird and the creepers and the boobies and king-birds; -from what they eat, or are supposed to eat, like the -antbirds and plantain eaters and bee eaters; from what -they say, like the poor-will and the more-pork; from how -they say it, like the warblers and the screamers; from how -often they say it, like the brain-fever bird and the wideawake -terns; from where they nest, like the cliff swallow -and the house martin and the chimney swift; and some -<span class="pagenum" id="Page_52">- 52 -</span> -from their non-bird associates, like the cowbird, moose-bird, -and the monkey bird.</p> - -<p>It is the monkey birds that have taken our fancy at the -moment. The forests of Africa, the jungles of Borneo, and -the forests of the Philippine Islands each have a bird that -associates so often with monkeys that this habit became -incorporated into its local name. The birds are not at all -closely related. One is a hornbill, one is a drongo shrike, -and one is the fairy bluebird. The hornbill goes in parties -of their own kind, but apparently the drongo, and certainly -the fairy bluebird prefer the society of monkeys to -that of their own kind.</p> - -<p>The stories we have of them stress the utilitarian aspect -of the association; that the monkeys as they travel about -through the trees scare insects out of their hiding places -and the birds, being on hand, can snap up the insects more -easily than if they had to search them out for themselves.</p> - -<p>The monkey bird in Africa, which is a hornbill, follows, -along below the monkeys in the lower branches of the -trees. It used to be thought this was for the fruit the -monkeys dropped, but then it was found the hornbills were -insectivorous. Instead of being scavengers the hornbills -are using the monkeys to beat out their game for them.</p> - -<p>Hamba Kerah, the slave of the monkeys, is what the -Malays of Borneo call the racket-tailed drongo. This is -from its habit of stationing itself behind a band of monkeys -traveling through the forest. But Mr. Ridley, who watched -them, decided it was the other way around; the monkeys, -unwittingly of course, were working for the drongo, acting -as beaters to drive out the insects which the bird snapped -up in the air.</p> - -<p><span class="pagenum" id="Page_53">- 53 -</span></p> - -<p>In the Philippines it is "the sentinel of the monkey" -that is applied to the fairy bluebird. The bluebird seldom -associates with its own kind, but is almost invariably associated -with a band of crab-eating macaques. But here -again it seems the monkeys are acting as beaters for the -bird, driving out insects.</p> - -<p>This is a sort of unconscious co-operation one finds in -the bird world. One animal helps out another without being -aware of it. Birds are ever ready to profit by such behavior, -and when it proves of enough benefit, the habit -can become usual for the species, as in the cowbird-cow -relationship, or indispensable as with the oxpecker-hoofed-animal -association.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_54">- 54 -</span></p> - -<h2 class="nobreak tdl2" id="BIRD-MADE_INCUBATORS">BIRD-MADE INCUBATORS <span class="ref"><a href="#ref_13">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_54" style="width: 279px;"> - <img src="images/054.png" width="279" height="194" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>ncubators</span> as we know them on chicken farms are electrical -gadgets with thermostats to control the temperature, -or at least with oil lamps to supply the heat necessary for -the young chick in the egg to grow. Naturally we wouldn't -expect anything so artificial as this in the bird world, but -there is one group of birds that does not brood its eggs but -has employed another method of incubating.</p> - -<p>The birds that do this are fowl-like birds of the Australasian -area. They are variously called "mound builders" -from the nest mound they construct, "megapodes" from -the large size of their scratching feet, or bush turkeys, presumably -from their edible qualities. These birds bury their -<span class="pagenum" id="Page_55">- 55 -</span> -eggs and leave them thus to hatch without any brooding -by the bird. The birds have adapted their habits to two -different sources of natural heat. On some of the Pacific -islands there is local volcanism making the sand warm. To -such places the birds come to bury their eggs.</p> - -<p>But in many of the tropical forests there is not this convenient -natural heat. Another method is employed. The -birds take advantage of the heat generated by rotting vegetation. -They scratch up the surface litter of the forest floor -into mounds—structures that may be a yard or two high -and five or six yards across. Some much larger have been -observed. It is into these the hens burrow and lay their -eggs. The temperatures in them have been recorded as -95° to 96° F., which compares with normal bird temperatures -of just over 100° (bird temperatures are a few degrees -higher than normal human temperature).</p> - -<p>The bush turkeys from Queensland have been bred in -captivity, and have given some extremely interesting data, -according to an article by Mr. Coles in the proceedings of -the Zoological Society of London for 1937. It was the male -who did all the building of the mound. Though the female -started to cover the eggs laid singly in burrows in the -mound, the male finished this. And it was the male that -looked after the nest mound during the incubation period, -continually scratching over the surface layer. Both parents -helped the young emerge, by digging burrows into the -mound which the emerging young, who had started to -burrow out, could use.</p> - -<p>The young are in a very advanced state and apparently -are able to fly and look after themselves upon emerging. -On the day after hatching one chick is reported as able to -<span class="pagenum" id="Page_56">- 56 -</span> -flutter up to a perch six feet high. In the captive birds -mentioned above, the parents, though they were attending -to the mound and helped the chick out, appeared to take -no further interest in the chick once it was out.</p> - -<p>There are a few other cases when birds cover or bury -their eggs. With the grebes it has been said they covered -them and left them to be incubated, but that is doubtful. -Certainly the megapodes are the only ones to present a -dear case of "artificial" incubation.</p> - -<p>This burying of eggs by the megapodes of course brings -to mind the way some reptiles, such as turtles, bury their -eggs. And considering that from an evolutionary viewpoint -birds are really only modified reptiles, it is perhaps -not surprising that they too have this habit. But that it is -really an ancestral trait retained by the megapodes is -doubtful. Rather I'm inclined to think it's another example -of the many ways birds have evolved, or changed -their habits so as to utilize as much of the environment as -they can in as many ways as possible.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_57">- 57 -</span></p> - -<h2 class="nobreak tdl2" id="CORMORANT_FISHING">CORMORANT FISHING <span class="ref"><a href="#ref_14">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_57" style="width: 267px;"> - <img src="images/057.png" width="267" height="209" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>n western Europe</span>, when falconry was in favor for taking -game on land and in the air, there was a certain vogue -for training cormorants to take fish. Like the falcons, the -cormorants were hooded and carried on the wrist, but of -course where the falcons flew to their game, the cormorants -swam to theirs.</p> - -<p>It was in China where cormorants were domesticated, -"completely and perfectly," as that eminent Sinologist Dr. -Laufer says. Extensive breeding establishments have been -maintained. The eggs of the breeding flock of cormorants -are given to a hen to hatch, for cormorants as mothers -prove unsatisfactory under domestication. When the eggs -<span class="pagenum" id="Page_58">- 58 -</span> -hatch the young cormorants must have special care; for, -unlike the young of ducks and geese, young cormorants at -hatching are not down-covered and able to run about, but -are weak, helpless things sensitive to cold. They are placed -in cotton batting, artificial heat provided when necessary, -and they are fed by hand on a diet composed basically of -chopped eel.</p> - -<p>Finally the young are full grown and fully feathered. -The training is now started. First the young are tied to a -stake at the water's edge. A whistle signal is given and the -young cormorant is pushed into the water. Thus he learns -to know and obey the signal to go into the water. Then the -trainer throws him little fish. These the cormorant catches -in its beak and when he does the trainer whistles another -signal, to bring the bird back to him with the fish. And the -cord tied to the bird is used to demonstrate what is meant -and make sure its done. So the training goes on until the -bird has graduated to a class taught from a boat. Sometimes -a small float is attached to the cormorant by a short -cord, and it can be drawn in with a bamboo hook. If young -birds are trained in the company of trained birds, it takes -but half as long. Finally the training is complete and the -fisherman sets out with his birds. This is no sporting event; -it is the serious business of life, getting a living from fishing. -On the sampan or the bamboo raft there may be from -two to a dozen birds; sometimes they may have special -perches built for them along each side of the boat. Sometimes -the cormorant has a cord or band around its neck. -The reason for this is disputed. Some say its a place to attach -a cord; a place to get hold of the bird; some say each -man's cormorant is thus specially marked for identification; -<span class="pagenum" id="Page_59">- 59 -</span> -some that it's to prevent the bird from swallowing -its prey. With well-trained cormorants it is sometimes dispensed -with. At a signal the cormorants go into the water, -swim, and dive seeking fish. The fisherman, by stamping -his feet, by voice or whistle, and by hitting the water with -a bamboo directs and encourages the birds. When the -cormorant catches a fish it brings it back to the boat, and -the fisherman may use a net, or may lift up the cormorant -onto the boat on an oar or pole, and take the fish from the -bird. If a bird is lazy it's encouraged by beating the water -near it with a bamboo pole. As cormorants' plumage is -only partly waterproof they cannot stay in the water indefinitely, -and this, as well as fatigue, probably determines -the rest periods when the birds are lifted aboard. Sometimes -the fisherman helps attract fish to the boat for the -cormorants to catch by scattering grains of rice in the -water.</p> - -<p>When the day is finished the cormorants are collected, -fed, and the fisherman goes home with the sustenance for -his family, gathered by a bird.</p> - -<p>In Japan the cormorant is also used, but apparently -somewhat differently. There cormorant fishing may partake -of the nature of a sport. Sometimes the cormorants -are "harnessed" into a team, each attached by a cord to a -single line, directed by one master. In China the fishing is -usually done during the day, but in Japan night fishing is -common, the scene being illuminated by fires in braziers -or cressets on the boat, or lanterns.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_60">- 60 -</span></p> - -<h2 class="nobreak tdl2" id="THE_SHRIKES_LARDER">THE SHRIKE'S LARDER <span class="ref"><a href="#ref_15">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_60" style="width: 285px;"> - <img src="images/060.png" width="285" height="197" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">O</span>ur northern shrike</span> is a songbird which has developed -feeding habits along the lines of those of a hawk. Whereas -most birds its size are content with fruits, seeds, or insects -of a size it can beat or bite and then swallow whole, our -northern shrike takes not only small insects but prefers -large ones, and mice and birds too big to be swallowed -whole. It is an opportunist and takes what is most abundant -and easily accessible. The shrike's strong hooked bill -is a powerful weapon, used with a nipping motion that is -directed at the back of the head or neck of mouse or bird.</p> - -<p>Now with the dead sparrow or mouse the shrike is at a -disadvantage. With a powerful bill hooked at the tip its -<span class="pagenum" id="Page_61">[Pg 61]</span> -feet are still those of a songbird and are not strong enough -to hold its large prey while pulling it to pieces. Only small -insects are held in one foot and pulled to pieces. To meet -this need for holding large dead prey the impaling habit -was evolved. The result of this is the so-called larders, -which form a fancied resemblance to meat hanging in a -butcher shop, and have given the birds their name of -butcherbird. A thorn tree, a splintered end of a branch, or -even the barbs of wire fencing may serve. The shrike flies -to one of these, carrying the prey in its bill (rarely in its -feet), and with a pulling motion fixes the prey on a projection -point. Sometimes instead of impaling the mouse or -bird it pulls it into the fork of a branch, and so wedges it -there. Now the food is firmly held, and the shrike can use -its bill effectively to pull off pieces of flesh and swallow -them. When the bird has fed, it leaves the rest of the -animal hanging where it was. It may return to this food -and make repeated meals of it if not spoiled, or dried up, -until the whole is devoured. But often parts of meals are -left hanging and discarded. If suitable thorn bushes are -scarce the shrike may return time after time to the same -tree with its prey, and in time this tree may come to be -decked with many partly devoured carcasses. Such trees -are the so-called "larders." There is another aspect of -shrike behavior that adds to these larders. The shrike, even -when replete, may seize any prey that appears and impale -it. The bird's organization is such that the sight of a small -moving animal may start the actions that end with impalement -even when the bird is not hungry. This food usually -is not eaten later.</p> - -<p>Thus the shrike's "butcher shop" is not primarily a store -<span class="pagenum" id="Page_62">- 62 -</span> -of food, even though it sometimes serves as such when -in times of scarcity remains of old meals are eaten. It is -not a gathering of food in time of plenty and saving it for -a later use. Rather the placing of many items in one tree -is the result of its being a favorable impaling place. And -the impaling is behavior developed to overcome the weakness -of the claws in a bird whose disposition and strong -beak enable it to prey habitually on larger animals which -otherwise it could not tear to pieces and eat.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_63">- 63 -</span></p> - -<h2 class="nobreak tdl2" id="BIRD_FLAVORS">BIRD FLAVORS <span class="ref"><a href="#ref_16">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_63" style="width: 285px;"> - <img src="images/063.png" width="285" height="195" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">P</span>articularly</span> in the study of insects it has been shown -that bright or contrasting and conspicuous colors tend to -be associated with ill-flavor in the animals that wear them, -while insects with a good flavor tend to be so colored that -they are difficult to see. The first is a warning coloration—advertising -to a predator that he will not enjoy eating this -insect and better leave it alone; the other is concealing -color, its function apparently to keep predators from finding -their prey. The tasters in the experiments that have -been used to work out the above generalizations were -usually birds, but, as checks, a variety of other animals -were used, and the magpie moth (<i>Abraxas grossulariata</i>), -<span class="pagenum" id="Page_64">- 64 -</span> -for instance, was found to be distasteful to certain spiders, -frogs, lizards, various birds, a bat, and finally "the late -Dr. Hans Gadow (one of the leading ornithologists of his -day), who made a practice of sampling caterpillars, remarked -on trying an <i>A. grossulariata</i> that it was quite one -of the worst he had ever eaten!" Apparently ideas in -taste are similar throughout large sections of the predatory -animal world. Reversing the usual role, and using insects -(hornets) as tasters of bird flesh, the celebrated British -naturalist, Dr. H. B. Cott, has recently studied the question -of the palatability in birds and their coloration. -Naturally Dr. Cott, with his customary thoroughness, -compared hornets as tasters with other animals, including -cats and men, and found a surprisingly close agreement -in the results.</p> - -<p>The experimental procedure was to expose the flesh of -two different birds (without feathers) at the same time, -and see which the wasps ate first. Thus a graded series -was built up of the 38 species of birds tested, with a -palatability rating of from 1 to 38. The wryneck and the -crested lark stood at the top of the list, and the pied kingfisher -and the white-rumped black chat, as the least palatable, -at the bottom with Numbers 37 and 38.</p> - -<p>Then, surveying the coloration of the birds, and their -habits, Dr. Cott made the important correlation that in -general the birds whose flesh was most edible were protectively -colored, and those whose flesh was least palatable -tended to be conspicuous in color and behavior!</p> - -<p>To relate it to the theory of evolution Cott concludes -that selective pressure by predators seems to have forced -<span class="pagenum" id="Page_65">- 65 -</span> -vulnerable species along two divergent lines of specialization: -leading in those which are relatively palatable -toward concealment, and in those which are relatively -distasteful toward advertisement.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_66">- 66 -</span></p> - -<h2 class="nobreak tdl2" id="HOW_MANY_FEATHERS_HAS_A_BIRD">HOW MANY FEATHERS HAS A BIRD? <span class="ref"><a href="#ref_17">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_66" style="width: 260px;"> - <img src="images/066.png" width="260" height="205" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he question</span> as to the number of feathers on a bird -seems a simple one without complication. Dr. Wetmore, -the well-known ornithologist who was secretary of the -Smithsonian Institute, has given us some data. The number -varies with the species, of course: the smallest bird, a hummingbird -from Cuba, had the fewest, 940 feathers; larger -birds had more, the robin 2587, and the mourning dove -2635 feathers. A glaucous-winged gull had 6540; a mallard -11,903 feathers; a Plymouth Rock chicken was said to have -8325 feathers; and a later investigator reported 25,216 -feathers on a swan.</p> - -<p>But as one thinks of it, more questions arise, as in any -<span class="pagenum" id="Page_67">- 67 -</span> -investigation. The answer to one question poses two more. -The first question is, do not the birds in winter need a -wanner plumage to keep out the cold than they do in -summer, when it is warm? Do they have more feathers -then? This was definitely true in the case of the goldfinch: -a bird in summer dress had only 1439 feathers, while one -in winter plumage had 2368 feathers, obviously an adaptation -for cold weather.</p> - -<p>The next question is more abstruse, but eminently practical: -the smaller a body, the larger exposed surface for -its weight it presents. That is, for its weight a small bird -has a proportionately much greater surface from which -heat is lost than does a larger one. With equal heat-producing -mechanism and metabolism, a small bird would -need more insulation than a large one. Reduced to its -simplest: one would expect small birds to have relatively -more feathers than large ones: more feathers per gram -of weight. Is this true? Two members of the Department -of Poultry Husbandry at Cornell University, Dr. F. B. Hutt -and Lelah Ball, supplied the answer. Small birds do have -more feathers per gram of body weight than do larger ones. -A hummingbird weighing 2.8 grams had 940 feathers or -335 feathers per gram; a nighthawk weighing 67.9 grams -had 2034 feathers or 29 feathers per gram; while a swan -weighing 6123 grams had 25,216 feathers or 4 feathers -per gram of body weight.</p> - -<p>Presumably there are still other relations: Do the birds -that live in the tropics where it is warm have fewer -feathers than species of the same size of arctic climates, -as one would expect? Are certain types of feathers such as -those of aquatic birds better insulated than those of land -<span class="pagenum" id="Page_68">- 68 -</span> -birds, so that the bird requires fewer of them to keep -warm? Does a dense coat of down reduce the number of -feathers needed to keep warm? Do the loose feathers of -ostriches, lacking barbules, necessitate some adjustment -in numbers? The things we've learned point the way to -other questions to be investigated.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_69">- 69 -</span></p> - -<h2 class="nobreak tdl2" id="LAST_YEARS_BIRDS_NESTS">LAST YEAR'S BIRDS' NESTS <span class="ref"><a href="#ref_18">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_69" style="width: 275px;"> - <img src="images/069.png" width="275" height="197" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he wisdom</span> of our fathers is sometimes embodied in -what we call old saws, to wit, "Many hands make light -work," to which the iconoclast retorts, "Too many cooks -spoil the broth." And when we come to the phrase, "As -useless as a last year's bird's nest," we must reply, "Circumstances -alter cases." For many a bird's nest of yesteryear -still has its use; some a biological use to other birds; -some to feed and clothe man.</p> - - -<p class="pmt2"><span class="allsmcap">SUBLEASES</span> The snug, secure cavity that a woodpecker -chisels in some tree trunk for its nest will last for many -years, a shelter in which tree swallows, house wrens, -<span class="pagenum" id="Page_70">- 70 -</span> -screech owls, bluebirds, or wood mice may make headquarters -and use as a nursery. In the strange forests of -saguaro, a giant cactus of southern Arizona, the nest -cavities of the gila woodpeckers and the gilded flickers in -the cactus trunks seem necessary for the presence of many -nesting birds. Without them the birds would have to go -elsewhere for cavities in which to nest. In old woodpecker -nest cavities the elf owl, pigmy owl, screech owl, sparrow -hawk, ash-throated flycatcher, martin, and crested flycatcher -commonly nest, and cactus wrens and even Lucy's -warbler may use them. Their use is not confined to birds -alone, for scaly lizards, snakes, rats, and mice have been -found in them. In the Argentine there is a woodhewer -that appears to depend on the domed mud nest of the red -oven-bird for its nesting sites. It takes over a recently -vacated or an old nest of the oven-bird and lines it with -grass and feathers for its own use. In Africa and Madagascar -the great domed nest of the hammerkop stork may -find a secondary use in sheltering barn owls.</p> - - -<p class="pmt2"><span class="allsmcap">SANDPIPERS AND EAGLES</span> But it is not only burrows -and domed nests that when deserted by their original -occupants are used by other birds. The solitary sandpiper -of our northlands belongs to a group in which nest -building is reduced to a minimum, usually little more than -a hollow in the ground with a few bits of material added. -But the solitary sandpiper, and the green sandpiper of -the Old World have broken with tradition and customarily -lay their eggs in the abandoned nest of some thrush. Our -great homed owl is another bird that may use the discarded -nest of a crow or hawk for its eggs and young. And -<span class="pagenum" id="Page_71">- 71 -</span> -age in the eagle's nest means little to the eagle. Frances -Herrick, the noted chronicler of the life of the American -bald eagle, writes of one nest in the crotch of a lofty tree -that had been in use for thirty-six years. Each year more -material was added until the nest became 12 feet high, -8½ feet across the top, and was estimated to weigh 2 tons.</p> - -<p>Man has found, among others, the following two direct -uses for two kinds of birds' nests: one he uses for food; -of another he makes covering for himself.</p> - -<p>The swift's nests used for food have been discussed in -another chapter, "Birds' Nests and Their Soup," so here I -will only tell of the use of birds' nests as human covering.</p> - - -<p class="pmt2"><span class="allsmcap">EIDER-DOWN BLANKETS</span> An eider-down has come -to mean a comforter, a sleeping bag, or even a padded -jacket. But to an ornithologist eider down still has its -older meaning: the down of an eider duck. It is this -material gathered from the eider ducks' nests which forms -the article of commerce. The eider's nest may contain grass, -seaweed, and sticks, but it is notable for the blanket of -down on which the eggs rest, and with which the female -covers the eggs when she leaves them. This down is -plucked from the breast of the female. If it is taken from -the nest she replaces it with more, and it is on this principle -that harvesting of the down is carried out. On islands and -islets in the northern part of the North Atlantic eiders -nest in great numbers in dense colonies. Some of these are -jealously guarded by the local inhabitants, who gather -the first blanket of down from the eggs, and later, after -the eggs have hatched, gather the second crop of down -with which the female has replaced the first to guard her -<span class="pagenum" id="Page_72">- 72 -</span> -eggs against the inclement weather of those boreal latitudes. -Each nest may yield an ounce or so of the precious -down, which is carefully cleaned and sent to market. It is -this material, extremely light, extremely elastic, and one -of the best non-conductors of heat, which finally becomes -the important part of real eider-down comforters, sleeping -bags, and padded jackets.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_73">- 73 -</span></p> - -<h2 class="nobreak tdl2" id="SYMBIOSIS_ANIMALS_LIVING_IN_MIXED_HOUSEHOLDS">SYMBIOSIS—ANIMALS LIVING IN MIXED HOUSEHOLDS <span class="ref"><a href="#ref_19">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_73" style="width: 284px;"> - <img src="images/073.png" width="284" height="195" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">S</span>ymbiosis</span>, a term from the Greek, is what the biologist -uses for the living together of two dissimilar organisms. In -a broad sense it includes such diverse relations as the lice -living on man and rats in his house, the union of an alga -and a fungus to form a lichen, and the cross-pollination -of flowers by hummingbirds.</p> - -<p>The story of the burrowing owls of our Western plains -living in amity with prairie dogs and rattlesnakes as one -happy family comes to mind as an example. But "foolish -nonsense" is how the noted biographer of North American -birds, A. C. Bent, characterizes such stories. He then goes -on to quote evidence as to what actually happens, and one -<span class="pagenum" id="Page_74">- 74 -</span> -can see how the story originated. The prairie dogs, which -are really plump, dumpy, ground squirrels and not dogs at -all, dig their burrows close to each other on the prairie in -colonies which have come to be called prairie-dog towns, -or dog towns or simply "towns." Burrowing owls also take -up their residence in these towns, probably because they -find burrows ready made and do not have to dig their -own as they are quite able to do.</p> - - -<p class="pmt2"><span class="allsmcap">MODERATELY PREDATORY</span> The owls may make an -occasional meal of a young prairie dog, and a prairie dog -may perhaps dine occasionally on owl eggs, but on the -whole owls and dogs get along on terms of easy familiarity. -Sometimes when alarmed, both may scuttle into the same -burrow for safety, but each has its own burrow. With the -rattlesnake it is different. The rattlesnake may live in burrows -in the dog town, but when it is hungry it eats owl -or dog as occasion offers. While the picture of a happy -family of owl, dog, and snake is a myth, the symbiosis of -owl and dog, at least in the same colony, is striking.</p> - -<p>In Africa there is a tiny falcon only about eight inches -long which is called a pygmy falcon because of its small -size. When Dr. Friedmann was studying the social weavers -in South Africa, birds which nest in large colonies under a -common roof they make in a savanna tree, he found these -falcons occupying nest chambers in thriving weaver colonies. -There was no friction between the weaverbirds and -the falcons, and they were sometimes seen to sit side by -side. When Friedmann collected three of these falcons he -found bird remains in their stomachs but they were not -remains of the social weavers. Apparently the falcons were -<span class="pagenum" id="Page_75">- 75 -</span> -feeding largely on small birds, but they did not molest the -weaverbirds which had made the nests the falcons were -using.</p> - - -<p class="pmt2"><span class="allsmcap">PARROT-DUCK-OPOSSUM MÉNAGE</span> We occasionally -find a mallard nesting in a tree, on an old crow or hawk -nest, and there are ducks like the wood duck and the -golden-eye, which usually nest in holes in trees, but a -South American duck called the tree teal habitually nests -in a parrot's nest. The parrots, called monk parakeets, -make their nests in compact colonies in the branches of -trees, so close together that they form a single mass. The -tree teal's usual manner of nesting is to lay its eggs in one -of the chambers in this apartment-house colony. At first -the eggs are laid on the rough twig floor of the nest, but as -the eggs increase in number a lining of down, plucked -from the breast of the bird, is added until it may even -extend out the entrance of the nest. Apparently parrot -and duck both get along amicably in their pendant treetop -cradles. An opossum sometimes also finds these parrot -nests to its liking, though one wonders if it may not have -a meal of young parrot or duck in mind. But be that as it -may, in different chambers of a single communal nest of -these parrots, parrots, a duck, and an opossum have been -found.</p> - -<p>On islets off the New Zealand coast lives a rather large-sized -lizard called <i>Sphenodon</i>. It's rather well known by -name, at least, for it is one of those relics of a formerly more -widespread group which are called living fossils. It is also -noted for its remarkable development of a pineal eye, the -remnant of an important sense organ in ancestral forms, -<span class="pagenum" id="Page_76">- 76 -</span> -and formerly an organ some philosophers supposed to be -the seat of the soul. But here we are interested in the fact -that petrels swarm to these same islands to dig their burrows -and lay their eggs in them, and it is in these same -burrows that <i>Sphenodon</i> spends its daylight hours. Apparently -the insect-eating <i>Sphenodon</i> and the oceanic-feeding -petrels share the burrows amicably, adding still -another example of a rather long list of dissimilar organisms -whose lives are associated.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_77">- 77 -</span></p> - -<h2 class="nobreak tdl2" id="BIRD_APARTMENT_HOUSES">BIRD APARTMENT HOUSES <span class="ref"><a href="#ref_20">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_77" style="width: 267px;"> - <img src="images/077.png" width="267" height="218" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">E</span>very now and then</span> in our press appear blasts against -crowded living conditions in our cities, and the tenements -where people are crowded together. Often there is the -implication that this type of thing is unnatural and abnormal. -And yet when we look about us in the bird world -we see that gregariousness is a common trait. We have -only to remember the great flocks of starlings and blackbirds -in the autumn, or the massed flights of water fowl. -Not only in traveling and in feeding, but also at nesting -time birds may gather together, and some birds nest in -such close association that the term "apartment houses" or -"tenement" is really applicable.</p> - -<p><span class="pagenum" id="Page_78">- 78 -</span></p> - -<p>The martins' house on our lawn with perhaps dozens of -closely spaced rooms (some houses have as many as two -hundred rooms) is a case in point. The neat martin house, -made of boards, is a man-made thing, but even before the -white man came to this continent, and before the Choctaw -Indians hung up groups of hollow gourds for the martin -colonies to use, the martins nested in colonies. Even in -recent years certain colonies we might consider unprogressive -have been reported as using such diverse nesting -situations as among the boulders of a lake shore in Minnesota, -and the closely spaced woodpecker holes which -riddled a dead pine in Florida. And probably it was always -thus. The martins liked company at nesting.</p> - - -<p class="pmt2"><span class="allsmcap">CLIFF DWELLERS, TOO</span> Perhaps it would not be -proper to consider a colony of bank swallows, each with a -separate burrow in the same small cut bank and roofed -with the same few square yards of turf of mother earth, -as a real apartment house of cliff dwellers. But the term -has been used in connection with a West Indian woodpecker, -where a dozen pairs were nesting in a single dead -tree, and "the trunk was a veritable apartment house." A -similar situation exists with the naked-faced barbet of West -Africa. This bird too makes a hole in a dead tree for its -nest, like a woodpecker, and colonies of thirty to fifty birds -may be found nesting in a single dead tree, while other -dead trees nearby, apparently equally suitable, are untenanted. -Colonies of hundreds of nests of cliff swallows, -the nests touching and overlapping, may be under the -eaves of a single barn, or as they used to be and some still -are, on the sheltered side of a cliff. But as these birds had -<span class="pagenum" id="Page_79">- 79 -</span> -nothing to do with the making of the roof, perhaps these -too do not deserve to be rated as apartment houses.</p> - -<p>In southern South America there is a monk parakeet that -makes a real tenement. It nests colonially in treetops, and -the nests of sticks are placed so close together that they -merge and form a single mass, up to nine feet across, in -which each parakeet has its own nest. Similar to this is the -palm chat. This West Indian bird is small and thrush-sized, -dull in color, brownish with a streaked breast, nothing remarkable -to look at, but it carries amazingly large sticks, -little thinner than a lead pencil and as much as two feet -and more long up to the top of a palm tree, and there it -makes its bulky community nest.</p> - - -<p class="pmt2"><span class="allsmcap">BUILD NESTS CO-OPERATIVELY</span> These stick nests, -which may be four feet and more across, are conspicuous -and regular features of the landscape in Hispaniola. The -colony consists of four to eight pairs of birds, and each has -its own apartment in the bulky structure, and its own -passageway to the outside. But in the parts of the community -nests that hold the individual nests together and -cover them there are roughly defined passages running -through the interlacing twigs of the top of the nest so that -the birds can creep about under cover. Apparently some -of the work is carried on in common, for as many as half -a dozen birds may be working close together, pulling and -twisting twigs more firmly into place.</p> - -<p>The social weaver is the most advanced apartment -builder. It, like the palm chat, has little of distinction in -its appearance, being mostly dull brownish with a black -face. But in its home country, the savannas of Rhodesia in -<span class="pagenum" id="Page_80">- 80 -</span> -southeastern Africa, its huge community nests in the savanna -trees may be seen from afar. The largest Friedmann -saw when he was studying the bird there was about 25 -feet by 15 feet, by 5 feet high, and contained about 95 -nests. And this might have been still bigger, for part of it -had broken the branch on which it rested and fallen to -the ground. Sir Andrew Smith, the early ornithologist of -South Africa, has written that when these birds start a -colony they first of all make a roof of coarse grass. The -group to which the social weaver belongs gets its name -from the remarkable ability some of them have of weaving -their nesting materials. But the social weaver neither -plaits nor weaves its roof. It puts the roof together in the -form of a well-made hayrick with a fairly definite thatching -arrangement so that the water runs off. This is a community -effort. Under this roof each individual pair makes -its own separate nest. These apartment houses are used -year after year, but last year's chambers are not used, new -ones being made under the roof each year, and so it grows -bigger and bigger until the weight of the mass may break -the branches and cause a part or the whole to fall to the -ground.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_81">- 81 -</span></p> - -<h2 class="nobreak tdl2" id="BIRD_HELPERS_AT_NESTING_TIME">BIRD HELPERS AT NESTING TIME <span class="ref"><a href="#ref_21">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_81" style="width: 280px;"> - <img src="images/081.png" width="280" height="208" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>n many</span> a well-run American home the children have -definite responsibilities, the older children may help look -after the younger, and even grown-up relatives may stay -as part of the family group. As in so many cases there may -be found parallels to this in the bird world.</p> - -<p>The ani, the curious tropical American cuckoo that -makes communal nests, is gregarious and the young of the -first brood become part of the parent flock. Two more -broods may be raised during one season in Cuba, and the -young of the earlier brood may feed their younger brothers -and sisters of the later brood. The same has been recorded -for many other species in the wild: in eastern bluebirds, -<span class="pagenum" id="Page_82">- 82 -</span> -mountain bluebirds, wheatears, long-tailed titmice, barn -swallows, coots, rails, and gallinules young have been recorded -as feeding still younger birds. In captivity this -habit has been seen a number of times. Young birds hardly -able to feed themselves may help feed still younger individuals -of the same or other species, and a nestling -crowned hornbill has been seen to offer food to its nestmates. -This tendency to feed nestmates evidently appears -very early in the life of the bird, as Dr. C. O. Whitman, -who worked intensively with pigeons at the University of -Chicago, recorded a hybrid dove only twelve days old that -fed its nestmate.</p> - - -<p class="pmt2"><span class="allsmcap">FIVE JAYS AT A NEST</span> It was rather generally known -that occasionally more than the two parent birds attended -a nest, but until 1935, when Alexander Skutch, the authority -on the biology of Central American birds, published -his paper "Helpers at the Nest," few of us realized how -widespread this was. Since most birds of a species are -difficult to identify individually, one must actually see the -extra, unmated helpers at the nest along with the parents -to be sure they are there. In the brown jays of Central -America that Skutch studied closely the colors of the soft -parts, bill, feet, and eye rings were variable and he was -able to recognize many individual birds. At five nests he -watched he found at least one helper at each nest, and at -one there were five helpers, all bringing food. Sometimes, -if between an incoming, food-laden bird and the young, -they would take the food and pass it on to the nestling. At -one nest the unmated helper was more zealous in guarding -the nest than were the rightful parents. Sometimes, -<span class="pagenum" id="Page_83">- 83 -</span> -perhaps, these helpers were unmated young of the parents' -previous year's brood, but this could hardly have been -the case where there were five helpers, for the brown jay -ordinarily raises no more than three young a year. A black-eared -bush tit of Central America seems to have a great -preponderance of males and at one nest in addition to the -parents there were three other males bringing food to the -young.</p> - - -<p class="pmt2"><span class="allsmcap">MATERNAL PENGUINS</span> Perhaps the most striking example -among birds is the emperor penguin. These birds -breed in the dark and cold of the antarctic winter, on the -edge of the ice shelf. The single egg is carried on the feet -of the brooding bird; indeed one wonders what other -adaptation for holding the egg would be possible in this -land of ice, snow, and water. Only a few of the adults in -each colony lay eggs any year, perhaps one in five, or one -in twelve. But all the adults in the colony have the urge to -incubate and brood. Thus many old birds, rather than -merely the two parents, may take turns caring for each -egg or chick, leaving the rest ample time to feed. So strong -is the urge to brood that struggles may take place over a -chick and it may be very roughly handled. Indeed the -chicks may so resent this that they may creep away into -ice crevices and freeze to death. Another strange turn this -behavior may take is that frozen eggs, dead chicks, and -even bumps of ice of suitable size are carried on the feet -and covered with the birds' feathers by their "would-be -fathers and mothers."</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_84">- 84 -</span></p> - -<h2 class="nobreak tdl2" id="A_NAME_FOR_A_BOAT">A NAME FOR A BOAT</h2> -</div> - -<div class="figcenter" id="img_84" style="width: 282px;"> - <img src="images/084.png" width="282" height="188" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">A</span> request</span> for the name of a sea bird, a name to be used -for a boat, came to me at my desk in the museum one day. -My memory was quickly exhausted with sea gull, sea -swallow, and albatross. But I keep within reach the handy -guide, <i>Birds of the Ocean</i>, by W. B. Alexander. In the -index I found twenty pages of names, two columns to a -page. They started with <i>aalge, Uria</i>, and went on down -through the alphabet to <i>yelkouan, Puffinus</i>, and to <i>zimmermanni, -Sterna</i>.</p> - - -<p class="pmt2"><span class="allsmcap">EUPHONY NEEDED</span> A name should be short, pleasant-sounding, -and easy to remember and to say, so obviously -<span class="pagenum" id="Page_85">- 85 -</span> -such words as <i>Macronectes</i>, <i>Brachyramphus</i>, <i>Aptenodytes</i>, -and <i>Coprotheres</i> are ruled out among the scientific names. -But further, when choosing a name for a boat from among -those of water birds, one should consider the kind of a -boat. There should be some appropriateness; some points -of resemblance between the boat and the bird, or between -the boat owner and the bird. Albatross seems right for a -seagoing sailing ship, sailing to southern oceans; tern (or -sea swallow) appropriate for light, dainty coastal sailing -craft; puffin or auk or murre for power craft, for these -birds spend most of their time stolidly on the water and -when they fly have a direct buzzing flight. Loon and dabchick -would do well for fresh-water boats. But one objection -to both them and the various auks for a name is that -these birds spend much time swimming underwater. They -might better give their names to submarines. The big, -stocky sea ducks, called scoters and eiders might suit -some stout craft that ply to arctic waters.</p> - - -<p class="pmt2"><span class="allsmcap">SCIENTIFIC NAMES AVAILABLE</span> I reviewed the -host of other names. Scientific names need not be ignored -either. What is nicer than <i>Gygis</i>, the name of the white, -fairy, or love tern of the South Seas for a small summer -sail boat? Then going farther afield into austral waters for -far traveling craft there's <i>Diomedea</i>, the name of the albatross, -and <i>Daption</i>, the medium-sized petrel that also is -called pintado for the same reason a white-splashed horse -is called a pinto, and <i>Prion</i>, the tiny whalebirds of the -antarctic whose blue-gray back is near the ideal ocean-camouflage -color. <i>Larus</i>, a good honest name without frills, -belonging to the gulls that haunt our harbors, coasts, and -<span class="pagenum" id="Page_86">- 86 -</span> -lakes, would do for a plain, everyday sort of boat. Kittiwake -is another gull that spends more time at sea. Gannets -are boldly black and white, strong-flying birds of the North -Atlantic, and one could use that, or its scientific equivalent, -<i>Moris</i>, for a boat.</p> - -<p>Penguin and pelican I'm doubtful about; I can't imagine -a boat for either. Skua or jaeger would, of course, be a -lovely symbol for a pirate vessel, as would frigate bird; -both are birds that practice the stand-and-deliver method -of getting food from weaker fisherfolk. The petrels called -shearwaters are among the hardiest seagoing birds, but the -name has little association for most people beyond wondering -if they feed around breakwaters. Petrel itself isn't a -bad name, though one might think of the storm petrels, -which are also called Mother Carey's chickens, and have -been considered the souls of drowned sailors, though their -name perhaps refers to Peter, and his attempt to walk on -the water, as these birds are continually trying to do.</p> - -<p>Phalaropes are snipes of sorts that have taken up a -periodic seagoing habit, and their name might often be -appropriate. Even their habit of spinning quickly about as -they sit on the water might still agree. A Chicago man -named his Chris-Craft <i>Sandpiper</i>, after, as he said, the -bird that goes hopping along the beach before the waves.</p> - -<p><i>Sula</i> is a good sort of a word, and the name of birds that -are strong, swift fliers of the tropics. But in English they're -usually called booby, which is an English word meaning -simpleton (which name the birds got from stupidly perching -on ships). <i>Alle</i> for the little auk or dovekie would do -for a tiny boat in northern waters, and I knew of one boat -called the <i>Alca</i>, after the razor-billed auk, while <i>Cepphus</i>, -<span class="pagenum" id="Page_87">- 87 -</span> -the name of the black guillemots, is equally good, as is -both <i>Lunda</i> and its equivalent puffin.</p> - -<p>Some names have a stark simplicity that would attract -few, like shag, used for the cormorant, and muttonbird for -a petrel. The cahow people might shy from because for -many years we were not sure whether this West Indian -petrel was extinct or not.</p> - -<p>Myself, there are two names I rather like and I've been -saving for the last: for a small sailboat I'd say the <i>Wideawake</i>, -as the sooty tern is called in its tropical home, and -the other, for a larger seagoing boat, is the <i>Mollymawk</i>, a -sailor's name for the albatross.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_88">- 88 -</span></p> - -<h2 class="nobreak tdl2" id="WEAVERS_AND_TAILORS_IN_THE_BIRD_WORLD">WEAVERS AND TAILORS IN THE BIRD WORLD <span class="ref"><a href="#ref_23">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_88" style="width: 273px;"> - <img src="images/088.png" width="273" height="196" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">O</span>ne can imagine</span> the consternation in trade-union circles -when it becomes known that there are, among birds, those -who weave and those who sew. Their products are entirely -for home consumption and there are no minimum wage, -no maximum hours, or any fair-trade or quality agreements. -None of the Audubon societies have even touched -on the matter.</p> - - -<p class="pmt2"><span class="allsmcap">WEAVING</span> The sewing and the weaving is done entirely -in the construction of nests. To take up the weavers first, -we can point to the Baltimore oriole, which makes a sac-shaped, -pendant nest, often hung from the trailing tips of -<span class="pagenum" id="Page_89">- 89 -</span> -elm branches. The walls of this sac are formed of fibers -pushed and pulled back and forth with the birds' bills in -a seeming haphazard way so that a roughly woven or -stitched fabric results. But the finest weavers belong to -that group of birds known as weaverbirds. One might expect -that to be an expert weaver a bird would have to -have a slender bill. But no, their bills are short, stout, -clumsy-looking, and sparrowlike. And yet these are the -birds that weave elaborate pendant nests of fibers and -straws. The finest are in shape like an inverted retort, with -the nest proper in an oval chamber, fastened to a branch -by a special strand of fibers, and with a tube or funnel for -an entrance. The walls of these fine weaverbirds' nests are -amazingly strongly and neatly woven. In captivity one of -the weaverbirds, the red-billed weaver, was studied at its -nest building and it was found that the strong, intricate, -and beautiful weaving of this species actually included -knots of several sorts.</p> - - -<p class="pmt2"><span class="allsmcap">TAILORING</span> The tailoring is done by birds of quite another -group. They are Old World warblers of several sorts, -some in southern Asia and some in Africa. The tailoring -consists of sewing the edges of leaves together to form a -place for their tiny nests. The Indian tailorbird is perhaps -the best known. When these tiny olive-green and gray birds -set about nest building the female punctures the margins -of the leaves with her bill. Then she brings cobwebs and -pushes them through the punctures in the edges of the -leaves, and winds them around, and draws the edges of -the leaves together. Strands of cotton are used too for this. -Sometimes a single leaf is used; its two edges being drawn -<span class="pagenum" id="Page_90">- 90 -</span> -together to form a funnel. Sometimes a number of leaves -are joined. Sometimes it is claimed knots are used, but -this seems not to be the case. What are mistaken for knots -seem made in this way: The cotton used is soft and frays -easily, so that the part of it forced through a tiny aperture -issues as a fluffy knob, which looks like a knot. "The bird -makes no knots; she merely forces a portion of the cotton -strand through a puncture," and the edges of the puncture -catch and hold it, according to Casey Wood, who studied -the birds in India. The lining of the nest is of soft material -and this the bird anchors by making a puncture in the -leaf, grasping a strand of this material, and pulling it out; -the cotton outside then expands into a minute button -which helps hold the nest and contents in place as though -riveted. One nest is recorded as having been so riveted in -seventy-five places.</p> - -<p>The camouflage of the tailorbirds' nests is very good; -it is usually built in thick foliage, the leaves are little deranged, -the punctures do not cause the leaf to die; and the -leaves being the same as the others, there is little for the -eye to pick up as indicating a bird's nest.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_91">- 91 -</span></p> - -<h2 class="nobreak tdl2" id="SOCIAL_PARASITES_AMONG_BIRDS">SOCIAL PARASITES AMONG BIRDS <span class="ref"><a href="#ref_24">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_91" style="width: 291px;"> - <img src="images/091.png" width="291" height="215" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he mother</span> who would leave her infant on a stranger's -doorstep, to be brought up an orphan, not even knowing -its own parents, is a despicable character in human society. -But when we leave the man-made society we must leave -man-made rules of behavior and man-made prejudices behind. -Morals are human. The rest of the animal world is -not immoral, it is amoral. It cannot afford criteria beyond -survival and reproduction. So while we call certain birds -"social parasites," we attach no stigma to them. They represent -several groups: the cowbirds, the weavers, the -cuckoos, the honey-guides, and the ducks.</p> - -<p>Carelessness in egg laying is common even in birds that -<span class="pagenum" id="Page_92">- 92 -</span> -ordinarily lay their eggs in their own nest and care for -them themselves, as for instance the robins' eggs that you -may find on your lawn (which of course are wasted; addling -and rotting). Perhaps the fate of the eggs of pheasants -and ruffed grouse which are found in the same nest -may be more happy. Ducks usually make their own nests, -but many species occasionally lay eggs in the nest of another -species, and one South American duck no longer -makes any nest of its own, but is a social parasite, not only -on other kinds of ducks, but also on coots and some other -birds.</p> - -<p>The small, well-marked family of honey-guides of Africa, -notable in other ways, also is remarkable for being social -parasites. Their favorite host species, chosen to look after -the eggs and young, are their close relatives, the barbets -(which themselves are most closely related to our woodpeckers).</p> - -<p>The nesting of certain African weaverbirds was long a -puzzle to ornithologists until it was found they too were -social parasites, on other weaverbirds.</p> - - -<p class="pmt2"><span class="allsmcap">VARIED NESTING HABITS</span> The cowbirds, of several -species in North and South America, belong to a family -notable for the variation in its nesting habits. Their nests -vary from the elaborate purse-shaped structures of the -oropendola and orioles to the dome-shaped nest on the -ground of the meadow lark, the simple cup of the bobolink -and redwing; the cowbird makes none. The cowbird lays -its eggs in the nests of a wide variety of other species to be -cared for by them. Here those who discuss the relative -importance of heredity versus environment can profit by -<span class="pagenum" id="Page_93">- 93 -</span> -considering these social parasites. The young cowbird, -hatched and brought up by, say, a yellow warbler, remains -a cowbird. As soon as it no longer needs its foster parents' -care it flocks with other cowbirds, with all their mannerisms -and characteristics, and next season it mates with another -cowbird. There is nothing left of its early environment.</p> - -<p>The cuckoos of the New World and some of those of the -Old make their own nests in normal avian fashion. But a -number of Old World species are social parasites, and their -behavior has long been a subject of study and discussion. -Specializations indicate that here perhaps we have the -highest stages of social parasitism. Whereas the cowbird -may grow up with nestmates that are the young of the -foster parent, unless perchance it crowds them out or -starves them if it is larger, the young cuckoo gets the -rightful occupants of the nest on its back and throws them -out of the nest to perish.</p> - - -<p class="pmt2"><span class="allsmcap">EGGS LOOK ALIKE</span> Another refinement in social parasitism -by the European cuckoo is that apparently certain -individuals, and apparently certain strains, lay their eggs -only in the nests of certain host species. And these cuckoos' -eggs resemble those of the particular species in whose nest -the cuckoos' eggs are laid. For example, if certain cuckoos -lay their eggs only in the nests of meadow pipits these -cuckoos' eggs would resemble those of meadow pipits, -while another group of cuckoos specializing in hedge-sparrows -would have eggs resembling those of hedge-sparrows. -Another oriental cuckoo has a color adaptation -in the young. In southern Asia these cuckoos parasitize -<span class="pagenum" id="Page_94">- 94 -</span> -crows, and the nestling cuckoos have black feathers like -the young crows; in the Australian area where the same -species of cuckoo occurs it parasitizes grayish-brown honey -eaters and the young are brown, more like the rightful -nestlings. Both these resemblances apparently reduce the -chances of the cuckoos' offspring being rejected by the -foster parents.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_95">- 95 -</span></p> - -<h2 class="nobreak tdl2" id="FISH_EATS_BIRD">FISH EATS BIRD! <span class="ref"><a href="#ref_25">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_95" style="width: 278px;"> - <img src="images/095.png" width="278" height="245" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>t has become</span> commonplace to hear about birds eating -fish. The government gets out reports on the relation of -fish-eating birds to fish abundance. The cries of commercial -fisheries have caused inquiries to be instituted into -the food of cormorants that were supposed to be eating -the fish before they grew up enough for us to eat. The -scarcity of salmon in some of our Northeastern streams -has caused the allocation of biologists to study the predation -of kingfisher and merganser on salmon fry and -fingerlings.</p> - -<p>But fish get some of their own back by eating birds. It's -not as spot news as the "man bites dog" angle, but it's -certainly less widely known.</p> - -<p><span class="pagenum" id="Page_96">- 96 -</span></p> - -<p>To one who has fished for large-mouth black bass -among the cypress trees and the bonnets of water hyacinth, -and seen the bass strike savagely at surface lures as soon -as they hit the surface, it comes as no surprise to find they -strike at, and catch, such birds as Maryland yellow-throats -that flutter across close to the surface of the water.</p> - -<p>Young ducks, too, are good game to the large-mouth, -and probably many a young duck finds its way into the -maw of a bass. On a pond where bass had taken many -young ducks I heard a story of a fisherman who made a -floating model of a mother duck, powered it with a propeller, -and attached to it by lines of various lengths several -floating models of downy ducklings. In each duckling was -concealed a hook. The whole flotilla was set afloat, and -drifted across the pond. Mother steamed ahead, with -young following. Soon the bass, used to a duck diet, began -to grab the ducklings. When the model was retrieved -several large bass were taken.</p> - -<p>In Northern waters, where Northern pike, or jackfish, -as they're called in the North, abound in duck-nesting -waters, pike are accused of eating enough ducklings to -affect the survival of the broods. Many a marshland traveler -has reported young ducks and young grebes diving, -to be seen no more. He's blamed the pike. Sometimes -perhaps the young bird has simply come up unobserved. -But enough pike's stomachs have proved to have young -ducks in them to demonstrate pike do eat ducklings. -Strangely, in some areas, pike eat many ducklings; in -others they do not eat them. But it's not alone young birds -or small birds that get eaten by fish.</p> - -<p>A twenty-four-inch bass is recorded as having been -<span class="pagenum" id="Page_97">- 97 -</span> -caught while it still had the legs of a full-grown coot -projecting from its mouth. From beak to tip of its outstretched -legs the coot measured seventeen inches and it -weighed one and one quarter pounds.</p> - -<p>Angler fish weighing between forty and fifty pounds -have been found to have eaten birds. One had the band -from a Manx shearwater in its stomach, and another had -an adult American merganser. In tropical and subtropical -seas the examination of birds seemed to indicate they had -been attacked by some fish and seized by the feet, but -were able to escape, and a white-winged black tern off -Corsica has been seen to disappear under the water, presumably -dragged under by a fish.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_98">- 98 -</span></p> - -<h2 class="nobreak tdl2" id="CROWS_ARE_SMARTER_THAN_WISE_OWLS">CROWS ARE SMARTER THAN "WISE" OWLS <span class="ref"><a href="#ref_26">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_98" style="width: 281px;"> - <img src="images/098.png" width="281" height="218" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he owl</span> has always been considered the symbol of -wisdom. The old saying has it that "fine feathers don't -make fine birds," but I'm afraid that the owl has taken -in people with its appearance. The owl's reputation for -wisdom seems to be based on a staid, impressive appearance -combined with an inarticulate disposition. Though -owls do at times make a great deal of noise, hooting, -shrieking, and whistling, much of the time the owl sits -quietly looking wise and saying nothing. But owls don't -seem to have much behind the front they put up. People -who have studied them find the young are very slow to -learn to feed themselves, and one saw-whet owl that was -<span class="pagenum" id="Page_99">- 99 -</span> -kept captive refused to eat liver put into its cage, apparently -not recognizing the meat as food. But when the liver -was stuffed into an empty mouse skin the owl at once ate -it. One might conclude that the owl was the original -"stuffed shirt."</p> - -<p>The crows and their relative, the jays, are the birds -that are really intelligent. They are active and usually -have little trouble getting enough to eat. They have an -abounding curiosity that leads them to spend their time -investigating things and getting new experiences. And -they seem to profit by these experiences, too.</p> - -<p>The following is how three ravens co-operated in getting -a bone from a dog, as written by B. J. Bretherton:</p> - -<p>"He was espied by a raven who flew down and tried to -scare the dog by loud cawing, in which he was shortly -afterwards assisted by another, both birds sidling up to -the dogs head until they were barely out of his reach. -Just at this time a third raven appeared on the scene and -surveyed the situation from an adjacent fence, but soon -flew down behind the dog and advanced until within reach -of his tail, which he seized so roughly that the dog turned -for an instant to snap at him, and at the same moment -the bone was snatched away by one of the ravens at his -head."</p> - - -<p class="pmt2"><span class="allsmcap">CROWS LEARN FROM OTHERS</span> Crows have been recorded -as profiting by the experience of one of their numbers. -In Washington, when almonds were ripening in the -almond orchards and crows were swarming there threatening -to destroy the nut crop, an estimated 30,000 crows -were involved and the destruction of an $800 crop was -<span class="pagenum" id="Page_100">- 100 -</span> -complete in two days. Various methods of control were -tried unsuccessfully. Finally some almonds were slit open, -poisoned, and scattered about in the orchards. Very few -crows were actually poisoned, not exceeding 1 per cent of -the flock. The first reaction of the crows when one of their -number was poisoned was one of extreme panic. There -was tumultuous clamoring and confusion. Then the flock -abandoned the attempts to feed on almonds and left the -area completely. Here we have a case of superior intelligence, -birds profiting by the sight of a few of their numbers -being poisoned fleeing the area and so escaping being -poisoned themselves.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_101">- 101 -</span></p> - -<h2 class="nobreak tdl2" id="TAME_WILD_BIRDS">TAME WILD BIRDS <span class="ref"><a href="#ref_27">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_101" style="width: 294px;"> - <img src="images/101.png" width="294" height="210" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">W</span>e think</span> of wild birds as being shy creatures by nature. -For those of us who have kept a feeding station for birds -in the winter so as to have the pleasure of association with -the chickadee, nuthatches, woodpeckers, and other visitors, -one of the most attractive things is that the wild -birds become tame. Through association with persons they -gradually learn that human beings are not to be feared. -The high point of many a bird lover's experience is when -a chickadee becomes so tame that it will perch on his body -and without fear will feed from his hand.</p> - -<p>It seems to be true that birds in wilderness areas are -wilder and more shy of men than those living about dwellings -<span class="pagenum" id="Page_102">- 102 -</span> -where they are protected. This is notably true of -the robin. In villages they hop around on the ground unmindful -of the near presence of humans. How different -they are in the wilderness, where the robins fly away apparently -in great fear, while the human intruder is still -far distant.</p> - -<p>It comes as a considerable surprise to find that here and -there over the world there are instances of birds with so -little fear of humans that they come and perch on them.</p> - - -<p class="pmt2"><span class="allsmcap">PERCHING ON PEOPLE</span> In the Galápagos Islands, -where the general fearlessness of birds is famous, one of -these cases is recorded. David Lack, who was studying the -biology of the Galápagos Islands' birds, found when walking -through the woods on Indefatigable Island that a flycatcher -would sometimes try to settle on his head. Lack -stood still and found the bird's object was to pull out -some of his hair. The bird, having failed to detach any of -the hair of his head, tried, apparently with no better success, -to pull out hair from his eyebrows and then from his -chest. This was at the height of the breeding season and -apparently the bird was trying to get nesting material. -This seemed to be a usual type of behavior there, and -Lack correlated it with the general tameness of the birds -on the islands.</p> - -<p>There is a honey eater in Australia that includes in its -pattern of behavior perching on people's heads and shoulders -and attempting to pull out hair for use in its nest. -A. H. Chisholm writes of going to certain places and taking -companions with him for the sake of experiencing this, -and the practice is so common with the species that Australians -<span class="pagenum" id="Page_103">- 103 -</span> -refer to this honey eater as "the hair dresser." In -this case it is not tameness alone. The white-eared honey -eater, which indulges in this practice, is no more tame -most of the time than any of the other small local birds -that live in that part of Australia. Only at nesting time -does it attempt to light on persons. Chisholm correlates -this hair-plucking trait with other habits of the honey eater: -he speaks of its gathering hair from such animals as rock -wallabies and gathering bristles from farmyard pigs and -goats.</p> - -<p>Our familiar phoebe has been recorded as perching on -deer hunters in the fall and using them as a vantage point -from which to conduct its hunting. This was in North -Carolina, and the weather being warm, mosquitoes were -notably in evidence. The bird showed no sign of fear or -nervousness, but perched on the hunter's gun, on top of -his head, and various parts of his body, and then flew out -and picked up mosquitoes. As the hunter's face seemed to -be attracting more mosquitoes the phoebe directed his attentions -there. In picking mosquitoes off his face the sharp -points of the bird's bill were noticeably felt at every capture -and the irritation caused by a succession of these -pricks caused the hunter to decide that he could take care -of the mosquito situation better without the help of the -phoebe. As H. H. Brimley, the hunter, put it "... my face -was beginning to feel somewhat inflamed from the frequent -pecks to which it had been subjected so I called it -a day and told the phoebe to stop pestering me." This -took place in a wild part of North Carolina and Brimley -suggested that the phoebe's abnormal lack of fear was -caused by its having never seen a human being before.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_104">- 104 -</span></p> - -<h2 class="nobreak tdl2" id="BIRDS_AS_PILFERERS">BIRDS AS PILFERERS <span class="ref"><a href="#ref_28">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_105" style="width: 293px;"> - <img src="images/105.png" width="293" height="204" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">P</span>ilfering</span>, or petty theft, is one of the less desirable but -very human attributes of our race. But it's also pretty -widespread in the animal kingdom. Theft as the usual -thing is practiced by only a few birds. But when it's a case -of petty theft, happening now and then, it is common -enough in the bird world. It's not restricted to any group -of birds, but may crop up almost anywhere. There's no -threat or fight about it usually. The bird, which gets its -food by means of the acuity of its vision and the quick -co-ordination of its movements with the recognition of its -food, sees the food in another bird's possession and just -goes up and takes it. Sometimes the food is taken from a -<span class="pagenum" id="Page_105">- 105 -</span> -larger and stronger bird, an achievement accomplished by -audacity, agility, and quickness. A sparrow hawk, that inoffensive -little rufous-red falcon that spends most of its -time catching grasshoppers, was sitting on a telephone -wire holding a small mammal it had caught, apparently -about to devour it, when a loggerhead shrike sitting nearby -flew straight to the hawk, seized its prey, and made off, -leaving the hawk sitting there, apparently dumfounded by -the audacity and success of the attack. A case in which the -pilfering caused a mild fuss involved an English kingfisher -and a dipper. The kingfisher lit above a pool where a dipper -was feeding, obtaining food in the pool and bringing -it ashore to eat it. When the dipper next came ashore the -kingfisher flew down, there was a momentary scuffle, and -the dipper departed, leaving its food to the kingfisher, who -promptly ate it. Despite this occurrence the dipper allowed -itself to lose its prey again before it left, and the kingfisher -presumably had to resume fishing for itself.</p> - - -<p class="pmt2"><span class="allsmcap">THEFT NOT RESENTED</span> It is sometimes surprising -that this pilfering, when it occurs over and over again, is -not actively resented, particularly when the pilferer is a -smaller bird. Some of the thrushes are especially docile -when they're victimized. Sometimes when American robins -are feeding on the ground, house sparrows hop along with -them, and when the robin finds a worm the sparrow hops -up quietly and boldly takes the worm from the robin with -scarcely a protest from the victim. One robin is reported to -have been robbed six times, of six worms, one right after -the other by a small flock of sparrows while the robin continued -to hunt for worms.</p> - -<p><span class="pagenum" id="Page_106">- 106 -</span></p> - -<p>The starling, an aggressive Old World species introduced -and very successful here, also victimizes the American -robin. In one case a starling made four successful raids in -five minutes, the robin not attempting to fight or defend its -food, but simply moving off a little way and continuing to -hunt for worms while the starling waited nearby.</p> - -<p>This is not a new trait of the starling, for in its Old -World home, in Britain, it has been seen to victimize -blackbirds and song thrushes (relatives of our robin). -This happened when a blackbird pulled up a worm, a -starling flew to the spot, and the blackbird moved away, -leaving the worm to the starling. This method of obtaining -worms was sometimes used by all the starlings on a lawn -where both species were feeding, much to the hindrance -in the feeding of both blackbirds and song thrushes.</p> - -<p>Gulls have been recorded as snatching fish from mergansers -that had caught fish by underwater dives and -brought them to the surface to eat. Gulls also follow pelicans, -and just after the pelican has completed its plunge -and before it can swallow the fish protruding from its bill, -a gull may flutter in, alight on the water or even on the -pelican's head, and seize the fish. The pelican does not -attempt to do anything about it, but accepts the pilfering -with stoic calm.</p> - -<p>Grackles victimizing ibises seems perhaps the strangest -of the whole series of reports. The ibis often attempts to -elude the grackles but without success. About Lake Okeechobee, -Florida, where ibis are common, they feed largely -on crayfish, which they secure by probing the holes made -by these creatures. Grackles swarm there, and, on occasion, -no sooner does an ibis seize a crayfish than one to four -<span class="pagenum" id="Page_107">- 107 -</span> -grackles try to secure it. The ibis may take flight and attempt -to escape with its prey, but one of the grackles -usually gets the crayfish away from it.</p> - -<p>Possibly some of these birds are on their way to becoming -habitual pilferers, in which such social parasitism is a -fixed mode of life. With evolution, if this thieving benefits -the species that snatch the food, it may become a usual -habit. For habits, like structures, are subject to variations, -to selection, and thus to change and elaboration.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_108">- 108 -</span></p> - -<h2 class="nobreak tdl2" id="HIBERNATION_IN_BIRDS">HIBERNATION IN BIRDS <span class="ref"><a href="#ref_29">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_108" style="width: 263px;"> - <img src="images/108.png" width="263" height="205" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">N</span>ot until</span> 1948 did the scientific world have satisfactory -evidence that any bird hibernated. True, it was an established -fact that sometimes in cold weather some birds, -notably swifts and hummingbirds, might become torpid -for a short time, but this was not hibernation.</p> - -<p>The early literature, of more than a century ago, contained -many accounts, some claiming to be firsthand, of -birds hibernating. Swallows in particular were reported as -seen to submerge in ponds in the autumn. Numbers of -them were said to have been found hanging to submerged -willow branches apparently sleeping the winter away. -When ponds were drained in winter, sometimes swallows -<span class="pagenum" id="Page_109">- 109 -</span> -were said to have been found buried in the mud, revived, -and upon occasion kept alive indoors until the spring. -Sometimes slime-covered swallows, evidently just out of -hibernation, were reported found in the spring. Swallows -were the most commonly recorded, but other species, too, -were mentioned as hibernating, such as the cuckoo that -shed its feathers and crept into a crevice to sleep away -the winter.</p> - -<p>Such accounts gradually disappeared from the literature. -We can accept none of them. The old records of underwater -and also the featherless hibernation of birds must -be discarded. The occasional torpidity, in cold weather, of -swallows, swifts, and hummingbirds is another matter, and -appears to be of sporadic though not common occurrence.</p> - - -<p class="pmt2"><span class="allsmcap">FROGS MISTAKEN FOR BIRDS</span> It is interesting to -speculate as to how the old "firsthand" accounts originated. -They had certain basis of fact. The first was that swallows -were seen flying about in summer. They disappeared in -winter. Aristotle claimed they hibernated, in a featherless -condition, so there was nothing unusual in seeing them -that way. Observation was less critical, and it is probable -that frogs from the mud of ponds were mistaken for naked -swallows, and perhaps bats, which do hibernate, taken -from caves or hollow trees, were also mistaken for swallows.</p> - - -<p class="pmt2"><span class="allsmcap">AN AUTHENTIC RECORD</span> In 1948, and again in 1949, -Edmund C. Jaeger, of California, published accounts of a -poor-will he found hibernating. This was the first acceptable -evidence that such a thing occurs. In a little cavity in -<span class="pagenum" id="Page_110">- 110 -</span> -the wall of a canyon in the Chuckawalla Mountains of the -Colorado desert in California, Jaeger found a poor-will in -a state of profound torpidity in December, 1946. He could -pick out the bird in his hand, examine it and put it back -in the little cavity it occupied without eliciting more than -a slight movement of its eyelids. On a later occasion handling -it revived it somewhat.</p> - -<p>The next winter Jaeger found a poor-will, perhaps the -same bird, hibernating in the same niche. Over a period of -eighty days, from November 26, 1947, to February 14, -1948, he visited it periodically, examined it, and took its -temperature. The body temperature was low, 64°-68° F., -compared with more than 100° F. of an active bird; with -a medical stethoscope he could detect no heartbeat, and -a cold metal mirror held directly in front of its nostrils -collected no moisture from its breathing. The body processes -were evidently very low. The bird was banded for -identification, and in the third winter the same bird wearing -the same band was found to have returned to hibernate -again in the same rock niche. But on subsequent visits it -was missing—perhaps having lived out its allotted span, -perhaps the prey of some predator.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_111">- 111 -</span></p> - -<h2 class="nobreak tdl2" id="SNAKESKINS_IN_BIRDS_NESTS">SNAKESKINS IN BIRDS' NESTS <span class="ref"><a href="#ref_30">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_111" style="width: 278px;"> - <img src="images/111.png" width="278" height="178" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>here are</span> occasionally discovered behavior patterns of -birds that are so unusual as to make one stop and wonder. -They are unusual for birds generally, but in a species here -and there they are the regular thing. Such is the placing of -a shed snakeskin in their nests by some birds.</p> - -<p>A bird like the English sparrow, or the road runner, -which uses a variety of material coarse or fine, would be -expected to use shed snakeskins occasionally, as it came -across them. But there are a number of species that seem -to use snakeskins regularly in their nests. It would seem -that the birds deliberately sought out the skins for this -purpose, as though they were as much a part of the nest as -the mud in the bottom of a robin's nest or the fresh green -<span class="pagenum" id="Page_112">- 112 -</span> -grass heads ornamenting the entrance to some weaverbirds' -nests.</p> - - -<p class="pmt2"><span class="allsmcap">SOME HABITS BAFFLING</span> I have long since given up -thinking that every aspect of a bird's life must serve a -useful purpose. Indeed I have already pointed out some -definite maladaptations. But usually every type of behavior -has a logical origin. By considering its occurrence in various -species and against the background of the bird's -everyday life some correlations usually can be found.</p> - -<p>The list of birds habitually using snakeskins in their -nests is short, as follows:</p> - -<p>1. Great-crested flycatcher—belonging to the New -World flycatchers, breeding in Eastern North America and -nesting in holes.</p> - -<p>2. Arizona crested flycatcher—a relative of the great-crested -variety, with similar habits.</p> - -<p>3. Blue grosbeak—an American member of the sparrow -family, making an open nest in bushes.</p> - -<p>4. Black-crested titmouse—a member of the chickadee -family, living in Western North America and nesting in -holes.</p> - -<p>5. Bank mynah—a starling, living in southern Asia and -nesting in holes in banks.</p> - -<p>6. Rifle bird—an Australian bird of paradise, making a -cup-shaped nest in trees.</p> - -<p>7. Madagascar bulbul—making a cup-shaped nest in -trees.</p> - - -<p class="pmt2"><span class="allsmcap">LIKE A DECORATION</span> Twenty or more other species -of birds have been recorded as using snakeskins more or -<span class="pagenum" id="Page_113">- 113 -</span> -less commonly, or occasionally perhaps on the basis of -availability or of chance. But with the above they're an -essential part of the nest. In some of the species the snakeskins -are arranged as a rim around the edge of the nest -almost as a decoration; sometimes the snakeskins may -make up most of the nest.</p> - -<p>Now as to possible correlations. The species are not -closely related. Except for the two flycatchers the other -five represent five different families. The distribution over -the world is wide, too: America, Asia, Madagascar, Australia. -Various explanations for the behavior have been -advanced. It has been suggested that it's correlated with -hole nesting, but three of the seven do not nest in holes. -The most common theory is that it's to frighten away -possible predators by making them think there is a snake -in the nest. However, this is not very likely, and, too, one -wonders why the birds that use the snakeskins are not -frightened themselves. Indeed, one writer, surely not seriously, -has suggested that the fright in early life of crested -flycatchers at finding a snakeskin in the nest accounts for -the upstanding crest in this species!</p> - - -<p class="pmt2"><span class="allsmcap">"BURGLAR ALARM" THEORY</span> Another suggestion is -that the snakeskin, by the rustling noise it makes when -touched, acts as an alarm bell or a burglar alarm to warn -the rightful occupants of the nest when an intruder approaches. -This also seems a rather weak explanation.</p> - -<p>We are left, then, with the fact that this curious habit -has been developed in a few birds, not closely related, that -live in various parts of the world and that have very different -<span class="pagenum" id="Page_114">- 114 -</span> -habits. It is usual with them. A number of others -occasionally have this habit.</p> - -<p>My first clue as to the proper background against which -to solve this habit came when, unpacking a bird collection -made in Borneo by curator of anatomy D. Dwight Davis, -I took out a bulbul's nest. In its outer edge were flat, -weathered leaves that resembled snakeskins. Later, when -we received a bird collection from Dr. D. S. Rabor of the -Philippines there was a nest of another species of bulbul -and this too had flat, dead, weathered leaves in it that -looked like snakeskin. When I was in Madagascar, in 1929-31, -I had found three nests of the Madagascar bulbul with -a snakeskin used in each. Here was a clue. I decided to -investigate the nests of the other species of bulbuls of -southern Asia and Africa where the family is represented -by many species. By considering the snakeskin-using -species against the background of the nesting of the other -species some correlation might appear.</p> - - -<p class="pmt2"><span class="allsmcap">BOOKWORK</span> This became a library problem at once. I -had to look up the earlier reviews of the problem in the -ornithological journals, <i>The Auk</i> and the <i>Ornithologische -Monatsberichte</i>, then in Strong's <i>Bibliography of Birds</i>, to -make sure that no important papers were missing from my -own subject file. Stuart Baker's <i>Fauna of British India, -Birds</i> had a large part of one volume devoted to bulbuls, -and gave excellent summaries of the nidification of each -species occurring there. Bannerman's <i>Birds of Tropical -West Africa</i> covered the western part of that continent, -and Jackson's and Sclater's <i>Birds of Kenya Colony</i> did the -same for the eastern part. For collateral material I looked -<span class="pagenum" id="Page_115">- 115 -</span> -in Mathews' <i>Birds of Australia</i>, Volume 12, Forbush's -<i>Birds of Massachusetts</i>, and Mrs. F. M. Bailey's <i>Birds of -New Mexico</i>, and a dozen minor publications.</p> - -<p>But it was worth it.</p> - -<p>Perhaps my earlier thinking was dominated by the -thought that the shed snakeskins had been parts of animals -toward which many birds show an antipathy. But it's extremely -probable a bird does not recognize the snakeskin -as such. Rather to it the shed snakeskin is a strip of thin, -flexible material. Obviously it would be used, by chance, -by many bird species, such as the house wren, which, in -addition to using such natural materials as twigs, grass, -and hair, has been recorded as using lead pencils, paper, -nails, safety pins, and snakeskins in its nest.</p> - -<p>As to the regular users of snakeskin, the snakeskin-using -Madagascar bulbul did fit into a pattern. Bulbuls in general -make characteristic simple cup nests. Some species -use almost any available material. But quite a few species -had specific choices of materials: one species' nest had -tendrils of vines in its base; another a lining of grass heads -of a certain color; another pine needles; another red dead -leaves; and the Madagascar bulbul snakeskins.</p> - - -<p class="pmt2"><span class="allsmcap">A SOLUTION</span> There seems to be a tendency for many -species to make distinctive nests. They often accomplish -this by a choice of material used by few or no other -species. What more natural than that one species, being in -a country where snakes are common, should hit on shed -snakeskins!</p> - -<p>To show that the choice of snakeskin as nesting material -is an expression of a tendency for each species of bird to -<span class="pagenum" id="Page_116">- 116 -</span> -make a different kind of nest may not be much of an answer. -But it is to an extent. No longer do we say, "Why -are certain birds' nests characterized by snakeskins?" -Rather we have the broader, more general question, "Why -does each kind of bird tend to build a nest different from -that of every other kind?" Thus, little by little, we clear -away small, vexing questions and resolve them into larger, -more general questions. For answers to these we sometimes -plan extended work involving field studies, studies -of specimens, and books. And sometimes, as we examine a -specimen, read a paper, or unpack a shipment, an answer, -or at least a clue, springs to our mind.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_117">- 117 -</span></p> - -<h2 class="nobreak tdl2" id="CO-OPERATION_BY_BIRDS">CO-OPERATION BY BIRDS <span class="ref"><a href="#ref_31">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_117" style="width: 286px;"> - <img src="images/117.png" width="286" height="207" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he importance</span> of co-operation, contrasted with competition, -has assumed increased importance in discussions -of evolution, as it has in discussions of human social progress. -Co-operation in nature is of various kinds; from the -manner in which a forest shelters the squirrel to the -manner in which two or more individuals of one species -work together for a common object. The working together -of two birds to rear a family is so well known an affair that -one forgets that it is an example of co-operation, not only -in building the nest and brooding and feeding the young, -but also in defending the nest and the young.</p> - -<p>Sometimes more than one species will join in ousting an -<span class="pagenum" id="Page_118">- 118 -</span> -enemy. For example, when a cat caught a young robin, recently -out of the nest, the parents, in their frantic effort to -make the cat release the bird, attracted the attention of -another robin and a pair of cardinals nesting nearby in a -honeysuckle. All five birds dived at the cat, screaming and -pecking it so vigorously that it released the young robin -and fled.</p> - - -<p class="pmt2"><span class="allsmcap">EAGLES JOIN EFFORTS</span> More spectacular are some -of the co-operative activities of birds in food getting. Bald -eagles sometimes feed on ducks. Frequently two eagles -may combine their efforts. The two birds may work together -to force a black duck from the air onto the water, -and when they are trying to catch a diving duck, they -much more quickly exhaust their prey by swooping at it in -turn. Bald eagles sometimes take water birds too large for -them to carry, and then they must flap along dragging -their prey on the surface of the water to the nearest shore. -On one occasion an eagle dragging a large cormorant -ashore was joined by two other birds, and all three took -turns in dragging it. When they got it ashore, all three -shared it.</p> - -<p>Several fish-eating birds co-operate in capturing their -prey. "The merganser is primarily a fishing duck ... -very skillful and a voracious feeder. It pursues underwater -and catches successfully the swiftest fish. Often a party of -sheldrakes may be seen fishing together, driving the panic-stricken -fish into the shallows or into some small pool -where they may be more easily caught," according to -A. C. Bent.</p> - -<p>When a school of fish approached a flock of white pelicans, -<span class="pagenum" id="Page_119">- 119 -</span> -the birds suddenly assumed a circular position, surrounding -the school. All the pelicans moved slowly but -cautiously toward the center of the circle, their heads near -the surface of the water or partly submerged and their -necks slightly extended. The birds moved in perfect -unison, making the circle progressively smaller, ready to -engulf their helpless victims at the first opportunity. When -all the pelicans were close to the fish, the birds made rapid -jabs at the fish and apparently consumed a large number -of them. It appeared that every bird got from one to several -fish.</p> - - -<p class="pmt2"><span class="allsmcap">13,000 BAND TOGETHER</span> Avocets and, to a lesser -extent, the black-necked stilts also band together for co-operative -drives on small fry and aquatic insects. Such -drives are made in water of wading depth. Instead of -forming circles the birds present compact spearhead and -wedge formations and sweep the bottom muck with the -characteristic back-and-forth side movements of their long -bills. As many as 13,000 avocets have been observed taking -part in such co-operative feeding projects.</p> - -<p>Another striking example is furnished by black vultures -observed by E. A. McIlhenny. A three-quarters-grown -skunk was wandering across a field. A vulture alighted -near the skunk which immediately stopped and raised its -tail. Other nearby vultures joined the one nearby the -skunk, and when six or eight of them had gathered one -suddenly attacked it. The skunk immediately discharged -its defensive scent, but without effect, for the vultures attacked -in a mass and other vultures circling above joined -in until there were probably twenty-five or more around -<span class="pagenum" id="Page_120">- 120 -</span> -the skunk. With much flapping and croaking, the vultures -pulled it about until it was dead, and then devoured it.</p> - -<p>On another occasion a black vulture came from high in -the air to alight near two full-grown opossums following -a narrow cattle trail. The first vulture was almost at once -joined by many others until there were probably between -seventy-five and one hundred black vultures following the -opossums. Suddenly three or four of the vultures attacked -and the others joined in. Quickly both opossums were covered -with a swarm of hissing, flapping birds, and within -fifteen minutes there was nothing left of them but the -larger bones and the hides, and these were stripped of -every vestige of flesh.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_121">- 121 -</span></p> - -<h2 class="nobreak tdl2" id="WATCHDOGS_AT_THE_NEST">WATCHDOGS AT THE NEST <span class="ref"><a href="#ref_32">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_121" style="width: 281px;"> - <img src="images/121.png" width="281" height="220" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">A</span> savage watchdog</span> outside his master's house helps to -protect it. If an intruder comes, the watchdog, if it's the -right kind, simply bites him without preliminaries. There's -a parallel to this in the bird world. Some birds often have -their nests close to wasps' or bees' nests, or in trees inhabited -by biting ants. The birds and the ants, wasps, or -bees get along without disturbing each other. But when -intruders come along the insects swarm out, biting or -stinging and driving the intruder away. The insects are -protecting their own homes, but one of the results, the -protecting of the birds' homes, is just as satisfactory to the -birds as if they did it on purpose. This building of birds' -<span class="pagenum" id="Page_122">- 122 -</span> -nests close to wasps' nests is a common practice with certain -sunbirds and weaverbirds, especially in Africa. It occurs -too often to be chance. The question naturally arises -as to how much the birds understand of it all—do they -actually seek out the association? That's difficult to say, -but the facts of the association are still there.</p> - -<p>Though some of these associations are evidently fairly -common and chosen deliberately by the birds—and one -can easily visualize how the protection works—field observations -as to the natural enemies against which they -are effective, and how effective they are, are largely lacking. -Usually the records are something like those of Van -Rossem for the Giraud's flycatcher in El Salvador, in -which he points out that this bird usually nests in certain -mimosa trees armed with numerous heavy, curved thorns. -These thorns are hollowed out and inhabited by swarms -of small but extremely hostile antlike insects, so that the -nest is well protected. However, the effectiveness of ant -and bee protection against human predation can be seen in -the following.</p> - -<p>Take the case of Mr. M. E. W. North, who arranged a -rope to climb to a fish eagle's nest in East Africa. He had -gotten about fifty feet up and was considering going out -on the big limb on which the nest was, when he noticed a -wild bee on his sleeve. Realizing that he was disturbing a -wild-bee hive, and knowing that the sting of these vicious -bees can be dangerous, fatalities having been reported, he -came down his rope at express speed, crashing through -projecting branches and brambles. Reaching the ground, -he freed himself from the rope and fled to a safe distance, -<span class="pagenum" id="Page_123">- 123 -</span> -considering himself lucky to have received only three -stings.</p> - -<p>On another occasion, again in East Africa, Mrs. R. E. -Moreau attempted to reach a hawk's nest to measure the -eggs, but when she was up in the tree, savage, biting red -ants drove her out.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_124">- 124 -</span></p> - -<h2 class="nobreak tdl2" id="BIRD_GUIDES_TO_HONEY">BIRD GUIDES TO HONEY <span class="ref"><a href="#ref_33">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_124" style="width: 295px;"> - <img src="images/124.png" width="295" height="222" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>n Africa</span> there are birds which lead men to honey. They -are called honey-guides and their family name, Indicatoridae, -has the same idea incorporated into it. Though -there are several species of these small, dull-colored birds, -which are related on the one hand to woodpeckers and -on the other to barbets, it is only one species, the common -or black-throated honey-guide that is well known as a -guide to honey.</p> - -<p>The traveler in the country may find one of these birds -chattering and flying ahead of him. The natives, who know -this bird well and favorably will tell the traveler to follow; -it will lead to a bee tree. The native, as he follows this -<span class="pagenum" id="Page_125">- 125 -</span> -guide, gives occasional whistles, as if to encourage the -bird. The bird continues, flying from perch to perch, -ahead, and chattering noisily. Sometimes it may return to -see if the men are following; sometimes it remains chattering -on its perch until the followers catch up. Finally the -bird will go no farther. It flies about aimlessly and allows -one to approach closely. This is the spot. In a hole in the -tree trunk, or in the ground nearby the bees' nest is to be -found.</p> - -<p>When the beehive is opened, and the honey taken, the -honey-guide will eat the comb that is left, and apparently -it is for this that the complicated behavior of leading of -man to the beehive is developed.</p> - -<p>Wax of the honeycomb is a usual food of this species, -judging by stomach examinations, and one wonders how -they get it when man is not about to open the bee trees -for them. The birds have no special adaptation for getting -into the hives; indeed their only apparent adaptation for -this habit is a thick skin, perhaps a protection against bee -stings. Perhaps, as has been suggested, other animals, -squirrels, monkeys, or honey badgers may unwittingly -aid them by opening up bee trees for their own purposes -and allow the honey-guides to snatch food for themselves.</p> - -<p>An amusing side of the picture is that sometimes the -honey-guides may lead the honey hunter to a beehive -owned by a native.</p> - -<p>There are also records of the honey-guide leading men -to big game: leopard or lions. That this occurs is amply -documented, but one wonders whether or not this was -<span class="pagenum" id="Page_126">- 126 -</span> -accidental; the honey-guide leading the way to honey perhaps -by accident leads the way past the resting place of -one of these big cats so that the man stumbles over the -big game and perhaps gets the impression he was led to -the animal.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_127">- 127 -</span></p> - -<h2 class="nobreak tdl2" id="OXPECKERS">OXPECKERS <span class="ref"><a href="#ref_34">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_127" style="width: 284px;"> - <img src="images/127.png" width="284" height="206" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he lives</span> of oxpeckers are so linked to those of large, -hoofed game or domestic cattle that in West Africa where -game is scarce the birds depend on cattle, and their range -is restricted accordingly. There the cattle are confined -to the higher and more northern areas, free of tsetse flies, -from Senegal to Northern Cameroon. Thus tsetse flies help -to determine the limits of the oxpeckers' range.</p> - -<p>Except for their nesting, which is in holes in trees, and -their sleeping, most of their time is spent on the bodies of -the larger herbivores. There they run about over the hides -and legs of the beasts, like woodpeckers on a tree. They -stay remarkably close to the animals, and even ride on -<span class="pagenum" id="Page_128">- 128 -</span> -them as they travel. The oxpeckers' food is largely ticks, -which it gets from the hide of the animal by working over -it with the side of its bill, shearing off the ticks with a -scissorlike action of its mandibles. But when an animal has -sores or cuts or scratches the oxpecker may peck into them, -and eat flesh and blood of its host.</p> - -<p>Correlated with this unusual and close relationship, a -modification in the oxpeckers has taken place. There are -only two species, both African, and they are dull-colored, -modified starlings. The legs are stout, with curved, very -sharp claws for clinging to the hides of animals, and the -bill, very sharp at the tip, with the cutting edge of the -mandible very sharp to aid in scissoring off ticks.</p> - -<p>All the larger herbivores are attended by oxpeckers except -the elephant and the hippo, but the favorite seems to -be the rhino, and for this he's sometimes called the rhino -bird as well as tickbird and oxpecker. The rhino gives the -bird its food, and in return the bird provides a service of -a value difficult to evaluate. It acts as a sentinel and may -warn the rhino of the approach of hunters, for which habit -it is execrated by sportsmen.</p> - -<p>It would seem that such relationships could have developed -only where the supply of big game was large. -With the introduction of cattle and other domestic animals -it was natural the oxpecker should turn its attention to -them. Here the question arose as to the attentions of the -oxpeckers being harmful or otherwise to the herds. Mr. -R. E. Moreau, formerly of the East African Research Station -at Amani, has investigated the problem. He finds that -white men who own herds tend to consider the oxpecker -a nuisance; Africans tend to consider it beneficial and -<span class="pagenum" id="Page_129">- 129 -</span> -some African cattle owners object to having the birds -killed; the beasts themselves tolerate the birds.</p> - -<p>There is the possibility on the one hand of oxpeckers -spreading certain cattle diseases that are mechanically -transmitted, and on the other hand they may help reduce -disease by eating ticks, the vectors of certain diseases. Of -course dipping the cattle takes care of ticks on them, and -here we see another indirect effect of civilization on bird -life. When cattle have been dipped the oxpeckers disappear -from the herd. Perhaps it is because there is no longer -food for them there; perhaps they get enough of the -poison dip left on the beasts' hair to be lethal.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_130">- 130 -</span></p> - -<h2 class="nobreak tdl2" id="WINGS_IN_FEEDING">WINGS IN FEEDING <span class="ref"><a href="#ref_35">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_130" style="width: 272px;"> - <img src="images/130.png" width="272" height="206" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he obvious adaptation</span> of a bird's wings is for locomotion; -to fly in the air. It is true that some few birds are -flightless, and some like the penguins use their wings for -underwater swimming, but this does not spoil the generalization.</p> - -<p>Secondary uses, some with special adaptations, occur: -the owl at bay spreads its wings wide, with the effect of -increasing its apparent size and being more terrifying to a -predator. The young bird, begging to be fed, flutters its -wings in a characteristic way, and the female, in some of -her mating behavior, may also flutter her wings like those -of a young bird.</p> - -<p><span class="pagenum" id="Page_131">- 131 -</span></p> - -<p>In courtship the wings may play an important part in -display. In the Australian rifle bird they are held out, fully -spread on each side of the bird like a velvet curtain against -which the vivid iridescence of the throat patch stands out -more vividly. The argus pheasant has the inner secondaries -greatly elongated and ornamented in a fashion recalling -the decoration of a peacock's tail and these he spreads to -show in his courtship, while the ruffed grouse uses his -wings to make instrumental music, his drumming.</p> - -<p>Wings in geese and swans may be used in fighting, and -tame birds may severely buffet humans who take too close -an interest in their young. In the related screamers of -South America the bend of the wing is equipped with -long, very sharp spurs, which undoubtedly make formidable -weapons in fighting.</p> - -<p>In addition wings are used in at least three different -ways in feeding. The red-tailed hawk may spread its wings -as it sits on its prey, perhaps a behavior adapted to help -the bird maintain its balance when dealing with struggling -prey, perhaps to help smother the struggles of its -prey.</p> - -<p>The secretary bird of Africa is said to feed on snakes, -poisonous and non-poisonous ones, and is said to use its -huge wings as shields for its body in attacking them.</p> - -<p>But the strangest use of wings in feeding is that practiced -by a blackish African heron. In feeding in shallow -water it takes a few rapid steps, apparently to bring it -within reach of fish it has sighted, then spreads its wings, -bringing them forward until they meet, and with the tips -of the quills in the water. The head is in the canopy -<span class="pagenum" id="Page_132">- 132 -</span> -formed by the wings, and apparently it is here under this -canopy that the fish on which it feeds are caught. The suggestion -as to the correlation that presents itself is that the -dark canopy thrown over the fish confuses them and makes -them easier to catch.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_133">- 133 -</span></p> - -<h2 class="nobreak tdl2" id="INSTRUMENTAL_MUSIC_OF_BIRDS">INSTRUMENTAL MUSIC OF BIRDS</h2> -</div> - -<div class="figcenter" id="img_133" style="width: 282px;"> - <img src="images/133.png" width="282" height="204" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">V</span>ocal music</span> bulks large in our avian springtime chorus, -but don't overlook the instrumental music that accompanies -it. The drumming of the downy woodpecker on the -dead limb of a maple near my bedroom window is as much -a part of my spring as is the cheery cheerup of our robin. -It's not that woodpeckers are voiceless that they drum. -The flicker can be called in with his particularly rich -repertoire to repudiate it vociferously. All day the downy -woodpecker goes about pounding his head against tree -trunks, with his bill chiseling out wood-boring insects to -eat. What more natural when springtime comes and he -wants to tell the world, and especially other woodpeckers -<span class="pagenum" id="Page_134">- 134 -</span> -about it, to select a dead limb with a nice tone in my -maple tree and hammer out a rolling tattoo—his love song -and his challenge.</p> - - -<p class="pmt2"><span class="allsmcap">A DRUMMER</span> The gray-brown ruffed grouse of a wood -lot we used to have in the Chicago area is a drummer I -miss. "Thump-thump ..." he started slowly, and then -quickened to a roll that filled the forest with hollow sound -and you wondered whence it came, unless you happened -to know, as I did, that an old log in the patch of gray birch -was the old cock's favorite performing stand. There he -came to roll out his invitation to the demure hen grouse. -A drummer, I've called him, yet he has no drum. It's his -wings, striking the air, that thump and build up into a roll, -its volume testifying to his great breast muscles as well as -does the whir of wings as he hurtles away through the air -when I come too close.</p> - -<p>The snipe of a nearby marsh makes music with feathers -and wind, music that is more enthralling to me than the -song of the yellowthroat or the vocal imitation of stake -driving by the bittern. Circling high, then with a change -of pace, his "winnowing" or "bleating" spring song comes -drifting down. There is still room for argument, but probably -it's air rushing past the outer tail feathers that makes -the sound. One year a short-eared owl nested in the nearby -meadow. Owls generally are vocalists, even if we don't -rate very high their hoots or yelps, but the short-eared owl -also has an instrumental performance. Sometimes, when -giving his mating song on the wing, a series of "toots," he -interrupted this by a dive in which he brought his wings -together under his body, with a clapping sound. It's part -<span class="pagenum" id="Page_135">- 135 -</span> -of the performance, but not, as might be said, the owl applauding -his own show.</p> - -<p>Over our public school each evening in early summer a -nighthawk booms. He has a voice, and he uses it, calling -"beep" as he circles high. But the climax of his performance -is instrumental, wind on feathers. He heads down, -wings high, toward the flat gravel roof on which his mate -is sitting. As he approaches the roof he moves his wings -down; the air rushing past the quills gives a tearing boom -as he comes out of the dive and mounts skyward again.</p> - -<p>At dusk, at a damp corner of our old wood lot, in the -spring, I listened for the woodcock's flight song, a twittering -of wing music as he circles up, and sweet music, too, -for a wild fowler's ears, is the whistling of the wings of a -passing pair of black ducks on their way in the early darkness.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_136">- 136 -</span></p> - -<h2 class="nobreak tdl2" id="CONDITIONING_IN_BIRDS">CONDITIONING IN BIRDS <span class="ref"><a href="#ref_37">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_136" style="width: 281px;"> - <img src="images/136.png" width="281" height="208" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he classical experiment</span> in conditioning and reflexes -is that of Pavlov. It consisted of sounding a bell each time -food was given to a dog. Finally the salivary response resulted -even when the bell was rung, without the food -being given to the dog. The dog was <i>conditioned</i> to the -bell. First it had responded to the food, then to the food -and the bell, and finally to the bell alone, by a flow of -saliva. The beauty of this experiment is in its simplicity, -dealing as it does with a single reflex.</p> - -<p>Though much behavior is more complex, experiments -have been worked out to show how the environment, in a -broad sense, can influence inherited behavior. An illuminating -<span class="pagenum" id="Page_137">- 137 -</span> -example of this is the one I made dealing with -young loggerhead shrikes and the duration of their infantile -behavior. Young shrikes, as with young passerine -birds in general, while in the nest are fed directly by the -parents, who place food in their mouths. One of the earliest -behavior patterns these young birds perform is to -stretch up with widely opened mouth, fluttering wings, -and buzzing calls, in anticipation of being fed. This we -call begging. Though typically infantile behavior, it may -reappear in courtship, but this latter we will not consider -here.</p> - -<p>Ordinarily this infantile begging behavior is discontinued -shortly after the young birds leave the nest and -become able to feed themselves. Observations indicate -that in a state of nature this change is probably hastened -in part by the young birds themselves, who come to avoid -having food thrust down their gullets, and prefer to pick -up the food for themselves, and in part by the waning -interest of the parents in the young, which confers an advantage -on the young who early become self-supporting.</p> - - -<p class="pmt2"><span class="allsmcap">CASE OF RETARDED DEVELOPMENT</span> Certain observations -made from time to time have indicated that -though the age at which young birds changed from infantile -begging for food to self-supporting independence -was a fixed thing, started by instinct, certain external -factors, notably the amount of care the young received, -could affect the age at which this change occurred. Indeed -there was a record of a young cedar waxwing raised by -hand who never learned to feed itself.</p> - -<p>When I secured a brood of four young loggerhead -shrikes, or butcherbirds, the material was available to -<span class="pagenum" id="Page_138">- 138 -</span> -conduct a controlled experiment. The young birds were raised -together by hand to the stage where they were ready to -begin to pick up things, to feed themselves, and to begin -to abandon their infantile behavior of begging for food. -This was when they were twenty-one days old. They were -then divided into two lots and housed separately. One -couple had a supply of food kept in front of them, and -hand feeding was gradually discontinued and stopped as -soon as possible. At the age of twenty-eight days they fed -themselves well, though they still begged freely when I -approached. By the time they were thirty-nine days old -they begged rarely, and after the age of forty-five days -they were not seen to beg.</p> - -<p>The other couple had no free food available at any time, -and they were fed completely by hand, the food being -placed in their mouths. At the age of twenty-eight days -they had made no effort to feed themselves. By the time -they were fifty-three days old they made efforts to feed -themselves, trying to peck the food from the fingers instead -of having it thrust into their mouths, and evidently -would have changed quickly to independent self-feeding -and abandoned their infantile begging behavior. But hand -feeding was continued. At the age of seven and a half -months, when the experiment was discontinued, though -these birds were capable of feeding themselves, as was -seen when food was accidentally dropped on the floor of -their cage, they still begged for food from their human -foster parent.</p> - - -<p class="pmt2"><span class="allsmcap">OBJECT LESSON FOR PARENTS</span> These four birds -used in this experiment were nestmates, and had similar -<span class="pagenum" id="Page_139">- 139 -</span> -heredity and early environment. The birds in the lot which -received only enough care to ensure proper development -became self-feeding, independent, and lost their infantile -begging behavior when they were about a month and a -half old. The other lot, which received an excessive amount -of care in the latter part of infancy, and were hand fed -without being allowed to develop the behavior that would -have made them independent, retained the infantile behavior -pattern of begging to be fed until the end of the -experiment. They were then seven and a half months old, -and their nestmates, under a different set of conditions, -had lost their infantile behavior six months earlier.</p> - -<p>With some birds it appears excessive care can be a conditioning -factor. It can delay the loss of infantile behavior -and the acquiring of the normal independence. Though -instinctively the young shrikes tried to develop their independent -behavior, when this was not possible they continued -their dependent, conditioned behavior.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_140">- 140 -</span></p> - -<h2 class="nobreak tdl2" id="POISONOUS_BIRDS">POISONOUS BIRDS <span class="ref"><a href="#ref_38">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_140" style="width: 279px;"> - <img src="images/140.png" width="279" height="213" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">P</span>oison we know</span> perhaps best in the plant world, whence -comes, for example, strychnine. The deadly nightshade, a -common weed, is another well-known poison plant. In the -animal world we know poison best as something that is injected -into the body by stings of bees, bites of spiders, the -bites of insects, and even bites of shrews. In addition some -animals having irritating, bad-tasting, or poisonous secretions -which presumably protect the possessor from predators. -This has received most attention in the insect world, -the bad-tasting grasshoppers being examples. Toads have -an acrid secretion from their skins which deters many -would-be toad eaters, and pickerel frogs have somewhat -the same thing.</p> - -<p><span class="pagenum" id="Page_141">- 141 -</span></p> - -<p>The following three birds, which are recorded as having -poisonous flesh, are, strangely enough, all members of -groups ordinarily considered good table birds. Further, it -seems the poisonous properties of their flesh are not constant, -but apparently depend on what they have been -eating.</p> - -<p>The ruffed grouse of the United States is regarded by -many as the finest of upland game birds and favored by -the epicure. However, Mr. E. H. Forbush, in his monumental -<i>Birds of Massachusetts and Other New England -States</i>, gives accounts to show that in winter the ruffed -grouse is known to eat leaves of laurel, which have poisonous -properties, and that there are stories of serious poisoning -resulting from eating the flesh of the birds. Such -poisoning, Forbush points out, seems to have taken place -only long ago and only by winter-taken birds. Perhaps now -that it is illegal to shoot grouse in the winter when they -may have been feeding on laurel, such poisoning does not -occur. This seems an additional reason for obeying the -game laws.</p> - -<p>Pigeons in the tropics are abundant both as to individuals -and as to species and many are favored as food. -However, Messrs. D. L. Serventy and H. M. Mitchell, in -their recent volume on the birds of Western Australia, report -that bronze-wing pigeons of two species are given to -feeding on the seeds of the box-poison plant, and when -they have been feeding on these seeds their entrails and -bones, but not the flesh, are poisonous to dogs and cats. -The effects of eating this poison seems to be that the dogs -and cats have fits, become mad, bite at anyone within -reach, and finally die in convulsions.</p> - -<p><span class="pagenum" id="Page_142">- 142 -</span></p> - -<p>During Colonel Meinertzhagen's study of the birds of -Mauritius he found that one of the pigeons there had a bad -reputation from a culinary point of view. Reports have it -that some of the people who have eaten the flesh of this -pigeon suffered from extreme lassitude, while others reported -the effects as convulsions. Strangely some of the -people who reported sickness from eating this pigeon say -it tastes well, while others who have eaten it without ill -effects say that the flesh is bitter.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_143">- 143 -</span></p> - -<h2 class="nobreak tdl2" id="KINGFISHERS_ON_THE_TELEPHONE">KINGFISHERS ON THE TELEPHONE</h2> -</div> - -<div class="figcenter" id="img_143" style="width: 280px;"> - <img src="images/143.png" width="280" height="203" alt="" /> -</div> - - -<p>"<span class="smcap">What color</span> is the kingfisher? Not the American one, but -the European and Asiatic one? My husband is painting -one and needs to know the colors," a lady's voice came -over the telephone. I thought quickly. "Will it help if I explain -the various kinds and colors of kingfishers and where -they live? But no, lessons on taxonomy and zoogeography -fall too flat most of the time." The lady's voice had a Central -European quality. To her "the kingfisher" probably -meant the little sparrow-sized kingfisher of the Old World -scientists know as <i>Alcedo atthis</i>. So I'd better start with -that. I described the cobalt-blue back, with darker wings, -and dark bars on the crown; an earth-brown stripe through -<span class="pagenum" id="Page_144">- 144 -</span> -the side of the head, paling to whitish posteriorly, and -with ocherous underparts.</p> - -<p>"What color is the eye?"</p> - -<p>"Brown."</p> - -<p>"And the feet?"</p> - -<p>"Red."</p> - -<p>"And the nails?"</p> - -<p>"Black."</p> - -<p>She thanked me prettily. I tried to tell her about some -of the other kingfishers, but she said no, she had enough, -and hung up.</p> - -<p>I sighed and thought regretfully of all the other things -I had ready to tell her.</p> - -<p>In the United States we think of the kingfisher as the -belted kingfisher, larger than a jay, with a tousled crest -and a voice like a watchman's rattle. But there are other -species farther south in the Americas, and in the Old -World there are still more. The tropics are their home. -Only one species reaches Northern United States, and only -one reaches Britain. But in New Guinea, for instance, -there are about twenty-four of the ninety or so known -kinds of kingfishers; the smallest tiny as a warbler, the -largest nearly crow size.</p> - -<p>Kingfishers, we call them, but many live on the dry land, -and instead of catching fish catch insects or other tiny -animals from the ground. One large species, with a broad -shovel-like bill, is even reputed to dig in the earth to get -its food of earthworms.</p> - -<p>They all look much alike in shape. Once you overcome -your surprise at seeing a kingfisher as big as a crow, or -<span class="pagenum" id="Page_145">- 145 -</span> -smaller than a sparrow, you recognize one anywhere—big-headed, -large-billed birds with tiny feet that sit up quietly -much of the time. Blue is a common color, but not all are -blue. Some are generally reddish in color, some patterned -with browns, grays, and whites tinged with blue. Many -are decorated with crests, and a few species have elongated -spatulate-tipped central tail feathers that have -earned the species the name paradise kingfishers.</p> - -<p>Its voice has given one species its name: the laughing -jackass, the jackass kingfisher, or the kookaburra of Australia. -"Ha ha huh huh ho ha ha huk" in a deafening chorus -has been given as a description of its call. A. H. S. Lucas -and W. H. D. Le Souëf, no doubt with tongue in cheek, -record that "<i>on dit</i> that the jackass has been heard to laugh -while a cicada [it had eaten whole] has been skirring inside -him."</p> - - -<p class="pmt2"><span class="allsmcap">CLASSICAL ALLUSIONS</span> Halcyon, Alcyone, and -Ceyx appear in the scientific names of kingfishers. Scientific -names make the layman shudder. Latin, he says, and -if he's told they're not Latin, but rather Greek, it doesn't -help any. But once you know the story of Halcyon (or -Alcyone) and Ceyx, the names stick in your mind. In ancient -times Halcyon was the daughter of Aeolus. And in -grief for her drowned husband, Ceyx, she threw herself -into the sea. The gods, out of compassion, changed both -into kingfishers. Halcyon was also used by the Greeks as a -name for the kingfisher and it was fabled to make its nest -on the sea, and to quiet the waves for its incubation period. -Poets still use Halcyon for the kingfishers in reference to -<span class="pagenum" id="Page_146">- 146 -</span> -calm, happy, peaceful days, Halcyon days; the sort of days -in which the kingfishers can nest on the quiet waves.</p> - -<p>The lady had not waited for all this. She had gone. I -would have liked to see the picture her husband was painting -when it was finished.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_147">- 147 -</span></p> - -<h2 class="nobreak tdl2" id="ON_IDENTIFYING_SEA_SERPENTS">ON IDENTIFYING SEA SERPENTS</h2> -</div> - -<div class="figcenter" id="img_147" style="width: 301px;"> - <img src="images/147.png" width="301" height="227" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he lock ness monster</span> reappears periodically in the -newspapers. This monster seems to belong in the general -category of "sea serpent." As a museum zoologist I've had -little to do with such things. The stock in trade of a -museum is specimens and if someone sends us a "sea serpent" -(and I don't mean a water snake or a sea snake), -we'll identify it. If it doesn't have a name we'll give it one -and make a place for it in our classification. Until then we -are aloof. We've had some little experience at times with -"sea serpents" and the following will illustrate the sort of -investigation and the results that we've had.</p> - -<p>Years ago Sir Frederick Jackson was an administrator -<span class="pagenum" id="Page_148">- 148 -</span> -in East Africa. In addition to his official duties he was an -enthusiastic and an able naturalist. So when a "sea serpent" -was reported there he investigated.</p> - - -<p class="pmt2"><span class="allsmcap">IN KENYA</span> The sea serpent was said to frequent Lake -Naivasha in the Rift Valley of Kenya Colony. Up until -1909 there were many rumors of it, and Europeans had -seen it with their own eyes. It always appeared on the lake -about the same time each day, about five o'clock in the -afternoon, always about the same distance from the shore, -and was always traveling in the same direction, from -north to south. All descriptions agreed that it was long, -black, and reptilelike, and that it kept appearing and disappearing -on the surface of the water at short intervals.</p> - -<p>Sir Frederick kept watch with one of the people who -had reported it. And, sure enough, what appeared like a -long black reptile appearing and disappearing, or like a -school of porpoises, rising and disappearing, came into -view. But Sir Frederick had binoculars and was able to -make out that what to other people had been a long black -reptile was in reality a long line of white-breasted cormorants -in flight, on their way to their roosting quarters. As -they flapped steadily along they were plainly evident, to -the naked eye, as a moving black line; as they paused in -their flapping and sailed on motionless wings they became -invisible to the naked eye, though, of course, still visible -through the binoculars.</p> - - -<p class="pmt2"><span class="allsmcap">IN NEW GUINEA</span> Once, for a few startled moments, I -thought I had a sea serpent before my very eyes. It was -on the middle Fly River in south New Guinea. We were -<span class="pagenum" id="Page_149">- 149 -</span> -camped on a bamboo-covered bluff overlooking the river. -Though about one hundred miles from the mouth, the -tide made itself strongly felt here, and there was an -abundance of driftwood. This driftwood, varying from -freshly uprooted trees that had fallen into the river to -waterlogged timber that had been long in the river, went -up and down on the tide until it got out in the main -channel and so on to the sea. One day at lunch, sitting in -front of my tent, I was idly watching the driftwood. One -piece in particular caught my fancy. Apparently it was -the root of a partly submerged log, projecting about three -feet above the water, and curved at the end so that it -looked like the neck and head of a reptile with a casque on -its head. Knowing it was a waterworn root, in fancy I even -saw its eye. I called my companion's attention to it, as here -was as close as we were ever likely to get to a sea serpent. -Then, the "head" turned. It was alive. For a few startled -moments it was a sea serpent. You can imagine our amazement -at having a piece of driftwood that we had in fancy -turned into a sea serpent come to life. Investigation became -the order of the day. The binoculars that were constantly -at hand were trained on it. The reality came as a -further surprise. Our sea serpent was the head and shoulders -of a cassowary which was swimming the river. Later -I found that these large, ostrichlike birds, which have a -large casque on their heads, are well known to swim, but -I didn't then.</p> - -<p>This seemed an ideal opportunity to collect a specimen. -These birds may weigh up to 150 pounds. When shot in -the forest there is the question of lugging them perhaps -miles to camp. Here was one swimming up to our door.</p> - -<p><span class="pagenum" id="Page_150">- 150 -</span></p> - -<p>We sat quietly waiting for it. But our native boys had -seen it too, for next I saw them rowing the dinghy to it. -An oar was brought into play to stun it. And then both the -boys and ourselves found out something else. Dead cassowaries -sink. When the bird was stunned by a blow of an -oar, it disappeared below the surface and was never seen -again.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_151">- 151 -</span></p> - -<h2 class="nobreak tdl2" id="CONSERVATION_OVER_THE_TELEPHONE">CONSERVATION OVER THE TELEPHONE</h2> -</div> - -<div class="figcenter" id="img_151" style="width: 288px;"> - <img src="images/151.png" width="288" height="197" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">R</span>ichard Orr</span>, the <i>Tribune</i> reporter, called me one day -about bronze grackles. It seems that the Chicago <i>Tribune</i>, -in their "Day by Day on the Farm," had told about the -grackles on the <i>Tribune</i> farm. A <i>Tribune</i> reader wrote in, -expressing surprise that grackles were permitted on the -<i>Tribune</i> farm and gave details of destruction by grackles -of other birds, personally observed. What were the facts -of the case? Should grackles be tolerated? Or should they -be eliminated? Orr wanted to know.</p> - -<p>This is the sort of question that is difficult. It is important, -too, for it involves basic conservation issues. And -there is no sharp, clear-cut yes-or-no answer. The question -<span class="pagenum" id="Page_152">- 152 -</span> -as to the grackle's character reminds me of the character -of Moses, as explained when I was in school by a -professor of the Bible: The black was there and the white -was there; Moses was a character sketch in gray. And so -with most creatures. They're both good and bad from our -standpoint. Grackles certainly do kill other birds at times, -and interrupt the nesting of some of our favorite songbirds. -And yet, liking birds as I do, I tolerate them in my -garden. On a trumpet vine on our garage in Chesterton, -Indiana, one year we had a grackle build its nest on top -of a domed English-sparrow nest. The young of both -sparrows and grackles hatched about the same time, and -the two families, within six inches of each other, were -successfully raised without friction between the parents.</p> - -<p>Quite evidently grackles are not always killers of other -birds. As to robins or grackles being the "better" birds, if -we had a robin's nest that we prized, and the grackle killed -the young in it, the grackle would be "bad." But if we were -an inquiring farmer, and had to weigh the grackle against -the robin, we might find the grackle "good" and the robin -"bad." The grackle feeds its young vast quantities of insects -harmful to the gardener; the robin sometimes seems -to specialize in earthworms. Earthworms are beneficial to -man, passing through the earth, making air and water -more accessible, and, by passing earth and vegetable matter -through their intestines, enrich the soil.</p> - -<p>The house wren that warned the <i>Tribune</i> reader when -the grackles were about is often prized as a garden bird; -it is bold, saucy in appearance, and a vigorous songster. -But it is also well known as a quarrelsome bird, prone to -punch holes in the eggs of its neighbors, and it also may -<span class="pagenum" id="Page_153">- 153 -</span> -fill up with sticks nesting boxes so that other birds cannot -use them.</p> - -<p>The above was the gist of what I told Orr, and appeared -in the May 5, 1950, <i>Tribune</i>.</p> - -<p>Thinking of it afterwards, as is usual, I thought of many -other things I could have said, and perhaps made more -clear that no bird is all good or all bad, from our human -point of view. Their relationships with the rest of the landscape -are complex. I like to see butterflies flit about my -garden. But butterflies are caterpillars at one stage. And -caterpillars may eat some of the things in my garden. -But some birds feed on caterpillars. If I eliminate the -caterpillars because they eat the plants I like, at one stroke -I eliminate the source of the butterflies I like, and food for -some birds I also like.</p> - -<p>Perhaps the partial answer, if answer there be in this -imperfect world, is summed up by moderation: I can have -some butterflies, some caterpillars, some plants, and some -birds in my garden. If one becomes too abundant and interferes -with the others, I prune it. Maintaining some sort -of a balance, we can have some of each.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_154">- 154 -</span></p> - -<h2 class="nobreak tdl2" id="BIRDS_WASHING_FOOD">BIRDS WASHING FOOD <span class="ref"><a href="#ref_42">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_154" style="width: 284px;"> - <img src="images/154.png" width="284" height="194" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">W</span>e not only wash</span> ourselves and our clothes, but certain -items of our food are regularly washed, as spinach, to get -the sand out of it. Washing has been so important in our -society that we've coined the term "Cleanliness is next -to godliness." Possibly we've the snobbish idea it's a -strictly human trait. Among other animals we don't expect -to find water used for such cleanliness, and the -raccoon, who does wash his food, is considered a sort of -biological oddity.</p> - -<p>But when we come to birds we find a surprising number -of them that wash their food.</p> - -<p>The dipper of our Western mountains in Oregon has -<span class="pagenum" id="Page_155">- 155 -</span> -been seen to wash insects and grubs before feeding them -to the young birds. The parents held the food crosswise in -the bill and the head was twisted rapidly from side to -side in the water. Not until then was the food taken to the -nest for the young.</p> - -<p>The scene shifts to Africa. Four buff-backed herons -were feeding on a flooded lawn at Gezira, Egypt. One of -the birds captured a large insect, apparently a large black -beetle. Holding the insect in the tip of its bill, the bird -walked to the water, immersed the beetle three times, -shaking and fumbling with it the while, and then swallowing -it.</p> - -<p>Then in Britain came a whole host of records, after an -observation in Holland in 1946 of curlew sandpipers washing -food. The birds were probing the dry mud at the edge -of a little creek. When one of the birds got a small sand -worm, it at once ran with quick steps to the creek and -stepped into the shallow water, where it dipped the -worm a few times into the water before swallowing -it. Then it trotted away for more. The editor of <i>British -Birds</i>, the journal in which this was published, suggested -that this might be a more common habit than the scanty -published records would indicate, and invited observations.</p> - -<p>A spate of records resulted in the succeeding numbers -of the journal: a whimbrel washing crabs; a snipe, earthworms; -godwits washing their food; with curlews it was -reported to be normal; dunlins, greenshanks, redshanks, -ringed plover, and oyster catchers were all reported doing -this until it appears that with the group of birds we call -<span class="pagenum" id="Page_156">- 156 -</span> -shore birds—sandpipers, snipes, plovers, and their relatives—it -may indeed be normal. The details of the observations -strongly suggest that the reason for the washing, in -many cases at least, is the same one that underlies our -washing spinach; to get the sand and mud out of it.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_157">- 157 -</span></p> - -<h2 class="nobreak tdl2" id="HOW_ANIMAL_VOICES_SOUND_TO_FOREIGN_EARS">HOW ANIMAL VOICES SOUND TO FOREIGN EARS</h2> -</div> - -<div class="figcenter" id="img_157" style="width: 287px;"> - <img src="images/157.png" width="287" height="211" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">W</span>hen in El Salvador</span> in 1951, I found that the common -barnyard animals had much the same voices as the ones -with which I was familiar in the United States. But when -I saw their utterances written down it was another matter. -The voices written in Spanish sometimes looked as different -as the names of the animals written in Spanish. -Take the donkey, for example (or <i>burro</i>, as they call it in -Spanish). In English we call its "song" "Heehaw!" In -Spanish they wrote it for me, "Aja! Aja! Ija! Ija!" There -were a number of German scientists at the Instituto Tropical -de Investigaciones Científicas, where I was working, -and for comparison I asked them to write for me what the -<span class="pagenum" id="Page_158">- 158 -</span> -same animals said in German. The burro (<i>Esel</i>, they call -it in German) says, "<i>Ihå! Ihå!</i>" in German. Despite the difference -in the appearance of these words, when they were -pronounced by the various nationalities they sounded very -similar. Compared with the original assinine pronunciation, -the Spanish version was awarded the prize for being -the best rendition of the beast's voice.</p> - -<p>The cat's "<i>Miau, miau, miau</i>" in Spanish, "<i>Miau, miau</i>" -in German, and "Meow" in English were all very similar in -appearance as well as sound. The duck's voice came out -differently. In Spanish it was "<i>Cuá, cuá, cuá</i>," in German -"<i>Wack, wack</i>," and in English the initial "Cu" or "Q" sound -of the Spanish, and the final "k" sound of the German are -united into "quack." The hoot owl came out much the -same in pronunciation, though it looked different in the -Spanish "<i>Ju</i>," in German "<i>Hu</i>," and in English "Who."</p> - -<p>The cow's, the pig's, and the frog's voices were also -rather similar in the three languages: the cow's in Spanish -being "<i>Meu, meu, muuu</i>," in German "<i>Mŭh, mŭh</i>," and in -English "Moo"; the pig's "<i>Grup-grup, wink</i>," "<i>Óŭik, Óŭik</i>," -and "Grunt, oink"; and the frog's "<i>Cruac, croac, croac</i>" -"<i>Quak, quak</i>," and "Croak." The barnyard rooster has a -difficult voice to transcribe in letters. In Spanish it was -"<i>Quiquiriguiiii</i>," in German "<i>Kickeriki</i>," and in English -"Cock-a-doodle-do." After listening to the various renditions -by the various nations I could see how each rendition -came into being, but as for deciding which was -closest to the original I hesitated to choose.</p> - -<p>When it came to the dog, the discrepancy was surprising: -in Spanish it was "<i>Guán, guán, guán</i>," in German -<span class="pagenum" id="Page_159">- 159 -</span> -"<i>Waŭ, waŭ</i>," and in English "Bowwow." The German and -the English are close enough. But though I went outside -and listened to the dogs in Salvador, never did they seem -to say, "<i>Guán, guán, guán</i>," though I must admit that -neither did they seem to say, "Bowwow."</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_160">- 160 -</span></p> - -<h2 class="nobreak tdl2" id="SIGHT_IDENTIFICATION">SIGHT IDENTIFICATION</h2> -</div> - -<div class="figcenter" id="img_160" style="width: 291px;"> - <img src="images/160.png" width="291" height="219" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">S</span>ometimes</span> when I'm trying to decide whether the birds -of the Cameroon Mountains of West Africa are the result -of one invasion and variation <i>in situ</i>, or of two invasions, or -whether the Himalayan red-billed choughs of Ladak are -different from those of Nepal, or how the molt of the -cassowary resembles that of penguins, I am called to the -telephone to identify a bird someone has seen.</p> - -<p>The chances are it's a starling. I've not kept a record, -but I fancy half the questions are on identification of -starlings. In the distance starlings are black, and people -know them. But close up, where details can be seen, they -puzzle people with their variety. The young may be dull -<span class="pagenum" id="Page_161">- 161 -</span> -brownish; the adults may be speckled in the winter; in the -spring the speckled tips of the feathers wear off and they're -all black. But the black is iridescent, and in sunshine glitters -purple or greenish. And the bill color changes too: it -becomes yellow in the spring.</p> - -<p>Sometimes it's surprising how you can spot a bird from a -brief description. Take this one: a bird that sits with its -stomach on the ground, and has a big mouth, and long -whiskers; a whippoorwill obviously. Or take this one: a bill -like a chicken and with flat feet at the back; obviously a -pied-billed grebe.</p> - -<p>There was one that absolutely stumped me for a day. -The lady said it had a bill like an eagle, and a tail that -stuck up. For the rest she was vague. Often habits, actions, -or habitat are a help to me in placing a bird, but I could -get nothing to help—not even where she had seen it. I admitted -I couldn't help her. The next day someone brought -in a picture puzzle out of a newspaper, and there, right -in the center, was my bird. It was a dodo! We don't mind -helping people learn things, indeed we consider it part of -our job, but to help them work puzzles is too much!</p> - - -<p class="pmt2"><span class="allsmcap">MY LESSON</span> Sight identifications of most students probably -contain errors. On common species it's not important, -as quantitatively they cancel out. But when a bird tripper, -anxious to make a new record, wants me to help him decide -he saw an exotic tern, I'm very careful—I've had -experience. Rarities have to be checked on all points, not -identified by elimination or on a few key characters. One -of the best lessons of caution I had in New Guinea. It was -in the mountains. Each morning I hunted in a forest where -<span class="pagenum" id="Page_162">- 162 -</span> -I'd found a new genus of bowerbird. Anything might -occur, I thought. Then I saw flying through the treetops -what could only be a magpie. A long-tailed, black and -white bird, its pattern was unmistakable. There was nothing -like it known from New Guinea. It would be an extension -of range from Asia. Or it was a new and unknown -species. Anyway I needed it as a specimen. But it was -shy and eluded me. Morning after morning I haunted the -forest. Finally I got the bird. And it turned out to be a -partly albinistic specimen of a common, black, long-tailed -bird of paradise. The abnormal white areas in its plumage -had fooled me completely. But it helped teach me caution -as to sight identifications.</p> - -<p>One of my Gary friends, Mr. Raymond Grow, who is a -keen bird student, has the proper approach, as his identification -of a winter duck showed. There were a number -of unusual winter birds that season (1951-52): brown-headed -chickadees, pine and evening grosbeaks, and red-breasted -nuthatches, all from the North, were present. -It was the sort of winter one expects other rarities from -the North.</p> - - -<p class="pmt2"><span class="allsmcap">DUCK CAUSES CONFUSION</span> Mr. Grow had seen at -the edge of Lake Michigan a duck he didn't know; it was -boldly patterned in black and white, a big duck. An immature -male eider seemed the only possibility. He came -into the museum and we went over specimens, noting -the difference in the shape of the head between the king -and the common eider. He studied the descriptions and -the plates. Nothing quite fitted. Unsatisfied, he went back -to Michigan City, found the duck again, and suddenly -<span class="pagenum" id="Page_163">- 163 -</span> -realized it was a muscovy duck, partly albinistic, and escaped -from someone's barnyard.</p> - -<p>It's not the first time a muscovy has caused confusion. -Only a year or so ago we had a duck sent us from the Philippines -that our correspondent wrote was shot swimming -in a river with a Philippine mallard and surely represented -a new species. But it turned out to be a muscovy whose -original home is tropical American but has become domesticated -and transported by man to far parts of the globe. -Occasionally birds escape and take to the wild, even as this -Philippine bird had done.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_164">- 164 -</span></p> - -<h2 class="nobreak tdl2" id="GREEN_HUNTING_JAYS_TURN_BLUE">GREEN HUNTING JAYS TURN BLUE</h2> -</div> - -<div class="figcenter" id="img_164" style="width: 259px;"> - <img src="images/164.png" width="259" height="218" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">S</span>ometimes</span> in "working out" a bird collection things get -dull. In identifying the specimens, and writing down why -they are this species, or that species, or subspecies, it seems -routine; as though it were simply routine putting things -in the categories ready for them.</p> - -<p>Such was my feeling one day as I worked over Himalayan -jays and magpies from Nepal. I'd done the yellow-billed -blue magpie, and the red-billed blue magpie, which -both fell into their places smoothly. Then I got out the -literature, the pertinent keys, and descriptions for the next -species, the green hunting jay. It's a beautiful, pale, apple-green -bird, with a green crest, and set off by dark red -<span class="pagenum" id="Page_165">- 165 -</span> -wings. It checked with the descriptions, and I wrote <i>Kitta -chinensis</i>, its scientific name, on the label. Then, to check -the species' identification and to determine the subspecies, -I turned to the collection, to the birds from India, -Siam, and north Indochina, which should all be the same.</p> - -<p>I pulled out the drawer—and blinked at the jays, rows -of them; all pale blue with brown wings. I looked at the -name on the case, on the tray, and the name on each specimen. -They all said the same, <i>Kitta chinensis chinensis</i>, and -it was the bird described as green, like my new specimen. -It was uncanny. The new green specimens and the old -blue ones were identical in size, in structure of bill, crest, -feet, tail; they must be the same. And they were. The book, -I found, described how the colors changed with age, and -in John Gould's magnificently illustrated folio, <i>Birds of -Asia</i>, published in 1861, he had the green hunting jay depicted -both as a green bird with red wings and, in the background, -a "blue" green hunting jay like our museum specimens. -When alive, and when freshly killed, the birds are -green. But with the passing of time the green changes to -pale blue, and the red wings to brown wings. Probably -my new specimen, now a year old, is less green than it was -when fresh. And when twenty years old, like our museum -skins, it will be blue too.</p> - -<p>The riddle was solved, and it fits into a well-known -phenomenon, "museum age" or post-mortem change. "Foxing," -we call it for short. We see it in the male American -merganser, where the lovely rich salmon color of the fresh -bird becomes plain white. The emerald cuckoo of Africa -has vivid rich yellow under parts when fresh, and this too -becomes dingy white. Gray Canada jays become more -<span class="pagenum" id="Page_166">- 166 -</span> -brownish. Birds that are olive or other shades of green tend -to become more olive; brown birds tend to become more -russet or foxy (hence the term "foxing"). We keep all our -specimens in dustproof, lightproof metal cases. The change -is not caused by fading. Apparently it's a change in the -pigment, perhaps from oxidation.</p> - -<p>Taxonomists, the men who classify and name birds, have -been fooled by it. Old skins used to represent the birds of -an area may give a quite different idea of what they are -like than do fresh skins, and when skins of different age are -compared, the conclusions may be wrong.</p> - -<p>Foxing is one of the pitfalls for the unwary taxonomist, -and something he has to guard against.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_167">- 167 -</span></p> - -<h2 class="nobreak tdl2" id="HOW_BIRDS_USE_COWS_AS_HUNTING_DOGS">HOW BIRDS USE COWS AS HUNTING DOGS <span class="ref"><a href="#ref_46">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_167" style="width: 280px;"> - <img src="images/167.png" width="280" height="235" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he sportsman</span> out for quail or woodcock uses dogs to -drive out the birds for him. Starlings and cowbirds about -Chicago use the same principle in hunting grasshoppers. -Instead of dogs they use cows, though of course the cows -are intent on something else and presumably unconscious -of the fact that they're helping the birds.</p> - -<p>As the cow grazes slowly across a meadow, it scares up -grasshoppers close in front of it. The cowbirds and starlings -take advantage of this. Instead of covering the meadow -on foot, constantly alert for a sitting grasshopper, or to -chase one they flush, the birds keep with a grazing cow. -They take up a position by the head, or a foot, and catch -<span class="pagenum" id="Page_168">- 168 -</span> -the insects the cow disturbs. The cow is so much larger -than the bird that it is likely to flush more insects. The -grasshoppers on the wing are much easier to see than when -at rest in the concealing grass, and some fly directly toward -the bird. Too, the grasshoppers fleeing a cow are less -likely to be alert to other dangers.</p> - - -<p class="pmt2"><span class="allsmcap">CONFIRMED BY OBSERVATION</span> The advantages of -this to the bird are obvious. But we've just assumed they -were, and we had no data on the relative efficiency of the -two methods of hunting. A few years ago, however, while -in El Salvador, I was able to get quantitative data proving -that using a cow as a beater was advantageous, as we suspected, -and showing how much more effective it was, -something we did not know.</p> - -<p>The bird concerned was not the starling, which does not -occur there, or a cowbird, which occurs but consorts little -with cows, but was the grove-billed ani, a black cuckoo -about twelve inches long of the tropics of Central and -South America. Like our starling and our cowbird, it kept -with cows, catching the grasshoppers and other insects -that flew up. Both anis and cows were common in the -grassy fields about our headquarters in San Salvador. We -decided, my son Stanley and I, to watch anis with cows for -a few hours, and then without cows for a few hours; thus -getting the average rate for each type of feeding. We -quickly found it wasn't as easy as that. Something always -happened; even on the levelest and most open fields the -birds were constantly disappearing behind a tuft of grass, -or in a hollow, or, if nothing else, behind the cow's head -or feet. Then, too, the ani we elected to watch wouldn't pay -<span class="pagenum" id="Page_169">- 169 -</span> -attention to the job in hand. It would wander off, or go to -sleep. And sometimes, when we were about to discontinue -watching a somnolent bird, it would snap up an insect. -Perhaps it had been watching all the time. Finally we -found we had to record observations of many short periods, -of from three to fourteen minutes each, and add them together.</p> - -<p>By dint of much patient watching we got our data. In -the dry season when insects were scarce and the grass -short, it took an ani, hunting alone, two minutes on the -average to find an insect. In the same length of time hunting -with a cow the catch averaged three insects. Thus -hunting with a cow as a beater was three times as effective -as hunting alone.</p> - -<p>The effect of the change of the season in abundance of -food for the ani was very striking. In the wet season the -grass began to grow fast, and insects became common. -Then the anis had an easy time. Without a cow an ani -averaged between three and four insects a minute, more -than six times as much as in the dry times. There was less -incentive to use a cow as a beater, with food so abundant, -but when the ani did so, its rate of finding insects was still -higher: between four and five insects per minute. In a table -it looks like this:</p> - - -<p class="tdc"><i>Average Number of Insects Per Minute Found by Ani Feeding</i></p> - -<table summary="data"> -<tr> - <td></td> - <td class="tdc smaller">WITHOUT COW</td> - <td class="tdc smaller">WITH COW</td> -</tr> -<tr> - <td class="tdl">Dry Season</td> - <td class="tdr">.5</td> - <td class="tdr">1.5</td> -</tr> -<tr> - <td class="tdl">Wet Season</td> - <td class="tdr">3.4</td> - <td class="tdr">4.7</td> -</tr> -</table> - -<p>But the three-times-greater-results in a given time in the -dry season do not tell the whole story as to the effectiveness -<span class="pagenum" id="Page_170">- 170 -</span> -of using a beater. When an ani was hunting by itself -it walked about, covering a surprisingly large amount of -ground. When using a cow as a beater, not only did it -catch more insects in a given length of time, but it also -walked about much less, saving a great deal of energy.</p> - -<p>This is not true co-operation between cow and bird, for -they're not working together toward a common end. It's -not exploitation of the cow by the birds, for the cows lose -nothing. It is closer to a form of harmless parasitism, for -the ani profits from the activities of the cow without either -harming or helping the cow. It also illustrates how sharp -birds are—ready to take advantage of any factor in their -environment that will help them get their food.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_171">- 171 -</span></p> - -<h2 class="nobreak tdl2" id="EARLY_BIRD_LISTING">EARLY BIRD LISTING</h2> -</div> - -<div class="figcenter" id="img_171" style="width: 284px;"> - <img src="images/171.png" width="284" height="225" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span> wonder</span> how many of the people who go out making lists -of spring birds know that bird listing goes back to ancient -times. It's a modern sport, but earlier bird watching was -serious, and a competitive listing of birds played a part in -as important an event as the selection of the site of the -city of Rome.</p> - -<p>The story, as Plutarch tells it, is that Romulus wanted -the city on what became known as Roma Quadrata; Remus -wanted it on the Aventine Mount. As was the custom in -those days, they concluded at last to decide by a divination -from a flight of birds. The twins placed themselves apart -at some distance and watched. Remus, they say, saw six -<span class="pagenum" id="Page_172">- 172 -</span> -vultures, a truly notable flight; Romulus saw twelve and -from this rare and unusual occurrence Romulus' choice of -the site for the city was accepted.</p> - - -<p class="pmt2"><span class="allsmcap">VULTURES HIGHLY REGARDED</span> Partly from this the -vulture became chiefly regarded by the Romans in their -divinations from birds. But even before this the vulture -was highly regarded. Hercules, it was said, was always very -joyful when a vulture appeared to him upon any occasion. -He considered it the least harmful of creatures; not pernicious -to corn, fruit tree, or cattle, it never killed or hurt -any living thing. It was also thought not to eat other birds, -a weighty point in its favor, as Plutarch quotes from -Aeschylus, "What bird is clean that preys on fellow bird?" -And apparently its deciding claim to esteem was its rarity -and infrequency, which gave rise to the opinion in some -that it came from another world, an opinion foisted by the -soothsayers of the day.</p> - -<p>Earlier yet, birds played a part in Rome's history. Plutarch -warns that some give you mere fables of the origin -of Rome, but it is widely current that Remus and Romulus, -fathered by Mars, the God of War, were exposed in a remote -place to perish. This would have taken place, but for -a she-wolf that nursed them, and birds of various sorts -that brought little morsels of food which they put into -their mouths. Some, however, hold the belief that not birds -of various sorts but a woodpecker was the bird that constantly -fed and watched the twins, and even in Plutarch's -time the Romans still worshiped and honored the woodpecker -for this service to the founder of the city.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_173">- 173 -</span></p> - -<h2 class="nobreak tdl2" id="BATTLE_OF_THE_SEXES_AND_ITS_EVOLUTIONARY_SIGNIFICANCE">BATTLE OF THE SEXES AND ITS EVOLUTIONARY SIGNIFICANCE <span class="ref"><a href="#ref_48">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_173" style="width: 304px;"> - <img src="images/173.png" width="304" height="216" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span> used to think</span> that the battle of the sexes so ably portrayed -by James Thurber was artificial, a man- and/or -woman-made thing. But recently I've come to see it as old—probably -as old as sex itself in the animal world.</p> - -<p>Under the severe tide, "Secondary Sexual Characters and -Ecological Competition," in a paper from the Bird Division -of the Chicago Museum, I've outlined the possibility of -competition for food, between the sexes, being a factor in -evolution, responsible in part for characteristics of structure -and traits that distinguish them.</p> - -<p>In circles that discuss evolution the idea is current that -food competition is important between species. It may -<span class="pagenum" id="Page_174">- 174 -</span> -even be stated as a rule: two species with the same food -habits cannot live in the same place. Competition drives -one out, unless they have different food habits. These -differences seem especially evident when you look at -closely related species, and they are accomplished in a -variety of ways. A habitat difference is very common. The -long-eared owl hunts in the woods—its cousin, the short-eared -owl, hunts the meadows; the song sparrow favors the -drier shrubbery while its cousin, the swamp sparrow, lives -in wetter shrubbery.</p> - - -<p class="pmt2"><span class="allsmcap">THE SIZE FACTOR</span> Sometimes the difference is accomplished -by size; take the downy and hairy woodpeckers -of our wood lots, very similar except that one is larger and -is adapted for larger prey, the other smaller and adapted -for smaller food items. Sometimes they feed differently, as -the Baltimore oriole, which picks flowers and pecks -through their sides, while the orchard oriole probes into -flowers as they hang on the branches. Thus more individuals -of several species live in an area.</p> - -<p>When a pair of birds "sets up housekeeping" and starts -"raising a family" they can no longer drift about, looking -for easy living and places where food is plentiful. Their -wanderings are restricted by having a fixed point, the nest, -as their center of interest. Two individuals must draw on -the food supply from an area about the nest. Competition -would be extreme, and, if there were a scarcity, perhaps -critical.</p> - -<p>We know how different the sexes may be; how different -the rooster is from the hen in our domestic fowl, or the -drake and the duck in the mallard, or the red male and the -<span class="pagenum" id="Page_175">- 175 -</span> -green female of the scarlet tanager. These sexual differences -have mostly correlated with display and mating. But -logically there should be differences in feeding behavior -and adaptations between the sexes.</p> - -<p>The basic idea is contained in the old nursery rhyme:</p> - -<div class="poetry-container"> -<div class="poetry"> - <div class="stanza"> - <div class="verse indent0">Jack Sprat could eat no fat,</div> - <div class="verse indent0">His wife could eat no lean;</div> - <div class="verse indent0">And so between them both,</div> - <div class="verse indent0">They licked the platter clean.</div> - </div> -</div> -</div> - -<p>The two birds of a mated pair, limited to a single area, -could be expected to have different food preferences or -adaptations for getting it. And we find that there are cases -of this. The most striking is that of the huia from New -Zealand, of which I've written in a Chicago Museum bulletin. -Both sexes have similar food preferences, especially -wood-inhabiting insects, but they get them in different -ways. The male has a short, straight, stout bill for digging -out the wood-boring grubs, woodpecker fashion; the female -has a much longer, slender, and curved bill for probing -into holes for them, creeper fashion. The female may -get grubs in wood too hard for the male to chisel. They -supplement each other.</p> - - -<p class="pmt2"><span class="allsmcap">DIET VARIATION BY SEX</span> It is possible that further -study may show more sexual differences to have a feeding -advantage; the larger size of female hawks fitting them to -take larger prey; the smaller size of certain female songbirds -fitting them for smaller prey, the smaller bills of female -hornbills, the straight bill of the male western grebe, -and the upturned bill of the female. Perhaps all are of -<span class="pagenum" id="Page_176">- 176 -</span> -advantage to the species in giving each sex slightly different -advantages in getting food.</p> - -<p>Selection could have its effect in the populations with -most sexual difference in feeding habits being most successful -in raising and leaving progeny. Thus, slowly, differences -between the sexes would accumulate. However, it -must be kept in mind that this sort of evolution would be -limited. The drifting apart of the sexes would be checked -by the necessity for their coming together periodically for -at least a short period, at nesting time.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_177">- 177 -</span></p> - -<h2 class="nobreak tdl2" id="WATER_IN_THE_DESERT">WATER IN THE DESERT <span class="ref"><a href="#ref_49">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_177" style="width: 285px;"> - <img src="images/177.png" width="285" height="218" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">W</span>ater</span> is a precious thing in the desert. Without it no life -is possible. When rains come plants spring into vigorous -growth. During the long stretches without rain they rest, -some as seed, while some plants store water in root -systems, or in large trunks. Animals have developed a number -of ways of surviving long dry spells in arid country.</p> - -<p>Among mammals the kangaroo rat of our Southwestern -desert seems able to get along without water. This is caused -by an arrangement within the body whereby the necessary -water is manufactured within the animal from other foodstuffs: -metabolic water.</p> - -<p>The accessibility of drinking water in a desert may be -<span class="pagenum" id="Page_178">- 178 -</span> -the determining factor in whether or not some birds can -survive there. The nests of Gambel's quail must be close -enough to drinking water for the newly hatched young to -walk there, else they perish of thirst. It has been said that -newly hatched chicks of the related valley quail of California -cannot travel more than a few hundred yards from -their hatching places without water. Broods hatched -farther away are doomed to die.</p> - -<p>Sand grouse, relatives of the pigeons that have adopted -the general appearance and habits of quail, live in the Old -World, primarily in arid or even desert areas. Where they -occur their daily traveling to water is a well-marked -phenomenon. Their flight is swift and powerful, and -though they may traverse long distances of barren, inhospitable -country to watering places, their punctuality in arriving -at water, morning and evening in some species, is -remarkable.</p> - -<p>But what of the young of these desert dwellers that need -water? A most unusual situation exists; indeed it seems to -be unique. The old birds bring water to the young! This -has long been recorded, but as recently as 1921 it has been -questioned. However, Mr. Meade-Waldo's observations on -birds in captivity seem to definitely establish the custom, -and its methods.</p> - - -<p class="pmt2"><span class="allsmcap">PARENTS CARRY WATER</span> Both birds incubate the -eggs, the male by night, the female by day, and both parents -care for the young. But it is the male only that brings -water to the young. He rubs his breast violently up and -down on the ground, and then, his feathers awry, he gets -into his drinking water and saturates the feathers of his -<span class="pagenum" id="Page_179">- 179 -</span> -under parts. Then, in captivity, he would run to the hen, -make a demonstration, whereupon the young would run -out from under her, get under him, and suck the water from -his feathers. This they did by passing the feathers through -their bills, continuing and changing about until the supply -was exhausted. It was found that until the young can fly -they take water in no other way.</p> - -<p>This was in captivity. Presumably in the wild the process -is the same, the adult flying with wet under parts from the -water hole to the resting place where the young are under -the care of the female.</p> - -<p>The similarity of the young sucking water from the -feathers to young mammals suckling their mother has been -pointed out. But another and a truer similarity exists: that -of the young sand grouse getting water from the feathers, -and young quail getting water from dew-wet leaves in -areas where dew is heavy and there is but little surface -water.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_180">- 180 -</span></p> - -<h2 class="nobreak tdl2" id="BIRD_GRAVEYARDS">BIRD GRAVEYARDS <span class="ref"><a href="#ref_50">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_180" style="width: 286px;"> - <img src="images/180.png" width="286" height="217" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he best-known stories</span> of animal graveyards are those -of elephants. But when I asked the curator of mammals -about them the answer I got was little better than a snort. -Apparently the evidence for them is so vague that it's little -better than a myth.</p> - -<p>But in birds we have a few bits of evidence from far-scattered -places that occasionally such things as graveyards -exist.</p> - -<p>In the antarctic Dr. Robert Cushman Murphy found on -the island of South Georgia a place where Johnny penguins -went to die. It was in a lake in a coastal range of hills. The -lake bottom was thickly strewn with scores of penguin -<span class="pagenum" id="Page_181">- 181 -</span> -bodies, all of which had apparently died a natural death. -The icy water, Murphy thought, might preserve them for -years. The hills, away from the sea, seem a surprising place -for the graveyard of such aquatic birds as the penguins, but -it correlates with another peculiarity of their mental makeup. -They like to nest on high land, or at least far from the -sea. The blind instinctiveness of much penguin behavior -is well shown by these birds when there is no high land on -their nesting island. Then they may nest so far from the -beach on which they land that they are close to the water -on the other side. Yet they always returned to the sea by -the long route, never taking the shorter route.</p> - -<p>Another aspect of this preference for land distant from -the sea is shown by their behavior when threatened with -danger from man or dog. They flee away from the sea, -back onto the land, when safety for them actually lies in -the sea. Presumably this fixed behavior dates back to the -time when the seal that is called the sea leopard was the -penguin's main enemy. Then the sea held their only danger. -With man's arrival the situation changed, but only -after considerable experience with man do the birds -change this behavior.</p> - -<p>Apparently, when the time came for the penguins in this -South Georgia graveyard to die, they followed their age-old -pattern, climbing to the high country and away from -the sea.</p> - - -<p class="pmt2"><span class="allsmcap">IN A HOLLOW TREE</span> In a hole about eighteen inches -in diameter and twelve feet deep in the trunk of a wych -elm in Hants, England, Ursula M. Grigg reports finding -the bones of at least ninety jackdaws, thirteen starlings, -<span class="pagenum" id="Page_182">- 182 -</span> -six green woodpeckers, and twenty-five stock doves. All -the remains were clean, and not much broken or decomposed. -The idea that these bones were the remains of -owls' or other predators' feasts was discarded for a number -of reasons; as was the idea that this had been a natural -trap, the birds entering to roost or nest and being unable -to escape. The most tenable idea seems to be that this was -a favorite roosting place in winter, and that during the -severe weather old and weakened birds, roosting there, -succumbed and added their bodies to this communal grave.</p> - - -<p class="pmt2"><span class="allsmcap">ON AN ISLAND</span> Another instance comes from the little -Cape Verde Isle of Cima in the South Atlantic. A photograph -in the <i>National Geographic</i> magazine for 1927, Vol. -52, P. 27, has the caption that this island is unique and uninhabited -and covered with the tiny bones of millions of -petrels which in ages past have come here to die. Certainly -the plate shows an amazing litter of bird bones on the tiny -plateau of this islet.</p> - -<p>Petrels are mostly pelagic birds, coming to the land only -to nest on isolated islets. Can this "graveyard" be merely -the normal accumulation of the bones of the nesting season -mortality, or can it be that the birds actually come -here to die?</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_183">- 183 -</span></p> - -<h2 class="nobreak tdl2" id="ANIMAL_GARDENS">ANIMAL GARDENS <span class="ref"><a href="#ref_51">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_183" style="width: 266px;"> - <img src="images/183.png" width="266" height="210" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">B</span>est known</span> of the "gardens" and "animal husbandry" of -the lower animals are those of the ants; the aphis kept by -the ants for the sake of a sweetish secretion, and the underground -fungus garden of the ants. In the vertebrates I -know nothing comparable to this, but we do get a number -of cases where there is a definite relation between the -animals and the growth of vegetation.</p> - -<p>It has been said that in the antarctic the nesting colonies -of some penguins are detrimental to the vegetation. The -constant passing and standing of the birds on the limited -areas of soil preclude the growing of vegetation over sufficiently -large areas to be an important factor in hindering -<span class="pagenum" id="Page_184">- 184 -</span> -plant growth. But the reverse is true of the Johnny penguin -in the Falklands, where it is sometimes known as the best -farmer in the country. The Falkland Islands, off southern -South America, are cold, wet, and windy. Sheep raising is -one of the main industries. And the Johnny penguin helps -to provide better pasture for the sheep. The birds nest in -colonies and their droppings help to enrich the land so -that the grass grows taller and richer. Rather than using -the same area for their breeding colony each year the -birds select a new, clean area at the beginning of each -breeding season, so that they improve the ground over a -larger area.</p> - -<p>From the arctic comes another example of a relationship -between bird and plant. On the arctic barrens, here and -there, are large boulders, erratics left by the glacier that -covered the land in times past. And on these boulders, and -here only, one finds patches of bright yellow or reddish -lichen known to scientists as <i>Xantheria</i> or <i>Xanthoria</i>. Apparently -its presence is owed to the fact that these boulders -are the lookout places of snowy owls, hawks, and other -birds. Their droppings, falling on the rocks, provide the -nutrient layer necessary for the growth of the lichens. It is -probable that these lichens are transported from place to -place by the birds carrying the soredia on their feet. In -recognition of the close relationship between these lichens -and birds an ecologist has coined the rather formidable -term "ornithocoprophilous" to express the relationship.</p> - -<p>Also in the arctic are the arctic-fox gardens. The arctic -fox often makes its burrows in sandy places, and about the -entrance to the burrow accumulate remains of former -meals, fox droppings, and suchlike animal debris. This in -<span class="pagenum" id="Page_185">- 185 -</span> -time enriches the soil and the vegetation there grows taller -and more lush than elsewhere on the barrens. This lush -vegetation attracts the small, mouselike arctic rodents, the -lemmings, that feed on green, succulent vegetation. There -is of course one further step in this chain. One of the important -foods of the arctic fox is the lemming, which he -thus brings to his door by the richer vegetation he unwittingly -causes to occur there. A charming arrangement, -one of the old naturalists called it.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_186">- 186 -</span></p> - -<h2 class="nobreak tdl2" id="DROPPING_THINGS">DROPPING THINGS <span class="ref"><a href="#ref_52">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_186" style="width: 288px;"> - <img src="images/186.png" width="288" height="224" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he story</span> is well known, being recorded by Pliny, of how -the poet Aeschylus came to his death through a bird mistaking -his bald head for a rock and dropping a turtle on it. -The bird was evidently the lammergeier or "lamb vulture," -one of the largest and most magnificent of the Old World -birds of prey; nearly four feet long. In the Atlas Mountains -of North Africa its normal food is turtles, and these it -cracks open, so that it can get at the meat, by carrying -them up into the air and dropping them on a rock. Now it -lives in the Himalayas and in Africa, having been almost -if not completely exterminated from Europe because of its -alleged predation on sheep. Not only turtles but bones are -<span class="pagenum" id="Page_187">- 187 -</span> -treated in the same manner, to get at the marrow. Though -the habit is well known, it is surprising how difficult it is to -find a firsthand description of it. So far I know of only one -description written by an eyewitness. And yet, in East -Africa recently a stony mountaintop was found littered -with broken bones that seemed to be the result of the -lammergeier's habit.</p> - - -<p class="pmt2"><span class="allsmcap">GULLS DO IT</span> As I have mentioned, gulls open clams -and mussels in this way; and crows, which are among the -most intelligent of birds, do it also. They pick up the -mussels left exposed by the falling tide, fly up above a hard -stretch of beach, a big rock, or a stretch of nearby paved -road, and drop the shellfish there. While in general this -practice is restricted to a few groups of birds, it is practiced -by them in many far parts of the world. The Pacific -gull of Australia, widely separated from its near relatives, -has the same maneuver for opening shellfish as has our -herring gull.</p> - -<p>It's hard to understand just how this habit came about. -One can imagine that some birds found it out by accident -when flying about with a stubborn "nut" they were unable -to crack. Or perhaps it was in play they found it. The -raven is known to fly about carrying and dropping things -in play.</p> - - -<p class="pmt2"><span class="allsmcap">SPARROWS DO IT TOO</span> Often, to find a background -if not an explanation of a habit, we look about to see if -it's used in some other connection. I've already mentioned -the play of some of the crows. Only one other "dropping" -habit has come to my attention, and that is a single record -<span class="pagenum" id="Page_188">- 188 -</span> -for the very common house sparrow. Edmund Jaeger -writes that in Nebraska, and again in Riverside, California, -he saw house sparrows on gravel roofs, dropping -small stones over the edge. The pebbles, or small bits of -crushed stone, were carried to the edge of the building by -the sparrows, dropped, and as each pebble was dropped -the sparrow turned its head, apparently the better to watch -or listen to the pebble fall and strike. No obvious utility -appeared in these actions. It, too, looked like pastime. Perhaps -there was no better reason behind them than that -behind small children dropping stones down a well.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_189">- 189 -</span></p> - -<h2 class="nobreak tdl2" id="LEARNING_BY_BIRDS">LEARNING BY BIRDS <span class="ref"><a href="#ref_53">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_189" style="width: 276px;"> - <img src="images/189.png" width="276" height="233" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">O</span>f course</span> birds can learn. Indeed there's a trite saying -that no animal has been discovered so low that it cannot -learn. One of the simplest cases of learning is shown by -parts of some experiments I carried out years ago on the -curve-billed thrasher. I had raised a number of these -thrashers by hand, and in connection with finding out -about their tasting abilities I first fed them on the white of -egg, hard-boiled and cut into little squares. They liked it. -Then I soaked more squares of boiled egg white in evil -tasting (to me) formalin. The birds came to the dish, and -also ate them. But after that for a week they refused to eat -such egg white. They had quickly learned to avoid the ill-tasting -food.</p> - -<p><span class="pagenum" id="Page_190">- 190 -</span></p> - - -<p class="pmt2"><span class="allsmcap">BAD-TASTING FOOD</span> Once I hand-raised a barred -owl from a nestling to adulthood. Sometimes getting food -for it was a problem, and upon occasion I fed it frogs, -which it seemed to like well enough. But then came a day -when I fed it a toad. The owl seized the toad at once. Now -toad skin, presumably as a defense weapon of the toad, -secretes a substance irritating to the mucous membranes -of some animals. And this was evidently irritating to the -owl, for it did not hold the toad long in its bill. It spat it -out, and the owl's face gave evidence of disgust. After that -the owl not only refused to take toads, but it also refused -to take frogs such as it had found palatable before. Evidently -frogs looked too much like toads. The learning was -effective, and extended not only to the original object, but -also to other, similar objects.</p> - - -<p class="pmt2"><span class="allsmcap">BUCKET-DRAWING</span> When in Florida with the Archbold -Expeditions I was studying blue jays. A very simple -but amusing thing that chickadees learn is to sit on a perch -and pull up a little container of food that dangles far below -the perch on a string. Jays, along with crows, are -among the most clever of birds, as I've said before, and I -gave two jays in one cage a chance to learn the trick. In -three days one of the jays was regularly and quickly pulling -up the little bucketlike container and getting its food -from it. The process was simple: the jay reached down, -seized the string in its beak, secured the slack under its -foot, and reached down again for another pull. Sometimes -five separate pulls were needed to raise the food bucket -the eight inches to the perch.</p> - -<p>The jays were regularly fed in this manner. Soon I -<span class="pagenum" id="Page_191">- 191 -</span> -noticed that only one of the two birds pulled up the -bucket, though the other also fed from it. In effect one was -depending on the work of the other. After this had gone -on for a month, I wondered if the second jay, which had -never done any of the work, would be able to pull up the -bucket if left alone. Certainly it had had lots of opportunity -to learn by seeing its cage mate go through the -motion. So I left it alone in the cage. This second jay, -despite its chances to learn by observation, took one day -longer to learn how to pull up the bucket of food than had -the first jay. The jays certainly learned the trick quickly -through a trial-and-error process, but simply watching -the process seemed to be of little help in learning it.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_192">- 192 -</span></p> - -<h2 class="nobreak tdl2" id="CAN_BIRDS_COUNT">CAN BIRDS COUNT? <span class="ref"><a href="#ref_54">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_192" style="width: 303px;"> - <img src="images/192.png" width="303" height="208" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">I</span>f birds</span> can count, it's a rather rudimentary thing—perhaps -no more than impressions of the size of groups. The -widely known example showing that birds don't seem to -distinguish between one and two persons is the ruse used -by bird photographers and students of birds who are using -blinds from which to watch the birds at close range.</p> - -<p>The hide, or blind, is a little hut built perhaps a few feet -from the nest to be photographed. If the photographer enters -the blind in the sight of the parent birds, and conceals -himself there, the birds who saw him go in will be a long -time in coming to the nest and in resuming their normal -activities. But if the photographer takes a companion with -<span class="pagenum" id="Page_193">- 193 -</span> -him, both go into the blind and conceal themselves, and -then one of them goes away leaving the other concealed, -the bird quickly disregards the intrusion and goes about -its activities as though no one were left in the blind. This -subterfuge has long been used and is very successful. Apparently -the bird is unable to distinguish between the two -people that arrive at the nest and the one only that leaves, -and behaves as if both had gone away.</p> - -<p>In my duck-hunting days a duck hunter who used -wooden decoys told me he was sure that there was a certain -number of decoys necessary before they were effective.</p> - -<p>The decoys were wooden blocks, carved and painted to -resemble life-sized ducks, weighted to float like them, and -anchored in shallow water in a flock within gunshot range -of the blind in which the duck shooter sat. The idea was -that ducks flying by would see the flock on the water, assume -that here was a safe resting place, and fly in and light, -or attempt to light among them, giving the wild-fowl -gunner an opportunity to shoot the wild birds.</p> - -<p>The duck shooter claimed that if less than twenty-five or -thirty decoys were put out in the flock, the setup was much -less effective than if more than twenty-five to thirty decoys -were used. He thought that the ducks could distinguish -between less than twenty-five or thirty and more than -twenty-five to thirty, and favored the latter. Though this -is distinguishing between greater and lesser amounts, it -hardly comes in the category of counting.</p> - - -<p class="pmt2"><span class="allsmcap">DISTINGUISH "MORE" FROM "LESS"</span> However, -a series of experiments summarized on Page 121 in -<span class="pagenum" id="Page_194">- 194 -</span> -the periodical <i>Bird Banding</i> for 1940 seem to indicate that -birds can distinguish between different numbers of things, -such as peas and numbers of dots. The birds, including -pigeons, parakeets, and jackdaws, were trained either to -choose a certain number of objects under certain circumstances, -or to choose between two quantities of objects -with reward and punishment motivation. It was found that -these birds were able to distinguish up to a maximum of -six. That this is really counting in the human sense of the -term, which is linked with speech or written symbols, is -improbable, but it does indicate, as one would expect, that -birds do at times distinguish between different quantities, -and sometimes with considerable precision.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_195">- 195 -</span></p> - -<h2 class="nobreak tdl2" id="COURTSHIP_FEEDING">COURTSHIP FEEDING <span class="ref"><a href="#ref_55">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_195" style="width: 280px;"> - <img src="images/195.png" width="280" height="212" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">A</span> young man</span>, giving his best girl a box of chocolates, -and a bird, giving his prospective mate a worm or a berry, -have this in common: they are both practicing courtship -feeding. Further, humans and birds are the only vertebrate -animals that do this.</p> - -<p>With birds, during courtship, the female often begs to -be fed by acting like a young bird—with fluttering wings -and widely gaping mouth. The male normally places the -food he has collected directly in the open mouth of the -female.</p> - -<p>The significance of this courtship feeding has been -<span class="pagenum" id="Page_196">- 196 -</span> -discussed especially by David Lack, in the scientific journal, -the <i>Auk</i>. It seems that in courtship feeding the food as -such is not of primary importance. The female does not -need the food she is begging for; indeed she may have had -a full meal since her mate, whom she is soliciting, had last -eaten. Perhaps it is of help in maintaining the bond between -the pair during the period that exists before they -have a nest and young to look after. In this connection it -is interesting that with waxwings during courtship feeding -the fruit that the male gives the female may be "handed" -back (by beak) and the food exchanged back and forth.</p> - -<p>In looking for significance and correlations in courtship -feeding we find that some species practice courtship feeding -and some do not. And the birds that do practice it are -usually those in which both sexes care for the young. It -might be considered an early, useless appearance of a -habit that later becomes useful when the male feeds the -incubating female and helps feed the young.</p> - -<p>This type of behavior, in which an act used elsewhere is -introduced into courtship, is sometimes called "symbolic." -Other such symbolic acts are the preening that sometimes -takes place between a pair of mating birds, and the passing -or the manipulation of nesting material long before -there is a nest to be built.</p> - -<p>Some species during courtship go through actions that -resemble courtship feeding except that no food is passed; -the bill touching of the mourning dove and of the waxwing -falls in this category. Perhaps it is incipient courtship -feeding on its way in the long course of evolution, either -upward, to include food, or downward, away from courtship -feeding.</p> - -<p><span class="pagenum" id="Page_197">- 197 -</span></p> - -<p>Their functions seem to be to give something for the -pair to do; something they can share. It helps fill up the -pair's day and keep them together. It is something that -helps strengthen the bond between them, against the day -when both will be working together raising a brood.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_198">- 198 -</span></p> - -<h2 class="nobreak tdl2" id="THEY_TURNED_THE_TABLES">THEY TURNED THE TABLES <span class="ref"><a href="#ref_56">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_198" style="width: 281px;"> - <img src="images/198.png" width="281" height="209" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">M</span>ost birds prey</span> on animals enough weaker than themselves -to be in no danger from their prey; their hunting is -more like that of the gunner after rabbits than that of the -hunter after lions. But there are exceptions.</p> - -<p>The great blue heron, armed with a spearheadlike bill, -lives largely on fish. These it spears in the water, stalking -about after them on its long legs, or waiting like a bird on a -Japanese screen, as patient as any fisherman, for its prey -to come within striking distance. The heron's size and its -great bill render it safe from most enemies. But it sometimes -overestimates its ability. Audubon recorded one on -the Florida coast that, standing in deep water, up to its -<span class="pagenum" id="Page_199">- 199 -</span> -belly, struck a fish too large for it. The fish dragged the -bird for several yards, now on the surface, now underwater. -Finally, after a severe struggle, the heron freed -itself. It was exhausted, and stood near the shore, head -turned away from the sea. As if, Audubon said, it was -afraid to make another attempt at fish catching.</p> - -<p>A more serious encounter for the bird was recorded in -<i>Field and Stream</i> magazine. The heron had caught a shad -about a foot long. He tried to swallow it, but it was too big -to go down. He tried to disgorge it, but the fins of the fish, -acting as barbs, kept it from slipping backwards and out. -The result was death for both bird and fish.</p> - - -<p class="pmt2"><span class="allsmcap">CAUGHT BY A CLAM</span> The oyster catcher, a large black -and white relative of the sandpiper, feeds on, among other -things, shellfish. Mussels and oysters look like hard nuts to -crack, even with a stout, wedgelike bill such as that of the -oyster catchers. The oyster catcher's favorite feeding times -are when the tide has fallen and the shellfish are first exposed -to the air and before they have closed up their -shells, and again when the tide is rising and the shells are -just beginning to open. The oyster catcher stabs into the -shell, and with its bill cuts the strong adductor muscles -that hold the shells of the bivalves together. The rest is -easy. But a danger lurks here: what about stabbing into -too big a shellfish, or making an inept stab? And this very -thing has happened. On the South Carolina coast Mr. -W. P. Baldwin found a trapped, drowned bird. It was held, -with the tip of its bill caught in the shell of a hard-shell -clam, as if in a trap. Apparently the rising tide had flooded -and drowned the bird.</p> - -<p><span class="pagenum" id="Page_200">- 200 -</span></p> - -<p>The raven eats most anything, living or dead, and except -for man has little to fear in the northern forests where it -lives. Yet from Wisconsin comes a record of one that met -his death through a porcupine. The porcupine's quills are -a dreadfully prickly covering that one would think would -protect it from most encounters. Yet one animal, the fisher, -kills and eats it as a matter of course, and wolves and bears -sometimes eat them without too many ill-effects from the -spines. The slow-moving porcupine has little regard for -automobiles, and many are run over on country roads. A -porcupine is too big and tough for a raven to kill and the -Wisconsin raven had probably fed on a dead porcupine. -Stuck through its gizzard was a quill, and another, which -had apparently caused its death, was stuck in its heart, -having apparently worked there from the digestive tract.</p> - -<p>Many small insectivorous birds eat spiders as well as -insects. This they do almost with impunity in temperate -latitudes, where only occasionally do spiders make webs -strong enough to trap a bird. But in the tropics, where -there are more large spiders, their webs must be a greater -hazard to birds. That the hazard exists in both climes, -however, is shown by a goldfinch reported caught in a -spider's web in Cape Cod, Massachusetts, and a dusky flycatcher -caught in a spider's web in Cameroons, West -Africa.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_201">- 201 -</span></p> - -<h2 class="nobreak tdl2" id="SURVIVAL_OF_THE_UNFIT">SURVIVAL OF THE UNFIT <span class="ref"><a href="#ref_57">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_201" style="width: 280px;"> - <img src="images/201.png" width="280" height="192" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>o care for</span> the weak, the unfit, and the cripple is -usually considered an extremely highly developed altruism -in our society. As our society progresses, more and -more provisions are made for the unfit.</p> - -<p>In nature the unfit usually is soon weeded out. If an -animal is unable to feed itself it is doomed; or if it is less -successful than its fellows it has less chance of leaving -progeny. That is natural selection.</p> - -<p>Hence on both counts it comes as a surprise to find -two well-authenticated cases of crippled birds, unable -to search for food for themselves, surviving for long -periods.</p> - -<p><span class="pagenum" id="Page_202">- 202 -</span></p> - -<p>The first is T. R. Peale's record in 1848 of a brown booby -on Enderby Island in the Pacific. An adult bird whose -plumage indicated it was several years old was found on -the island, and it had only one wing, the other having been -lost by some accident and the wound completely healed. -The bird was unable to go to sea and get its own food, and -was being fed by its fellows.</p> - -<p>The second was a frigate bird, found on the Revillagigedo -Islands, reported by A. W. Anthony in 1898. -This bird, too, was fat, and had one wing withered and -useless, evidently from hatching. It had never flown. -Frigate birds are masters of the air that snatch their -food on the wing from the surface of the water, and a -flightless frigate bird would be as badly off as a flightless -swallow. The cripple had been fed all its life by its -neighbors.</p> - -<p>At first the uncritical might think, What altruism, what -charity, for the healthy to feed these two cripples. But an -explanation involving less advanced principles, principles -more in keeping with what we know about bird behavior, -is possible. Remember that young birds that are unable to -begin feeding themselves at the proper time may continue -to beg for food, and be dependent for a long time, as I -have shown with young shrikes under the chapter, "Conditioning -in Birds." Remember that a young bird begging -for food may be fed by adults, not its parents, and even by -other young birds (shown in "Bird Helpers at Nesting -Time"); and we have the clue.</p> - -<p>The cripples, hungry, begged for food; the healthy birds -responded by feeding, as they might do to other begging -<span class="pagenum" id="Page_203">- 203 -</span> -young, and owing to the unusual circumstances both were -continued.</p> - -<p>These certainly are cases where the unfit survived. -Natural selection has not operated. But such cases are rare -exceptions.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_204">- 204 -</span></p> - -<h2 class="nobreak tdl2" id="DUST_AND_SNOW_BATHING">DUST AND SNOW BATHING</h2> -</div> - -<div class="figcenter" id="img_204" style="width: 282px;"> - <img src="images/204.png" width="282" height="201" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>he taxidermist</span> preparing a bird specimen for the -museum sometimes has to deal with one whose plumage -is soiled or stained. He may have to wash it with water. -Then, to dry the plumage, fluff it, and help in arranging -the plumage so it will lie smooth and natural, he may use -a powder: corn meal, sawdust, plaster, or plaster and -potato starch may be worked into the feathers, then dusted -out again. It is interesting that birds themselves use and -have used long before taxidermists a similar method of -using dust in dressing their feathers, a fact that anyone -who has watched domestic hens for any length of time -must be aware.</p> - -<p><span class="pagenum" id="Page_205">- 205 -</span></p> - - -<p class="pmt2"><span class="allsmcap">A DIRTY BATH</span> Recently I watched a house sparrow -dusting by the railway track in the city of Chicago. The -dust may have been in part "clean" earth, but in part it -was soot, city dust, and soft-coal debris. The sparrows -here were dingy, all had their plumage heavily impregnated -with city grime, and looked very different from -the sparrows in the country. And this sparrow I was -watching when it had finished dusting was the worst -of the lot. These city sparrows, even when they bathe in -water, seem never to get much of the grime out of their -feathers.</p> - -<p>This reminded me that Oscar Heinroth once wrote that -birds do not bathe to get themselves clean, but bathe as an -aid in bringing their feathers into order and making them -lie smoothly. Perhaps he is right. Certainly my sparrow did -nothing to clean himself.</p> - -<p>It is in arid countries, plains and deserts especially, -where many of the birds take only dust baths. In more -humid regions water bathing is the rule. But some birds do -both, like our flicker and our house sparrow, bathing now -in water, now in sand.</p> - -<p>In northern climates, when the land is held in the grip -of winter, the water frozen over, and the earth covered -with snow, neither dust nor water bathing is possible. -Then, it has been recorded, some birds find a substitute in -snow. Among other cases, in Alaska the hawk owl has been -seen to perch in the snow on the tops of telephone poles, -and go through the motions of bathing; in England a rook -was recorded as bathing "in crisp powdery snow as if it -were taking a bath in dust or water"; and in New England -<span class="pagenum" id="Page_206">- 206 -</span> -in midwinter juncos have been recorded bathing "in light -dry snow, just as other sparrows take dust baths in hot -weather."</p> - -<p>The snow evidently is used as a substitute for dust in -these northern latitudes.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_207">- 207 -</span></p> - -<h2 class="nobreak tdl2" id="DECORATION_IN_THE_HOME">DECORATION IN THE HOME <span class="ref"><a href="#ref_59">[Ref]</a></span></h2> -</div> - -<div class="figcenter" id="img_207" style="width: 288px;"> - <img src="images/207.png" width="288" height="222" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">T</span>o use</span> a bunch of flowers or a spray of leaves in decorating -a room in a house is a refinement of civilization. As -the flowers fade, or the leaves wilt, they are replaced with -fresh ones. Sometimes a winter bouquet is used that will -serve for months.</p> - -<p>There are several birds that habitually deck their nests -with green vegetation, and when it is wilted, it is renewed -with fresh. The reason is not clear. It has been suggested -it is to supply humidity and, by evaporation, coolness; it -has also been suggested that its use serves a sanitary purpose. -But whatever the reason in birds' eyes, it looks like -decoration to human eyes.</p> - -<p><span class="pagenum" id="Page_208">- 208 -</span></p> - -<p>This habit is common with a number of different hawks: -for example, the red-tailed hawk is reported sometimes to -have its nest, a bulky flat, basin-shaped structure in the -crotch of a tree, "profusely and beautifully lined with -fresh green sprigs of white pine, which are frequently renewed -during incubation and during the earlier stages in -the growth of the young." The golden eagle is said to add -green grass, or green leaves often attached to the twigs -from time to time to the lining of the nest, especially after -the young are hatched; and the broad-winged hawk is said -to add green leaves to the lining of its nest. In quite another -group of birds the same thing also occurs. A carrion -crow's nest in England was visited periodically from -March to August. Strangely no eggs were laid during this -whole period, but the birds remained in attendance. When -found, fresh sprigs of oak leaves were interwoven around -the rim of the nest. On subsequent visits the oak leaves -were found to have been replaced with fresh ones, and the -leaves were kept fresh until late August.</p> - -<p>The purple martin supplies another example. The nest -boxes we put up for them supply their main breeding -places in some areas. "The parents have a habit of collecting -many green leaves and placing them in the nest, a -practice which may tend by evaporation to reduce the -heat" in the next box. "Where large colonies are breeding -they sometimes injure pear trees by stripping certain -branches of their leaves," according to E. H. Forbush.</p> - -<p>A Madagascar weaverbird provides an example of decorating -the nest entrance of a quite different type of nest; -in this case the nest is in the shape of an inverted retort, -with the entrance through the spout. The entrance is decorated -<span class="pagenum" id="Page_209">- 209 -</span> -with green grass heads or with green leaves, and the -males keep adding fresh green decorations even when the -eggs are being incubated by the female.</p> - -<p>It seems hard to believe that this is really decoration, -that it is not for some purpose—either connected with the -raising of the young, or more probably a leisure or substitute -activity—something to keep the bird busy and -strengthen the bond between bird and nest when it is not -otherwise directly occupied with nesting activities.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_210">- 210 -</span></p> - -<h2 class="nobreak tdl2" id="CURIOSITY_IN_BIRDS">CURIOSITY IN BIRDS</h2> -</div> - -<div class="figcenter" id="img_210" style="width: 261px;"> - <img src="images/210.png" width="261" height="201" alt="" /> -</div> - - -<p><span class="smcap"><span class="fntsz2">B</span>eing unable</span> to ask birds questions that will receive answers, -we have to judge their motives from appearances. -And from the way some birds act curiosity seems a strong -motivation at times. They show a disposition to inquire -into things, especially strange things.</p> - -<p>Young blue jays that I've raised and studied are among -the most prying, investigating, inquisitive birds I've -known. When well fed they devoted much time to examining -things. Humans, of course, would examine objects -by picking them up in their hands, looking at and -feeling them, perhaps tasting them. The jays, with more -limited equipment, would examine them with bill and eye. -<span class="pagenum" id="Page_211">- 211 -</span> -When the jays were very young their toes interested them. -They pecked at and twisted their own and their neighbor's -toes. Pencils and crayons on my desk appeared to interest -them particularly. These they were continually pulling -about and pecking at. They went about picking at lines on -paper, knotholes in the walls of their cage, the red letters -printed on a bottle label, and the buttons on our clothes. -Cigarettes they liked to investigate by pulling them to -pieces. It looked as if the jays were interested in finding -out about the things around them by touch and taste as -much as they could.</p> - - -<p class="pmt2"><span class="allsmcap">LURED INTO DANGER</span> Compared with jays, ducks -seem rather stolid creatures, but they have curiosity too. -This was well known to the old-time duck hunters who -capitalized on it in duck shooting. The technique is known -as "tolling" and I've used two variations of it in museum -collecting.</p> - -<p>Once on a little mountain lake in New Guinea I found a -pair of ducks of a rare species I especially needed for our -collection. I stalked them to the farthest bit of cover I -could reach, a tussock of grass on the lake margin, behind -which I lay concealed. But the ducks were still too far -away for me to reach, and their feeding did not seem to -be drawing them nearer. I remembered the gunners' trick -of tolling, and tried it. I took out my white handkerchief, -held it above the tussock of grass while I kept well hidden, -and waved the handkerchief back and forth. The response -was surprisingly prompt and gratifying. The two ducks -turned at once and swam right in to me so that I secured -them without any trouble.</p> - -<p><span class="pagenum" id="Page_212">- 212 -</span></p> - -<p>Once on a lake in central New York State there was a -flock of scaup ducks swimming well offshore. It looked as -if they never would come in near the bank. Quite by accident -a setter dog that accompanied us began to cavort -along the beach. Again the ducks turned and the whole -flock came swimming in. Only then did I remember that -among old-time gunners there was the practice of using a -dog thus, a dog that was even trained for the purpose, to -jump high and run about very conspicuously while the -ducks were far out, and as the ducks came swimming in, -to keep lower and frisk about partly concealed so that the -ducks would have to come close to satisfy their curiosity.</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_213">- 213 -</span></p> - -<h2 class="nobreak" id="REFERENCES">REFERENCES</h2> -</div> - - -<p>Is it true? Did it really happen? The implications and correlations -are my own, and some of the accounts on the previous -pages are based on my experiences. But many of the facts come -from the writings of others. Where the incidents are well -known no documentation is given. But when the behavior described -is little known or only recently discovered I've given a -reference so that the source can be consulted. These are arranged -under the appropriate chapter headings.</p> - - -<p class="tdl caption3nb" id="ref_1">BIRDS USING TOOLS</p> - -<div class="blockquot"> - -<p>Edna Fisher, <i>Jour. Mammalogy</i>, Vol. 20, p. 21 (sea otter). -P. A. Gilbert, 1939, <i>Emu</i>, Vol. 39, pp. 18-22 (satin bower -bird). D. Lack, 1947, <i>Darwin's Finches</i>, p. 59 (woodpecker -finch). D. Morris, 1954, <i>British Birds</i>, Vol. 47, p. 33 (song -thrush). A. C. Bent, 1921, <i>U. S. Natl. Mus. Bull.</i> 113, p. -111 (gull and crow).</p> -</div> - - -<p class="tdl caption3nb" id="ref_2">BIRDS AS BRIGANDS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1954, <i>Fieldiana-Zoology</i> (Chicago), Vol. 36, -p. 35 (eagle, skua, frigate bird).</p> -</div> - - -<p class="tdl caption3nb" id="ref_3">BIRDS BATHING</p> - -<div class="blockquot"> - -<p>F. N. Bassett, 1922, <i>Condor</i>, Vol. 24, p. 63 (hummingbirds). -A. C. Bent, 1937, <i>U. S. Natl. Mus. Bull.</i>, 167, p. 370 (osprey).</p> -</div> - - -<p class="tdl caption3nb" id="ref_4">HOW BIRDS ANOINT THEIR FEATHERS</p> - -<div class="blockquot"> - -<p>W. L. McAtee, 1938, <i>Auk</i>, Vol. 55, p. 98 (review).</p> -</div> - - -<p class="tdl caption3nb" id="ref_5">TRAVELING BIRDS' NESTS</p> - -<div class="blockquot"> - -<p>H. S. Swarth, 1935, <i>Condor</i>, Vol. 37, p. 84 (barn swallows). -M. A. Common, 1942, <i>Auk</i>, Vol. 59, p. 43 (tree swallow). -D. L. Serventy and H. M. Whittell, 1948, <i>Birds of Western -Australia</i>, p. 243 (welcome swallow).</p> -</div> - -<p><span class="pagenum" id="Page_214">- 214 -</span></p> - - -<p class="tdl caption3nb" id="ref_6">MALADAPTATION IN BIRDS</p> - -<div class="blockquot"> - -<p>J. Grinnell, 1926, <i>Condor</i>, Vol. 28, p. 97 (robin). -W. H. Bergtold, 1930, <i>Auk</i>, Vol. 47, p. 571 (robin). -H. W. Henshaw, 1921, <i>Condor</i>, Vol. 23, p. 109 (California -woodpecker). D. Bannerman, 1933, <i>Birds Tropical West -Africa</i>, Vol. 3, p. 415 (thick-billed honey-guide).</p> -</div> - - -<p class="tdl caption3nb" id="ref_7">FEATHERED BABY SITTERS AND CO-OP NURSERY NESTS</p> - -<div class="blockquot"> - -<p>D. Davis, 1940, <i>Auk</i>, Vol. 57, p. 179 (ani). -A. C. Bent, 1925, <i>U. S. Natl. Mus. Bull.</i>, 130, p. 85 (eider -duck). R. C. Murphy, 1936, <i>Oceanic Birds of South America</i>, -Vol. 1, p. 398 (penguins).</p> -</div> - - -<p class="tdl caption3nb" id="ref_8">BIRDS' NESTS AND THEIR SOUP</p> - -<div class="blockquot"> - -<p>Gibson-Hill, 1948, <i>Malay. Nat. Jour.</i>, Vol. 3, p. 190; F. H. -Giles, 1935, <i>Jour. Siam Soc. Nat. Hist. Suppl.</i>, Vol. 10, p. 137; -and Jabouille, 1931, <i>L'Oiseau et Rev. Franc. d'Ornith.</i>, Vol. 1, -n.s., p. 219 (swiftlets).</p> -</div> - - -<p class="tdl caption3nb" id="ref_9">WALLED WIVES OF HORNBILLS</p> - -<div class="blockquot"> - -<p>R. E. Moreau, 1937, <i>Proc. Zool. Soc.</i> London, 1937, p. 331 -(hornbills).</p> -</div> - - -<p class="tdl caption3nb" id="ref_10">BURIED EGGS AND YOUNG</p> - -<div class="blockquot"> - -<p>A. Newton, 1893, <i>Dictionary of Birds</i>, p. 733; and D. Bannerman, -1931, <i>Birds Trop. West Africa</i>, Vol. II, p. 205 (crocodile -bird). Deusing, 1939, <i>Auk</i>, Vol. 56, p. 367 (grebe). Bent, -1925, <i>U. S. Natl. Mus. Bull.</i>, 130, p. 98 (eider duck).</p> -</div> - - -<p class="tdl caption3nb" id="ref_11">THE SNOWY OWL AS A TRADE INDEX</p> - -<div class="blockquot"> - -<p>A. Gavin, 1947, <i>Wilson Bull.</i>, Vol. 59, p. 202 (snowy owl).</p> -</div> - - -<p class="tdl caption3nb" id="ref_12">MONKEY BIRDS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1954, <i>Fieldiana-Zoology</i> (Chicago), Vol. 36, -p. 23 (various "monkey-birds").</p> -</div> - - -<p class="tdl caption3nb" id="ref_13">BIRD-MADE INCUBATORS</p> - -<div class="blockquot"> - -<p>C. G. Sibley, 1946, <i>Condor</i>, Vol. 48, p. 92; Coles, 1937, <i>Proc. -Zool. Soc. London</i>, 1937, pp. 261-73; Fleay, 1937, <i>Emu</i>, Vol. -36, pp. 153-63 (mound builders).</p> -</div> - -<p><span class="pagenum" id="Page_215">- 215 -</span></p> - -<p class="tdl caption3nb" id="ref_14">CORMORANT FISHING</p> - -<div class="blockquot"> - -<p>B. Laufer, 1931, <i>Publ. Field Mus. Nat. Hist. (Anthr. Ser.)</i>, -18, pp. 201-62; Gudger, 1926, Amer. Nat., 60, p. 5 (cormorant -fishing).</p> -</div> - - -<p class="tdl caption3nb" id="ref_15">THE SHRIKE'S LARDER</p> - -<div class="blockquot"> - -<p>A. C. Bent, 1950, <i>U. S. Natl. Mus. Bull.</i> 197, p. 120 (shrike's -larder).</p> -</div> - - -<p class="tdl caption3nb" id="ref_16">BIRD FLAVORS</p> - -<div class="blockquot"> - -<p>H. B. Cott, 1946, <i>Proc. Zool. Soc. London</i>, Vol. 116, pp. 371-524 -(bird flavors).</p> -</div> - - -<p class="tdl caption3nb" id="ref_17">HOW MANY FEATHERS HAS A BIRD?</p> - -<div class="blockquot"> - -<p>A. Wetmore, 1936, <i>Auk</i>, Vol. 53, p. 159; F. B. Hutt and -L. Ball, 1938, <i>Auk</i>, 55, p. 651 (number of feathers).</p> -</div> - - -<p class="tdl caption3nb" id="ref_18">LAST YEAR'S BIRDS' NESTS</p> - -<div class="blockquot"> - -<p>A. C. Bent, 1925, <i>U. S. Natl. Mus. Bull.</i> 130, pp. 91, 92; H. F. -Lewis, 1938, <i>Bird-Lore</i>, Vol. 40, p. 239 (eider down).</p> -</div> - - -<p class="tdl caption3nb" id="ref_19">SYMBIOSIS—ANIMALS LIVING IN MIXED HOUSEHOLDS</p> - -<div class="blockquot"> - -<p>A. C. Bent, 1938, <i>U. S. Natl. Mus. Bull.</i> 170, pp. 384-86, 398 -(burrowing owl). H. Friedmann, 1930, <i>Natural History</i>, Vol. -30, p. 205 (social weaver). W. H. Hudson, 1920, <i>Birds of -La Plata</i>, Vol. 2, p. 31 (monk parrot). W. R. B. Oliver, 1930, -New Zealand Birds, p. 118 (<i>Sphenodon</i>).</p> -</div> - - -<p class="tdl caption3nb" id="ref_20">BIRD APARTMENT HOUSES</p> - -<div class="blockquot"> - -<p>A. C. Bent, 1942, <i>U. S. Natl. Mus. Bull.</i> 179, p. 490 (purple -martin). A. Wetmore and F. C. Lincoln, 1933, <i>Proc. U. S. -Nat. Mus.</i>, Vol. 82, art. 25, p. 44 (West Indian woodpecker). -D. Bannerman, 1933, <i>Birds of Tropical West Africa</i>, Vol. 3, -p. 381 (barbets). J. T. Emlen, 1954, <i>Auk</i>, Vol. 71, p. 16 (cliff -swallows). W. H. Hudson, 1920, <i>Birds of La Plata</i>, Vol. 2, -p. 31 (monk parrot). A. Wetmore and B. H. Swales, <i>U. S. -Natl. Mus. Bull.</i> 155, p. 346 (palm chat); H. Friedmann, -1930, <i>Nat. Hist.</i>, Vol. 30, p. 205 (social weaver).</p> -</div> - - -<p class="tdl caption3nb" id="ref_21">BIRD HELPERS AT NESTING TIME</p> - -<div class="blockquot"> - -<p>A. Skutch, 1935, <i>Auk</i>, 52, p. 257 (helpers at nest). M. M. -Nice, 1943, <i>Trans. Linn. Soc.</i>, Vol. 6, p. 79 (young feeding -<span class="pagenum" id="Page_216">- 216 -</span> -young). R. C. Murphy, 1936, <i>Oceanic Birds of South America</i>, -Vol. 1, p. 360 (emperor penguins).</p> -</div> - - -<p class="tdl caption3nb" id="ref_23">WEAVERS AND TAILORS IN THE BIRD WORLD</p> - -<div class="blockquot"> - -<p>H. Friedmann, 1922, <i>Zoologica</i>, Vol. 2, p. 355 (weaverbird). -C. A. Wood, 1926, <i>Smithsonian Rept.</i>, p. 349 (tailorbird).</p> -</div> - - -<p class="tdl caption3nb" id="ref_24">SOCIAL PARASITES AMONG BIRDS</p> - -<div class="blockquot"> - -<p>A. H. Miller, 1946, <i>Sci. Monthly</i>, Vol. 62, p. 238 (social parasites).</p> -</div> - - -<p class="tdl caption3nb" id="ref_25">FISH EATS BIRD!</p> - -<div class="blockquot"> - -<p>W. E. Glegg, 1945, <i>Ibis</i>, p. 422 (fish eating birds).</p> -</div> - - -<p class="tdl caption3nb" id="ref_26">CROWS ARE SMARTER THAN "WISE" OWLS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1943, <i>Canad. Field Nat.</i>, Vol. 57, p. 35 (saw-whet -owl). A. L. Rand, 1942, <i>Bull. Amer. Mus. Nat. Hist.</i>, 79, -p. 518 (blue jay). A. C. Bent, 1946, <i>U. S. Natl. Mus. Bull.</i> -191, p. 196 (raven), p. 266 (crow).</p> -</div> - - -<p class="tdl caption3nb" id="ref_27">TAME WILD BIRDS</p> - -<div class="blockquot"> - -<p>D. Lack, 1942, <i>Ibis</i>, p. 271 (flycatcher). A. H. Chisholm, -1943, <i>Ibis</i>, p. 105 (honey eaters). H. H. Brimley, 1934, <i>Auk</i>, -51, p. 237 (phoebe).</p> -</div> - - -<p class="tdl caption3nb" id="ref_28">BIRDS AS PILFERERS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1954, <i>Fieldiana-Zoology</i>, Vol. 36, p. 31 (pilfering, -several species).</p> -</div> - - -<p class="tdl caption3nb" id="ref_29">HIBERNATION IN BIRDS</p> - -<div class="blockquot"> - -<p>W. L. McAtee, 1947, <i>Amer. Midland. Nat.</i>, 38, p. 191 (old -records on torpidity). E. C. Jaeger, 1949, <i>Condor</i>, 51, p. 105 -(poor-will).</p> -</div> - - -<p class="tdl caption3nb" id="ref_30">SNAKESKINS IN BIRDS' NESTS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1953, <i>Nat. Hist. Miscl.</i> (Chicago), No. 125 -(snakeskins in nests).</p> -</div> - - -<p class="tdl caption3nb" id="ref_31">CO-OPERATION BY BIRDS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1954, <i>Fieldiana-Zool.</i> (Chicago), Vol. 36, pp. 10, -12 (co-operation, various species).</p> -</div> - -<p><span class="pagenum" id="Page_217">- 217 -</span></p> - -<p class="tdl caption3nb" id="ref_32">WATCHDOGS AT THE NEST</p> - -<div class="blockquot"> - -<p>R. E. Moreau, 1942, <i>Ibis</i>, p. 240 (in Africa). D. R. Dickey -and A. J. van Rossem, 1938, <i>Publ. Field Mus. Nat. Hist.</i>, -<i>Zool. Ser.</i>, Vol. 23, p. 360 (in El Salvador).</p> -</div> - - -<p class="tdl caption3nb" id="ref_33">BIRD GUIDES TO HONEY</p> - -<div class="blockquot"> - -<p>H. Friedmann, 1954, <i>Nat. Geog. Mag.</i>, Vol. 105, p. 551 -(honey-guides).</p> -</div> - - -<p class="tdl caption3nb" id="ref_34">OXPECKERS</p> - -<div class="blockquot"> - -<p>D. Bannerman, 1948, <i>Birds of Tropical West Africa</i>, Vol. 6, -p. 105 (oxpecker).</p> -</div> - - -<p class="tdl caption3nb" id="ref_35">WINGS IN FEEDING</p> - -<div class="blockquot"> - -<p>J. Delacour, 1946, <i>Auk</i>, Vol. 63, p. 441 (black heron).</p> -</div> - - -<p class="tdl caption3nb" id="ref_37">CONDITIONING IN BIRDS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1942, <i>Bull. Amer. Mus. Nat. Hist.</i>, Vol. 79, p. 517 -(shrikes).</p> -</div> - - -<p class="tdl caption3nb" id="ref_38">POISONOUS BIRDS</p> - -<div class="blockquot"> - -<p>E. H. Forbush, 1927, <i>Birds of Mass.</i>, etc., Vol. 2, p. 34 -(ruffed grouse). D. L. Serventy and H. M. Whittell, 1948, -<i>Birds of Western Australia</i>, pp. 73, 74 (Australian pigeons). -R. Meinertzhagen, 1912, <i>Ibis</i>, p. 96 (Mauritius pigeon).</p> -</div> - - -<p class="tdl caption3nb" id="ref_42">BIRDS WASHING FOOD</p> - -<div class="blockquot"> - -<p>F. G. Evenden, 1943, <i>Condor</i>, 45, p. 120 (dipper). For divers -records of washing food see <i>British Birds</i> for 1946, 6 and 8.</p> -</div> - - -<p class="tdl caption3nb" id="ref_46">HOW BIRDS USE COWS AS HUNTING DOGS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1953, <i>Auk</i>, 70, p. 26 (ani).</p> -</div> - - -<p class="tdl caption3nb" id="ref_48">BATTLE OF THE SEXES AND ITS EVOLUTIONARY SIGNIFICANCE</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1952, <i>Fieldiana-Zoology</i> (Chicago), Vol. 34, -p. 65.</p> -</div> - - -<p class="tdl caption3nb" id="ref_49">WATER IN THE DESERT</p> - -<div class="blockquot"> - -<p>C. T. Vorhies, 1945, <i>Univ. Ariz. Agri. Exp. Sta. Tech. Bull.</i> -107 (water need in desert). J. T. Emlen, Jr., and B. Blading, -1945, <i>Univ. Calif. Coll. Agri. Bull.</i> 695, p. 34 (valley quail). -<span class="pagenum" id="Page_218">- 218 -</span> -E. G. B. Meade-Waldo, 1922, <i>Bull. Brit. Orn. Cl.</i>, Vol. 42, -p. 69 (sand grouse).</p> -</div> - - -<p class="tdl caption3nb" id="ref_50">BIRD GRAVEYARDS</p> - -<div class="blockquot"> - -<p>R. C. Murphy, 1936, <i>Oceanic Birds of South America</i>, Vol. 1, -p. 372 (penguins). U. M. Grigg, 1950, Brit. Birds, Vol. 43, -pp. 11-13 (graveyard in hollow tree). G. Simmons, 1927, -<i>Nat. Geog. Mag.</i>, Vol. 52, p. 27 (petrel bones on Cima).</p> -</div> - - -<p class="tdl caption3nb" id="ref_51">ANIMAL GARDENS</p> - -<div class="blockquot"> - -<p>R. C. Murphy, 1936, <i>Oceanic Birds of South America</i>, Vol. -1, p. 374 (penguins). F. Harper, 1953, <i>Amer. Midland Nat.</i>, -Vol. 49, p. 6 (birds and lichens). H. W. Feilden, 1877, -<i>Zoologist</i>, Vol. 1, p. 319 (arctic-fox gardens).</p> -</div> - - -<p class="tdl caption3nb" id="ref_52">DROPPING THINGS</p> - -<div class="blockquot"> - -<p>M. E. W. North, 1948, <i>Ibis</i>, p. 138-41 (lammergeier). -E. Jaeger, 1951, <i>Condor</i>, 53, p. 207 (sparrow).</p> -</div> - - -<p class="tdl caption3nb" id="ref_53">LEARNING BY BIRDS</p> - -<div class="blockquot"> - -<p>A. L. Rand, 1941, <i>Bull. Amer. Mus. Nat. Hist.</i>, Vol. 78, p. 222 -(thrasher). A. L. Rand, 1942, <i>Bull. Amer. Mus. Nat. Hist.</i>, -Vol. 79, p. 518 (blue jay).</p> -</div> - - -<p class="tdl caption3nb" id="ref_54">CAN BIRDS COUNT?</p> - -<div class="blockquot"> - -<p><i>Bird-banding</i>, 1940, Vol. 11, p. 121 (summary various experiments).</p> -</div> - - -<p class="tdl caption3nb" id="ref_55">COURTSHIP FEEDING</p> - -<div class="blockquot"> - -<p>D. Lack, 1940, <i>Auk</i>, Vol. 57, p. 169 (courtship feeding).</p> -</div> - - -<p class="tdl caption3nb" id="ref_56">THEY TURNED THE TABLES</p> - -<div class="blockquot"> - -<p>A. C. Bent, 1926, <i>U. S. Natl. Mus. Bull.</i> 135, p. 109 (great -blue heron). W. P. Baldwin, 1946, <i>Auk</i>, Vol. 63, p. 589 -(oyster catcher). G. Mackay, 1929, <i>Auk</i>, 46, p. 123 (goldfinch). -D. Bannerman, 1936, <i>Birds Tropical West Africa</i>, -Vol. 4, p. 244 (dusky flycatcher).</p> -</div> - - -<p class="tdl caption3nb" id="ref_57">SURVIVAL OF THE UNFIT</p> - -<div class="blockquot"> - -<p>A. W. Anthony, 1898, <i>Auk</i>, Vol. 15, p. 314 (frigate bird). -J. Cassin, 1858, <i>United States exploring expedition ..., -Mammals and Birds</i>, Philadelphia, p. 364 (brown booby).</p> -</div> - -<p><span class="pagenum" id="Page_219">- 219 -</span></p> - -<p class="tdl caption3nb" id="ref_59">DECORATION IN THE HOME</p> - -<div class="blockquot"> - -<p>A. C. Bent, 1937, <i>U. S. Nat. Mus. Bull.</i> 167, p. 151 (red-tailed -hawk), p. 296 (golden eagle). M. R. Lieff and N. P. -Jordan, 1950, <i>British Birds</i>, Vol. 43, p. 56 (carrion crow). -E. H. Forbush, 1929, <i>Birds of Mass., etc.</i>, Vol. 3, p. 141 -(purple martin). A. L. Rand, 1936, <i>Bull. Amer. Mus. Nat. -Hist.</i>, Vol. 72, pp. 487, 490 (weaverbird).</p> -</div> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_221">- 221 -</span></p> -<h2 class="nobreak" id="INDEX">INDEX</h2> -</div> - - -<p> -<span style="margin-left: 1em;">adaptation, 31</span><br /> -<span style="margin-left: 1em;">Aeschylus, death of, 186</span><br /> -<span style="margin-left: 1em;">Aeschylus on vultures, 172</span><br /> -<span style="margin-left: 1em;">ani, feeding rates of, 168</span><br /> -<span style="margin-left: 1em;">anointing feathers, 25</span><br /> -<span style="margin-left: 1em;">anting, 27</span><br /> -<span style="margin-left: 1em;">anvil, thrush's, 15</span><br /> -<span style="margin-left: 1em;">apartment houses, 77</span><br /> -<span style="margin-left: 1em;">Arctic fox and snowy owl, 49</span><br /> -<span style="margin-left: 1em;">association of: burrowing owl, prairie dog, snake, 73</span><br /> -<span style="margin-left: 2em;">lizard, petrel, 75</span><br /> -<span style="margin-left: 2em;">parrot, duck, opossum, 75</span><br /> -<span style="margin-left: 2em;">social weaver, falcon, 74</span><br /> -<br /> -<span style="margin-left: 1em;">baby sitters, 35</span><br /> -<span style="margin-left: 1em;">bad and good birds, 152</span><br /> -<span style="margin-left: 1em;">bathing in dust, 204</span><br /> -<span style="margin-left: 1em;">bathing in snow, 204</span><br /> -<span style="margin-left: 1em;">bathing in water, 22, 205</span><br /> -<span style="margin-left: 1em;">beehives, guiding to, 125</span><br /> -<span style="margin-left: 1em;">beeswax as bird food, 125</span><br /> -<span style="margin-left: 1em;">bird of paradise, 162</span><br /> -<span style="margin-left: 1em;">boat names, 84</span><br /> -<span style="margin-left: 1em;">booming of nighthawk, 135</span><br /> -<span style="margin-left: 1em;">bower, painting of, 16</span><br /> -<span style="margin-left: 1em;">brigands, birds as, 19</span><br /> -<span style="margin-left: 1em;">brush turkey, 54</span><br /> -<span style="margin-left: 1em;">bucket drawing by jay, 190</span><br /> -<span style="margin-left: 1em;">buried eggs, 45</span><br /> -<span style="margin-left: 1em;">buried young, 45</span><br /> -<br /> -<span style="margin-left: 1em;">cassowaries swim, 149</span><br /> -<span style="margin-left: 1em;">cattle disease and oxpeckers, 129</span><br /> -<span style="margin-left: 1em;"><i>Chicago Tribune</i> farm, 151</span><br /> -<span style="margin-left: 1em;">cliff dwellers, 78</span><br /> -<span style="margin-left: 1em;">colony, mixed, 73</span><br /> -<span class="pagenum" id="Page_222">- 222 -</span><span style="margin-left: 1em;">colony nesters, 77</span><br /> -<span style="margin-left: 1em;">color, change in jay, 164</span><br /> -<span style="margin-left: 1em;">color and palatability, 63</span><br /> -<span style="margin-left: 1em;">communistic care of young, 37</span><br /> -<span style="margin-left: 1em;">community nests, 35</span><br /> -<span style="margin-left: 1em;">conditioning, 136</span><br /> -<span style="margin-left: 1em;">conservation, 151</span><br /> -<span style="margin-left: 1em;">co-operation, 117</span><br /> -<span style="margin-left: 1em;">co-operation: birds and monkeys, 51-53</span><br /> -<span style="margin-left: 2em;">cow and ani, 167</span><br /> -<span style="margin-left: 2em;">in carrying prey, 118</span><br /> -<span style="margin-left: 2em;">in fishing by pelican, 118</span><br /> -<span style="margin-left: 2em;">in killing skunk, 119</span><br /> -<span style="margin-left: 1em;">co-op nursery, 35</span><br /> -<span style="margin-left: 1em;">cormorant: fishing with, 57</span><br /> -<span style="margin-left: 2em;">training, 58</span><br /> -<span style="margin-left: 1em;">cosmetics, various, 26</span><br /> -<span style="margin-left: 1em;">counting, of photographers, 193</span><br /> -<span style="margin-left: 2em;">distinguishing more from less, 193</span><br /> -<span style="margin-left: 1em;">courtship feeding, 195</span><br /> -<span style="margin-left: 2em;">function of, 197</span><br /> -<span style="margin-left: 2em;">significance of, 195</span><br /> -<span style="margin-left: 1em;">covering eggs: by eider duck, 47</span><br /> -<span style="margin-left: 2em;">by grebe, 47</span><br /> -<span style="margin-left: 1em;">cows, use as hunting dogs, 167</span><br /> -<span style="margin-left: 1em;">credit and snowy owl, 48</span><br /> -<span style="margin-left: 1em;">cripples, cared for, 201</span><br /> -<span style="margin-left: 1em;">crocodile bird, 45</span><br /> -<span style="margin-left: 1em;">crow, intelligence of, 98</span><br /> -<span style="margin-left: 1em;">crows profit by experience, 99</span><br /> -<span style="margin-left: 1em;">curiosity, 210</span><br /> -<br /> -<span style="margin-left: 1em;">dangerous prey, 198</span><br /> -<span style="margin-left: 1em;">death: caused by clam, 199</span><br /> -<span style="margin-left: 2em;">by porcupine, 202</span><br /> -<span style="margin-left: 2em;">by spiders, 200</span><br /> -<span style="margin-left: 1em;">decoration: function of, 209</span><br /> -<span style="margin-left: 2em;">in nests, 207</span><br /> -<span style="margin-left: 2em;">snakeskin in, 113</span><br /> -<span style="margin-left: 1em;">droppings things: 186</span><br /> -<span style="margin-left: 2em;">by crows, 16</span><br /> -<span style="margin-left: 2em;">by gulls, 16, 187</span><br /> -<span style="margin-left: 2em;">by lammergeier, 186</span><br /> -<span style="margin-left: 2em;">by sparrow, 187</span><br /> -<span style="margin-left: 2em;">reason for, 188</span><br /> -<span style="margin-left: 1em;">drumming: of grouse, 134</span><br /> -<span style="margin-left: 2em;">of woodpecker, 133</span><br /> -<span style="margin-left: 1em;">drunkenness, 32</span><br /> -<span style="margin-left: 1em;">duck, muscovy, 162</span><br /> -<br /> -<span style="margin-left: 1em;">ecological competition, 173</span><br /> -<span style="margin-left: 1em;">eggs: buried, 55</span><br /> -<span style="margin-left: 2em;">covered, 46, 47</span><br /> -<span style="margin-left: 2em;">in other birds' nests, 91</span><br /> -<span style="margin-left: 2em;">specializations, 93</span><br /> -<span style="margin-left: 1em;">eider down, 71</span><br /> -<span style="margin-left: 1em;">environment modifies heredity, 139</span><br /> -<span style="margin-left: 1em;">Eskimo, credit to, 48</span><br /> -<span style="margin-left: 1em;">experience: crows profit by, 99</span><br /> -<span style="margin-left: 2em;">learning by, 189</span><br /> -<br /> -<span style="margin-left: 1em;">feathers: and size of bird, 67</span><br /> -<span style="margin-left: 2em;">and temperature, 67</span><br /> -<span style="margin-left: 2em;">number of, 66</span><br /> -<span style="margin-left: 1em;">feeding rates of ani, 168</span><br /> -<span style="margin-left: 1em;">fish eats bird, 95</span><br /> -<span style="margin-left: 1em;">fishing with cormorants, 57</span><br /> -<span style="margin-left: 1em;">flavor of flesh, 63, 142</span><br /> -<span style="margin-left: 1em;">flesh: flavor of, 63, 142</span><br /> -<span style="margin-left: 2em;">poisonous, 141</span><br /> -<span style="margin-left: 1em;">fluctuations in the Arctic, 48</span><br /> -<span style="margin-left: 1em;">food: impaling of by shrike, 61</span><br /> -<span style="margin-left: 2em;">storage of, 32, 61</span><br /> -<span style="margin-left: 1em;">foster parents, 93</span><br /> -<span style="margin-left: 1em;">foster young, specialization in, 93</span><br /> -<span style="margin-left: 2em;">foxing, 166</span><br /> -<span style="margin-left: 1em;">frogs mistaken for birds, 109</span><br /> -<br /> -<span style="margin-left: 1em;">gardens: animal, 183</span><br /> -<span style="margin-left: 2em;">ecological balance in, 153</span><br /> -<span style="margin-left: 2em;">of Arctic fox, 185</span><br /> -<span style="margin-left: 1em;">good and bad birds, 152</span><br /> -<span style="margin-left: 1em;">grackles, character of, 152</span><br /> -<span style="margin-left: 1em;">graveyards: 180</span><br /> -<span style="margin-left: 2em;">in hollow tree, 181</span><br /> -<span style="margin-left: 2em;">on island, 182</span><br /> -<span style="margin-left: 2em;">penguins', 180</span><br /> -<span style="margin-left: 1em;">green hunting jay, 164</span><br /> -<span style="margin-left: 1em;">guarding birds' nests, by insects, 121</span><br /> -<span style="margin-left: 1em;">guides to honey, 124</span><br /> -<br /> -<span style="margin-left: 1em;">hair pulling, 102</span><br /> -<span class="pagenum" id="Page_223">- 223 -</span><span style="margin-left: 1em;">helpers at nesting time, 81</span><br /> -<span style="margin-left: 1em;">heredity modified by environment, 139</span><br /> -<span style="margin-left: 1em;">hibernation, 108</span><br /> -<span style="margin-left: 1em;">honey guides: 124</span><br /> -<span style="margin-left: 2em;">lead to big game, 125</span><br /> -<span style="margin-left: 1em;">hornbills' nests, 42</span><br /> -<span style="margin-left: 1em;">households, mixed, 73</span><br /> -<br /> -<span style="margin-left: 1em;">identification: caution in making, 161</span><br /> -<span style="margin-left: 2em;">errors in, 161</span><br /> -<span style="margin-left: 2em;">over the telephone, 160</span><br /> -<span style="margin-left: 2em;">sight, 161</span><br /> -<span style="margin-left: 1em;">incubation, artificial, 56</span><br /> -<span style="margin-left: 1em;">incubators, bird-made, 54</span><br /> -<span style="margin-left: 1em;">infantile behavior modified, 137</span><br /> -<span style="margin-left: 1em;">inquisitive birds, 210</span><br /> -<span style="margin-left: 1em;">instrumental music, 133</span><br /> -<span style="margin-left: 1em;">intelligence, comparative, 98</span><br /> -<span style="margin-left: 1em;">intoxication, 32</span><br /> -<br /> -<span style="margin-left: 1em;">jays: change of color in, 164</span><br /> -<span style="margin-left: 2em;">helping at nest, 81</span><br /> -<br /> -<span style="margin-left: 1em;">kingfisher: a painting of, 143</span><br /> -<span style="margin-left: 2em;">classical allusions to, 145</span><br /> -<span style="margin-left: 2em;">on the telephone, 143</span><br /> -<span style="margin-left: 2em;">variation in, 144</span><br /> -<br /> -<span style="margin-left: 1em;">lammergeier and Aeschylus, 186</span><br /> -<span style="margin-left: 1em;">larder, shrike's, 60</span><br /> -<span style="margin-left: 1em;">laughing jackass, voice of, 145</span><br /> -<span style="margin-left: 1em;">learning, 189</span><br /> -<span style="margin-left: 1em;">lemming and Arctic fox, 49</span><br /> -<span style="margin-left: 1em;">lichens and birds, 184</span><br /> -<span style="margin-left: 1em;">listing of birds, early, 171</span><br /> -<br /> -<span style="margin-left: 1em;">maladaptation, 31</span><br /> -<span style="margin-left: 1em;">megapode nesting, 54</span><br /> -<span style="margin-left: 1em;">migration, 28</span><br /> -<span style="margin-left: 1em;">mixed households, 73</span><br /> -<span style="margin-left: 1em;">monkey birds: 51</span><br /> -<span style="margin-left: 2em;">and birds, various, 52-53</span><br /> -<span style="margin-left: 1em;">mound builder and nest, 54</span><br /> -<span style="margin-left: 1em;">music, instrumental, 133</span><br /> -<br /> -<span style="margin-left: 1em;">names: appropriateness, 51, 85</span><br /> -<span style="margin-left: 2em;">available scientific, 85</span><br /> -<span style="margin-left: 2em;">domestic and foreign, 157</span><br /> -<span style="margin-left: 2em;">euphony needed, 84</span><br /> -<span style="margin-left: 2em;">for boats, 84</span><br /> -<span style="margin-left: 2em;">how given, 51</span><br /> -<span style="margin-left: 1em;">natural selection not operating, 203</span><br /> -<span style="margin-left: 1em;">nests: co-operative, 79</span><br /> -<span style="margin-left: 2em;">decoration of, 207</span><br /> -<span style="margin-left: 2em;">Guarded by insects, 121</span><br /> -<span style="margin-left: 2em;">helpers at, 81</span><br /> -<span style="margin-left: 2em;">in soup, 38, 48</span><br /> -<span style="margin-left: 2em;">last year's, 69</span><br /> -<span style="margin-left: 2em;">leaves in, 207</span><br /> -<span style="margin-left: 2em;">megapodes, 54</span><br /> -<span style="margin-left: 2em;">parasitism, 91</span><br /> -<span style="margin-left: 2em;">secondhand, 69</span><br /> -<span style="margin-left: 2em;">subleases on, 69</span><br /> -<span style="margin-left: 2em;">transportation of, 28</span><br /> -<span style="margin-left: 2em;">use by man, 71</span><br /> -<span style="margin-left: 2em;">use of snakeskin in, 111</span><br /> -<span style="margin-left: 2em;">walled, of hornbill, 42—44</span><br /> -<span style="margin-left: 1em;">nest building, co-operative, 79</span><br /> -<span style="margin-left: 1em;">nidification, reptile type, 56</span><br /> -<span style="margin-left: 1em;">nursery, 35</span><br /> -<br /> -<span style="margin-left: 1em;">oil glands, 25</span><br /> -<span style="margin-left: 1em;">owl, and toad, 190</span><br /> -<span style="margin-left: 1em;">owl, intelligence of, 98</span><br /> -<span style="margin-left: 1em;">oxpecker: 127</span><br /> -<span style="margin-left: 2em;">value to herds, 128</span><br /> -<br /> -<span style="margin-left: 1em;">painting a kingfisher, 143</span><br /> -<span style="margin-left: 1em;">painting of bower, 16</span><br /> -<span style="margin-left: 1em;">palatability, 63</span><br /> -<span style="margin-left: 1em;">penguins, maternal, 36</span><br /> -<span style="margin-left: 1em;">people, birds perching on, 102</span><br /> -<span style="margin-left: 1em;">pilfering: 104</span><br /> -<span style="margin-left: 2em;">by grackle, 106</span><br /> -<span style="margin-left: 2em;">by kingfisher, 105</span><br /> -<span style="margin-left: 2em;">by shrike, 105</span><br /> -<span style="margin-left: 2em;">by starling, 105</span><br /> -<span style="margin-left: 1em;">poison fruit, 31</span><br /> -<span style="margin-left: 1em;">poisonous birds, 140</span><br /> -<span style="margin-left: 1em;">poor-will in hibernation, 109</span><br /> -<span style="margin-left: 1em;">powder down, 26</span><br /> -<span style="margin-left: 1em;">preening, 25</span><br /> -<span style="margin-left: 1em;">probe, used by finch, 17</span><br /> -<br /> -<span style="margin-left: 1em;">references, 213</span><br /> -<span class="pagenum" id="Page_224">- 224 -</span><span style="margin-left: 1em;">retarded development, 137</span><br /> -<span style="margin-left: 1em;">rhino bird, 128</span><br /> -<span style="margin-left: 1em;">robbery: by birds, 19,104</span><br /> -<span style="margin-left: 2em;">by eagle, 19, 20</span><br /> -<span style="margin-left: 2em;">by frigate bird, 20</span><br /> -<span style="margin-left: 2em;">by raven, 99</span><br /> -<span style="margin-left: 2em;">by skua, 21</span><br /> -<span style="margin-left: 1em;">Rome, founding of, 171</span><br /> -<span style="margin-left: 1em;">Romulus and Remus as bird watchers, 171</span><br /> -<br /> -<span style="margin-left: 1em;">Salvador bird voices, 157</span><br /> -<span style="margin-left: 1em;">sand grouse carrying water, 178</span><br /> -<span style="margin-left: 1em;">sea serpents: identification of, 147</span><br /> -<span style="margin-left: 2em;">in Kenya, 148</span><br /> -<span style="margin-left: 2em;">in New Guinea, 148</span><br /> -<span style="margin-left: 1em;">sentinel of the monkey, 53</span><br /> -<span style="margin-left: 1em;">sewing nests, 89</span><br /> -<span style="margin-left: 1em;">sexes: battle of, 173</span><br /> -<span style="margin-left: 2em;">different diets of, 175</span><br /> -<span style="margin-left: 1em;">sexual differences, ecological significance of, 173</span><br /> -<span style="margin-left: 1em;">shrike's larder, 60</span><br /> -<span style="margin-left: 1em;">shrike, young, infantile behavior prolonged, 137</span><br /> -<span style="margin-left: 1em;">slave of the monkeys, 52</span><br /> -<span style="margin-left: 1em;">snails, broken on anvil, 15</span><br /> -<span style="margin-left: 1em;">snakeskins: in nests, 111</span><br /> -<span style="margin-left: 2em;">as decorations, 112</span><br /> -<span style="margin-left: 2em;">bibliographic work on use of, 114</span><br /> -<span style="margin-left: 2em;">reasons for using, 115</span><br /> -<span style="margin-left: 2em;">theories of use, 113</span><br /> -<span style="margin-left: 1em;">snowy owl, as trade index, 49</span><br /> -<span style="margin-left: 1em;">social parasites, 33, 91</span><br /> -<span style="margin-left: 1em;">soothsayers use birds, 172</span><br /> -<span style="margin-left: 1em;">sounds produced mechanically, 134</span><br /> -<span style="margin-left: 1em;">soup, birds'-nest, 38</span><br /> -<span style="margin-left: 1em;">storage: of acorns, 32</span><br /> -<span style="margin-left: 2em;">of fish, 33</span><br /> -<span style="margin-left: 1em;">survival of unfit, 201</span><br /> -<span style="margin-left: 1em;">swifts' nests, 38-41</span><br /> -<span style="margin-left: 1em;">symbiosis, 73</span><br /> -<br /> -<span style="margin-left: 1em;">tables turned, 198</span><br /> -<span style="margin-left: 1em;">tailorbirds, 89</span><br /> -<span style="margin-left: 1em;">tameness, 101</span><br /> -<span style="margin-left: 1em;">taste in birds, 189</span><br /> -<span style="margin-left: 1em;">telephone: conversations on, 143, 151</span><br /> -<span style="margin-left: 2em;">identification over, 160</span><br /> -<span style="margin-left: 1em;">theft, petty, 104</span><br /> -<span style="margin-left: 1em;">thrush, breaking snail's shell, 15</span><br /> -<span style="margin-left: 1em;">tick bird, 128</span><br /> -<span style="margin-left: 1em;">ticks, food of oxpecker, 128</span><br /> -<span style="margin-left: 1em;">tolling of ducks, 211</span><br /> -<span style="margin-left: 1em;">tool, use of, 15</span><br /> -<span style="margin-left: 1em;">torpidity, 108</span><br /> -<span style="margin-left: 1em;">trade index, snowy owls as, 49</span><br /> -<br /> -<span style="margin-left: 1em;">unfit survive, 201</span><br /> -<br /> -<span style="margin-left: 1em;">vegetation and penguins, 183</span><br /> -<br /> -<span style="margin-left: 1em;">washing food: 154</span><br /> -<span style="margin-left: 2em;">reasons for, 156</span><br /> -<span style="margin-left: 1em;">watchdogs at nests, 121</span><br /> -<span style="margin-left: 1em;">water: carried by birds, 46, 178</span><br /> -<span style="margin-left: 2em;">flights to, 178</span><br /> -<span style="margin-left: 2em;">need of, 177</span><br /> -<span style="margin-left: 1em;">weaving nests, 88</span><br /> -<span style="margin-left: 1em;">wing music of owl, 134</span><br /> -<span style="margin-left: 1em;">wings: use of, 130</span><br /> -<span style="margin-left: 2em;">in feeding, 131</span><br /> -<span style="margin-left: 1em;">winnowing of snipe, 134</span><br /> -<span style="margin-left: 1em;">wisdom, owl, symbol of, 98</span><br /> -<br /> -<span style="margin-left: 1em;">young: buried, 45</span><br /> -<span style="margin-left: 2em;">communistic care of, 37</span><br /> -<span style="margin-left: 2em;">fed by other young, 81, 203</span><br /> -<span style="margin-left: 2em;">honey-guide's, 33</span><br /> -<span style="margin-left: 2em;">independent from hatching, 55</span><br /> -</p> - - -<hr class="tb" /> - - -<div class="transnote"> - -<p class="caption3nb">Transcriber Note</p> - -<p class="tdc">Minor typos corrected.</p> - -</div> - -<div style='display:block; margin-top:4em'>*** END OF THE PROJECT GUTENBERG 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