diff options
| author | nfenwick <nfenwick@pglaf.org> | 2025-02-06 00:40:15 -0800 |
|---|---|---|
| committer | nfenwick <nfenwick@pglaf.org> | 2025-02-06 00:40:15 -0800 |
| commit | 00036d95ce20d0c98121cdc2c9391197952ced1e (patch) | |
| tree | a38acc4e8f0820c6b27b3400856eb516e08cc77e | |
| parent | 3435958fde06b58778d39078c73c1f54e75faff5 (diff) | |
| -rw-r--r-- | .gitattributes | 4 | ||||
| -rw-r--r-- | LICENSE.txt | 11 | ||||
| -rw-r--r-- | README.md | 2 | ||||
| -rw-r--r-- | old/52382-8.txt | 2481 | ||||
| -rw-r--r-- | old/52382-8.zip | bin | 44712 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h.zip | bin | 296870 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/52382-h.htm | 2720 | ||||
| -rw-r--r-- | old/52382-h/images/cover.png | bin | 13676 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/images/fig1.jpg | bin | 48129 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/images/fig2.jpg | bin | 48329 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/images/fig3.jpg | bin | 26323 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/images/fig4.jpg | bin | 46670 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/images/fig5.jpg | bin | 44006 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/images/fig6.jpg | bin | 25833 -> 0 bytes | |||
| -rw-r--r-- | old/52382-h/images/logo.png | bin | 392 -> 0 bytes |
15 files changed, 17 insertions, 5201 deletions
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..99c3277 --- /dev/null +++ b/README.md @@ -0,0 +1,2 @@ +Project Gutenberg (https://www.gutenberg.org) public repository for +eBook #52382 (https://www.gutenberg.org/ebooks/52382) diff --git a/old/52382-8.txt b/old/52382-8.txt deleted file mode 100644 index 341a9fd..0000000 --- a/old/52382-8.txt +++ /dev/null @@ -1,2481 +0,0 @@ -The Project Gutenberg EBook of Studies of Birds Killed in Nocturnal -Migration, by Harrison B. Tordoff and Robert M. Mengel - -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'll have -to check the laws of the country where you are located before using this ebook. - - - -Title: Studies of Birds Killed in Nocturnal Migration - -Author: Harrison B. Tordoff - Robert M. Mengel - -Release Date: June 20, 2016 [EBook #52382] - -Language: English - -Character set encoding: ISO-8859-1 - -*** START OF THIS PROJECT GUTENBERG EBOOK STUDIES OF BIRDS *** - - - - -Produced by Judith Wirawan, Chris Curnow, Joseph Cooper -and the Online Distributed Proofreading Team at -http://www.pgdp.net - - - - - - - - - - - UNIVERSITY OF KANSAS PUBLICATIONS - MUSEUM OF NATURAL HISTORY - - - Volume 10, No. 1, pp. 1-44, 6 figures in text, 2 tables - - September 12, 1956 - - - Studies of Birds - Killed in Nocturnal Migration - - - BY - HARRISON B. TORDOFF AND ROBERT M. MENGEL - - - UNIVERSITY OF KANSAS - LAWRENCE - 1956 - - * * * * * - - UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY - - Editors: E. Raymond Hall, Chairman, A. Byron Leonard, - Robert W. Wilson - - - Volume 10, No. 1, pp. 1-44, 6 figures in text, 2 tables - Published September 12, 1956 - - - UNIVERSITY OF KANSAS - Lawrence, Kansas - - - PRINTED BY - FERD VOILAND, JR., STATE PRINTER - TOPEKA, KANSAS - 1956 - - [Illustration: Logo] - - 26-3856 - - - * * * * * - -Studies of Birds Killed in Nocturnal Migration - -BY HARRISON B. TORDOFF AND ROBERT M. MENGEL - - - - -Contents - - - PAGE - - Introduction 4 - - Accidents to Migrating Birds in early October, 1954 6 - General 6 - Accidents at Topeka, Kansas 6 - Description of WIBW-TV tower 7 - Weather conditions 7 - - Acknowledgments 7 - - Notes on the Species Killed at Topeka 8 - - Randomness of the Sample 17 - - Number of Migrants 18 - - Differential Migration of Sex- and Age-classes 20 - History of the subject 20 - Differential migration of sex- and age-classes as - shown by the Topeka sample 23 - - Molt in Relation to Migration 29 - General comment 29 - Molt in the Topeka sample 30 - - Size Differences according to Sex and Age 31 - Linear measurements 31 - Weights 32 - - Computations of Longevity and Survival 38 - - Processing of Samples 38 - - Summary 39 - - Literature Cited 41 - - - - - -Introduction - - -This paper is primarily an analysis of a sample of migrant birds -killed in the autumn of 1954 by striking a television tower one mile -west of Topeka, Shawnee County, Kansas. Secondarily, some aspects of -migration involved in studies of this kind are discussed and -historical background is presented. - -Considerable interest has been occasioned in recent years in the -eastern United States by large-scale accidents to night-migrating -birds. Most accidents have occurred in the autumn. The widespread -adoption by airports of an instrument called the ceilometer, which -measures the height of cloud ceilings by reflecting from them a -high-powered beam of light, has proved under certain conditions to be -catastrophic to night-flying birds. Among the recent reports of such -accidents are those of Spofford (1949) and Laskey (1951) for -Nashville, Tennessee, Howell and Tanner (1951) for Knoxville, -Tennessee, and Lovell (1952) for Louisville, Kentucky. Recently -Howell, Laskey, and Tanner (1954) reviewed ceilometer "tragedies" -without being able to determine the exact reason for their lethal -effectiveness. Less publicized so far have been mass collisions of -birds with another class of obstacles, tall radio and television -towers. These slender towers, usually 500 to 1000 feet tall, are -increasing rapidly in numbers and there is reason to suppose that they -will take a correspondingly larger toll of bird life. - -Notice has long been given by ornithologists to mass destruction of -birds by more conventional solid obstructions to passage, and -newspapers occasionally mention birds killed at such well-known points -as the Washington Monument and the Empire State Building. - -Seventy-five years ago, J. A. Allen (1880) published the results of -questionnaires circulated by William Brewster to lighthouse keepers. -Brewster himself (1886) described destruction of birds at a lighthouse -in the Bay of Fundy, paying keen attention to behavior of the birds -and the exact conditions under which nocturnal flight and accidents -occurred. The subject also received attention in several countries -across the Atlantic. Destruction of birds at Irish lighthouses was -carefully noted over a period of years and the results were published -periodically, culminating in R. M. Barrington's massive report (1900) -which remains in some ways the most thorough of its type. - -While conservation-minded individuals have been concerned with the -tremendous mortality involved in these various events, the ill wind -blows some good in that, properly used, the data provided by such -accidents can shed light on many obscure aspects of bird migration. -Each accidental kill of birds affords a cross-section, approaching in -variable degree a random sample, of the migrants passing a given point -on a given date. The types of information provided by such kills are -numerous, for example: (1) information on the presence of various -species and the dates of their occurrence; (2) information on the -relative abundance of species; (3) quantitative data on the relative -sizes of males and females, and immatures and adults (of importance to -taxonomic ornithology); (4) information on the relative times of -migration of males, females, adults, and young; (5) information on -molts and plumages; (6) quantitative information on composition by -subspecies of migrants of the same species; (7) physiological data -(fat condition, _etc._) pertinent to the study of migration; and -probably others. - -In spite of the great potential of this kind of material, the majority -of ornithologists with access to such data have contented themselves -with listing the species and sometimes the numbers of birds killed. A -few have gone further. James T. Tanner (unpublished) attempted to -compute the longevity of the Ovenbird (_Seiurus aurocapillus_) by -analysis of ceilometer-killed birds at Knoxville, Tennessee (see -below). Mention should be made of the reports of Rintoul and Baxter -(1914) supplemented by Ticehurst (1916) who used rather small numbers -of birds killed at Scottish lighthouses in studies of molt. However, -the only effort to utilize the results of accidental kills on a large -scale over a period of years appears to have been that, already -mentioned, of Barrington (1900) and his co-workers in Ireland. An idea -of the potentialities of the large recent kills in the United States -may be obtained when it is recalled that in the 18 years of -Barrington's work, which embodied some 1000 reports from lighthouse -keepers, Barrington obtained for study only about 2000 specimens, many -of these consisting of wings and feet only (Barrington's paper not -seen in original; see J. A. Allen, 1901:205). More recently Dobben and -Bruyns (1939) have analyzed the age and sex classes of some birds -killed at lighthouses in Holland. - -As far as we have learned, there is no previous thorough analysis in -the literature of large, accidentally-killed samples of birds. On the -following pages we emphasize some of the uses which can be made of -such material. We think that intensive analyses of such events, -whenever they occur, should become a regular part of ornithological -investigation and that integration of numerous studies of such -incidents will provide an unprecedented mass of information on -migration. - - - - -Accidents to Migrating Birds in early October, 1954 - - -GENERAL.--The few days around the end of the first week of October, -1954, were notable for a series of accidents which occurred to -migrating birds over much of eastern United States. So far as we know, -these were all associated with an extensive belt of bad weather (cold -fronts and stationary fronts) which covered much of the country during -that period, and the accidents involved ceilometers and solid -structures alike. Accidents known to us occurred as far south as -Macon, Georgia (David W. Johnston, letter: Nov. 1, 1954), as far north -as New York City, where many migrants were killed at the Empire State -Building (_New York Times_, Thursday, October 7, 1954, p. 1) and -elsewhere, and as far west as Smoky Hill Air Force Base at Salina, -Kansas (ceilometer, October 7, some birds received at the University -of Kansas). Some of the above, and incidents from a number of other -localities, were mentioned in varying detail in _Audubon Field Notes_ -(vol. 9, no. 1, pp. 6, 10, 15, 17, 18, 32, February, 1955). Still -other accidents occurred at Columbia, Missouri (Richard P. -Grossenheider, verbal communication), and Topeka, Kansas (present -paper). Some probably have escaped our notice; summaries of some of -these will probably appear in ornithological journals for some time to -come. At Robins Air Force Base near Macon, Georgia, at least 50,000 -birds were killed, of which about 2500, representing 54 species, were -picked up (Johnston, _loc. cit._). - - -ACCIDENTS AT TOPEKA, KANSAS.--At Topeka, Shawnee County, Kansas, all -birds were killed by collision with the newly-erected (1954) -television transmitting tower of station WIBW-TV. This tower is one -mile west of the city. - -The first casualties (see Table 1 for all others) were a Sora -(_Porzana carolina_) and a Yellow-bellied Flycatcher (_Empidonax -flaviventris_) found on September 7. The major accidents, however, -occurred on the nights of September 24-25, September 30-October 1, -October 5-6, and October 6-7. Totals of birds picked up (probably over -95 per cent of birds killed) are given in Table 1, in which each date -given is that of the day after the kill, _i. e._, the date on which -the birds were collected. - -All major kills occurred on cloudy and foggy nights associated with -frontal weather. Throughout the period a few birds struck the tower -even on fairly clear nights, and minor but appreciable "falls" -occurred on the nights of October 4-5, 7-8, and 22-23. A few birds -killed probably were overlooked for a time and found their way into -later samples. This is especially probable in the case of some birds -entered under date of October 23, as many of these were somewhat -desiccated. Weights clearly altered by desiccation or mutilation were -not recorded. Reports of these accidents have been published by Carson -(1954 a, b, and c). - -According to Carson (1954c:27), the majority of birds killed on nights -of heavy flight fell "between three and four o'clock in the morning -when skies were overcast and a cool front moved in from the north. Due -to the cooperation of the watchmen it is thought that most of the -birds that were killed were recovered. Of course some injured birds in -hiding were not found and some were lost to predators." - - -DESCRIPTION OF WIBW-TV TOWER.--The tower is 950 feet tall and stands -on a hill approximately 1000 feet above sea level. The fact that the -tower is on a hill places the top of the tower at 1010 feet above the -elevation of the average local terrain. The tower is triangular in -cross-section, each face seven feet wide, and is constructed of -six-inch steel L-beams with three-inch cross-members every seven feet -and smaller diagonal cross-members. It has no taper and bears a -transmitting antenna on the top. The tower is supported by 12 guy -wires, 3 wires attaching at each of 4 levels. The cables extend south, -WNW, and NNE from the tower and are 1-1/2 inches in diameter. The -tower is lighted by a series of red lights, some flashing and others -steady. The transmitter was not in operation when the accidents took -place. - - -WEATHER CONDITIONS.--All major kills at Topeka occurred when migrating -birds encountered either a cold front or a stationary front lying over -eastern Kansas. Typically, this frontal weather included rain, fog, -and cloud ceilings down to as low as 800 to 1000 feet. Weather of this -type presumably forces the migrating birds to fly below the cloud -ceiling and thus brings them within the altitudinal range of the -television towers. - - - - -Acknowledgments - - -We gratefully acknowledge our debt to the Topeka Audubon Society for -making this study possible by carefully collecting birds killed at the -television tower. L. B. Carson deserves special mention for his -general supervision of the bird collecting by the members of the -Topeka Audubon Society. Members of the Society and others who picked -up birds under the television tower were: Mrs. Lloyd Biggs, Elaine -Carson, L. B. Carson, Jesse A. Eddy, Elizabeth Fisher, Mrs. Walter -Huxman, Florence McKinney, Mrs. Charles Martin, Mrs. Fred P. Martin, -T. W. Nelson, Fred Prebble, Grace Prebble, Orville Rice, Mrs. G. -Warren Scholl, E. W. Senne, and Beatrice Swenson. - -We received equally important assistance from students and staff of -the University of Kansas in recording of data and preparation of -specimens. The following helped in these ways: Rollin H. Baker, R. W. -Dickerman, David L. Hardy, J. W. Hardy, Jane S. Mengel, Larry D. -Mosby, Richard Van Gelder, South G. Van Hoose, and Glen E. Woolfenden. -We are indebted to the Interlibrary Loan Service of the University of -Kansas Library for help in securing certain reference works. Robert -Sokal of the University of Kansas gave helpful advice concerning -statistical procedures. - - - - -Notes on the Species Killed at Topeka - - -A list of numbers and kinds of birds killed is given in Table 1. -Discussion of data afforded by certain species for which, large -samples were available will be found below. There are additionally -certain data afforded by the sample and certain comments to be made on -various species which can be handled most conveniently in an annotated -list. In this list we have included all weight data (still scarce for -many North American birds), comments on status in Kansas of various -species, results of comparisons to determine subspecies, and -miscellaneous observations. Weights of birds are given in grams and -were taken on a triple-beam balance. Fat condition is given in the -scale proposed by McCabe (1943:556). Weight data from birds migrating -at night should be especially useful because these migrants all have -relatively empty crops and stomachs, thus reducing variability. Not -all birds were suitable for weighing and measuring, for a variety of -reasons. This accounts for discrepancies in totals between Table 1 and -the annotated list. - -All passerine species were aged by noting the degree of ossification -of the skull. In no case, of the more than a thousand passerines aged -by examination of the skull, did we find difficulty in determining -whether an individual was a bird of the year or an adult. We found no -specimens in which ossification of the skull was nearing completion. -In the several species in our sample with distinctive first-winter -plumages, we found complete agreement in age as shown by plumage and -by condition of the skull. We think this is further proof, if such is -needed, that this method of aging is thoroughly reliable in early -autumn for the passerine species included in our sample and for others -with similar breeding seasons. - -TABLE 1.--BIRDS KILLED AT A TELEVISION TOWER AT TOPEKA, KANSAS, IN -1954 - -See annotated list for division into sex- and age-classes. Where -discrepancies exist between totals given here and totals given in the -annotated list, these result from the fact that some specimens could -not be sexed and aged. - - A: Sept. 25 - B: Oct. 1 - C: Oct. 3 - D: Oct. 4 - E: Oct. 5 - F: Oct. 6 - G: Oct. 7 - H: Oct. 8 - I: Oct. 9 - J: Oct. 10 - K: Oct. 23 - L: Totals - - =======================+===+===+===+===+===+===+===+===+===+===+===+==== - | A | B | C | D | E | F | G | H | I | J | K | L - -----------------------+---+---+---+---+---+---+---+---+---+---+---+---- - Pied-billed Grebe | | 1| | | | 1| | | 1| | | 3 - Green Heron | | | | | | 1| | | | | | 1 - Blue-winged Teal | | 1| | | | 1| 6| | | | | 8 - Virginia Rail | | 3| | | | 1| | | | | | 4 - Sora | 1| 6| | | | 1| 1| 1| | | | 10 - American Coot | | | | | | 3| | | | | | 3 - Mourning Dove | | 8| | | 1| | | | | | 1| 10 - Yellow-billed Cuckoo | | | | | | 1| | | | | | 1 - Black-billed Cuckoo | | | | | | | 1| | | | | 1 - Yellow-shafted Flicker | 3| | | | | | | | | | | 3 - Yellow-bellied | | | | | | | | | | | | - Flycatcher | | | | | | | 1| | | | | 1 - House Wren | 2| 3| | | | 1| 2| 1| | | 1| 10 - Long-billed Marsh Wren | | 1| | | | 1| 1| | | | | 3 - Short-billed Marsh Wren| 1| 2| | | | | 1| | | | | 4 - Catbird | 1| 28| 1| | 1| 6| 6| | | | | 43 - Brown Thrasher | | 1| | | | 1| | 1| | | | 3 - Wood Thrush | | 3| | | | | | | | | | 3 - Hermit Thrush | | | | | | | | | | 1| | 1 - Olive-backed Thrush | | 14| | 1| | | 1| | | | | 16 - Golden-crowned Kinglet | | | | | | | | | | 1| 5| 6 - Ruby-crowned Kinglet | 2| 1| | | | | 8| 1| 1| | 1| 14 - Yellow-throated Vireo | | 1| | | | | | | | | | 1 - Blue-headed Vireo | 1| 19| | 1| 2| 5| 8| 3| 1| | | 40 - Red-eyed Vireo | 18| 36| | | 2| 13| 2| 3| | | 1| 75 - Philadelphia Vireo | 3| 9| | | | | | | | | | 12 - Warbling Vireo | 8| 19| 1| | 4| 1| 1| | | | | 34 - Black and White Warbler| 1| 1| | | | 3| | | | | | 5 - Tennessee Warbler | | 1| | | 1| 2| 1| | | | | 5 - Orange-crowned Warbler | 7| 14| | | 1| 4| 19| 5| 1| 1| | 52 - Nashville Warbler | 7| 94| 4| | 3| 39| 27| 5| | 1| 1| 181 - Parula Warbler | | | | | | | 1| | 1| | | 2 - Yellow Warbler | 3| 3| | | | 1| 1| | | | | 8 - Magnolia Warbler | | 1| | | | 2| | | | | | 3 - Black-throated Blue | | | | | | | | | | | | - Warbler | | | | | | | 2| | | | 1| 3 - Myrtle Warbler | | | | | | | | | 1| | | 1 - Black-throated Green | | | | | | | | | | | | - Warbler | | | | | | | | | | 1| | 1 - Chestnut-sided Warbler | | 1| | | | | | | 1| | | 2 - Bay-breasted Warbler | 1| | | | | 2| | | | | | 3 - Palm Warbler | 3| | | | | | | | | | 1| 4 - Oven-bird | 4| 21| | | | 2| 3| 1| | | 1| 32 - Northern Water-thrush | | 5| | | | | | | | 1| | 6 - Mourning Warbler | 15| 64| | | 2| 11| 2| 1| | | | 95 - Yellow-throat | 10|115| 2| | 4| 25| 18| 1| 1| | | 176 - Yellow-breasted Chat | | 1| | | | | | | | | | 1 - Wilson Warbler | 1| 2| | | | | | | | | | 3 - Canada Warbler | | 2| | | | | | | | | | 2 - American Redstart | 1| | | | | | | | | | | 1 - Bobolink | | 4| | | | | | | | | | 4 - Rose-breasted Grosbeak | | 2| | | | | | | | | | 2 - Indigo Bunting | | 1| | | 2| 3| 1| | | | | 7 - Dickcissel | | 31| | | 1| 3| 1| | | | | 36 - Savannah Sparrow | 1| 6| | 1| | 1| 5| 1| | | 1| 16 - Grasshopper Sparrow | | 7| | | 2| 3| 3| 1| 1| | 1| 18 - Leconte Sparrow | | | | | | | | | | | 3| 3 - Sharp-tailed Sparrow | | | | | | 1| 1| | | 1| | 3 - Slate-colored Junco | | | | | | | | | | | 1| 1 - Clay-colored Sparrow | | 11| 1| | | 2| | 1| | | | 15 - Fox Sparrow | | | | | | | | | | | 1| 1 - Lincoln Sparrow | 41| 7| | | 5| 22| 3| 1| | | 3| 82 - Swamp Sparrow | | 1| | | | 1| 2| | | | | 4 - Song Sparrow | | | | | | | | | | | 2| 2 - Total--species | 22| 41| 6| 3| 13| 31| 29| 16| 10| 8| 15| 61 - Total--individuals | 94|585| 16| 3| 26|146|147| 31| 10| 8| 24|1090 - ------------------------------------------------------------------------ - -The annotated list may be consulted for further data in connection -with the species listed in Table 1. As is indicated below, we regard -the figures of this sample as unreliable to an unknown degree in -comparing the relative abundance of one species with another. -Accumulation of such data from various localities, however, should -prove useful in another type of comparison. Samples of the same -species killed in the same way at about the same time at different -localities should be directly comparable. Eventually, this should -provide us with a means of determining relative abundance of a species -in different parts of its migratory route. - -Approximately 200 of the most interesting specimens were preserved as -study skins and are in the University of Kansas Museum of Natural -History. An effort was made to preserve at least one of each species, -and we fell only a few short of this goal. All of the forms rare in -Kansas are represented by skins. We could see no reason to list the -preserved specimens in detail here. Species of which no study skins -were made, however, are so marked. - -So far as we can tell, no truly western subspecies (from west of the -Great Plains) occurred in the Topeka sample. Probably most or all of -the birds came from areas more or less directly north of eastern -Kansas. - -In critical areas where different subspecies of the same species occur -together in migration, data from samples of this kind should prove -enlightening. In future analyses, conducted in such areas, it might be -possible to preserve all specimens of some of the variable species, or -at least to measure all individuals of species in which size is the -most important variable character. Quantitative study could then be -made of the different geographic variants occurring, their proportions -in the migrant population determined, and their origins deduced. In -studying populations of Painted Buntings (_Passerina ciris_) wintering -in Mexico, Storer (1951) has provided an interesting demonstration of -methods which can be applied to such samples. - -A few bats killed at the tower provided a surprise. They will be -discussed separately by Richard Van Gelder. - - _Podilymbus p. podiceps._ Pied-billed Grebe.--Weights: male, - 394.8 (all weights in grams); females, 332.5, 289.7; all - fat. - - _Butorides v. virescens._ Green Heron.--Weight: 1 (unsexed), - 168.6. - - _Anas discors._ Blue-winged Teal.--Weights: 4 males, mean - 421.2 (391.3-458.1); 3 females, 367.7, 371.6, 393.2; all - fat. - - _Rallus limicola._ Virginia Rail.--Weights: 3 males, 73.7, - 83.2, 90.5; 1 female, 67.3; moderately fat to fat. - - _Porzana carolina._ Sora.--Weights: 4 males, mean 76.8 - (68.7-89.9); 3 females, 62.6, 63.2, 63.5; moderately fat to - very fat. - - _Fulica americana._ American Coot.--Weights: 2 females, - 385.3, 530.0, both fat. None preserved. - - _Zenaidura macroura marginella._ Mourning Dove.--Weights: 2 - adult males, 121.8, 140.2; 3 immature males, 113.1, 126.1, - 130.0; 3 adult females, 122.5, 126.9, 136.0; 2 immature - females, 129.4, 132.7; moderately fat to very fat. The - presence of Mourning Doves in the sample is interesting as - these birds are not generally regarded as night migrants. - Conceivably the specimens were local birds going to roost. - None preserved. - - _Colaptes auratus luteus._ Yellow-shafted Flicker.--Weights: - 2 males, 126.0, 139.4, little fat. Flickers have several - times been recorded as night migrants. - - _Empidonax flaviventris._ Yellow-bellied - Flycatcher.--Weight: 1 immature male, 11.9, moderately fat. - This is a rare species in Kansas, the present being the - ninth preserved specimen for the State. - - _Troglodytes aëdon parkmanii._ House Wren.--Weights: 4 adult - males, mean 10.5 (9.8-10.9), 2 immature males, 9.0, 11.3; 1 - adult female, 9.9, 1 immature female, 7.0; no fat (im. - [**Female symbol]) to fat. - - _Telmatodytes palustris dissaëptus._ Long-billed Marsh - Wren.--Weights: 1 adult male, 10.8; 1 adult female, 9.2; - both moderately fat. The specimens are moderately bright and - rufescent above, being typical of the populations of the - central plains. - - _Cistothorus platensis stellaris._ Short-billed Marsh - Wren.--Weights: 1 immature male, 8.2; 1 adult female, 8.1; - immature female, 8.2; all fat. - - _Dumetella carolinensis._ Catbird.--Weights: 6 adult males, - mean 37.5 (34.1-42.5), little fat to very fat; 14 immature - males, mean 37.57 ± .94 (standard error), S. D. (standard - deviation) 3.37, little fat to fat; 11 adult females, mean - 39.09 ± .94, S. D. 2.97, little fat to fat; 12 immature - females, mean 38.42 ± .83, S. D. 2.74, moderately fat to - fat. - - _Toxostoma r. rufum._ Brown Thrasher.--Weight: 1 immature - male, 60.2, little fat. - - _Hylocichla mustelina._ Wood Thrush.--Weights: 1 adult male, - 54.2, moderately fat; 2 adult females, 44.6, 45.7, little - fat and fat, respectively. - - _Hylocichla ustulata swainsonii._ Olive-backed - Thrush.--Weights: 6 immature males, mean 31.0 (28.1-33.2), - little fat to fat; 6 adult females, mean 29.6 (27.1-35.0), - moderately fat to fat; 3 immature females, 27.1, 33.8, 35.8, - little fat to fat. The absence of adult males in our sample - of 15 birds is noteworthy but inexplicable with our few - data. - - _Regulus s. satrapa._ Golden-crowned Kinglet.--Weights: 1 - adult male, 6.7, moderately fat; 2 immature males, 6.5, 7.4, - moderately fat and fat; 2 adult females, 7.3, 7.4, - moderately fat and fat; 1 immature female, 7.2, moderately - fat. - - _Regulus c. calendula._ Ruby-crowned Kinglet.--Weights: 3 - adult males, 6.2, 7.6, 8.2, little fat to fat; 1 immature - male, 6.6, fat; 4 adult females, mean 6.1 (5.6-6.7), - moderately fat to fat; 3 immature females, 5.8, 6.6, 7.0, - moderately fat to fat. - - _Vireo flavifrons._ Yellow-throated Vireo.--Weight: 1 - immature male, 21.5, very fat. - - _Vireo s. solitarius._ Blue-headed Vireo.--Weights: 9 adult - males, mean 17.7 (16.6-19.5), little fat to very fat; 17 - immature males, mean 17.53 ± .46, S. D. 1.83, no fat (13.8) - to very fat (21.3); 7 adult females, mean 17.6 (15.0-21.6), - moderately fat to very fat; 6 immature females, mean 17.0 - (14.5-18.9), moderately fat to fat. Surprisingly numerous in - the sample. - - _Vireo olivaceus._ Red-eyed Vireo.--Weights: 1 adult male, - 16.1, moderately fat; 38 immature males, mean 21.21 ± .43, - S. D. 2.60, little fat (1 specimen) to excessively fat, - mostly moderately fat or fat; 2 adult females, 18.1, 18.1, - both fat; 23 immature females, mean 19.28 ± .46, S. D. 2.16, - little (2 specimens) to very fat, mostly fat. - - Wing length: 1 adult male, 79.1; 38 immature males, mean - 78.05 ± .30, S. D. 1.80; 2 adult females, 76.3, 79.0, 23 - immature females, mean 75.83 ± .42, S. D. 1.99. - - As mentioned below, the presence of only 3 adults in the - sample of 64 Red-eyed Vireos is highly significant and their - occurrence only in the earlier samples is strong evidence of - early migration by the adults. - - _Vireo philadelphicus._ Philadelphia Vireo.--Weights: 2 - adult males, 12.1, 15.9, moderately fat and very fat; 2 - immature males, 11.1, 13.2, fat and very fat; 2 adult - females, 13.1, 14.2, both fat; 5 immature females, mean 14.1 - (12.0-15.2), moderately fat to very fat. - - This species previously has been collected in Kansas only - twice. Both records are from Doniphan County in September, - 1922. Field observers occasionally record the Philadelphia - Vireo in eastern Kansas. Long (1940:450) calls it a "very - rare migrant in the extreme east." Our sample of 12 birds - killed on two nights (and probably after the peak of - migration of this species) leads us to think that this vireo - is actually a regular, but overlooked, migrant in fair - numbers. - - _Vireo g. gilvus._ Warbling Vireo.--Weights: 12 adult males, - mean 15.92 ± .43, S. D. 1.44, moderately fat to very fat; 8 - immature males, mean 16.64 (14.2-17.8), fat to very fat; 5 - adult females, mean 16.1 (13.7-18.0), fat to very fat; 5 - immature females, mean 15.4 (14.1-17.8), little fat to fat. - - Wing length: 12 adult males, mean 73.08 ± .49, S. D. 1.64; 8 - immature males, mean 71.15 (69.9-72.8); 5 adult females, - mean 70.0 (69.2-71.0); 5 immature females, mean 68.4 - (67.7-70.3). - - Tail length: 12 adult males, mean 53.33 ± .53, S. D. 1.77; 8 - immature males, mean 50.03 (47.1-51.3); 4 adult females, - mean 48.6 (47.7-49.8); 5 immature females, mean 49.2 - (47.3-53.0). - - There is no indication that western birds (_V. g. - swainsonii_) make up any part of this sample. - - The sample of 34 Warbling Vireos is too small to show the - significance, if any, of the 2:1 ratio of males to females - in the sample. Adequate samples of this species, taken at - intervals, would add interesting information on time of - migration of the four sex- and age-classes. - - _Mniotilta varia._ Black and White Warbler.--Weights: 1 - adult male, 12.5, fat; 2 adult females, 10.0, 10.0, little - fat, fat. - - _Vermivora peregrina._ Tennessee Warbler.--Weights: 1 adult - male, 10.9, very fat; 1 immature male, 12.9, very fat; 2 - adult females, 9.1, 12.5, moderately fat and very fat. The - relative scarcity of Tennessee Warblers in the sample is - surprising. They are common in the area in spring. - - _Vermivora c. celata._ Orange-crowned Warbler.--Weights: 9 - adult males, mean 8.8 (7.7-10.9), little fat to fat; 13 - immature males, mean 8.92 ± .15, S. D. .53, little fat to - fat; 5 adult females, mean 8.8 (8.3-10.3), little fat to - moderately fat; 17 immature females, mean 9.13 ± .08, S. D. - .72, little fat to fat. Of the 19 Orange-crowned Warblers - killed on October 7, 11 had little fat, 6 were moderately - fat, and only 2 were fat. No one-night sample of any other - warbler killed at Topeka had less fat than this group of - warblers. Furthermore, our sample (including 11 males) from - October 7 (all sex- and age-classes) averaged 8.81 grams; - the sample of 13 (including only 4 males) from October 1 - averaged 9.1 grams. If one can assume, for any one species, - that individuals undertake nocturnal migration only when - they are physiologically ready, and this includes a certain - amount of fat as a fuel source (Wolfson, 1954), then this - further assumption seems justified: birds killed in - migration with little fat must have flown longer or farther - or both than birds killed with more fat. No further - speculation on this point is permissible with our data, but - the possibilities for study of future large kills, - especially where actual time of death of the birds is known, - are obvious. - - _Vermivora r. ruficapilla._ Nashville Warbler.--More - Nashville Warblers were picked up at Topeka than any other - species and they are discussed in detail elsewhere in this - report. The four sex- and age-classes can be identified with - fair accuracy on plumage characteristics alone. Adult males - have a large amount of reddish-brown in the crown, not - completely veiled by the gray tips of the crown feathers. - Immature males have a smaller but distinct crown patch, - usually completely veiled. All males, compared with females, - are grayer on the sides of the head, have a more nearly - white eye-ring, and show clearer yellow on the throat. Adult - females differ from immature females in that they more often - have a trace of rufous in the crown and tend to be brighter - below than the immatures. Of 177 specimens, 20 were very - fat, 108 were fat, 46 were moderately fat, and 3 had little - fat. - - _Parula americana._ Parula Warbler.--Weight: 1 adult female, - 7.9, fat. - - _Dendroica petechia aestiva._ Yellow Warbler.--Weights: 1 - immature male, 10.2, fat; 3 adult females, 8.8, 9.5, 10.1, - moderately fat; 2 immature females, 9.0, 9.4, little fat and - fat. - - _Dendroica magnolia._ Magnolia Warbler.--Weights: 1 adult - female, 9.0, moderately fat; 2 immature females, 7.9, 10.3, - moderately fat and fat. - - _Dendroica c. caerulescens._ Black-throated Blue - Warbler.--Weights: 2 immature males, 13.8, 14.1, excessively - fat; 1 immature female, 11.4, fat. This species is rare in - Kansas. Although its breeding range is almost entirely east - and north of Kansas, records in files at the University of - Kansas show that more specimens have been taken in western - than in eastern Kansas. - - _Dendroica c. coronata._ Myrtle Warbler.--Weight: 1 immature - female, 11.6, fat. - - _Dendroica pensylvanica._ Chestnut-sided Warbler.--Weights: - 2 immature females, 8.1, 10.0, little fat. Only one specimen - from Kansas had been preserved previously although the - species is a regular transient in small numbers throughout - the state. - - _Dendroica castanea._ Bay-breasted Warbler.--Weights: 1 - adult male, 19.2, excessively fat; 1 adult female, 11.7, - little fat; 1 immature female, 11.2, moderately fat. Only 5 - specimens of this warbler have been taken previously in - Kansas, 4 in spring (Ruth, 1952:18-19) and 1 in fall. - - _Dendroica p. palmarum._ Palm Warbler.--Weights: 2 immature - males, 9.9, 10.9, moderately fat; 2 unsexed immatures, 9.1, - 9.4, moderately fat. This species has been taken in fall in - Kansas only once before (KU 26353, taken by Wetmore, at - Lawrence, on October 5, 1907), but probably occurs regularly - in both spring and fall migration. - - _Seiurus a. aurocapillus._ Oven-bird.--Weights: 2 adult - males, 22.5, 23.8, fat and very fat; 14 immature males, mean - 21.89 ± .66, S. D. 2.46, fat to very fat; 8 adult females, - mean 21.4 (18.3-25.7), moderately fat to fat; 6 immature - females, mean 18.2 (15.6-20.0), moderately fat to fat. - - _Seiurus noveboracensis notabilis._ Northern - Water-thrush.--Weights: 3 immature males, 18.1, 18.6, 22.2, - moderately fat to fat; 1 immature female, 22.2, fat. - Referring these birds to _notabilis_ is a somewhat arbitrary - procedure. They display some intermediacy of characters and - probably stem from a population, intermediate between - _notabilis_ and _noveboracensis_, occupying much of central - North America (cf. McCabe and Miller, 1933). - - _Oporornis philadelphia._ Mourning Warbler.--Weight data - presented elsewhere. The birds killed at Topeka provide the - latest fall dates for this species in Kansas. Fifteen were - killed on September 25, 64 on October 1, 2 on October 5, 11 - on October 6, 2 on October 7, and 1 on October 8. We find no - other records later than September 15. Of 93 specimens - examined, 1 was excessively fat, 22 were very fat, 45 were - fat, 21 were moderately fat, and 4 had little fat. The - abundance of this secretive species in the sample was a - great surprise. It had previously been considered a rather - rare migrant in this area. - - _Geothlypis trichas occidentalis [>brachidactyla?]._ - Yellow-throat.--Weight data presented elsewhere. This - species was second in numbers only to the Nashville Warbler - in the total kill at Topeka. Of 167 birds examined, 29 were - very fat, 114 were fat, 23 were moderately fat, and 1 had - little fat. - - The Yellow-throats are greatly in need of meaningful and - comprehensive revision, which to date has been restricted to - the western subspecies (Behle, 1950). Since the appearance - of the 1931 A. O. U. Check-List a great deal of scattered - taxonomic work on the species, as yet unsynthesized, has - made the picture of its geographic variation a blurry one so - far as the details are concerned. Made in the absence of - adequate comparative material, the above identification is - to be regarded as tentative. Also, it is, unfortunately, - based only on those 6 of our 176 specimens preserved as - skins. Five of these are adult males, the sixth being an - immature female. Compared with a series of Kentucky - specimens regarded as typical _brachidactyla_, these birds - are paler and brighter above (tending toward gray-green - rather than brownish olive), brighter and more extensively - yellow below, with broader, more nearly white superciliary - stripes above their black masks (in males). In size they are - close to _occidentalis_ (see Behle, 1950:202). Five males - have an average wing-length of 56.6 mm. (53-59); one female - measures 53. Six males from Kentucky: 55.1 (53-56); four - females, 51.1 (48-56). Our birds may be assumed to have - stemmed from a population to the north and west which, if - not _occidentalis_ (or _campicola_ Behle and Aldrich, of - which no comparative material is at hand), is intermediate - between _brachidactyla_ and more western birds. Judging from - Behle's map (1950:fig. 32), these birds may have come from - an area near the confluence of three subspecies - (_campicola_, _occidentalis_, _brachidactyla_). Long - (1940:452) reports three subspecies breeding in Kansas - (_brachidactyla_, northeast; _occidentalis_, west; - _trichas_, southeast). The occurrence in Kansas of _G. t. - trichas_ as currently understood is completely out of the - question. - - _Icteria v. virens._ Yellow-breasted Chat.--Weight: 1 - unsexed immature, 29.7, moderately fat. - - _Wilsonia p. pusilla._ Wilson Warbler.--Weights: 2 adult - females, 7.5, 7.8, fat, moderately fat; 1 unsexed adult, - 8.3, fat. - - _Wilsonia canadensis._ Canada Warbler.--Weight: 1 immature - female, 10.0, little fat. We know of only five other - specimens from Kansas, although this warbler seems to be a - regular migrant in small numbers in the state. - - _Setophaga r. ruticilla._ American Redstart.--Weight: 1 - immature female, 9.1, moderately fat. - - _Dolichonyx oryzivorus._ Bobolink.--Weights: 2 adult - females, 39.5, 42.9; 2 immature females, 38.8, 42.0; all - excessively fat. Specimens of the Bobolink previously have - been taken in fall in Kansas only on September 20 and 24, - 1933, near Lawrence, by Long and Preble (Long, 1934). - - _Pheucticus ludovicianus._ Rose-breasted Grosbeak.--Weights: - 1 adult male, 50.4, fat; one immature male, 54.5, very fat. - - _Passerina cyanea._ Indigo Bunting.--Weights: 1 adult male, - 18.4, fat; 2 immature males, 17.2, 17.2, fat and very fat; 2 - adult females, 14.3, 16.9, moderately fat and very fat; 1 - immature female, 13.4, little fat. The sample was carefully - checked for Lazuli Buntings (_Passerina amoena_); none was - found. - - _Spiza americana._ Dickcissel.--Weight data presented - elsewhere in this paper. Dickcissels were picked up at the - television tower on October 1 (31), 5 (1), 6 (3), and 7 (1). - These birds, together with an adult female taken 3 miles - east and 3 miles south of Lawrence, on October 11, 1953, by - Tordoff, are the only specimens of this species taken as - late as October in Kansas. The Dickcissel becomes - inconspicuous in late summer and many observers here and - elsewhere have thought the species disappeared much earlier - than it really does (see Ganier, 1949). Of 34 specimens, 20 - were very fat and 14 were fat. - - _Passerculus sandwichensis nevadensis._ Savannah - Sparrow.--Weights: 1 adult male, 19.4, fat; 2 immature - males, 18.3, 19.0, moderately fat; 5 adult females, mean - 17.2 (14.8-19.5), little fat to fat; 4 immature females, - mean 18.0 (16.9-19.6), moderately fat to fat. Many of the - Savannah Sparrows migrating through Kansas have in the past - been referred to the subspecies _P. s. anthinus_ (= - _alaudinus_ of the 1931 A. O. U. Check-List) by various - workers (see Long, 1940:454). As Peters and Griscom - (1938:464-5) have shown, true _anthinus_, breeding in the - far northwest, ordinarily occurs in migration only in the - western part of the country, the breeding Savannah Sparrows - of a large part of the central continental region (east to - southern Wisconsin) being _P. s. nevadensis_ as now - understood. Migrants of this pale, clay-colored subspecies - should be abundant in Kansas, and all of the specimens in - the present sample are referable to it. - - _Ammodramus savannarum perpallidus._ Grasshopper - Sparrow.--Weights: 3 adult males, 16.4, 17.6, 20.6, - moderately fat, fat, fat; 5 immature males, mean 18.1 - (16.0-20.2), little fat to fat; 5 adult females, mean 17.9 - (16.8-18.9), moderately fat to very fat; 5 immature females, - mean 18.1 (16.8-20.6), fat to very fat. - - _Passerherbulus caudacutus._ Leconte Sparrow.--Weights: 1 - immature male, 11.2, moderately fat; 1 immature female, - 12.2, moderately fat. - - _Ammospiza caudacuta nelsoni._ Sharp-tailed - Sparrow.--Weights: 2 adult males, 15.2, 17.1, moderately fat - and very fat; 1 adult female, 13.3, little fat. Five - specimens of this species have been taken previously in - Kansas, all in October in the eastern part of the state. - Additionally, several observers have reported birds seen but - not collected. The three birds from Topeka were picked up on - October 6, 7, and 10 and are the only specimens taken since - 1907. Possibly our specimens from Topeka struck the tower on - the same night. Tordoff noticed, upon preparation, that the - specimens from October 7 and 10 showed progressive drying of - the extremities and spoilage as compared with the bird - picked up on October 6. - - _Junco hyemalis cismontanus._ Slate-colored Junco.--Weight: - 1 immature female, 16.4, little fat. Juncos of hybrid type, - whether _J. h. hyemalis_ × _J. oreganus_ subsp. or true _J. - h. cismontanus_, are fairly common in eastern Kansas. - - _Spizella pallida._ Clay-colored Sparrow.--Weights: 2 adult - males, 11.6, 12.2, both fat; 1 immature male, 11.8, fat; 1 - adult female, 12.5, fat; 7 immature females, mean 11.1 - (9.7-12.5), little fat to fat. - - _Passerella iliaca iliaca._ Fox Sparrow.--Weight: 1 adult - female, 29.4, little fat. A trifle grayer above than any of - several Kentucky specimens, this bird nevertheless seems - well within the range of variation of _iliaca_. - - _Melospiza l. lincolnii._ Lincoln Sparrow.--Weights and - measurements are discussed elsewhere. Of 81 specimens, 15 - were very fat, 47 were fat, 12 were moderately fat, and 7 - had little fat. Interestingly, there is no evidence that the - large southern montane subspecies (_M. l. alticola_) has - contributed to the present sample. No bimodality is evident - in the curve of wing-length in our birds, the largest of - which barely approach, the small extreme recorded for - _alticola_ by Miller and McCabe (1935:156). - - _Melospiza georgiana ericrypta._ Swamp Sparrow.--Weights: 3 - immature females, 14.3, little fat, 16.7, 17.0, moderately - fat. Swamp Sparrows examined were all more or less brightly - colored and seem to belong to this northern subspecies. - - _Melospiza melodia juddi._ Song Sparrow.--Weights: 1 adult - female, 19.4, little fat; 1 unsexed immature, 16.0, little - fat. A large proportion of the migrant and wintering Song - Sparrows in eastern Kansas probably originate from the range - of this subspecies in the northern plains. _Melospiza - melodia euphonia._--One immature female (not weighed) was - picked up below the tower on October 27, 1954, and thus does - not appear in Table 1. The specimen proved typical of this - generally more eastern subspecies upon comparison with a - large series from Kentucky. For what it may be worth we - refer the single specimen to this subspecies. Long - (1940:456) reported two eastern subspecies from Kansas - ("_beata_," _melodia_). All Kansas specimens genuinely of - eastern origin probably originate from the range of - _euphonia_, as now understood. - - - - -Randomness of the Sample - - -The reliability of certain of the conclusions which might be drawn -from data of the kind presented herein depends largely on the -randomness of the sample. To what degree does this sample provide a -true cross-section of the nocturnal migrants present over the area on -a given night or succession of nights? As far as the relative -abundance of species in the sample is concerned, there is little doubt -that it is not at all random. The absence of such species as the -Gray-cheeked Thrush (_Hylocichla minima_), among the passerines, and -many of the shorebirds known to be migrating through the area at the -time is evidence for this statement. Quite possibly many seminocturnal -species did not strike the tower at all for the simple reason that -they could see it, and certain large-eyed diurnal species (such as -thrushes and shorebirds) may avoid collision to some extent, thus not -appearing in the sample in proportion to their actual numbers. -Finally, some or all of the species concerned probably migrate partly -by day. The sample may to some degree reflect the true relative -abundance of closely related species. For example, there is little -doubt that, as shown by the sample, Nashville Warblers are more -numerous locally at this season than Tennessee Warblers, a fact that -can readily be corroborated by ordinary field observation. Also, the -sample is useful in suggesting the actual abundance of species which -are furtive and/or difficult to identify under normal field -conditions, for example, the Mourning Warbler and Philadelphia Vireo. -It is obvious that the sample should reflect the true relative -abundance at one place and time of any two species with equal tendency -to migrate by night and equal tendency to strike the tower. Since the -facts in regard to both tendencies are at present unknown for most -species, we think that interspecific comparisons should be avoided or -approached with extreme caution. - -In respect to the relative abundance of the various sex- and -age-classes within a given species, the sample is, we think, as close -to random as is possible to obtain. Certainly it is greatly superior -to samples obtained by field collecting, where possible differences in -habits, wariness, and experience of the birds, and subconscious (if -not conscious) selection by collectors can all bias the results. -Dwight (1900:128-9) believed that the greater wariness of adult birds -was almost entirely responsible for the seemingly disproportionate -number of immatures in autumn and gave some observational evidence in -favor of his views. The large percentage of adults in some of the -samples here treated tends to reinforce Dwight's position. To a -somewhat lesser extent, this advantage in randomness of accidental -kills over routine collecting may be supposed to apply also in -demonstrating the composition by subspecies of a single migrant -species. - -So far as particulars already mentioned are concerned, the present -sample or other samples of tower-killed birds would seem to be in no -way superior (that is, more nearly random) to samples obtained in -connection with lighthouses and other lighted objects, and -ceilometers. In one important respect, however, it is probably -somewhat superior to these as the dimly red-lighted structure has not -been shown to have any important collecting or attracting influence. -Thus, in computations intended to estimate the over-all abundance of -migrants, the sample should be more reliable than samples involving -bright light with its possible attracting effect. - - - - -Number of Migrants - - -If it can be assumed that nocturnally migrating birds are -approximately uniformly spaced across the sky and that the red lights -did not attract birds which would otherwise have missed the tower, it -is possible to compute the volume of migration from the sample killed. -In regard to the first assumption, both Stone (1906:250-251) and -Lowery (1951:409-413) have presented evidence of fairly uniform -distribution of nocturnal migrants. We have no information on the -second assumption beyond the facts that birds do not strike the high -towers on clear nights or lower towers even on stormy nights. - -On nights when large numbers of birds struck the 950 foot Topeka -tower, only a few struck a 500 foot radio tower, also lighted with red -lights, at Lawrence, 24 miles east, under similar weather conditions. -Most of the birds found at Topeka were fairly close to the base of the -tower, indicating that they struck the tower itself or that they were -flying high enough to strike guy wires only fairly close to the tower. -The scarcity of birds under the guy wires some distance from the tower -at Topeka and at the radio tower at Lawrence causes us to think that -most of the birds were flying more than 450 feet above the ground. On -this basis, we have computed numbers of migrants passing through a -plane one mile long and 500 feet high (2,640,000 square feet), -intersecting the assumed path of migration at right angles. -Vertically, the theoretical plane begins at 450 feet above ground and -has its top edge at 950 feet. The solid (discounting spaces between -girders, _etc._) cross-sectional area of the tower intersecting this -plane was computed by actual measurement to be 1685 square feet. On -the night of September 30-October 1, 585 birds were killed. By -computation (585/1685 = X/2,640,000), approximately 916,000 birds -passed through the mile-long plane that night. On each of the nights -of October 5-6 and October 6-7, approximately 230,000 birds passed -through this plane. By comparison, Lowery (1951:436) recorded maximum -station densities in one night in spring of 63,600 birds at Tampico, -Mexico, and 51,600 at Lawrence, Kansas, as determined by -moon-watching. Lowery's figures refer to numbers of birds crossing any -part of a circle one mile in diameter and are roughly comparable to -ours if, as we think, most of the birds at Topeka were flying at -altitudes between 450 and 950 feet above the ground. - -It must be realized that these figures are only approximations. One -variable ignored is the frontal extent (or area, viewed from the -front, subject to damage by striking an obstruction) of the birds -themselves. Since practically all birds killed showed head or trunk -injuries, rather than a high proportion with only broken wings, we -chose to disregard frontal extent of the birds in our calculations. If -our figures are inaccurate by as much as 50 per cent in either -direction, which seems unlikely to us, they still give some idea of -the tremendous volume of nocturnal migration under some conditions. - -It may be more meaningful to compute numbers of migrants by species. -This can be done readily by making appropriate substitutions from -Table 1 in the equation given above. For example, on the night of -September 30-October 1, approximately 147,000 Nashville Warblers -passed through the mile-long plane and on the same night, 100,000 -Mourning Warblers and 14,000 Philadelphia Vireos. Neither of the last -two species would be judged to be abundant migrants in autumn in -eastern Kansas by ordinary field observations; the television tower -sample, however, indicates that these as well as other species must -often be overlooked when they do stop in Kansas. - - - - -Differential Migration of Sex- and Age-classes - - -HISTORY OF THE SUBJECT.--For a long time it has been known in a -general way that old and young birds and males and females of some -species do not always migrate at the same times, by the same routes, -or even to the same places. This is a subject about which much has -been written. Reading the summaries of some general texts, it is easy -to acquire the impression that the facts of the matter are well known. -On the contrary, they are poorly known and much remains to be learned -before differential migration is understood. This can best be -indicated by a brief survey of the literature. - -The importance of the subject was emphasized by Meinertzhagen -(1930:52) in one of the later reviews of differential migration: "The -main problem concerns the Cause of Migration, the Stimulus which -compels Migration and the Origin of the Migratory Habit.... There is, -however, a minor problem which affords valuable evidence in helping us -to solve the major problem, bearing very directly on it, namely, the -order of sex and age on migration." - -The mystery of how birds, especially the young, find their way in -migration has fascinated students since the earliest times. The quite -natural though purely anthropomorphic conclusion of early scholars was -that the old birds led the young on migration. This attractive idea -persisted long after ornithology began to grow into a science. The -classic theory was restated by Palmén (1876:267), in one of the first -thorough reviews of the subject of migration, as follows: "Directe -Beobachtungen in der Natur ergeben, dass die Schaaren von ziehenden -Vögeln allgemein ältere und stärkere Individuen als Anführer des Zuges -haben." Variously modified, this view continued to crop up for some -time and still found support in the 1890's (see Dixon, 1892:69). Gätke -(1895:101) correctly questioned the credibility of Palmén's "direct -observations." - -With the gradual abandonment of the unsupportable classic theory, -diametrically opposed views were adopted by workers on opposite sides -of the Atlantic. The American stand was ably expressed by Brewster -(1886), who went to great pains to state his case and give evidence, -and who was later supported by Allen (1896:144-147; 1909:17). The -Americans held that adult birds nearly always preceded the young in -migration, and this was based on much evidence, whether or not -correctly interpreted. Dwight (1900:127) also gave evidence in favor -of this theory. Equally definite, if, as has later been shown, -somewhat vaguely documented, was the famous work of Gätke (1895:see -pp. 100-113), who after many years' observation of migrant birds in -Heligoland concluded the exact opposite, that young in general precede -adults (see critiques of Allen, 1896:144-147; Wiegold, 1926:5). -Gätke's dissenting opinion was for a time supported enthusiastically -by British workers (Gurney, 1923:579-580). - -As so often happens, neither extreme has withstood the test of time, -and more recent summaries (Meinertzhagen, 1930:55-56; Thomson, 1926, -1936:488-489; Wiegold, 1926) have tended to compromise. Many -exceptions to Gätke's extreme conclusion have been detected. -Exceptions to the Brewster-Allen stand have also been discovered, -although work along these lines on the American side has lagged -somewhat. Rowan (1926) has given further evidence on the migration of -certain shorebirds, and some evidence has accrued in relation to -particular species and groups as a result of life-history and banding -studies (see Pitelka, 1946). Authors of major works on migration, -however, have either been preoccupied with other phases of migration -or avoided the issue. In an able study (one of several on related -subjects) of the composition by sex and age of migrant populations in -north Germany, Drost (1935:177) did not go into the question of order -on migration. - -One is left with the impression that the whole subject is still -unsettled. While earlier workers sought to reduce the entire matter to -law, the latest disclaim the possibility of generalization. After -summarizing Brewster's and Gätke's opinions, Thomson (1926:79) wrote: -"It would seem, in any event, that no general rule can be laid down." -Meinertzhagen's summation (1930:56-57) still represents fairly well -the status of our knowledge: "Order of sex and age on autumn passage -is very difficult to arrive at, as evidence is conflicting. But, on -the whole, it seems that birds flock together, old and young, -preparatory to moving south, and do in many cases initiate migration -in company.... But once movement is initiated, among birds which do -not habitually fraternise in flocks, adults, and especially males, -will naturally outstrip the less virile females and still less virile -offspring.... The consequence is that any observer at an intermediate -station such as Heligoland is, in noting birds of the year as first -arrivals, has not had an opportunity of noting the flocks of adults -which have passed without alighting. On the other hand, there is very -definite evidence to show that among certain species, adults follow -their offspring on migration. The reason for different behaviour -among different types of birds remains obscure." We regard much of -this as still theory. - -[Illustration: FIG. 1. Composition by age and sex as found in one or -more series of each of eight species of birds included in the Topeka -sample. Each separate series is represented by a single histogram, the -histograms for a species being grouped with the earliest series on the -left. Each histogram expresses the numbers of adults (left-hand -column) and immatures (right-hand column) in terms of percentage of -the whole series. Thus the two bars of each couplet add up to 100 per -cent. The hatched portion of each bar represents males, the clear -portion females.] - -It would be difficult to imagine a better way of resolving the -problems and uncertainties just reviewed than by the detailed -analysis of large samples of migratory birds killed at random at -various points and times. An analysis of the sample of birds -accidentally killed at Topeka is presented here as an initial step in -this direction. Although the conclusions based on this sample are -tentative and may in time be altered, the data themselves are -definite. If this general type of analysis is repeated again and -again--applied to samples taken on many dates and in many -localities--a mass of hitherto unparalleled evidence for the study of -migration will emerge. - - -DIFFERENTIAL MIGRATION OF SEX- AND AGE-CLASSES AS SHOWN BY THE TOPEKA -SAMPLE.--Smaller samples have not been treated. Species affording -samples seemingly large enough to justify at least preliminary -analysis were: Catbird, Red-eyed Vireo, Mourning Warbler, Dickcissel, -Nashville Warbler, Orange-crowned Warbler, Yellow-throat, and Lincoln -Sparrow (Fig. 1). For all of these except the Catbird and Dickcissel, -at least two samples from a week or more apart were available for -comparison in an effort to detect trends in migration. Fig. 1 shows -the actual ratios of sex- and age-classes observed in samples of the -species listed above. Each of the last four species provided two -separate samples, of sufficient size to warrant an attempt at -measuring the statistical significance of the observed changes in -adult-immature ratios (Table 2). - -TABLE 2.--STATISTICS OF THE RATIOS OF ADULTS TO IMMATURES IN FOUR -SPECIES - - ======================================================================= - Species | Dates |Total | Number | Differ- |P[3] - | of samples |number| and | ence | - | | |percentage |(in %)[2]| - | | |of adults[1]| | - --------------|--------------------|------|------------|---------|---- - Nashville |Oct. 1 (93) | 156 | 45 (.484) | .071 |.36 - Warbler |Oct. 5-7 (63) | | 26 (.413) | | - | | | | | - Orange-crowned|Sept. 25-Oct. 1 (19)| 44 | 3 (.158) | .282 |.05 - Warbler |Oct. 5-9 (25) | | 11 (.440) | | - | | | | | - Yellow-throat |Oct. 1 (115) | 159 | 62 (.540) | .085 |.34 - |Oct. 5-8 (44) | | 20 (.455) | | - | | | | | - Lincoln |Oct. 1-3 (44) | 71 | 27 (.614) | .318 |.01 - Sparrow |Oct. 6-10 (27) | | 8 (.296) | | - ---------------------------------------------------------------------- - - Footnotes: - - [1] Percentage of immatures equals 1.000 minus percentage of - adults. - - [2] Standard error of the difference between ratios was - computed by the formula - [Greek: s]^e = sqrt(P_e Q_e (1/N_1 + 1/N_2)) - where P_e equals percentage of adults and Q_e equals - percentage of immatures in the entire sample. - - [3] Probability of error; _i. e._, a P of .01 means there is - one chance in 100 that the difference observed does not - represent an actual difference in nature. - -Upon the application of statistical methods it soon became evident -that, unless changes in ratio between two samples are marked, large -samples would be required in order to reach conclusions of high -statistical significance in a single study of the present type. In -this case (see Table 2), the Lincoln Sparrow and Orange-crowned -Warbler, though represented by only moderate-sized series, show marked -changes in age composition over the period studied, and the -statistical treatment indicates a high degree of probability that -these changes are real. Assurance that the lesser changes observed in -the Nashville Warbler and Yellow-throat are real, on the other hand, -is much less, even though the samples are larger. Few if any of the -samples here discussed are as large as might be desired. Therefore, -conclusions based upon them (see below) are to be regarded as -tentative. Many other, future, samples will perhaps also be -insufficient in size in themselves. There are, however, statistical -advantages to repetition which will serve to make the repeated -analysis even of small samples significant and valuable. - -Certain of the samples not treated statistically show ratios that can -be seen by inspection to be probably significant. For example the -almost complete absence of adults from the three samples of Red-eyed -Vireos (Fig. 1E) cannot be disregarded in view of the size of the -whole sample of the species. The same applies to the high percentage -of adult females and the near absence of adult males in the sample of -the Dickcissel (Fig. 1F). The continuity in direction of changes -observed in the three samples of the Mourning Warbler (Fig. 1G) and -Red-eyed Vireo is likewise probably significant, even though some of -the samples compared are small. It seems to us that the application of -statistical methods to these species should await the accumulation of -more material. For anyone desiring to treat them statistically now, -the data are inherent in this paper. - -We have not computed the standard errors of the ratios of sexes within -age groups (except experimentally in a few cases). This can easily be -done, however, and the significance of a given ratio determined, on -the assumption (perhaps sometimes dubiously justifiable) that the -sex-ratio in the species concerned is one:one. Obviously there is no -point in computation of the standard errors of adult-immature ratios -in single samples (such as that of the Dickcissel) until the actual -ratio prevailing in the species in nature at the season in question is -known for comparison with the observed ratio. Our formal statistical -treatment, therefore, has been limited to an examination of the -significance of the _changes_ between adult-immature ratios in samples -of the same species taken a number of days apart. - -The samples suggest several patterns of differential migration of sex- -and age-classes. Indeed, the important consideration brought out--in -our opinion not hitherto sufficiently emphasized in literature--seems -to be that in generalizing about adults and immatures, one must be -careful to take sexes into account, and conversely, in generalizing -about males and females, one must consider also age. In other words, -there are really four classes to be considered. This poses additional -problems in analysis and introduces the need for still larger samples -in order to reach significant conclusions. To illustrate: an -adult-immature ratio of 40:20 (N = 60) may be satisfactorily -significant, while within the 40 adults a ratio of 25 males:15 females -may not be. Were the original sample 80:40 (N = 120) with male adults -50 and female adults 30, it is obvious that the significance of the -latter ratio would be greater. The same applies in reverse if the -greater emphasis is placed on sex and the lesser on age. Because of -the moderate size of the samples this problem has been felt in the -present study in respect to sex ratios within age groups, many of -which must at present be regarded as of tentative significance. - -In short, what the earlier ornithologists regarded as a simple problem -is in reality a complex one. There are only two patterns in what may -be called the Brewster-Gätke argument: adults first or immatures first -(with of course the further possibility of both at the same time). -Both patterns occur, as is now known, at least to some extent. But -actual patterns, as suggested by our samples, are more complex when -all classes are considered. It will readily be seen that, if adult -males, immature males, adult females, and immature females be regarded -as units, each with certain migratory characteristics, the -combinations of these units in various orders of migratory precedence -are potentially numerous. In fact, of course, they do not behave -strictly as units (or perhaps very rarely so), but our data strongly -indicate that the tendency exists in many cases. This may be stated -another way. The present samples may be reduced to two basic patterns, -fitting the classic early American (adults first) and early European -(immatures first) theories. But, either such simple arrangement is -compounded in some, perhaps in truth in all, instances by differential -migration of the sexes _within_ each age class. This proposition can -also be stated backwards: the samples show differential times of -migration of the sexes, compounded by differential times of migration -of the age groups within each sex. The order in which these matters -are approached depends on what one is trying to find out. Influenced -by the literature, in which most emphasis has been placed on age, we -have approached the problem from that standpoint. The data and figures -here given, however, can be juggled if one wishes to place first -emphasis on the order of sexes in migration. - -Bearing in mind what has just been said, particularly in respect to -sizes of samples necessary for significance, let us consider the -patterns of migration suggested by the Topeka sample. These are as -follows: - -(1) _An early migration largely composed of adults, giving way later -on to a preponderance of immatures._ Regardless of variations among -them, samples showing this basic pattern are in line with the opinions -of Brewster (1886) and his followers. This pattern is here shown by -the Lincoln Sparrow, Yellow-throat, Nashville Warbler, Catbird (one -sample only), and Red-eyed Vireo (Fig. 1, A, B, C, D, E). The evidence -of these and all other samples would admittedly be more conclusive if -the samples were further apart in time or, better still, were there -more of them. There is evidence that differences in migration of the -sexes, within age classes, influence this pattern, sharply in some -instances. In the later samples of Lincoln Sparrow, Yellow-throat, and -Red-eyed Vireo (Fig. 1, A, B, E) there are relatively fewer males, -both adult and immature, than in the earlier samples and this may be -true also of the Catbird, judging from the single sample. The Red-eyed -Vireo (Fig. 1, E) is characterized by small number, or absence of, -males in each sample but the samples are not significantly different, -and can be regarded as one. Although the samples of the Dickcissel and -Mourning Warbler (Fig. 1, F, G) show a somewhat different over-all -pattern and are discussed further on, they also contain few adult -males. Since these samples are from a period that is near the end of -the migration of Red-eyed Vireos, Mourning Warblers, and Dickcissels, -it may be assumed tentatively that the adult males have already -migrated. Meinertzhagen (1930:56) postulated that in many species -there is an earlier or more rapid migration of adults, particularly -males, and the data for the above species in our sample tend to -support his assumption. But our data suggest in addition that in some -species _immature males_ migrate earlier, or more rapidly, than do -_immature females_, just as adult males precede adult females in some -instances. Within this general pattern (adults first) another -variation is shown by the Nashville Warbler (Fig. 1, C) in which the -later sample of adults is heavily weighted towards males, even though -an increasing over-all proportion of immatures is evidenced. In this -case, and contrary to Meinertzhagen's suggestion, it would seem that -adult females have preceded or outstripped adult males in migration. - -(2) _An early preponderance of immatures, followed by a preponderance -of adults._ The several species of birds at Topeka that display this -pattern conform with the conclusions of Gätke and other early Old -World ornithologists that in most species immatures precede adults in -migration. In the present sample two variations of this pattern occur. - -(a) In the Dickcissel (Fig. 1, F) and the Mourning Warbler (Fig. 1, -G), immatures decrease more markedly than adults (visible in samples -of Mourning Warbler; inferred in Dickcissel), leaving the adults in -the majority in the closing phase of migration. The distinctive and -interesting feature in each of these two species is the ascendancy in -numbers of adults _despite_ the almost complete disappearance of adult -males. The relative increase of adults is here caused by a retarded -migration of adult females, which linger conspicuously behind all -other classes. Something of this nature was suggested, in theory, by -Dixon (1892:70) who thought that adult females are delayed by -"maternal duties." It was hinted at also by Dwight (1900:127) who -thought that in some species females molted later than males as a -result of prolongation of parental responsibilities. As mentioned -already, there is need for caution in interpreting the present samples -because the Dickcissel is represented only by one sample and two of -the three samples of Mourning Warblers are small. In the case of the -Mourning Warbler, the samples may be regarded as one, nearly lacking -in adult males. The progressive increase of adult females, however, -may be significant; at least there are enough of these to make -division of the birds into three samples enlightening. There is, of -course, some chance that the majority of adult males have not yet -migrated, or are migrating by a different route. This seems unlikely -in both cases. October 1 is late in the migration of the Dickcissel -and it seems that large-scale migration would not occur much later, -and in the case of the Mourning Warbler adult males are rare in all -three samples, extending over a considerable period and reaching late -into the probable migration period of the species. It is interesting -to conjecture just when and where adult male Mourning Warblers do -migrate in autumn. Brewster (1886:16) wrote: "This species arrives at -Cambridge [Massachusetts] about September 12, and during the remainder -of the month is ... abundant.... The adults, however, are so very -uncommon that I have never known them [to] represent more than five -per cent of the total number of individuals. They do not seem to be -more numerous in the earlier flights than towards the close of the -month, and I am very sure that they cannot be found in this locality -before the young begin to appear." While the present samples show an -abundance of adult _females_ of this species (could Brewster have -failed to recognize these as adults?) the whereabouts of the adult -males remains a mystery. - -(b) Another variation is displayed by the Orange-crowned Warbler (Fig. -1, H). Here also there is an increase of adults towards the end of -migration, but this increase is marked by a growing percentage not of -females but of males. Locally this species is a late migrant compared -with most others of the Parulidae. Thus the first sample, composed of -birds taken September 25-October 1, may be regarded as fairly early in -the fall migration. Immature birds compose 84.2 per cent of this -sample, there being no adult males at all. By October 5-9 the picture -has changed markedly, the sample being composed of 44 per cent adults -(82 per cent of which, in turn, are males) and 56 per cent immatures. -In view of this trend one can not help suspecting that a still later -sample would show a majority of adults, perhaps nearly all males. This -of course does not necessarily follow; the migration of immatures -could simply be more protracted, and could have commenced earlier, -than that of adults. - -Little imagination is required to see how enlightening it might be -could we analyze thoroughly the patterns of all migrating species. -When the detailed facts are available, it seems likely that general -trends will emerge which may be of great significance to the study of -migration in general. A final point which must eventually be clarified -is determination of the extent of variability in the pattern of each -species from year to year and locality to locality. - -Once patterns of precedence in migration of different classes are -established, search into the life-histories of the species concerned -may help to explain the peculiarities discovered. In the present case, -for instance, we find a possible clue to the reason for the high -proportion of adult females of the Dickcissel late in migration, as -shown by our sample. Gross (1921:14-15) presented evidence that adult -female Dickcissels molt considerably later than their mates, and we -have independent evidence that individuals of this species are at -times almost flightless when molting the remiges! - - - - -Molt in Relation to Migration - - -GENERAL COMMENT.--The exact relationship between molt and migration -seems not to have been definitely established. The subject has -received cursory attention in the literature and conflicting opinions -have been expressed. Dwight (1900:126-128) believed that molt is -completed or nearly completed before migration in nearly all passerine -species that occur in New York save for certain swallows and -flycatchers. Molt has since been found to precede migration of at -least one of the flycatchers (_Empidonax virescens_) considered by -Dwight to be an exception to this rule (Mengel, 1952). In Great -Britain the subject of molt in migration was considered in some detail -by Rintoul and Baxter (1914) and Ticehurst (1916), who arrived at -conclusions similar to Dwight's. These workers also found certain -swallows to be exceptions to the rule. - -The above authors and others have shown that, at least among -passerines, some body molt is frequently found in migrating -individuals but that molt of tail feathers is much less often found -and molt of remiges almost nonexistent. Baxter and Rintoul noted only -four cases of molting wing feathers among hundreds of migrants. Among -the diverse non-passerine orders the picture seems to be more -complicated, as might be expected. We do not, however, comprehend the -reasoning which led Meinertzhagen (1930:56) to summarize: "... on the -whole it can be said that though birds seldom migrate when flight -feathers are in quill, moult in general does not influence migration." -This seems to us an obvious _non sequitur_. Meinertzhagen (_loc. -cit._) went on to say: "Males and females of one species are believed -to moult simultaneously [see, however, Dwight, 1900:127], and there is -no doubt that in some cases the two sexes migrate at slightly -different times, and occasionally prefer different winter quarters. -Birds of the year never moult their quills previous to their first -autumn migration [Consultation of Dwight, 1900, who gives many -examples of this, would have spared Meinertzhagen this error.], and -yet they frequently follow adults on passage and sometimes precede -them. There are no grounds for believing that adults have moulted -their quills before birds of the year are prepared to migrate [but -there are, in many cases; _cf._ Dwight, 1900:127], in the case where -adults precede the latter. Neither is there any evidence to show that -adults have not moulted their quills till after their offspring are -ready for passage, in the case where they follow their offspring. It -does not, therefore, appear that moult is an important factor." - -Comments interpolated above show our feeling that this summary is -inadequate and misleading. To us it seems that the extreme rarity in -migration of birds with remiges in molt is strong evidence that molt -_does_ influence at least the time of migration. It is immaterial -whether this molt occurs before or after migration, although in the -majority of cases it seems to take place before. Much more needs to be -known of the migration pattern and molt of each species before -generalizations can safely be made. - -Analysis of samples of migrants can show only the presence and nature -or the absence of molt in birds actually migrating. In the present -instance shortage of time and manpower for preserving some and -processing all of the sample resulted in incomplete data being kept on -molt. We include this section to emphasize uncertainties still -prevalent and to stimulate further work. - - -MOLT IN THE TOPEKA SAMPLE.--Our limited findings coincide with those -of Rintoul and Baxter (1914). Body molt was noted in a number of -individuals and species. When present, this molt almost invariably was -in its final stages. One immature male Rose-breasted Grosbeak (October -1) was in heavy body molt. It is perhaps worthy of mention here that -this grosbeak evidently migrates at times in extensive molt. An adult -male (RMM 1102) taken by Mengel near Henderson, Kentucky, on September -9, 1949, was molting plumage of body, wings, and tail, no feather of -the last being longer than one half inch. This remarkable specimen had -only five primaries on one side and four on the other fully -functional. The outermost on the left and two outermost on the right -were from the previous plumage, not yet dropped; the three innermost -of each wing were new and full-length. - -In the present sample molt of remiges was noted in one specimen, an -adult female Indigo Bunting (October 1) with outer primaries sheathed -and with molt in progress in the body plumage. The one (immature) -Yellow-breasted Chat in the sample (October 1) had all of its tail -feathers nearly full-length but in quill, possibly as a result of -accident, and two feathers were being replaced also in the tail of an -immature Clay-colored Sparrow (October 6), which was also in body molt -and had some, juvenal feathers on the belly and flanks. - -Body molt near completion was further noted as follows: immature male -Yellow-throated Vireo (October 1), adult male Blue-headed Vireo -(October 1), immature female Leconte Sparrow (October 23), several -Lincoln Sparrows (various dates). - - - - -Size Differences according to Sex and Age - - -LINEAR MEASUREMENTS.--Taxonomists long have recognized in many species -that males differ in size from females. Less attention, until -recently, has been paid to the relative sizes of adult and immature -birds. Many taxonomists, however, seem to have had an uneasy suspicion -that immature birds are "untrustworthy" in comparison with adults, and -immatures have often been excluded from samples when recognizable. -Since, however, there are still relatively few reliably aged specimens -in collections, for the most part only those immature birds -immediately recognizable as such by obvious plumage differences (which -are often present only in juvenal plumage) have been excluded from -series. The majority of birds in first winter plumage so closely -resemble adults that the two ages have been included in series for -measurement. In most passerines these younger birds still bear the -juvenal feathers in wing and tail and are, in size of these important -parts, quite as "untrustworthy" as birds still in juvenal body -plumage. Even if a complete postjuvenal molt occurs we still should -not assume that first winter feathers are as long as adult winter -feathers without first determining that this is so. Although aware of -this problem, systematists until recently seemingly have been more or -less content to disregard it, or forced to do so for practical -reasons. Miller (1941:179) had little choice but to hope that size -differences between adult and immature juncos were unimportant. Behle -(1942:217) wrote of Horned Larks, _Eremophila alpestris_: "... the -plumages of first-year birds and adults seem indistinguishable, though -I have never quite satisfied myself that there are no differences in -lengths of rectrices and remiges." He added, with logic confusing to -us: "Since it is a difficult problem to determine the ages of horned -larks that have passed the postjuvenal molt, this similarity of -plumages is fortunate for the systematist." - -In recent years, some workers have analyzed size differences between -adults and immatures. Sibley (1950:115) showed that adult Red-eyed -Towhees (_Pipilo erythrophthalmus_) had notably longer wings and tails -than immatures, and the same was demonstrated in Red Crossbills -(_Loxia curvirostra_) by Tordoff (1952). In work with jays -(_Aphelocoma_), Pitelka (1951:199) found that: "... in comparisons of -dimensions of sex and age groups within a given sample, although -magnitude of difference varies from one character to another, most of -the averages are successively smaller for first-year males and adult -and first-year females." He listed exceptions and concluded: -"Segregation [of sex and age classes] has proved to be of extreme -significance in an interpretation of individual and geographic -variation." - -Much along these lines can be learned by examination of large random -samples such as that afforded by the Topeka accident. Although only a -few species in this sample were measured, the results secured seem to -show further the need for segregation of age classes in taxonomic work -with some species. - -Figure 2 shows the variation in the lengths of wing and tail in the -Nashville Warbler. It is evident from the figure that in both of these -characters the four sex- and age-classes differ significantly. An -accurate idea of geographic variation in this species could not be -obtained without separating these classes in comparisons. Age classes -in spring and summer, long after the skull is completely ossified, can -be segregated only if differences in plumage can be found. In the -Nashville Warbler, such differences occur in fall (see annotated list) -but these probably are obliterated by the partial prenuptial molt. -These facts emphasize the importance, for taxonomic studies, of aged -specimens collected in late summer or early fall on their breeding -ground and in fresh winter plumage. Figure 3 shows the variation in -length of wing in the Lincoln Sparrow in which age seems to be of much -less importance than in the Nashville Warbler. Males and females of -the Lincoln Sparrow differ significantly in wing-length, but adults -and immatures are of nearly the same size. It would seemingly not be -necessary to separate age classes in studies of geographic variation -in the Lincoln Sparrow. Size data for some other species are given in -the annotated list. - - -WEIGHTS.--Little seems to have been done to determine the correlation -of weights with sex- and age-classes. Weight may be the best single -index of over-all size and is especially useful to students of the -physiology of migration. Weight, however, is subject to the -considerable variable imposed by fat condition. In large and -comparable series, this variable is probably removed insofar as -comparability of means is concerned, but the high variability of -weight in most cases naturally results in more overlap (less -separability) between populations with means close together than is -found with most linear measurements. - -[Illustration: FIG. 2. Statistics of variation in length of wing and -tail in the Nashville Warbler. The solid lines represent the observed -ranges in millimeters. The stippled boxes represent two standard -errors ([Greek: s]m) to each side of the means (vertical lines). The -open boxes represent one standard deviation ([Greek: s]) to each side -of the means.] - -[Illustration: FIG. 3. Statistics of variation in length of wing in -the Lincoln Sparrow.] - -Figures 4-6 show variation in weight in the samples of Nashville -Warbler, Mourning Warbler, Yellow-throat, Dickcissel, and Lincoln -Sparrow. Each figure is essentially self-explanatory. It will be seen -that in the Nashville Warbler and Lincoln Sparrow, weight is roughly -proportional to wing-length (shown in figs. 2 and 3), giving about -equally good separation of sex- and age-classes in the latter and -poorer separation in the former. Data for these and other species -indicate a generally greater weight of males than of females, but less -difference according to age. In some other species, for example the -Yellow-throat, immatures seem to be a little heavier on the average -than adults. It is unfortunate that wing-lengths are not at present -available for these. - -[Illustration: FIG. 4. Statistics of variation in weight in the -Nashville Warbler and Mourning Warbler.] - -[Illustration: FIG. 5. Statistics of variation in weight in the -Yellow-throat and Dickcissel.] - -[Illustration: FIG. 6. Statistics of variation in weight in the -Lincoln Sparrow.] - -These comments on weight suggest an additional factor which may play a -part in rate of migration and which some day may be profitably -studied. Suppose that in some species adults and immatures are nearly -the same in weight but that immatures have shorter wings. In such a -species the immatures are relatively shorter-winged for their weight -than adults. In aerodynamic terms, they would have a higher -"wing-loading." (Wing-loading is the result obtained by dividing area -of effective wing by total weight; it is here assumed that in a single -species wing area is directly proportional to wing length.) This being -the case, immatures with higher "wing-loading" would require more -energy (derived from fat) to fly the same distance as adults, or with -the same amount of fat they would fly a shorter distance. Thus they -might tend to be outstripped in migration by adults starting at the -same time. The reverse, of course, would also be theoretically true, -if adults possessed a higher wing-loading than immatures. Physical -factors such as these rather than the differential "virility" -postulated by Meinertzhagen (1930:56) might account for the arrival of -certain classes of some species on the wintering grounds in advance of -others. There are, of course, many other factors which must be taken -into account before the effect, if any, of the wing-loading factor can -be evaluated. Data for illuminating calculations will become -available, however, with the accumulation of abundant information on -weights, measurements, and migration patterns. - - - - -Computations of Longevity and Survival - - -Tanner (ms., and letter, April 21, 1955) recently devoted considerable -ingenuity to computing by actuarial methods the longevity of the -Oven-bird, using the adult-immature ratio in samples killed at a -ceilometer at Knoxville, Tennessee. Tanner's computations were based -on the simple assumption that - -S (survival rate) = Number of adults in population (or sample) / Total -size of population (or sample). - -Further application of such techniques may prove desirable and -rewarding. It would seem at present, however, to be a risky procedure, -as it has been abundantly shown (see above) that adults and immatures -often do not migrate at the same times and rates, and the ratios of -adults to immatures in samples of migrants are likely to be far from -representative of the true proportions in the populations concerned. -It should be added that Tanner is perfectly aware of this objection. - - - - -Processing of Samples - - -Thorough processing of large samples of birds killed accidentally is -time-consuming. We were fortunate in having considerable assistance; -even so, all desirable data could not be obtained from the 1090 birds -of the present sample. As aids to others conducting studies of this -kind we should mention a few points which may be of assistance. - -Birds should be picked up as soon as possible after death, certainly -by the end of the day after the accident and preferably much sooner. -They should be weighed as soon as possible after collection (weights -decrease rapidly, even under refrigeration), and the weights (in -grams, to one tenth of a gram) written on tags attached to a leg of -each specimen. The sample should then be sorted by species or groups -of species of approximately equal size (to avoid crushing of smaller -birds by larger ones), placed in boxes, paper bags, or better, -air-tight containers clearly marked with date, locality, and other -necessary particulars, and relegated to a deep-freeze compartment. For -all but the smallest samples, such freezing units are indispensable to -complete study. Once frozen, the birds may be selected for study at -leisure, but time is still important, as, even when frozen, gonads may -eventually deteriorate, and birds eventually become desiccated which -is a disadvantage if skins are to be made. - -In the cases of large kills, or limited manpower, or both, it may be -impossible to process all birds, however desirable this might be. If -possible, however, all should be collected, identified, the numbers -and species recorded, and rarities saved. Further, partial analysis, -or more properly, complete analysis of a partial sample, can be made. -Analyses which for any reason require randomness of sample pose a -special problem. We think that in very large kills the best way to -solve this problem is probably to make one or more transects across -the area where dead birds are found. These transects should cross both -the areas of greatest and least density (to allow for fast and slow -flying species). Their width may be adjusted to give the desired -number of birds, that is, the number that can be adequately processed. -Another alternative would be to decide to study certain abundant -species and pick up all of these. There are other possibilities, but -in any event the method of sampling should be thoroughly described -wherever all birds have not been processed. - - - - -Summary - - -The foregoing paper discusses accidents in which large numbers of -night-migrating birds are killed. A brief historical review of -ornithological interest in such occurrences is given, and the types of -data provided by the accidents are listed and discussed. In -particular, recent accidents occurring in early October, 1954, through -much of eastern United States are cited, and detailed analysis is -presented of a sample of 1090 birds killed one mile west of Topeka, -Shawnee County, Kansas, between September 25 and October 23, 1954. - -At Topeka during the period mentioned, 1090 birds representing 61 -species were collected and were processed at the University of Kansas. -For all specimens, weight, sex, age, and fat condition were recorded, -and certain species were measured as well. Some notes on molt were -taken. A total of 193 birds was preserved as study skins, and 49 as -skeletons. Comments on weight, size, sex, age, subspecific identity, -and status in Kansas are presented in an annotated list. - -Randomness of this and other similar samples is discussed. A -theoretical computation is given for several nights of the numbers of -migrants passing through a plane one mile in width, from 450 to 950 -feet above ground level, and oriented to face the arriving migrants. -The computed totals give some idea of the tremendous volume of -nocturnal migration under some conditions. Potentialities of further -study of such events are discussed and a comparison is made with lunar -observations. - -Differential migration of sex- and age-groups as shown by the larger -samples taken at Topeka (Catbird, Red-eyed Vireo, Nashville Warbler, -Yellow-throat, Mourning Warbler, Dickcissel, Lincoln Sparrow) is -discussed and the history of theories on this subject reviewed. It is -shown that age and sex must both be taken into account in studies of -differential migration. Several patterns of migration are displayed by -the species analyzed, adults migrating earlier than immatures in some -instances, young earlier than adults in others, but all seemingly -being complicated to varying degrees by differential migration of -sexes within age groups. It is suggested that explanations of these -patterns may be sought in the life histories of the species involved. - -Molt in relation to migration is discussed briefly, and it is held -that there is an important relationship between molt and time of -migration. Specimens noted to be in molt are listed. - -Size differences, in wing length, tail length, and weight are -discussed in relation to sex and age, and variation in one or more of -these characters is analyzed as found in the Topeka samples of -Nashville Warbler, Mourning Warbler, Yellow-throat, Dickcissel, and -Lincoln Sparrow. It seems that in some instances significant size -differences prevail between adults and immatures and that these age -classes should be separated in taxonomic work with species where -differences in size are known to exist. When the facts are not known -they should be determined, and the large samples collected in -accidents to nocturnal migrants present excellent opportunities for -ascertaining the facts. - -Other uses of material obtained in large migration accidents are -discussed, such as computations of longevity and the problems of -processing large, accidentally-killed samples. Care should be taken to -select samples as nearly random as possible when all birds cannot be -processed. - -Repeated and thorough analysis of accidental kills should provide a -mass of valuable data bearing on many questions and problems which -have thus far been little studied. - - - - -Literature Cited - - -ALLEN, J. A. - - 1880. Destruction of birds by light-houses. Bull. Nuttall - Orn. Club, 5(3):131-138, July. - - 1896. Gätke's 'Heligoland.' Auk, 13(2):137-153, April. - - 1901. Barrington's 'The Migration of Birds at Irish Light - Stations.' [Review.] Auk, 18(2):205-206, April. - - 1909. An American's views of bird migration. Brit. Birds, - 3(1):12-19, June 1. - -BARRINGTON, R. M. - - 1900. The migration of birds as observed at Irish - lighthouses and lightships [_etc._]. London, R. H. Porter; - Dublin, Edward Ponsonby. Pp. XXV, 285, 667. (Not seen; - citation from Mullens and Swann, Bibliogr. Brit. Orn., 1917, - p. 43 and Zimmer, Cat. Ayer Coll., I, p. 40, 1926; see also - reviews, Ibis, 1900:677-679, Auk, 1901:205-206; some sources - list pagination as XXV + 667, possibly in error.) - -BEHLE, W. H. - - 1942. Distribution and variation of the Horned Larks - (Otocoris alpestris) of western North America. Univ. - California Publ. Zoöl., 46(3):205-316, May 20. - - 1950. Clines in the Yellow-throats of western North America. - Condor, 52(5):193-219, September-October (September 25). - -BREWSTER, W. - - 1886. Bird migration. Mem. Nuttall Orn. Club, No. I, pp. - 1-22, Cambridge, March. - -CARSON, L. B. - - 1954a. [Destruction of birds at a television tower at - Topeka, Kansas.] Topeka Aud. News, 9(1):pp. = 1-2, July, - August, September [published October]. [Unsigned, unpaged, - and untitled article by L. B. Carson, ed.] - - 1954b. [Further destruction of birds at a television tower - at Topeka, Kansas.] Topeka Aud. News, 9(2):pp. = 5-7, - October, November, December [published December]. [Unsigned, - unpaged, and untitled article by L. B. Carson, ed.] - - 1954c. New records for fall migrants in eastern Kansas. - Kansas Orn. Soc. Bull., 5(4):27-29, December. - -DIXON, C. - - 1892. The migration of birds. London, Chapman and Hall. Pp. - XVI + 300. - -DOBBEN, W. W. H. VAN, and M. F. BRUYNS - - 1939. Zug nach Alter und Geschlecht an niederländischen - Leuchttürmen. Ardea, 28:61-79, December (not seen; see Auk, - 1940:271). - -DROST, R. - - 1935. Ueber das Zahlenverhältnis von Alter und Geschlecht - auf dem Herbst-und Frühjahrszuge. Vogelzug, 6(4):177-182, - October. - -DWIGHT, J., JR. - - 1900. The sequence of plumages and moults of the passerine - birds of New York. Annals New York Acad. Sci., 13(1):73-360, - October 19. - -GANIER, A. F. - - 1949. The late summer Dickcissel departure. Migrant, - 20(3):52-53, September. - -GÄTKE, H. - - 1895. Heligoland as an ornithological observatory. - Translated by Rudolph Rosenstock. Edinburgh, David Douglas. - Pp. X + II + 599 + 11 II. (advt.). - -GROSS, A. O. - - 1921. The Dickcissel (Spiza americana) of the Illinois - prairies. Auk, 38(1):1-26, January 18 (first of two parts). - -GURNEY, J. H. - - 1923. Bird migration as observed on the east coast of - England. Ibis, 11th ser., 5(4):573-603, October 3. - -HOWELL, J. C., LASKEY, A. R., and J. T. TANNER - - 1954. Bird mortality at airport ceilometers. Wilson Bull., - 66(3):207-215, September [published October 29]. - -HOWELL, J. C., and J. T. TANNER - - 1951. An accident to migrating birds at the Knoxville - airport. Migrant, 22(4):61-62, December. - -LASKEY, A. R. - - 1951. Another disaster to migrating birds at the Nashville - airport. Migrant, 22(4):57-60, December. - -LONG, W. S. - 1934. Notes from eastern Kansas. Auk, 51(2):255, April 4. - -1940. Check-list of Kansas birds. Trans. Kansas Acad. Sci., -43:433-456. - -LOVELL, H. B. - - 1952. Catastrophe to birds at a Louisville airport. Kentucky - Warbler, 28(1):5-6, February. - -LOWERY, G. H., JR. - - 1951. A quantitative study of the nocturnal migration of - birds. Univ. Kansas Publ., Mus. Nat. Hist., 3(2):361-472, - June 29. - -MCCABE, T. T. - - 1943. An aspect of collectors' technique. Auk, - 60(4):550-558, October 7. - -MCCABE, T. T., and A. H. MILLER - - 1933. Geographic variation in the Northern Water-thrushes. - Condor, 35(5):192-197, September-October (September 15). - -MEINERTZHAGEN, R. - - 1930. Nicoll's birds of Egypt. Vol. I (of 2). London, Hugh - Rees Ltd. Pp. XVI + 348. - -MENGEL, R. M. - - 1952. Certain molts and plumages of Acadian and - Yellow-bellied flycatchers. Auk, 69(3):273-283, July 7. - -MILLER, A. H. - - 1941. Speciation in the avian genus Junco. Univ. California - Publ. Zoöl., 44(3):173-434, May 24. - -MILLER, A. H., and T. T. MCCABE - - 1935. Racial differentiation in Passerella (Melospiza) - lincolnii. Condor, 37(3):144-160, May-June (May 15). - -PALMÉN, J. A. - - 1876. Ueber die Zugstrassen der Vögel. Leipzig, Wilhelm - Engelmann. Pp. VI + 292 + I. - -PETERS, J. L., and L. GRISCOM - - 1938. Geographical variation in the Savannah Sparrow. Bull. - Mus. Comp. Zoöl., 80(13):445-478, January. - -PITELKA, F. A. - - 1946. Age in relation to migration in the Blue Jay. Auk, - 63(1):82-84, January 25. - - 1951. Speciation and ecologic distribution in American jays - of the genus Aphelocoma. Univ. California Publ. Zoöl., - 50(3):195-464, July 20. - -RINTOUL, L. J., and E. V. BAXTER - - 1914. Notes on some passerine birds found migrating in - moult. Scottish Naturalist, no. 35, pp. 245-252, November. - -ROWAN, W. - - 1926. Notes on Alberta waders included on the British list. - Part II. Brit. Birds, 20(2):34-42, June 1. - -RUTH, E. L. - - 1952. The Bay-breasted Warbler in Kansas. Kansas Orn. Soc. - Bull., 3(3):18-19. - -SIBLEY, C. G. - - 1950. Species formation in the Red-eyed Towhees of Mexico. - Univ. California Publ. Zoöl., 50(2):109-194, November 24. - -SPOFFORD, W. R. - - 1949. Mortality of birds at the ceilometer of the Nashville - airport. Wilson Bull., 61(2):86-90, June. - -STONE, W. - - 1906. Some light on night migration. Auk, 23(3):249-252, - July. - -STORER, R. W. - - 1951. Variation in the Painted Bunting (_Passerina ciris_), - with special reference to wintering populations. Occas. - Papers Mus. Zool., Univ. Michigan, no. 532, pp. 1-12, June - 29. - -THOMSON, A. L. - - 1926. Problems of bird-migration. Boston and New York, - Houghton Mifflin Company. Pp. XV + I + 350. - - 1936. Recent progress in the study of bird-migration: a - review of the literature, 1926-35. Ibis, 13th ser., - 6(3):472-530, July 1. - -TICEHURST, C. B. - - 1916. Notes on migrants and moult, with special reference to - the moults of some of our summer visitants. Scottish - Naturalist, no. 50, pp. 29-38, February. - -TORDOFF, H. B. - - 1952. Notes on plumages, molts, and age variation of the Red - Crossbill. Condor, 54(4):200-203, July-August. - -WIEGOLD, H. - - 1926. Masse, Gewichte und Zug nach Alter und Geschlecht bei - Helgoländer Zugvögeln. Wissenschaftliche - Meeresuntersuchungen, Abt. Helgoland, Neue Folge, 15ter - Band, Heft 3, No. 17, Lipsius & Tischer, Kiel und Leipzig, - pp. 1-73. - -WOLFSON, A. - - 1954. Weight and fat deposition in relation to spring - migration in transient White-throated Sparrows. Auk, - 71(4):413-434. - -_Transmitted June 30, 1955._ - - - - -Transcriber's Notes: - - -Words surrounded by _ are italicized. - -Small capitals are presented as all capitals in this e-text. - -Obvious printer's errors have been repaired, other inconsistent -spellings have been kept, for example inconsistent use of hyphen (e.g. -"age-classes" and "age classes") and diacritical mark (e.g. "Zool." -and "Zoöl."). - - - - - -End of the Project Gutenberg EBook of Studies of Birds Killed in Nocturnal -Migration, by Harrison B. Tordoff and Robert M. Mengel - -*** END OF THIS PROJECT GUTENBERG EBOOK STUDIES OF BIRDS *** - -***** This file should be named 52382-8.txt or 52382-8.zip ***** -This and all associated files of various formats will be found in: - http://www.gutenberg.org/5/2/3/8/52382/ - -Produced by Judith Wirawan, Chris Curnow, Joseph Cooper -and the Online Distributed Proofreading Team at -http://www.pgdp.net - - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the United -States without permission and without paying copyright -royalties. Special rules, set forth in the General Terms of Use part -of this license, apply to copying and distributing Project -Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm -concept and trademark. Project Gutenberg is a registered trademark, -and may not be used if you charge for the eBooks, unless you receive -specific permission. If you do not charge anything for copies of this -eBook, complying with the rules is very easy. You may use this eBook -for nearly any purpose such as creation of derivative works, reports, -performances and research. They may be modified and printed and given -away--you may do practically ANYTHING in the United States with eBooks -not protected by U.S. copyright law. Redistribution is subject to the -trademark license, especially commercial redistribution. - -START: FULL LICENSE - -THE FULL PROJECT GUTENBERG LICENSE -PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK - -To protect the Project Gutenberg-tm mission of promoting the free -distribution of electronic works, by using or distributing this work -(or any other work associated in any way with the phrase "Project -Gutenberg"), you agree to comply with all the terms of the Full -Project Gutenberg-tm License available with this file or online at -www.gutenberg.org/license. - -Section 1. General Terms of Use and Redistributing Project -Gutenberg-tm electronic works - -1.A. By reading or using any part of this Project Gutenberg-tm -electronic work, you indicate that you have read, understand, agree to -and accept all the terms of this license and intellectual property -(trademark/copyright) agreement. If you do not agree to abide by all -the terms of this agreement, you must cease using and return or -destroy all copies of Project Gutenberg-tm electronic works in your -possession. If you paid a fee for obtaining a copy of or access to a -Project Gutenberg-tm electronic work and you do not agree to be bound -by the terms of this agreement, you may obtain a refund from the -person or entity to whom you paid the fee as set forth in paragraph -1.E.8. - -1.B. "Project Gutenberg" is a registered trademark. It may only be -used on or associated in any way with an electronic work by people who -agree to be bound by the terms of this agreement. There are a few -things that you can do with most Project Gutenberg-tm electronic works -even without complying with the full terms of this agreement. See -paragraph 1.C below. There are a lot of things you can do with Project -Gutenberg-tm electronic works if you follow the terms of this -agreement and help preserve free future access to Project Gutenberg-tm -electronic works. See paragraph 1.E below. - -1.C. The Project Gutenberg Literary Archive Foundation ("the -Foundation" or PGLAF), owns a compilation copyright in the collection -of Project Gutenberg-tm electronic works. Nearly all the individual -works in the collection are in the public domain in the United -States. If an individual work is unprotected by copyright law in the -United States and you are located in the United States, we do not -claim a right to prevent you from copying, distributing, performing, -displaying or creating derivative works based on the work as long as -all references to Project Gutenberg are removed. Of course, we hope -that you will support the Project Gutenberg-tm mission of promoting -free access to electronic works by freely sharing Project Gutenberg-tm -works in compliance with the terms of this agreement for keeping the -Project Gutenberg-tm name associated with the work. You can easily -comply with the terms of this agreement by keeping this work in the -same format with its attached full Project Gutenberg-tm License when -you share it without charge with others. - -1.D. The copyright laws of the place where you are located also govern -what you can do with this work. Copyright laws in most countries are -in a constant state of change. If you are outside the United States, -check the laws of your country in addition to the terms of this -agreement before downloading, copying, displaying, performing, -distributing or creating derivative works based on this work or any -other Project Gutenberg-tm work. The Foundation makes no -representations concerning the copyright status of any work in any -country outside the United States. - -1.E. Unless you have removed all references to Project Gutenberg: - -1.E.1. The following sentence, with active links to, or other -immediate access to, the full Project Gutenberg-tm License must appear -prominently whenever any copy of a Project Gutenberg-tm work (any work -on which the phrase "Project Gutenberg" appears, or with which the -phrase "Project Gutenberg" is associated) is accessed, displayed, -performed, viewed, copied or distributed: - - 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'll have to check the laws of the country where you - are located before using this ebook. - -1.E.2. If an individual Project Gutenberg-tm electronic work is -derived from texts not protected by U.S. copyright law (does not -contain a notice indicating that it is posted with permission of the -copyright holder), the work can be copied and distributed to anyone in -the United States without paying any fees or charges. If you are -redistributing or providing access to a work with the phrase "Project -Gutenberg" associated with or appearing on the work, you must comply -either with the requirements of paragraphs 1.E.1 through 1.E.7 or -obtain permission for the use of the work and the Project Gutenberg-tm -trademark as set forth in paragraphs 1.E.8 or 1.E.9. - -1.E.3. If an individual Project Gutenberg-tm electronic work is posted -with the permission of the copyright holder, your use and distribution -must comply with both paragraphs 1.E.1 through 1.E.7 and any -additional terms imposed by the copyright holder. Additional terms -will be linked to the Project Gutenberg-tm License for all works -posted with the permission of the copyright holder found at the -beginning of this work. - -1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm -License terms from this work, or any files containing a part of this -work or any other work associated with Project Gutenberg-tm. - -1.E.5. Do not copy, display, perform, distribute or redistribute this -electronic work, or any part of this electronic work, without -prominently displaying the sentence set forth in paragraph 1.E.1 with -active links or immediate access to the full terms of the Project -Gutenberg-tm License. - -1.E.6. You may convert to and distribute this work in any binary, -compressed, marked up, nonproprietary or proprietary form, including -any word processing or hypertext form. However, if you provide access -to or distribute copies of a Project Gutenberg-tm work in a format -other than "Plain Vanilla ASCII" or other format used in the official -version posted on the official Project Gutenberg-tm web site -(www.gutenberg.org), you must, at no additional cost, fee or expense -to the user, provide a copy, a means of exporting a copy, or a means -of obtaining a copy upon request, of the work in its original "Plain -Vanilla ASCII" or other form. Any alternate format must include the -full Project Gutenberg-tm License as specified in paragraph 1.E.1. - -1.E.7. Do not charge a fee for access to, viewing, displaying, -performing, copying or distributing any Project Gutenberg-tm works -unless you comply with paragraph 1.E.8 or 1.E.9. - -1.E.8. You may charge a reasonable fee for copies of or providing -access to or distributing Project Gutenberg-tm electronic works -provided that - -* You pay a royalty fee of 20% of the gross profits you derive from - the use of Project Gutenberg-tm works calculated using the method - you already use to calculate your applicable taxes. The fee is owed - to the owner of the Project Gutenberg-tm trademark, but he has - agreed to donate royalties under this paragraph to the Project - Gutenberg Literary Archive Foundation. Royalty payments must be paid - within 60 days following each date on which you prepare (or are - legally required to prepare) your periodic tax returns. Royalty - payments should be clearly marked as such and sent to the Project - Gutenberg Literary Archive Foundation at the address specified in - Section 4, "Information about donations to the Project Gutenberg - Literary Archive Foundation." - -* You provide a full refund of any money paid by a user who notifies - you in writing (or by e-mail) within 30 days of receipt that s/he - does not agree to the terms of the full Project Gutenberg-tm - License. You must require such a user to return or destroy all - copies of the works possessed in a physical medium and discontinue - all use of and all access to other copies of Project Gutenberg-tm - works. - -* You provide, in accordance with paragraph 1.F.3, a full refund of - any money paid for a work or a replacement copy, if a defect in the - electronic work is discovered and reported to you within 90 days of - receipt of the work. - -* You comply with all other terms of this agreement for free - distribution of Project Gutenberg-tm works. - -1.E.9. If you wish to charge a fee or distribute a Project -Gutenberg-tm electronic work or group of works on different terms than -are set forth in this agreement, you must obtain permission in writing -from both the Project Gutenberg Literary Archive Foundation and The -Project Gutenberg Trademark LLC, the owner of the Project Gutenberg-tm -trademark. Contact the Foundation as set forth in Section 3 below. - -1.F. - -1.F.1. Project Gutenberg volunteers and employees expend considerable -effort to identify, do copyright research on, transcribe and proofread -works not protected by U.S. copyright law in creating the Project -Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm -electronic works, and the medium on which they may be stored, may -contain "Defects," such as, but not limited to, incomplete, inaccurate -or corrupt data, transcription errors, a copyright or other -intellectual property infringement, a defective or damaged disk or -other medium, a computer virus, or computer codes that damage or -cannot be read by your equipment. - -1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right -of Replacement or Refund" described in paragraph 1.F.3, the Project -Gutenberg Literary Archive Foundation, the owner of the Project -Gutenberg-tm trademark, and any other party distributing a Project -Gutenberg-tm electronic work under this agreement, disclaim all -liability to you for damages, costs and expenses, including legal -fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT -LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE -PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE -TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE -LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR -INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH -DAMAGE. - -1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a -defect in this electronic work within 90 days of receiving it, you can -receive a refund of the money (if any) you paid for it by sending a -written explanation to the person you received the work from. If you -received the work on a physical medium, you must return the medium -with your written explanation. The person or entity that provided you -with the defective work may elect to provide a replacement copy in -lieu of a refund. If you received the work electronically, the person -or entity providing it to you may choose to give you a second -opportunity to receive the work electronically in lieu of a refund. If -the second copy is also defective, you may demand a refund in writing -without further opportunities to fix the problem. - -1.F.4. Except for the limited right of replacement or refund set forth -in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO -OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT -LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE. - -1.F.5. Some states do not allow disclaimers of certain implied -warranties or the exclusion or limitation of certain types of -damages. If any disclaimer or limitation set forth in this agreement -violates the law of the state applicable to this agreement, the -agreement shall be interpreted to make the maximum disclaimer or -limitation permitted by the applicable state law. The invalidity or -unenforceability of any provision of this agreement shall not void the -remaining provisions. - -1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the -trademark owner, any agent or employee of the Foundation, anyone -providing copies of Project Gutenberg-tm electronic works in -accordance with this agreement, and any volunteers associated with the -production, promotion and distribution of Project Gutenberg-tm -electronic works, harmless from all liability, costs and expenses, -including legal fees, that arise directly or indirectly from any of -the following which you do or cause to occur: (a) distribution of this -or any Project Gutenberg-tm work, (b) alteration, modification, or -additions or deletions to any Project Gutenberg-tm work, and (c) any -Defect you cause. - -Section 2. Information about the Mission of Project Gutenberg-tm - -Project Gutenberg-tm is synonymous with the free distribution of -electronic works in formats readable by the widest variety of -computers including obsolete, old, middle-aged and new computers. It -exists because of the efforts of hundreds of volunteers and donations -from people in all walks of life. - -Volunteers and financial support to provide volunteers with the -assistance they need are critical to reaching Project Gutenberg-tm's -goals and ensuring that the Project Gutenberg-tm collection will -remain freely available for generations to come. In 2001, the Project -Gutenberg Literary Archive Foundation was created to provide a secure -and permanent future for Project Gutenberg-tm and future -generations. To learn more about the Project Gutenberg Literary -Archive Foundation and how your efforts and donations can help, see -Sections 3 and 4 and the Foundation information page at -www.gutenberg.org Section 3. Information about the Project Gutenberg -Literary Archive Foundation - -The Project Gutenberg Literary Archive Foundation is a non profit -501(c)(3) educational corporation organized under the laws of the -state of Mississippi and granted tax exempt status by the Internal -Revenue Service. The Foundation's EIN or federal tax identification -number is 64-6221541. Contributions to the Project Gutenberg Literary -Archive Foundation are tax deductible to the full extent permitted by -U.S. federal laws and your state's laws. - -The Foundation's principal office is in Fairbanks, Alaska, with the -mailing address: PO Box 750175, Fairbanks, AK 99775, but its -volunteers and employees are scattered throughout numerous -locations. Its business office is located at 809 North 1500 West, Salt -Lake City, UT 84116, (801) 596-1887. Email contact links and up to -date contact information can be found at the Foundation's web site and -official page at www.gutenberg.org/contact - -For additional contact information: - - Dr. Gregory B. Newby - Chief Executive and Director - gbnewby@pglaf.org - -Section 4. Information about Donations to the Project Gutenberg -Literary Archive Foundation - -Project Gutenberg-tm depends upon and cannot survive without wide -spread public support and donations to carry out its mission of -increasing the number of public domain and licensed works that can be -freely distributed in machine readable form accessible by the widest -array of equipment including outdated equipment. Many small donations -($1 to $5,000) are particularly important to maintaining tax exempt -status with the IRS. - -The Foundation is committed to complying with the laws regulating -charities and charitable donations in all 50 states of the United -States. Compliance requirements are not uniform and it takes a -considerable effort, much paperwork and many fees to meet and keep up -with these requirements. We do not solicit donations in locations -where we have not received written confirmation of compliance. To SEND -DONATIONS or determine the status of compliance for any particular -state visit www.gutenberg.org/donate - -While we cannot and do not solicit contributions from states where we -have not met the solicitation requirements, we know of no prohibition -against accepting unsolicited donations from donors in such states who -approach us with offers to donate. - -International donations are gratefully accepted, but we cannot make -any statements concerning tax treatment of donations received from -outside the United States. U.S. laws alone swamp our small staff. - -Please check the Project Gutenberg Web pages for current donation -methods and addresses. Donations are accepted in a number of other -ways including checks, online payments and credit card donations. To -donate, please visit: www.gutenberg.org/donate - -Section 5. General Information About Project Gutenberg-tm electronic works. - -Professor Michael S. Hart was the originator of the Project -Gutenberg-tm concept of a library of electronic works that could be -freely shared with anyone. For forty years, he produced and -distributed Project Gutenberg-tm eBooks with only a loose network of -volunteer support. - -Project Gutenberg-tm eBooks are often created from several printed -editions, all of which are confirmed as not protected by copyright in -the U.S. unless a copyright notice is included. Thus, we do not -necessarily keep eBooks in compliance with any particular paper -edition. - -Most people start at our Web site which has the main PG search -facility: www.gutenberg.org - -This Web site includes information about Project Gutenberg-tm, -including how to make donations to the Project Gutenberg Literary -Archive Foundation, how to help produce our new eBooks, and how to -subscribe to our email newsletter to hear about new eBooks. - diff --git a/old/52382-8.zip b/old/52382-8.zip Binary files differdeleted file mode 100644 index 82dcc40..0000000 --- a/old/52382-8.zip +++ /dev/null diff --git a/old/52382-h.zip b/old/52382-h.zip Binary files differdeleted file mode 100644 index c55e858..0000000 --- a/old/52382-h.zip +++ /dev/null diff --git a/old/52382-h/52382-h.htm b/old/52382-h/52382-h.htm deleted file mode 100644 index 485c957..0000000 --- a/old/52382-h/52382-h.htm +++ /dev/null @@ -1,2720 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" - "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> -<!-- $Id: header.txt 236 2009-12-07 18:57:00Z vlsimpson $ --> - -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> - <head> - <meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1" /> - <meta http-equiv="Content-Style-Type" content="text/css" /> - <title> - The Project Gutenberg eBook of Studies of Birds Killed in Nocturnal Migration, by Harrison B. Tordoff And Robert M. Mengel. - </title> - <link rel="coverpage" href="images/cover.png"/> - <style type="text/css"> - -body {margin-left: 10%; margin-right: 10%;} -h1,h2 {text-align: center; clear: both;} -p {margin-top: .75em; text-align: justify; margin-bottom: .75em;} - -hr {width: 33%; margin-top: 2em; margin-bottom: 2em; margin-left: 33.5%; margin-right: 33.5%; clear: both;} -hr.chap {width: 65%; margin-left: 17.5%; margin-right: 17.5%} - -table {margin-left: auto; margin-right: auto;} -.bor_top {border-top-style: solid; border-width: 1px;} - - -.pagenum {position: absolute; left: 92%; font-size: smaller; text-align: right;} - -small {font-size:70%;} -big {font-size:130%;} - -.space-above {margin-top: 3em;} -.center {text-align: center;} -.right {text-align: right;} -.smcap {font-variant: small-caps;} -.lowercase {text-transform:lowercase;} -.caption {font-weight: bold;} - -/* Images */ -.figcenter {margin-left: auto; margin-right: auto; margin-top: 3em; text-align: center;} - -/* Footnotes */ -.footnote {margin-left: 10%; margin-right: 10%; font-size: 0.9em;} -.footnote .label {position: absolute; right: 84%; text-align: right;} -.fnanchor {vertical-align: super; font-size: .8em; text-decoration: none;} - -/* Transcriber's notes */ -.transnote {background-color: #E6E6FA; color: black; font-size:smaller; padding:0.5em; margin-bottom:5em; font-family:sans-serif, serif; } - </style> - </head> -<body> - - -<pre> - -The Project Gutenberg EBook of Studies of Birds Killed in Nocturnal -Migration, by Harrison B. Tordoff and Robert M. Mengel - -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'll have -to check the laws of the country where you are located before using this ebook. - - - -Title: Studies of Birds Killed in Nocturnal Migration - -Author: Harrison B. Tordoff - Robert M. Mengel - -Release Date: June 20, 2016 [EBook #52382] - -Language: English - -Character set encoding: ISO-8859-1 - -*** START OF THIS PROJECT GUTENBERG EBOOK STUDIES OF BIRDS *** - - - - -Produced by Judith Wirawan, Chris Curnow, Joseph Cooper -and the Online Distributed Proofreading Team at -http://www.pgdp.net - - - - - - -</pre> - -<hr class="chap" /> - - - -<p class="center"><span class="smcap">University of Kansas Publications</span></p> - -<p class="center"><span class="smcap">Museum of Natural History</span></p> - -<hr /> - -<p class="center">Volume 10, No. 1, pp. 1-44, 6 figures in text, 2 tables</p> - -<p class="center">———September 12, 1956———</p> - - -<h1 class="space-above">Studies of Birds<br /> -Killed in Nocturnal Migration</h1> - - -<p class="center">BY<br /> -HARRISON B. TORDOFF AND ROBERT M. MENGEL</p> - - -<p class="center space-above"><span class="smcap">University of Kansas<br /> -Lawrence</span><br /> -1956</p> - -<hr class="chap" /> - -<p class="center"><span class="smcap">University of Kansas Publications, Museum of Natural History</span></p> - -<p class="center">Editors: E. Raymond Hall, Chairman, A. Byron Leonard, -Robert W. Wilson</p> - -<p class="center space-above">Volume 10, No. 1, pp. 1-44, 6 figures in text, 2 tables<br /> -Published September 12, 1956</p> - - -<p class="center space-above"><span class="smcap">University of Kansas</span><br /> -Lawrence, Kansas</p> - -<p class="center space-above">PRINTED BY<br /> -FERD VOILAND, JR., STATE PRINTER<br /> -TOPEKA, KANSAS<br /> -1956</p> - -<div class="figcenter" style="width: 111px;"> -<img src="images/logo.png" width="111" height="44" alt="" /> -</div> - -<p class="center">26-3856</p> - -<hr class="chap" /> - -<p><span class="pagenum"><a name="Page_3" id="Page_3">[Pg 3]</a></span></p> - -<p class="center"><big>Studies of Birds<br /> -Killed in Nocturnal Migration</big></p> - -<p class="center">BY<br /> -HARRISON B. TORDOFF AND ROBERT M. MENGEL</p> - - - -<h2>Contents</h2> - - -<div class="center"> -<table border="0" cellpadding="4" cellspacing="0" summary="Contents"> -<tr><td></td><td align="right"><span class="smcap lowercase">PAGE</span></td></tr> -<tr><td align="left">Introduction</td><td align="right"><a href="#Page_4">4</a></td></tr> -<tr><td align="left">Accidents to Migrating Birds in early October, 1954</td><td align="right"><a href="#Page_6">6</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">General</span></td><td align="right"><a href="#Page_6">6</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">Accidents at Topeka, Kansas</span></td><td align="right"><a href="#Page_6">6</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">Description of WIBW-TV tower</span></td><td align="right"><a href="#Page_7">7</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">Weather conditions</span></td><td align="right"><a href="#Page_7">7</a></td></tr> -<tr><td align="left">Acknowledgments</td><td align="right"><a href="#Page_7">7</a></td></tr> -<tr><td align="left">Notes on the Species Killed at Topeka</td><td align="right"><a href="#Page_8">8</a></td></tr> -<tr><td align="left">Randomness of the Sample</td><td align="right"><a href="#Page_17">17</a></td></tr> -<tr><td align="left">Number of Migrants</td><td align="right"><a href="#Page_18">18</a></td></tr> -<tr><td align="left">Differential Migration of Sex- and Age-classes</td><td align="right"><a href="#Page_20">20</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">History of the subject</span></td><td align="right"><a href="#Page_20">20</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">Differential migration of sex- and age-classes as shown by the Topeka sample</span></td><td align="right"><a href="#Page_23">23</a></td></tr> -<tr><td align="left">Molt in Relation to Migration</td><td align="right"><a href="#Page_29">29</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">General comment</span></td><td align="right"><a href="#Page_29">29</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">Molt in the Topeka sample</span></td><td align="right"><a href="#Page_30">30</a></td></tr> -<tr><td align="left">Size Differences according to Sex and Age</td><td align="right"><a href="#Page_31">31</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">Linear measurements</span></td><td align="right"><a href="#Page_31">31</a></td></tr> -<tr><td align="left"><span style="margin-left: 1em;">Weights</span></td><td align="right"><a href="#Page_32">32</a></td></tr> -<tr><td align="left">Computations of Longevity and Survival</td><td align="right"><a href="#Page_38">38</a></td></tr> -<tr><td align="left">Processing of Samples</td><td align="right"><a href="#Page_38">38</a></td></tr> -<tr><td align="left">Summary</td><td align="right"><a href="#Page_39">39</a></td></tr> -<tr><td align="left">Literature Cited</td><td align="right"><a href="#Page_41">41</a></td></tr> -</table></div> - -<hr class="chap" /> - -<p><span class="pagenum"><a name="Page_4" id="Page_4">[Pg 4]</a></span></p> - - - -<h2>Introduction</h2> - - -<p>This paper is primarily an analysis of a sample of migrant birds -killed in the autumn of 1954 by striking a television tower one mile -west of Topeka, Shawnee County, Kansas. Secondarily, some aspects -of migration involved in studies of this kind are discussed and -historical background is presented.</p> - -<p>Considerable interest has been occasioned in recent years in the -eastern United States by large-scale accidents to night-migrating -birds. Most accidents have occurred in the autumn. The widespread -adoption by airports of an instrument called the ceilometer, -which measures the height of cloud ceilings by reflecting from them -a high-powered beam of light, has proved under certain conditions -to be catastrophic to night-flying birds. Among the recent reports -of such accidents are those of Spofford (1949) and Laskey (1951) -for Nashville, Tennessee, Howell and Tanner (1951) for Knoxville, -Tennessee, and Lovell (1952) for Louisville, Kentucky. Recently -Howell, Laskey, and Tanner (1954) reviewed ceilometer "tragedies" -without being able to determine the exact reason for their lethal -effectiveness. Less publicized so far have been mass collisions of -birds with another class of obstacles, tall radio and television towers. -These slender towers, usually 500 to 1000 feet tall, are increasing -rapidly in numbers and there is reason to suppose that they will -take a correspondingly larger toll of bird life.</p> - -<p>Notice has long been given by ornithologists to mass destruction -of birds by more conventional solid obstructions to passage, and -newspapers occasionally mention birds killed at such well-known -points as the Washington Monument and the Empire State Building.</p> - -<p>Seventy-five years ago, J. A. Allen (1880) published the results -of questionnaires circulated by William Brewster to lighthouse -keepers. Brewster himself (1886) described destruction of birds -at a lighthouse in the Bay of Fundy, paying keen attention to behavior -of the birds and the exact conditions under which nocturnal -flight and accidents occurred. The subject also received attention -in several countries across the Atlantic. Destruction of birds at -Irish lighthouses was carefully noted over a period of years and the -results were published periodically, culminating in R. M. Barrington's -massive report (1900) which remains in some ways the most -thorough of its type.</p> - -<p><span class="pagenum"><a name="Page_5" id="Page_5">[Pg 5]</a></span></p> - -<p>While conservation-minded individuals have been concerned with -the tremendous mortality involved in these various events, the ill -wind blows some good in that, properly used, the data provided -by such accidents can shed light on many obscure aspects of bird -migration. Each accidental kill of birds affords a cross-section, -approaching in variable degree a random sample, of the migrants -passing a given point on a given date. The types of information -provided by such kills are numerous, for example: (1) information -on the presence of various species and the dates of their occurrence; -(2) information on the relative abundance of species; (3) quantitative -data on the relative sizes of males and females, and immatures -and adults (of importance to taxonomic ornithology); (4) -information on the relative times of migration of males, females, -adults, and young; (5) information on molts and plumages; (6) -quantitative information on composition by subspecies of migrants -of the same species; (7) physiological data (fat condition, <i>etc.</i>) -pertinent to the study of migration; and probably others.</p> - -<p>In spite of the great potential of this kind of material, the majority -of ornithologists with access to such data have contented -themselves with listing the species and sometimes the numbers of -birds killed. A few have gone further. James T. Tanner (unpublished) -attempted to compute the longevity of the Ovenbird -(<i>Seiurus aurocapillus</i>) by analysis of ceilometer-killed birds at -Knoxville, Tennessee (see below). Mention should be made of the -reports of Rintoul and Baxter (1914) supplemented by Ticehurst -(1916) who used rather small numbers of birds killed at Scottish -lighthouses in studies of molt. However, the only effort to utilize -the results of accidental kills on a large scale over a period of years -appears to have been that, already mentioned, of Barrington (1900) -and his co-workers in Ireland. An idea of the potentialities of the -large recent kills in the United States may be obtained when it is -recalled that in the 18 years of Barrington's work, which embodied -some 1000 reports from lighthouse keepers, Barrington obtained for -study only about 2000 specimens, many of these consisting of wings -and feet only (Barrington's paper not seen in original; see J. A. -Allen, 1901:205). More recently Dobben and Bruyns (1939) have -analyzed the age and sex classes of some birds killed at lighthouses -in Holland.</p> - -<p>As far as we have learned, there is no previous thorough analysis -in the literature of large, accidentally-killed samples of birds. On -the following pages we emphasize some of the uses which can be -made of such material. We think that intensive analyses of such<span class="pagenum"><a name="Page_6" id="Page_6">[Pg 6]</a></span> -events, whenever they occur, should become a regular part of -ornithological investigation and that integration of numerous studies -of such incidents will provide an unprecedented mass of information -on migration.</p> - - - -<hr class="chap" /> -<h2>Accidents to Migrating Birds in early October, 1954</h2> - - -<p><span class="smcap">General.</span>—The few days around the end of the first week of -October, 1954, were notable for a series of accidents which occurred -to migrating birds over much of eastern United States. So -far as we know, these were all associated with an extensive belt of -bad weather (cold fronts and stationary fronts) which covered -much of the country during that period, and the accidents involved -ceilometers and solid structures alike. Accidents known to us -occurred as far south as Macon, Georgia (David W. Johnston, letter: -Nov. 1, 1954), as far north as New York City, where many -migrants were killed at the Empire State Building (<i>New York -Times</i>, Thursday, October 7, 1954, p. 1) and elsewhere, and as far -west as Smoky Hill Air Force Base at Salina, Kansas (ceilometer, -October 7, some birds received at the University of Kansas). Some -of the above, and incidents from a number of other localities, were -mentioned in varying detail in <i>Audubon Field Notes</i> (vol. 9, no. -1, pp. 6, 10, 15, 17, 18, 32, February, 1955). Still other accidents -occurred at Columbia, Missouri (Richard P. Grossenheider, verbal -communication), and Topeka, Kansas (present paper). Some probably -have escaped our notice; summaries of some of these will probably -appear in ornithological journals for some time to come. At -Robins Air Force Base near Macon, Georgia, at least 50,000 birds -were killed, of which about 2500, representing 54 species, were -picked up (Johnston, <i>loc. cit.</i>).</p> - - -<p><span class="smcap">Accidents at Topeka, Kansas.</span>—At Topeka, Shawnee County, -Kansas, all birds were killed by collision with the newly-erected -(1954) television transmitting tower of station WIBW-TV. This -tower is one mile west of the city.</p> - -<p>The first casualties (see Table 1 for all others) were a Sora (<i>Porzana -carolina</i>) and a Yellow-bellied Flycatcher (<i>Empidonax flaviventris</i>) -found on September 7. The major accidents, however, -occurred on the nights of September 24-25, September 30-October -1, October 5-6, and October 6-7. Totals of birds picked up (probably -over 95 per cent of birds killed) are given in Table 1, in which -each date given is that of the day after the kill, <i>i. e.</i>, the date on -which the birds were collected.</p> - -<p><span class="pagenum"><a name="Page_7" id="Page_7">[Pg 7]</a></span></p> - -<p>All major kills occurred on cloudy and foggy nights associated -with frontal weather. Throughout the period a few birds struck -the tower even on fairly clear nights, and minor but appreciable -"falls" occurred on the nights of October 4-5, 7-8, and 22-23. A few -birds killed probably were overlooked for a time and found their -way into later samples. This is especially probable in the case of -some birds entered under date of October 23, as many of these -were somewhat desiccated. Weights clearly altered by desiccation -or mutilation were not recorded. Reports of these accidents have -been published by Carson (1954 a, b, and c).</p> - -<p>According to Carson (1954c:27), the majority of birds killed on -nights of heavy flight fell "between three and four o'clock in the -morning when skies were overcast and a cool front moved in from -the north. Due to the cooperation of the watchmen it is thought -that most of the birds that were killed were recovered. Of course -some injured birds in hiding were not found and some were lost to -predators."</p> - - -<p><span class="smcap">Description of WIBW-TV TOWER</span>.—The tower is 950 feet tall -and stands on a hill approximately 1000 feet above sea level. The -fact that the tower is on a hill places the top of the tower at 1010 -feet above the elevation of the average local terrain. The tower -is triangular in cross-section, each face seven feet wide, and is -constructed of six-inch steel L-beams with three-inch cross-members -every seven feet and smaller diagonal cross-members. It has no -taper and bears a transmitting antenna on the top. The tower is -supported by 12 guy wires, 3 wires attaching at each of 4 levels. -The cables extend south, WNW, and NNE from the tower and are -1-1/2 inches in diameter. The tower is lighted by a series of red lights, -some flashing and others steady. The transmitter was not in operation -when the accidents took place.</p> - - -<p><span class="smcap">Weather conditions.</span>—All major kills at Topeka occurred when -migrating birds encountered either a cold front or a stationary front -lying over eastern Kansas. Typically, this frontal weather included -rain, fog, and cloud ceilings down to as low as 800 to 1000 feet. -Weather of this type presumably forces the migrating birds to fly -below the cloud ceiling and thus brings them within the altitudinal -range of the television towers.</p> - - - -<hr class="chap" /> -<h2>Acknowledgments</h2> - - -<p>We gratefully acknowledge our debt to the Topeka Audubon Society for -making this study possible by carefully collecting birds killed at the television -tower. L. B. Carson deserves special mention for his general supervision of -<span class="pagenum"><a name="Page_8" id="Page_8">[Pg 8]</a></span>the bird collecting by the members of the Topeka Audubon Society. Members -of the Society and others who picked up birds under the television tower were: -Mrs. Lloyd Biggs, Elaine Carson, L. B. Carson, Jesse A. Eddy, Elizabeth Fisher, -Mrs. Walter Huxman, Florence McKinney, Mrs. Charles Martin, Mrs. Fred P. -Martin, T. W. Nelson, Fred Prebble, Grace Prebble, Orville Rice, Mrs. G. -Warren Scholl, E. W. Senne, and Beatrice Swenson.</p> - -<p>We received equally important assistance from students and staff of the -University of Kansas in recording of data and preparation of specimens. The -following helped in these ways: Rollin H. Baker, R. W. Dickerman, David -L. Hardy, J. W. Hardy, Jane S. Mengel, Larry D. Mosby, Richard Van Gelder, -South G. Van Hoose, and Glen E. Woolfenden. We are indebted to the Interlibrary -Loan Service of the University of Kansas Library for help in securing -certain reference works. Robert Sokal of the University of Kansas gave helpful -advice concerning statistical procedures.</p> - - - -<hr class="chap" /> -<h2>Notes on the Species Killed at Topeka</h2> - - -<p>A list of numbers and kinds of birds killed is given in Table 1. -Discussion of data afforded by certain species for which, large -samples were available will be found below. There are additionally -certain data afforded by the sample and certain comments to -be made on various species which can be handled most conveniently -in an annotated list. In this list we have included all weight -data (still scarce for many North American birds), comments on -status in Kansas of various species, results of comparisons to determine -subspecies, and miscellaneous observations. Weights of -birds are given in grams and were taken on a triple-beam balance. -Fat condition is given in the scale proposed by McCabe (1943:556). -Weight data from birds migrating at night should be especially -useful because these migrants all have relatively empty -crops and stomachs, thus reducing variability. Not all birds were -suitable for weighing and measuring, for a variety of reasons. This -accounts for discrepancies in totals between Table 1 and the annotated -list.</p> - -<p>All passerine species were aged by noting the degree of ossification -of the skull. In no case, of the more than a thousand passerines -aged by examination of the skull, did we find difficulty in determining -whether an individual was a bird of the year or an adult. -We found no specimens in which ossification of the skull was nearing -completion. In the several species in our sample with distinctive -first-winter plumages, we found complete agreement in -age as shown by plumage and by condition of the skull. We think -this is further proof, if such is needed, that this method of aging is -thoroughly reliable in early autumn for the passerine species included -in our sample and for others with similar breeding seasons.</p> - -<p><span class="pagenum"><a name="Page_9" id="Page_9">[Pg 9]</a></span></p> - -<p class="center"><span class="smcap">Table 1.—Birds Killed at a Television Tower at Topeka, Kansas, in 1954</span></p> - -<p>See annotated list for division into sex- and age-classes. Where discrepancies -exist between totals given here and totals given in the annotated list, these -result from the fact that some specimens could not be sexed and aged.</p> - -<div class="center"> -<table border="1" cellpadding="4" cellspacing="0" summary="Birds Killed"> -<tr><td></td> - <td>Sept. 25</td><td>Oct. 1</td><td>Oct. 3</td><td>Oct. 4</td><td>Oct. 5</td><td>Oct. 6</td><td>Oct. 7</td><td>Oct. 8</td><td>Oct. 9</td><td>Oct. 10</td><td>Oct. 23</td> - <td>Totals</td></tr> -<tr><td align="left">Pied-billed Grebe</td> - <td></td><td>1</td><td></td><td></td><td></td><td>1</td><td></td><td></td><td>1</td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Green Heron</td> - <td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">Blue-winged Teal</td> - <td></td><td>1</td><td></td><td></td><td></td><td>1</td><td>6</td><td></td><td></td><td></td><td></td> - <td>8</td></tr> -<tr><td align="left">Virginia Rail</td> - <td></td><td>3</td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td><td></td> - <td>4</td></tr> -<tr><td align="left">Sora</td> - <td>1</td><td>6</td><td></td><td></td><td></td><td>1</td><td>1</td><td>1</td><td></td><td></td><td></td> - <td>10</td></tr> -<tr><td align="left">American Coot</td> - <td></td><td></td><td></td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Mourning Dove</td> - <td></td><td>8</td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td><td></td><td>1</td> - <td>10</td></tr> -<tr><td align="left">Yellow-billed Cuckoo</td> - <td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">Black-billed Cuckoo</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">Yellow-shafted Flicker</td> - <td>3</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Yellow-bellied Flycatcher</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">House Wren</td> - <td>2</td><td>3</td><td></td><td></td><td></td><td>1</td><td>2</td><td>1</td><td></td><td>1</td><td></td> - <td>10</td></tr> -<tr><td align="left">Long-billed Marsh Wren</td> - <td></td><td>1</td><td></td><td></td><td></td><td>1</td><td>1</td><td></td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Short-billed Marsh Wren</td> - <td>1</td><td>2</td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td> - <td>4</td></tr> -<tr><td align="left">Catbird</td> - <td>1</td><td>28</td><td>1</td><td></td><td>1</td><td>6</td><td>6</td><td></td><td></td><td></td><td></td> - <td>43</td></tr> -<tr><td align="left">Brown Thrasher</td> - <td></td><td>1</td><td></td><td></td><td></td><td>1</td><td></td><td>1</td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Wood Thrush</td> - <td></td><td>3</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Hermit Thrush</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td> - <td>1</td></tr> -<tr><td align="left">Olive-backed Thrush</td> - <td></td><td>14</td><td></td><td>1</td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td> - <td>16</td></tr> -<tr><td align="left">Golden-crowned Kinglet</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td>5</td> - <td>6</td></tr> -<tr><td align="left">Ruby-crowned Kinglet</td> - <td>2</td><td>1</td><td></td><td></td><td></td><td></td><td>8</td><td>1</td><td>1</td><td></td><td>1</td> - <td>14</td></tr> -<tr><td align="left">Yellow-throated Vireo</td><td></td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">Blue-headed Vireo</td> - <td>1</td><td>19</td><td></td><td>1</td><td>2</td><td>5</td><td>8</td><td>3</td><td>1</td><td></td><td></td> - <td>40</td></tr> -<tr><td align="left">Red-eyed Vireo</td> - <td>18</td><td>36</td><td></td><td></td><td>2</td><td>13</td><td>2</td><td>3</td><td></td><td></td><td>1</td> - <td>75</td></tr> -<tr><td align="left">Philadelphia Vireo</td> - <td>3</td><td>9</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>12</td></tr> -<tr><td align="left">Warbling Vireo</td> - <td>8</td><td>19</td><td>1</td><td></td><td>4</td><td>1</td><td>1</td><td></td><td></td><td></td><td></td> - <td>34</td></tr> -<tr><td align="left">Black and White Warbler</td> - <td>1</td><td>1</td><td></td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td></td> - <td>5</td></tr> -<tr><td align="left">Tennessee Warbler</td> - <td></td><td>1</td><td></td><td></td><td>1</td><td>2</td><td>1</td><td></td><td></td><td></td><td></td> - <td>5</td></tr> -<tr><td align="left">Orange-crowned Warbler</td> - <td>7</td><td>14</td><td></td><td></td><td>1</td><td>4</td><td>19</td><td>5</td><td>1</td><td>1</td><td></td> - <td>52</td></tr> -<tr><td align="left">Nashville Warbler</td> - <td>7</td><td>94</td><td>4</td><td></td><td>3</td><td>39</td><td>27</td><td>5</td><td></td><td>1</td><td>1</td> - <td>181</td></tr> -<tr><td align="left">Parula Warbler</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td>1</td><td></td><td></td> - <td>2</td></tr> -<tr><td align="left">Yellow Warbler</td> - <td>3</td><td>3</td><td></td><td></td><td></td><td>1</td><td>1</td><td></td><td></td><td></td><td></td> - <td>8</td></tr> -<tr><td align="left">Magnolia Warbler</td> - <td></td><td>1</td><td></td><td></td><td></td><td>2</td><td></td><td></td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Black-throated Blue Warbler</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td>2</td><td></td><td></td><td></td><td>1</td> - <td>3</td></tr> -<tr><td align="left">Myrtle Warbler</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">Black-throated Green Warbler</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td> - <td>1</td></tr> -<tr><td align="left">Chestnut-sided Warbler</td> - <td></td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td> - <td>2</td></tr> -<tr><td align="left">Bay-breasted Warbler</td> - <td>1</td><td></td><td></td><td></td><td></td><td>2</td><td></td><td></td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Palm Warbler</td> - <td>3</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td> - <td>4</td></tr> -<tr><td align="left">Oven-bird</td> - <td>4</td><td>21</td><td></td><td></td><td></td><td>2</td><td>3</td><td>1</td><td></td><td></td><td>1</td> - <td>32</td></tr> -<tr><td align="left">Northern Water-thrush</td> - <td></td><td>5</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td> - <td>6</td></tr> -<tr><td align="left">Mourning Warbler</td> - <td>15</td><td>64</td><td></td><td></td><td>2</td><td>11</td><td>2</td><td>1</td><td></td><td></td><td></td> - <td>95</td></tr> -<tr><td align="left">Yellow-throat</td> - <td>10</td><td>115</td><td>2</td><td></td><td>4</td><td>25</td><td>18</td><td>1</td><td>1</td><td></td><td></td> - <td>176</td></tr> -<tr><td align="left">Yellow-breasted Chat</td> - <td></td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">Wilson Warbler</td> - <td>1</td><td>2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>3</td></tr> -<tr><td align="left">Canada Warbler</td> - <td></td><td>2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>2</td></tr> -<tr><td align="left">American Redstart</td> - <td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>1</td></tr> -<tr><td align="left">Bobolink</td> - <td></td><td>4</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>4</td></tr> -<tr><td align="left">Rose-breasted Grosbeak</td> - <td></td><td>2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td> - <td>2</td></tr> -<tr><td align="left">Indigo Bunting</td> - <td></td><td>1</td><td></td><td></td><td>2</td><td>3</td><td>1</td><td></td><td></td><td></td><td></td> - <td>7</td></tr> -<tr><td align="left">Dickcissel</td> - <td></td><td>31</td><td></td><td></td><td>1</td><td>3</td><td>1</td><td></td><td></td><td></td><td></td> - <td>36</td></tr> -<tr><td align="left">Savannah Sparrow</td> - <td>1</td><td>6</td><td></td><td>1</td><td></td><td>1</td><td>5</td><td>1</td><td></td><td></td><td>1</td> - <td>16</td></tr> -<tr><td align="left">Grasshopper Sparrow</td> - <td></td><td>7</td><td></td><td></td><td>2</td><td>3</td><td>3</td><td>1</td><td>1</td><td></td><td>1</td> - <td>18</td></tr> -<tr><td align="left">Leconte Sparrow</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>3</td> - <td>3</td></tr> -<tr><td align="left">Sharp-tailed Sparrow</td> - <td></td><td></td><td></td><td></td><td></td><td>1</td><td>1</td><td></td><td></td><td>1</td><td></td> - <td>3</td></tr> -<tr><td align="left">Slate-colored Junco</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td> - <td>1</td></tr> -<tr><td align="left">Clay-colored Sparrow</td> - <td></td><td>11</td><td>1</td><td></td><td></td><td>2</td><td></td><td>1</td><td></td><td></td><td></td> - <td>15</td></tr> -<tr><td align="left">Fox Sparrow</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td> - <td>1</td></tr> -<tr><td align="left">Lincoln Sparrow</td> - <td></td><td>41</td><td>7</td><td></td><td></td><td>5</td><td>22</td><td>3</td><td>1</td><td></td><td>3</td> - <td>82</td></tr> -<tr><td align="left">Swamp Sparrow</td> - <td></td><td>1</td><td></td><td></td><td></td><td></td><td>1</td><td>2</td><td></td><td></td><td></td> - <td>4</td></tr> -<tr><td align="left">Song Sparrow</td> - <td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td> - <td>2</td></tr> -<tr><td align="left">Total—species</td> - <td>22</td><td>41</td><td>6</td><td>3</td><td>13</td><td>31</td><td>29</td><td>16</td><td>10</td><td>8</td><td>15</td> - <td>61</td></tr> -<tr><td align="left">Total—individuals</td> - <td>94</td><td>585</td><td>16</td><td>3</td><td>26</td><td>146</td><td>147</td><td>31</td><td>10</td><td>8</td><td>24</td> - <td>1090</td></tr> -</table></div> - -<p><span class="pagenum"><a name="Page_10" id="Page_10">[Pg 10]</a></span>The annotated list may be consulted for further data in connection -with the species listed in Table 1. As is indicated below, we -regard the figures of this sample as unreliable to an unknown degree -in comparing the relative abundance of one species with another. -Accumulation of such data from various localities, however, -should prove useful in another type of comparison. Samples of the -same species killed in the same way at about the same time at different -localities should be directly comparable. Eventually, this -should provide us with a means of determining relative abundance -of a species in different parts of its migratory route.</p> - -<p>Approximately 200 of the most interesting specimens were preserved -as study skins and are in the University of Kansas Museum -of Natural History. An effort was made to preserve at least one of -each species, and we fell only a few short of this goal. All of the -forms rare in Kansas are represented by skins. We could see no -reason to list the preserved specimens in detail here. Species of -which no study skins were made, however, are so marked.</p> - -<p>So far as we can tell, no truly western subspecies (from west of -the Great Plains) occurred in the Topeka sample. Probably most -or all of the birds came from areas more or less directly north of -eastern Kansas.</p> - -<p>In critical areas where different subspecies of the same species -occur together in migration, data from samples of this kind should -prove enlightening. In future analyses, conducted in such areas, -it might be possible to preserve all specimens of some of the variable -species, or at least to measure all individuals of species in which<span class="pagenum"><a name="Page_11" id="Page_11">[Pg 11]</a></span> -size is the most important variable character. Quantitative study -could then be made of the different geographic variants occurring, -their proportions in the migrant population determined, and their -origins deduced. In studying populations of Painted Buntings -(<i>Passerina ciris</i>) wintering in Mexico, Storer (1951) has provided -an interesting demonstration of methods which can be applied to -such samples.</p> - -<p>A few bats killed at the tower provided a surprise. They will be -discussed separately by Richard Van Gelder.</p> - -<blockquote> - -<p><i>Podilymbus p. podiceps.</i> Pied-billed Grebe.—Weights: male, 394.8 (all -weights in grams); females, 332.5, 289.7; all fat.</p> - -<p><i>Butorides v. virescens.</i> Green Heron.—Weight: 1 (unsexed), 168.6.</p> - -<p><i>Anas discors.</i> Blue-winged Teal.—Weights: 4 males, mean 421.2 (391.3-458.1); -3 females, 367.7, 371.6, 393.2; all fat.</p> - -<p><i>Rallus limicola.</i> Virginia Rail.—Weights: 3 males, 73.7, 83.2, 90.5; 1 female, -67.3; moderately fat to fat.</p> - -<p><i>Porzana carolina.</i> Sora.—Weights: 4 males, mean 76.8 (68.7-89.9); 3 females, -62.6, 63.2, 63.5; moderately fat to very fat.</p> - -<p><i>Fulica americana.</i> American Coot.—Weights: 2 females, 385.3, 530.0, both -fat. None preserved.</p> - -<p><i>Zenaidura macroura marginella.</i> Mourning Dove.—Weights: 2 adult males, -121.8, 140.2; 3 immature males, 113.1, 126.1, 130.0; 3 adult females, 122.5, -126.9, 136.0; 2 immature females, 129.4, 132.7; moderately fat to very fat. -The presence of Mourning Doves in the sample is interesting as these birds -are not generally regarded as night migrants. Conceivably the specimens were -local birds going to roost. None preserved.</p> - -<p><i>Colaptes auratus luteus.</i> Yellow-shafted Flicker.—Weights: 2 males, 126.0, -139.4, little fat. Flickers have several times been recorded as night migrants.</p> - -<p><i>Empidonax flaviventris.</i> Yellow-bellied Flycatcher.—Weight: 1 immature -male, 11.9, moderately fat. This is a rare species in Kansas, the present being -the ninth preserved specimen for the State.</p> - -<p><i>Troglodytes aëdon parkmanii.</i> House Wren.—Weights: 4 adult males, -mean 10.5 (9.8-10.9), 2 immature males, 9.0, 11.3; 1 adult female, 9.9, 1 immature -female, 7.0; no fat (im. ♀) to fat.</p> - -<p><i>Telmatodytes palustris dissaëptus.</i> Long-billed Marsh Wren.—Weights: -1 adult male, 10.8; 1 adult female, 9.2; both moderately fat. The specimens -are moderately bright and rufescent above, being typical of the populations of -the central plains.</p> - -<p><i>Cistothorus platensis stellaris.</i> Short-billed Marsh Wren.—Weights: 1 immature -male, 8.2; 1 adult female, 8.1; immature female, 8.2; all fat.</p> - -<p><i>Dumetella carolinensis.</i> Catbird.—Weights: 6 adult males, mean 37.5 -(34.1-42.5), little fat to very fat; 14 immature males, mean 37.57 ± .94 (standard -error), S. D. (standard deviation) 3.37, little fat to fat; 11 adult females, -mean 39.09 ± .94, S. D. 2.97, little fat to fat; 12 immature females, mean -38.42 ± .83, S. D. 2.74, moderately fat to fat.</p> - -<p><i>Toxostoma r. rufum.</i> Brown Thrasher.—Weight: 1 immature male, 60.2, -little fat.</p> -<p><span class="pagenum"><a name="Page_12" id="Page_12">[Pg 12]</a></span></p> -<p><i>Hylocichla mustelina.</i> Wood Thrush.—Weights: 1 adult male, 54.2, moderately -fat; 2 adult females, 44.6, 45.7, little fat and fat, respectively.</p> - -<p><i>Hylocichla ustulata swainsonii.</i> Olive-backed Thrush.—Weights: 6 immature -males, mean 31.0 (28.1-33.2), little fat to fat; 6 adult females, mean 29.6 (27.1-35.0), -moderately fat to fat; 3 immature females, 27.1, 33.8, 35.8, little fat to fat. -The absence of adult males in our sample of 15 birds is noteworthy but inexplicable -with our few data.</p> - -<p><i>Regulus s. satrapa.</i> Golden-crowned Kinglet.—Weights: 1 adult male, -6.7, moderately fat; 2 immature males, 6.5, 7.4, moderately fat and fat; 2 adult -females, 7.3, 7.4, moderately fat and fat; 1 immature female, 7.2, moderately -fat.</p> - -<p><i>Regulus c. calendula.</i> Ruby-crowned Kinglet.—Weights: 3 adult males, -6.2, 7.6, 8.2, little fat to fat; 1 immature male, 6.6, fat; 4 adult females, mean -6.1 (5.6-6.7), moderately fat to fat; 3 immature females, 5.8, 6.6, 7.0, moderately -fat to fat.</p> - -<p><i>Vireo flavifrons.</i> Yellow-throated Vireo.—Weight: 1 immature male, 21.5, -very fat.</p> - -<p><i>Vireo s. solitarius.</i> Blue-headed Vireo.—Weights: 9 adult males, mean -17.7 (16.6-19.5), little fat to very fat; 17 immature males, mean 17.53 ± .46, -S. D. 1.83, no fat (13.8) to very fat (21.3); 7 adult females, mean 17.6 (15.0-21.6), -moderately fat to very fat; 6 immature females, mean 17.0 (14.5-18.9), -moderately fat to fat. Surprisingly numerous in the sample.</p> - -<p><i>Vireo olivaceus.</i> Red-eyed Vireo.—Weights: 1 adult male, 16.1, moderately -fat; 38 immature males, mean 21.21 ± .43, S. D. 2.60, little fat (1 -specimen) to excessively fat, mostly moderately fat or fat; 2 adult females, -18.1, 18.1, both fat; 23 immature females, mean 19.28 ± .46, S. D. 2.16, little -(2 specimens) to very fat, mostly fat.</p> - -<p>Wing length: 1 adult male, 79.1; 38 immature males, mean 78.05 ± .30, -S. D. 1.80; 2 adult females, 76.3, 79.0, 23 immature females, mean 75.83 ± -.42, S. D. 1.99.</p> - -<p>As mentioned below, the presence of only 3 adults in the sample of 64 -Red-eyed Vireos is highly significant and their occurrence only in the earlier -samples is strong evidence of early migration by the adults.</p> - -<p><i>Vireo philadelphicus.</i> Philadelphia Vireo.—Weights: 2 adult males, 12.1, -15.9, moderately fat and very fat; 2 immature males, 11.1, 13.2, fat and very -fat; 2 adult females, 13.1, 14.2, both fat; 5 immature females, mean 14.1 -(12.0-15.2), moderately fat to very fat.</p> - -<p>This species previously has been collected in Kansas only twice. Both -records are from Doniphan County in September, 1922. Field observers occasionally -record the Philadelphia Vireo in eastern Kansas. Long (1940:450) -calls it a "very rare migrant in the extreme east." Our sample of 12 birds -killed on two nights (and probably after the peak of migration of this species) -leads us to think that this vireo is actually a regular, but overlooked, migrant -in fair numbers.</p> - -<p><i>Vireo g. gilvus.</i> Warbling Vireo.—Weights: 12 adult males, mean 15.92 -± .43, S. D. 1.44, moderately fat to very fat; 8 immature males, mean 16.64 -(14.2-17.8), fat to very fat; 5 adult females, mean 16.1 (13.7-18.0), fat to -very fat; 5 immature females, mean 15.4 (14.1-17.8), little fat to fat.</p> - -<p>Wing length: 12 adult males, mean 73.08 ± .49, S. D. 1.64; 8 immature -<span class="pagenum"><a name="Page_13" id="Page_13">[Pg 13]</a></span>males, mean 71.15 (69.9-72.8); 5 adult females, mean 70.0 (69.2-71.0); 5 -immature females, mean 68.4 (67.7-70.3).</p> - -<p>Tail length: 12 adult males, mean 53.33 ± .53, S. D. 1.77; 8 immature -males, mean 50.03 (47.1-51.3); 4 adult females, mean 48.6 (47.7-49.8); 5 immature -females, mean 49.2 (47.3-53.0).</p> - -<p>There is no indication that western birds (<i>V. g. swainsonii</i>) make up any -part of this sample.</p> - -<p>The sample of 34 Warbling Vireos is too small to show the significance, if -any, of the 2:1 ratio of males to females in the sample. Adequate samples of -this species, taken at intervals, would add interesting information on time of -migration of the four sex- and age-classes.</p> - -<p><i>Mniotilta varia.</i> Black and White Warbler.—Weights: 1 adult male, 12.5, -fat; 2 adult females, 10.0, 10.0, little fat, fat.</p> - -<p><i>Vermivora peregrina.</i> Tennessee Warbler.—Weights: 1 adult male, 10.9, -very fat; 1 immature male, 12.9, very fat; 2 adult females, 9.1, 12.5, moderately -fat and very fat. The relative scarcity of Tennessee Warblers in the -sample is surprising. They are common in the area in spring.</p> - -<p><i>Vermivora c. celata.</i> Orange-crowned Warbler.—Weights: 9 adult males, -mean 8.8 (7.7-10.9), little fat to fat; 13 immature males, mean 8.92 ± .15, -S. D. .53, little fat to fat; 5 adult females, mean 8.8 (8.3-10.3), little fat to -moderately fat; 17 immature females, mean 9.13 ± .08, S. D. .72, little fat to -fat. Of the 19 Orange-crowned Warblers killed on October 7, 11 had little -fat, 6 were moderately fat, and only 2 were fat. No one-night sample of any -other warbler killed at Topeka had less fat than this group of warblers. Furthermore, -our sample (including 11 males) from October 7 (all sex- and age-classes) -averaged 8.81 grams; the sample of 13 (including only 4 males) from -October 1 averaged 9.1 grams. If one can assume, for any one species, that -individuals undertake nocturnal migration only when they are physiologically -ready, and this includes a certain amount of fat as a fuel source (Wolfson, -1954), then this further assumption seems justified: birds killed in migration -with little fat must have flown longer or farther or both than birds killed with -more fat. No further speculation on this point is permissible with our data, -but the possibilities for study of future large kills, especially where actual time -of death of the birds is known, are obvious.</p> - -<p><i>Vermivora r. ruficapilla.</i> Nashville Warbler.—More Nashville Warblers -were picked up at Topeka than any other species and they are discussed in -detail elsewhere in this report. The four sex- and age-classes can be identified -with fair accuracy on plumage characteristics alone. Adult males have a -large amount of reddish-brown in the crown, not completely veiled by the -gray tips of the crown feathers. Immature males have a smaller but distinct -crown patch, usually completely veiled. All males, compared with females, are -grayer on the sides of the head, have a more nearly white eye-ring, and show -clearer yellow on the throat. Adult females differ from immature females in -that they more often have a trace of rufous in the crown and tend to be -brighter below than the immatures. Of 177 specimens, 20 were very fat, 108 -were fat, 46 were moderately fat, and 3 had little fat.</p> - -<p><i>Parula americana.</i> Parula Warbler.—Weight: 1 adult female, 7.9, fat.</p> - -<p><i>Dendroica petechia aestiva.</i> Yellow Warbler.—Weights: 1 immature male, -<span class="pagenum"><a name="Page_14" id="Page_14">[Pg 14]</a></span>10.2, fat; 3 adult females, 8.8, 9.5, 10.1, moderately fat; 2 immature females, -9.0, 9.4, little fat and fat.</p> - -<p><i>Dendroica magnolia.</i> Magnolia Warbler.—Weights: 1 adult female, 9.0, -moderately fat; 2 immature females, 7.9, 10.3, moderately fat and fat.</p> - -<p><i>Dendroica c. caerulescens.</i> Black-throated Blue Warbler.—Weights: 2 -immature males, 13.8, 14.1, excessively fat; 1 immature female, 11.4, fat. -This species is rare in Kansas. Although its breeding range is almost entirely -east and north of Kansas, records in files at the University of Kansas show -that more specimens have been taken in western than in eastern Kansas.</p> - -<p><i>Dendroica c. coronata.</i> Myrtle Warbler.—Weight: 1 immature female, -11.6, fat.</p> - -<p><i>Dendroica pensylvanica.</i> Chestnut-sided Warbler.—Weights: 2 immature -females, 8.1, 10.0, little fat. Only one specimen from Kansas had been preserved -previously although the species is a regular transient in small numbers -throughout the state.</p> - -<p><i>Dendroica castanea.</i> Bay-breasted Warbler.—Weights: 1 adult male, 19.2, -excessively fat; 1 adult female, 11.7, little fat; 1 immature female, 11.2, moderately -fat. Only 5 specimens of this warbler have been taken previously in -Kansas, 4 in spring (Ruth, 1952:18-19) and 1 in fall.</p> - -<p><i>Dendroica p. palmarum.</i> Palm Warbler.—Weights: 2 immature males, -9.9, 10.9, moderately fat; 2 unsexed immatures, 9.1, 9.4, moderately fat. This -species has been taken in fall in Kansas only once before (KU 26353, taken -by Wetmore, at Lawrence, on October 5, 1907), but probably occurs regularly -in both spring and fall migration.</p> - -<p><i>Seiurus a. aurocapillus.</i> Oven-bird.—Weights: 2 adult males, 22.5, 23.8, -fat and very fat; 14 immature males, mean 21.89 ± .66, S. D. 2.46, fat to very -fat; 8 adult females, mean 21.4 (18.3-25.7), moderately fat to fat; 6 immature -females, mean 18.2 (15.6-20.0), moderately fat to fat.</p> - -<p><i>Seiurus noveboracensis notabilis.</i> Northern Water-thrush.—Weights: 3 -immature males, 18.1, 18.6, 22.2, moderately fat to fat; 1 immature female, -22.2, fat. Referring these birds to <i>notabilis</i> is a somewhat arbitrary procedure. -They display some intermediacy of characters and probably stem from a -population, intermediate between <i>notabilis</i> and <i>noveboracensis</i>, occupying -much of central North America (cf. McCabe and Miller, 1933).</p> - -<p><i>Oporornis philadelphia.</i> Mourning Warbler.—Weight data presented elsewhere. -The birds killed at Topeka provide the latest fall dates for this species -in Kansas. Fifteen were killed on September 25, 64 on October 1, 2 on -October 5, 11 on October 6, 2 on October 7, and 1 on October 8. We find -no other records later than September 15. Of 93 specimens examined, 1 was -excessively fat, 22 were very fat, 45 were fat, 21 were moderately fat, and 4 -had little fat. The abundance of this secretive species in the sample was a -great surprise. It had previously been considered a rather rare migrant in -this area.</p> - -<p><i>Geothlypis trichas occidentalis [>brachidactyla?].</i> Yellow-throat.—Weight -data presented elsewhere. This species was second in numbers only to the -Nashville Warbler in the total kill at Topeka. Of 167 birds examined, 29 -were very fat, 114 were fat, 23 were moderately fat, and 1 had little fat.</p> - -<p>The Yellow-throats are greatly in need of meaningful and comprehensive -revision, which to date has been restricted to the western subspecies (Behle, -1950). Since the appearance of the 1931 A. O. U. Check-List a great deal -<span class="pagenum"><a name="Page_15" id="Page_15">[Pg 15]</a></span>of scattered taxonomic work on the species, as yet unsynthesized, has made -the picture of its geographic variation a blurry one so far as the details are -concerned. Made in the absence of adequate comparative material, the above -identification is to be regarded as tentative. Also, it is, unfortunately, based -only on those 6 of our 176 specimens preserved as skins. Five of these are -adult males, the sixth being an immature female. Compared with a series of -Kentucky specimens regarded as typical <i>brachidactyla</i>, these birds are paler -and brighter above (tending toward gray-green rather than brownish olive), -brighter and more extensively yellow below, with broader, more nearly white -superciliary stripes above their black masks (in males). In size they are -close to <i>occidentalis</i> (see Behle, 1950:202). Five males have an average -wing-length of 56.6 mm. (53-59); one female measures 53. Six males from -Kentucky: 55.1 (53-56); four females, 51.1 (48-56). Our birds may be assumed -to have stemmed from a population to the north and west which, if -not <i>occidentalis</i> (or <i>campicola</i> Behle and Aldrich, of which no comparative -material is at hand), is intermediate between <i>brachidactyla</i> and more western -birds. Judging from Behle's map (1950:fig. 32), these birds may have come -from an area near the confluence of three subspecies (<i>campicola</i>, <i>occidentalis</i>, -<i>brachidactyla</i>). Long (1940:452) reports three subspecies breeding in Kansas -(<i>brachidactyla</i>, northeast; <i>occidentalis</i>, west; <i>trichas</i>, southeast). The occurrence -in Kansas of <i>G. t. trichas</i> as currently understood is completely out of -the question.</p> - -<p><i>Icteria v. virens.</i> Yellow-breasted Chat.—Weight: 1 unsexed immature, -29.7, moderately fat.</p> - -<p><i>Wilsonia p. pusilla.</i> Wilson Warbler.—Weights: 2 adult females, 7.5, 7.8, -fat, moderately fat; 1 unsexed adult, 8.3, fat.</p> - -<p><i>Wilsonia canadensis.</i> Canada Warbler.—Weight: 1 immature female, 10.0, -little fat. We know of only five other specimens from Kansas, although this -warbler seems to be a regular migrant in small numbers in the state.</p> - -<p><i>Setophaga r. ruticilla.</i> American Redstart.—Weight: 1 immature female, -9.1, moderately fat.</p> - -<p><i>Dolichonyx oryzivorus.</i> Bobolink.—Weights: 2 adult females, 39.5, 42.9; -2 immature females, 38.8, 42.0; all excessively fat. Specimens of the Bobolink -previously have been taken in fall in Kansas only on September 20 and 24, -1933, near Lawrence, by Long and Preble (Long, 1934).</p> - -<p><i>Pheucticus ludovicianus.</i> Rose-breasted Grosbeak.—Weights: 1 adult male, -50.4, fat; one immature male, 54.5, very fat.</p> - -<p><i>Passerina cyanea.</i> Indigo Bunting.—Weights: 1 adult male, 18.4, fat; 2 -immature males, 17.2, 17.2, fat and very fat; 2 adult females, 14.3, 16.9, moderately -fat and very fat; 1 immature female, 13.4, little fat. The sample was -carefully checked for Lazuli Buntings (<i>Passerina amoena</i>); none was found.</p> - -<p><i>Spiza americana.</i> Dickcissel.—Weight data presented elsewhere in this -paper. Dickcissels were picked up at the television tower on October 1 (31), -5 (1), 6 (3), and 7 (1). These birds, together with an adult female taken -3 miles east and 3 miles south of Lawrence, on October 11, 1953, by Tordoff, -are the only specimens of this species taken as late as October in Kansas. The -Dickcissel becomes inconspicuous in late summer and many observers here and -elsewhere have thought the species disappeared much earlier than it really -does (see Ganier, 1949). Of 34 specimens, 20 were very fat and 14 were fat.</p> - -<p><span class="pagenum"><a name="Page_16" id="Page_16">[Pg 16]</a></span></p> - -<p><i>Passerculus sandwichensis nevadensis.</i> Savannah Sparrow.—Weights: 1 -adult male, 19.4, fat; 2 immature males, 18.3, 19.0, moderately fat; 5 adult -females, mean 17.2 (14.8-19.5), little fat to fat; 4 immature females, mean -18.0 (16.9-19.6), moderately fat to fat. Many of the Savannah Sparrows migrating -through Kansas have in the past been referred to the subspecies <i>P. s. -anthinus</i> (= <i>alaudinus</i> of the 1931 A. O. U. Check-List) by various workers -(see Long, 1940:454). As Peters and Griscom (1938:464-5) have shown, -true <i>anthinus</i>, breeding in the far northwest, ordinarily occurs in migration -only in the western part of the country, the breeding Savannah Sparrows of -a large part of the central continental region (east to southern Wisconsin) -being <i>P. s. nevadensis</i> as now understood. Migrants of this pale, clay-colored -subspecies should be abundant in Kansas, and all of the specimens in the -present sample are referable to it.</p> - -<p><i>Ammodramus savannarum perpallidus.</i> Grasshopper Sparrow.—Weights: -3 adult males, 16.4, 17.6, 20.6, moderately fat, fat, fat; 5 immature males, -mean 18.1 (16.0-20.2), little fat to fat; 5 adult females, mean 17.9 (16.8-18.9), -moderately fat to very fat; 5 immature females, mean 18.1 (16.8-20.6), -fat to very fat.</p> - -<p><i>Passerherbulus caudacutus.</i> Leconte Sparrow.—Weights: 1 immature male, -11.2, moderately fat; 1 immature female, 12.2, moderately fat.</p> - -<p><i>Ammospiza caudacuta nelsoni.</i> Sharp-tailed Sparrow.—Weights: 2 adult -males, 15.2, 17.1, moderately fat and very fat; 1 adult female, 13.3, little fat. -Five specimens of this species have been taken previously in Kansas, all in -October in the eastern part of the state. Additionally, several observers have -reported birds seen but not collected. The three birds from Topeka were -picked up on October 6, 7, and 10 and are the only specimens taken since -1907. Possibly our specimens from Topeka struck the tower on the same night. -Tordoff noticed, upon preparation, that the specimens from October 7 and 10 -showed progressive drying of the extremities and spoilage as compared with the -bird picked up on October 6.</p> - -<p><i>Junco hyemalis cismontanus.</i> Slate-colored Junco.—Weight: 1 immature -female, 16.4, little fat. Juncos of hybrid type, whether <i>J. h. hyemalis</i> × <i>J. -oreganus</i> subsp. or true <i>J. h. cismontanus</i>, are fairly common in eastern Kansas.</p> - -<p><i>Spizella pallida.</i> Clay-colored Sparrow.—Weights: 2 adult males, 11.6, -12.2, both fat; 1 immature male, 11.8, fat; 1 adult female, 12.5, fat; 7 immature -females, mean 11.1 (9.7-12.5), little fat to fat.</p> - -<p><i>Passerella iliaca iliaca.</i> Fox Sparrow.—Weight: 1 adult female, 29.4, little -fat. A trifle grayer above than any of several Kentucky specimens, this bird -nevertheless seems well within the range of variation of <i>iliaca</i>.</p> - -<p><i>Melospiza l. lincolnii.</i> Lincoln Sparrow.—Weights and measurements are -discussed elsewhere. Of 81 specimens, 15 were very fat, 47 were fat, 12 were -moderately fat, and 7 had little fat. Interestingly, there is no evidence that -the large southern montane subspecies (<i>M. l. alticola</i>) has contributed to the -present sample. No bimodality is evident in the curve of wing-length in our -birds, the largest of which barely approach, the small extreme recorded for -<i>alticola</i> by Miller and McCabe (1935:156).</p> - -<p><i>Melospiza georgiana ericrypta.</i> Swamp Sparrow.—Weights: 3 immature -females, 14.3, little fat, 16.7, 17.0, moderately fat. Swamp Sparrows examined -were all more or less brightly colored and seem to belong to this northern subspecies.</p> - -<p><i>Melospiza melodia juddi.</i> Song Sparrow.—Weights: 1 adult female, 19.4, -<span class="pagenum"><a name="Page_17" id="Page_17">[Pg 17]</a></span>little fat; 1 unsexed immature, 16.0, little fat. A large proportion of the migrant -and wintering Song Sparrows in eastern Kansas probably originate from -the range of this subspecies in the northern plains. <i>Melospiza melodia euphonia.</i>—One -immature female (not weighed) was picked up below the tower -on October 27, 1954, and thus does not appear in Table 1. The specimen -proved typical of this generally more eastern subspecies upon comparison with -a large series from Kentucky. For what it may be worth we refer the single -specimen to this subspecies. Long (1940:456) reported two eastern subspecies -from Kansas ("<i>beata</i>," <i>melodia</i>). All Kansas specimens genuinely of -eastern origin probably originate from the range of <i>euphonia</i>, as now understood.</p></blockquote> - - - -<hr class="chap" /> -<h2>Randomness of the Sample</h2> - - -<p>The reliability of certain of the conclusions which might be -drawn from data of the kind presented herein depends largely on -the randomness of the sample. To what degree does this sample -provide a true cross-section of the nocturnal migrants present over -the area on a given night or succession of nights? As far as the -relative abundance of species in the sample is concerned, there is -little doubt that it is not at all random. The absence of such species -as the Gray-cheeked Thrush (<i>Hylocichla minima</i>), among the -passerines, and many of the shorebirds known to be migrating -through the area at the time is evidence for this statement. Quite -possibly many seminocturnal species did not strike the tower at all -for the simple reason that they could see it, and certain large-eyed -diurnal species (such as thrushes and shorebirds) may avoid collision -to some extent, thus not appearing in the sample in proportion -to their actual numbers. Finally, some or all of the species concerned -probably migrate partly by day. The sample may to some -degree reflect the true relative abundance of closely related species. -For example, there is little doubt that, as shown by the sample, -Nashville Warblers are more numerous locally at this season than -Tennessee Warblers, a fact that can readily be corroborated by -ordinary field observation. Also, the sample is useful in suggesting -the actual abundance of species which are furtive and/or difficult -to identify under normal field conditions, for example, the Mourning -Warbler and Philadelphia Vireo. It is obvious that the sample -should reflect the true relative abundance at one place and time -of any two species with equal tendency to migrate by night and -equal tendency to strike the tower. Since the facts in regard to -both tendencies are at present unknown for most species, we think -that interspecific comparisons should be avoided or approached -with extreme caution.</p> - -<p>In respect to the relative abundance of the various sex- and -age-<span class="pagenum"><a name="Page_18" id="Page_18">[Pg 18]</a></span>classes within a given species, the sample is, we think, as close to -random as is possible to obtain. Certainly it is greatly superior to -samples obtained by field collecting, where possible differences in -habits, wariness, and experience of the birds, and subconscious (if -not conscious) selection by collectors can all bias the results. -Dwight (1900:128-9) believed that the greater wariness of adult -birds was almost entirely responsible for the seemingly disproportionate -number of immatures in autumn and gave some observational -evidence in favor of his views. The large percentage of -adults in some of the samples here treated tends to reinforce -Dwight's position. To a somewhat lesser extent, this advantage in -randomness of accidental kills over routine collecting may be supposed -to apply also in demonstrating the composition by subspecies -of a single migrant species.</p> - -<p>So far as particulars already mentioned are concerned, the present -sample or other samples of tower-killed birds would seem to be in -no way superior (that is, more nearly random) to samples obtained -in connection with lighthouses and other lighted objects, and -ceilometers. In one important respect, however, it is probably -somewhat superior to these as the dimly red-lighted structure has -not been shown to have any important collecting or attracting influence. -Thus, in computations intended to estimate the over-all -abundance of migrants, the sample should be more reliable than -samples involving bright light with its possible attracting effect.</p> - - - -<hr class="chap" /> -<h2>Number of Migrants</h2> - - -<p>If it can be assumed that nocturnally migrating birds are approximately -uniformly spaced across the sky and that the red lights did -not attract birds which would otherwise have missed the tower, it -is possible to compute the volume of migration from the sample -killed. In regard to the first assumption, both Stone (1906:250-251) -and Lowery (1951:409-413) have presented evidence of fairly uniform -distribution of nocturnal migrants. We have no information -on the second assumption beyond the facts that birds do not strike -the high towers on clear nights or lower towers even on stormy -nights.</p> - -<p>On nights when large numbers of birds struck the 950 foot Topeka -tower, only a few struck a 500 foot radio tower, also lighted -with red lights, at Lawrence, 24 miles east, under similar weather -conditions. Most of the birds found at Topeka were fairly close -to the base of the tower, indicating that they struck the tower itself<span class="pagenum"><a name="Page_19" id="Page_19">[Pg 19]</a></span> -or that they were flying high enough to strike guy wires only fairly -close to the tower. The scarcity of birds under the guy wires some -distance from the tower at Topeka and at the radio tower at Lawrence -causes us to think that most of the birds were flying more -than 450 feet above the ground. On this basis, we have computed -numbers of migrants passing through a plane one mile long and -500 feet high (2,640,000 square feet), intersecting the assumed path -of migration at right angles. Vertically, the theoretical plane begins -at 450 feet above ground and has its top edge at 950 feet. The -solid (discounting spaces between girders, <i>etc.</i>) cross-sectional area -of the tower intersecting this plane was computed by actual measurement -to be 1685 square feet. On the night of September 30-October -1, 585 birds were killed. By computation (585/1685 = -X/2,640,000), approximately 916,000 birds passed through the mile-long -plane that night. On each of the nights of October 5-6 and -October 6-7, approximately 230,000 birds passed through this plane. -By comparison, Lowery (1951:436) recorded maximum station -densities in one night in spring of 63,600 birds at Tampico, Mexico, -and 51,600 at Lawrence, Kansas, as determined by moon-watching. -Lowery's figures refer to numbers of birds crossing any part of a -circle one mile in diameter and are roughly comparable to ours if, -as we think, most of the birds at Topeka were flying at altitudes between -450 and 950 feet above the ground.</p> - -<p>It must be realized that these figures are only approximations. -One variable ignored is the frontal extent (or area, viewed from the -front, subject to damage by striking an obstruction) of the birds -themselves. Since practically all birds killed showed head or trunk -injuries, rather than a high proportion with only broken wings, we -chose to disregard frontal extent of the birds in our calculations. -If our figures are inaccurate by as much as 50 per cent in either -direction, which seems unlikely to us, they still give some idea of -the tremendous volume of nocturnal migration under some conditions.</p> - -<p>It may be more meaningful to compute numbers of migrants by -species. This can be done readily by making appropriate substitutions -from Table 1 in the equation given above. For example, -on the night of September 30-October 1, approximately 147,000 -Nashville Warblers passed through the mile-long plane and on the -same night, 100,000 Mourning Warblers and 14,000 Philadelphia -Vireos. Neither of the last two species would be judged to be -abundant migrants in autumn in eastern Kansas by ordinary field<span class="pagenum"><a name="Page_20" id="Page_20">[Pg 20]</a></span> -observations; the television tower sample, however, indicates that -these as well as other species must often be overlooked when they -do stop in Kansas.</p> - - - -<hr class="chap" /> -<h2>Differential Migration of Sex- and Age-classes</h2> - - -<p><span class="smcap">History of the Subject.</span>—For a long time it has been known in -a general way that old and young birds and males and females of -some species do not always migrate at the same times, by the same -routes, or even to the same places. This is a subject about which -much has been written. Reading the summaries of some general -texts, it is easy to acquire the impression that the facts of the matter -are well known. On the contrary, they are poorly known and much -remains to be learned before differential migration is understood. -This can best be indicated by a brief survey of the literature.</p> - -<p>The importance of the subject was emphasized by Meinertzhagen -(1930:52) in one of the later reviews of differential migration: -"The main problem concerns the Cause of Migration, the -Stimulus which compels Migration and the Origin of the Migratory -Habit.... There is, however, a minor problem which affords -valuable evidence in helping us to solve the major problem, bearing -very directly on it, namely, the order of sex and age on migration."</p> - -<p>The mystery of how birds, especially the young, find their way -in migration has fascinated students since the earliest times. The -quite natural though purely anthropomorphic conclusion of early -scholars was that the old birds led the young on migration. This -attractive idea persisted long after ornithology began to grow into -a science. The classic theory was restated by Palmén (1876:267), -in one of the first thorough reviews of the subject of migration, as -follows: "Directe Beobachtungen in der Natur ergeben, dass die -Schaaren von ziehenden Vögeln allgemein ältere und stärkere Individuen -als Anführer des Zuges haben." Variously modified, this -view continued to crop up for some time and still found support in -the 1890's (see Dixon, 1892:69). Gätke (1895:101) correctly questioned -the credibility of Palmén's "direct observations."</p> - -<p>With the gradual abandonment of the unsupportable classic -theory, diametrically opposed views were adopted by workers on -opposite sides of the Atlantic. The American stand was ably expressed -by Brewster (1886), who went to great pains to state his -case and give evidence, and who was later supported by Allen -(1896:144-147; 1909:17). The Americans held that adult birds -nearly always preceded the young in migration, and this was based -on much evidence, whether or not correctly interpreted. Dwight<span class="pagenum"><a name="Page_21" id="Page_21">[Pg 21]</a></span> -(1900:127) also gave evidence in favor of this theory. Equally -definite, if, as has later been shown, somewhat vaguely documented, -was the famous work of Gätke (1895:see pp. 100-113), who after -many years' observation of migrant birds in Heligoland concluded -the exact opposite, that young in general precede adults (see critiques -of Allen, 1896:144-147; Wiegold, 1926:5). Gätke's dissenting -opinion was for a time supported enthusiastically by British -workers (Gurney, 1923:579-580).</p> - -<p>As so often happens, neither extreme has withstood the test of -time, and more recent summaries (Meinertzhagen, 1930:55-56; -Thomson, 1926, 1936:488-489; Wiegold, 1926) have tended to compromise. -Many exceptions to Gätke's extreme conclusion have been -detected. Exceptions to the Brewster-Allen stand have also been -discovered, although work along these lines on the American side -has lagged somewhat. Rowan (1926) has given further evidence -on the migration of certain shorebirds, and some evidence has accrued -in relation to particular species and groups as a result of -life-history and banding studies (see Pitelka, 1946). Authors of -major works on migration, however, have either been preoccupied -with other phases of migration or avoided the issue. In an able -study (one of several on related subjects) of the composition by sex -and age of migrant populations in north Germany, Drost (1935:177) -did not go into the question of order on migration.</p> - -<p>One is left with the impression that the whole subject is still unsettled. -While earlier workers sought to reduce the entire matter -to law, the latest disclaim the possibility of generalization. After -summarizing Brewster's and Gätke's opinions, Thomson (1926:79) -wrote: "It would seem, in any event, that no general rule can be -laid down." Meinertzhagen's summation (1930:56-57) still represents -fairly well the status of our knowledge: "Order of sex and -age on autumn passage is very difficult to arrive at, as evidence is -conflicting. But, on the whole, it seems that birds flock together, -old and young, preparatory to moving south, and do in many cases -initiate migration in company.... But once movement is initiated, -among birds which do not habitually fraternise in flocks, -adults, and especially males, will naturally outstrip the less virile -females and still less virile offspring.... The consequence is -that any observer at an intermediate station such as Heligoland is, -in noting birds of the year as first arrivals, has not had an -opportunity of noting the flocks of adults which have passed without -alighting. On the other hand, there is very definite evidence to -show that among certain species, adults follow their offspring on<span class="pagenum"><a name="Page_22" id="Page_22">[Pg 22]</a></span> -migration. The reason for different behaviour among different types -of birds remains obscure." We regard much of this as still theory.</p> - -<div class="figcenter" style="width: 400px;"> -<img src="images/fig1.jpg" width="400" height="531" alt="" /> -<span class="caption"><span class="smcap">Fig. 1.</span> Composition by age and sex as found in one or more series of -each of eight species of birds included in the Topeka sample. Each separate -series is represented by a single histogram, the histograms for a species -being grouped with the earliest series on the left. Each histogram expresses -the numbers of adults (left-hand column) and immatures (right-hand -column) in terms of percentage of the whole series. Thus the two bars -of each couplet add up to 100 per cent. The hatched portion of each bar -represents males, the clear portion females.</span> -</div> - -<p>It would be difficult to imagine a better way of resolving the -problems and uncertainties just reviewed than by the detailed analy<span class="pagenum"><a name="Page_23" id="Page_23">[Pg 23]</a></span>sis -of large samples of migratory birds killed at random at various -points and times. An analysis of the sample of birds accidentally -killed at Topeka is presented here as an initial step in this direction. -Although the conclusions based on this sample are tentative and -may in time be altered, the data themselves are definite. If this -general type of analysis is repeated again and again—applied to -samples taken on many dates and in many localities—a mass of -hitherto unparalleled evidence for the study of migration will -emerge.</p> - - -<p><span class="smcap">Differential Migration OF Sex- and Age-classes as shown by -the Topeka Sample.</span>—Smaller samples have not been treated. -Species affording samples seemingly large enough to justify at least -preliminary analysis were: Catbird, Red-eyed Vireo, Mourning -Warbler, Dickcissel, Nashville Warbler, Orange-crowned Warbler, -Yellow-throat, and Lincoln Sparrow (Fig. 1). For all of these except -the Catbird and Dickcissel, at least two samples from a week -or more apart were available for comparison in an effort to detect -trends in migration. Fig. 1 shows the actual ratios of sex- and age-classes -observed in samples of the species listed above. Each of -the last four species provided two separate samples, of sufficient -size to warrant an attempt at measuring the statistical significance -of the observed changes in adult-immature ratios (Table 2).</p> - -<p class="center"><span class="smcap">Table 2.—Statistics of the Ratios of Adults to -Immatures in Four Species</span></p> - - -<div class="center"> -<table border="1" cellpadding="4" cellspacing="0" summary="Table 2"> -<tr><td>Species</td><td>Dates of samples</td><td>Total number</td> - <td>Number and percentage of adults<a name="FNanchor_1_1" id="FNanchor_1_1"></a><a href="#Footnote_1_1" class="fnanchor">[1]</a></td><td>Difference (in %)<a name="FNanchor_2_2" id="FNanchor_2_2"></a><a href="#Footnote_2_2" class="fnanchor">[2]</a></td><td>P<a name="FNanchor_3_3" id="FNanchor_3_3"></a><a href="#Footnote_3_3" class="fnanchor">[3]</a></td></tr> -<tr><td align="left">Nashville Warbler</td><td>Oct. 1 (93)<br />Oct. 5-7 (63)</td><td>156</td> - <td>45 (.484)<br />26 (.413)</td><td>.071</td><td>.36</td></tr> -<tr><td align="left">Orange-crowned Warbler</td><td>Sept. 25-Oct. 1 (19)<br />Oct. 5-9 (25)</td><td>44</td> - <td>3 (.158)<br />11 (.440)</td><td>.282</td><td>.05</td></tr> -<tr><td align="left">Yellow-throat</td><td>Oct. 1 (115)<br />Oct. 5-8 (44)</td><td>159</td> - <td>62 (.540)<br />20 (.455)</td><td>.085</td><td>.34</td></tr> -<tr><td align="left">Lincoln Sparrow</td><td>Oct. 1-3 (44)<br />Oct. 6-10 (27)</td><td>71</td> - <td>27 (.614)<br />8 (.296)</td><td>.318</td><td>.01</td></tr> -</table></div> - -<div class="footnote"> - -<p><a name="Footnote_1_1" id="Footnote_1_1"></a><a href="#FNanchor_1_1"><span class="label">[1]</span></a> Percentage of immatures equals 1.000 minus percentage of adults.</p></div> - -<div class="footnote"> - -<p><a name="Footnote_2_2" id="Footnote_2_2"></a><a href="#FNanchor_2_2"><span class="label">[2]</span></a> Standard error of the difference between ratios was computed by the -formula</p> - - -<div class="center"> -<table border="0" cellpadding="4" cellspacing="0" summary="formula"> -<tr><td rowspan="2">σ<sup>e</sup> =</td> - <td rowspan="2" align="right"><span style='font-size:300%;font-weight:lighter;margin:0;line-height:1em;text-indent:0;'>√</span></td> - <td rowspan="2" class="bor_top">P<sub>e</sub> Q<sub>e</sub> (</td><td class="bor_top">1</td><td rowspan="2" class="bor_top">+</td><td class="bor_top">1</td><td rowspan="2" class="bor_top">)</td> - <td rowspan="2">,</td></tr> -<tr><td class="bor_top">N<sub>1</sub></td><td class="bor_top">N<sub>2</sub></td></tr> -</table></div> - -<p>where P<sub>e</sub> equals percentage of adults and Q<sub>e</sub> -equals percentage of immatures in the entire sample.</p></div> - -<div class="footnote"> - -<p><a name="Footnote_3_3" id="Footnote_3_3"></a><a href="#FNanchor_3_3"><span class="label">[3]</span></a> Probability of error; <i>i. e.</i>, a P of .01 means there is one chance in 100 -that the difference observed does not represent an actual difference in nature.</p></div> - -<p><span class="pagenum"><a name="Page_24" id="Page_24">[Pg 24]</a></span></p> - -<p>Upon the application of statistical methods it soon became evident -that, unless changes in ratio between two samples are marked, -large samples would be required in order to reach conclusions of -high statistical significance in a single study of the present type. In -this case (see Table 2), the Lincoln Sparrow and Orange-crowned -Warbler, though represented by only moderate-sized series, show -marked changes in age composition over the period studied, and -the statistical treatment indicates a high degree of probability that -these changes are real. Assurance that the lesser changes observed -in the Nashville Warbler and Yellow-throat are real, on the other -hand, is much less, even though the samples are larger. Few if any -of the samples here discussed are as large as might be desired. -Therefore, conclusions based upon them (see below) are to be regarded -as tentative. Many other, future, samples will perhaps also -be insufficient in size in themselves. There are, however, statistical -advantages to repetition which will serve to make the repeated -analysis even of small samples significant and valuable.</p> - -<p>Certain of the samples not treated statistically show ratios that -can be seen by inspection to be probably significant. For example -the almost complete absence of adults from the three samples of -Red-eyed Vireos (Fig. 1E) cannot be disregarded in view of the -size of the whole sample of the species. The same applies to the -high percentage of adult females and the near absence of adult -males in the sample of the Dickcissel (Fig. 1F). The continuity -in direction of changes observed in the three samples of the Mourning -Warbler (Fig. 1G) and Red-eyed Vireo is likewise probably -significant, even though some of the samples compared are small. -It seems to us that the application of statistical methods to these -species should await the accumulation of more material. For anyone -desiring to treat them statistically now, the data are inherent -in this paper.</p> - -<p>We have not computed the standard errors of the ratios of sexes -within age groups (except experimentally in a few cases). This -can easily be done, however, and the significance of a given ratio -determined, on the assumption (perhaps sometimes dubiously justifiable) -that the sex-ratio in the species concerned is one:one. Obviously -there is no point in computation of the standard errors of -adult-immature ratios in single samples (such as that of the Dickcissel) -until the actual ratio prevailing in the species in nature at -the season in question is known for comparison with the observed -ratio. Our formal statistical treatment, therefore, has been limited<span class="pagenum"><a name="Page_25" id="Page_25">[Pg 25]</a></span> -to an examination of the significance of the <i>changes</i> between adult-immature -ratios in samples of the same species taken a number of -days apart.</p> - -<p>The samples suggest several patterns of differential migration of -sex- and age-classes. Indeed, the important consideration brought -out—in our opinion not hitherto sufficiently emphasized in literature—seems -to be that in generalizing about adults and immatures, -one must be careful to take sexes into account, and conversely, in -generalizing about males and females, one must consider also age. -In other words, there are really four classes to be considered. This -poses additional problems in analysis and introduces the need for -still larger samples in order to reach significant conclusions. To -illustrate: an adult-immature ratio of 40:20 (N = 60) may be satisfactorily -significant, while within the 40 adults a ratio of 25 -males:15 females may not be. Were the original sample 80:40 -(N = 120) with male adults 50 and female adults 30, it is obvious -that the significance of the latter ratio would be greater. The same -applies in reverse if the greater emphasis is placed on sex and the -lesser on age. Because of the moderate size of the samples this -problem has been felt in the present study in respect to sex ratios -within age groups, many of which must at present be regarded as -of tentative significance.</p> - -<p>In short, what the earlier ornithologists regarded as a simple problem -is in reality a complex one. There are only two patterns in -what may be called the Brewster-Gätke argument: adults first or -immatures first (with of course the further possibility of both at the -same time). Both patterns occur, as is now known, at least to some -extent. But actual patterns, as suggested by our samples, are more -complex when all classes are considered. It will readily be seen -that, if adult males, immature males, adult females, and immature -females be regarded as units, each with certain migratory characteristics, -the combinations of these units in various orders of migratory -precedence are potentially numerous. In fact, of course, -they do not behave strictly as units (or perhaps very rarely so), -but our data strongly indicate that the tendency exists in many -cases. This may be stated another way. The present samples may -be reduced to two basic patterns, fitting the classic early American -(adults first) and early European (immatures first) theories. But, -either such simple arrangement is compounded in some, perhaps in -truth in all, instances by differential migration of the sexes <i>within</i> -each age class. This proposition can also be stated backwards:<span class="pagenum"><a name="Page_26" id="Page_26">[Pg 26]</a></span> -the samples show differential times of migration of the sexes, compounded -by differential times of migration of the age groups within -each sex. The order in which these matters are approached depends -on what one is trying to find out. Influenced by the literature, -in which most emphasis has been placed on age, we have approached -the problem from that standpoint. The data and figures -here given, however, can be juggled if one wishes to place first -emphasis on the order of sexes in migration.</p> - -<p>Bearing in mind what has just been said, particularly in respect -to sizes of samples necessary for significance, let us consider the -patterns of migration suggested by the Topeka sample. These are -as follows:</p> - -<p>(1) <i>An early migration largely composed of adults, giving way -later on to a preponderance of immatures.</i> Regardless of variations -among them, samples showing this basic pattern are in line with -the opinions of Brewster (1886) and his followers. This pattern -is here shown by the Lincoln Sparrow, Yellow-throat, Nashville -Warbler, Catbird (one sample only), and Red-eyed Vireo (Fig. 1, -A, B, C, D, E). The evidence of these and all other samples would -admittedly be more conclusive if the samples were further apart in -time or, better still, were there more of them. There is evidence -that differences in migration of the sexes, within age classes, influence -this pattern, sharply in some instances. In the later samples -of Lincoln Sparrow, Yellow-throat, and Red-eyed Vireo (Fig. 1, -A, B, E) there are relatively fewer males, both adult and immature, -than in the earlier samples and this may be true also of the Catbird, -judging from the single sample. The Red-eyed Vireo (Fig. -1, E) is characterized by small number, or absence of, males in -each sample but the samples are not significantly different, and can -be regarded as one. Although the samples of the Dickcissel and -Mourning Warbler (Fig. 1, F, G) show a somewhat different over-all -pattern and are discussed further on, they also contain few adult -males. Since these samples are from a period that is near the end -of the migration of Red-eyed Vireos, Mourning Warblers, and Dickcissels, -it may be assumed tentatively that the adult males have -already migrated. Meinertzhagen (1930:56) postulated that in -many species there is an earlier or more rapid migration of adults, -particularly males, and the data for the above species in our sample -tend to support his assumption. But our data suggest in addition -that in some species <i>immature males</i> migrate earlier, or more rapidly, -than do <i>immature females</i>, just as adult males precede adult<span class="pagenum"><a name="Page_27" id="Page_27">[Pg 27]</a></span> -females in some instances. Within this general pattern (adults -first) another variation is shown by the Nashville Warbler (Fig. 1, -C) in which the later sample of adults is heavily weighted towards -males, even though an increasing over-all proportion of immatures -is evidenced. In this case, and contrary to Meinertzhagen's suggestion, -it would seem that adult females have preceded or outstripped -adult males in migration.</p> - -<p>(2) <i>An early preponderance of immatures, followed by a preponderance -of adults.</i> The several species of birds at Topeka that -display this pattern conform with the conclusions of Gätke and -other early Old World ornithologists that in most species immatures -precede adults in migration. In the present sample two variations -of this pattern occur.</p> - -<p>(a) In the Dickcissel (Fig. 1, F) and the Mourning Warbler -(Fig. 1, G), immatures decrease more markedly than adults (visible -in samples of Mourning Warbler; inferred in Dickcissel), leaving -the adults in the majority in the closing phase of migration. The -distinctive and interesting feature in each of these two species is -the ascendancy in numbers of adults <i>despite</i> the almost complete -disappearance of adult males. The relative increase of adults is -here caused by a retarded migration of adult females, which linger -conspicuously behind all other classes. Something of this nature -was suggested, in theory, by Dixon (1892:70) who thought that -adult females are delayed by "maternal duties." It was hinted at -also by Dwight (1900:127) who thought that in some species females -molted later than males as a result of prolongation of parental -responsibilities. As mentioned already, there is need for caution -in interpreting the present samples because the Dickcissel is represented -only by one sample and two of the three samples of Mourning -Warblers are small. In the case of the Mourning Warbler, the -samples may be regarded as one, nearly lacking in adult males. -The progressive increase of adult females, however, may be significant; -at least there are enough of these to make division of the -birds into three samples enlightening. There is, of course, some -chance that the majority of adult males have not yet migrated, or -are migrating by a different route. This seems unlikely in both -cases. October 1 is late in the migration of the Dickcissel and it -seems that large-scale migration would not occur much later, and -in the case of the Mourning Warbler adult males are rare in all -three samples, extending over a considerable period and reaching -late into the probable migration period of the species. It is -inter<span class="pagenum"><a name="Page_28" id="Page_28">[Pg 28]</a></span>esting to conjecture just when and where adult male Mourning -Warblers do migrate in autumn. Brewster (1886:16) wrote: "This -species arrives at Cambridge [Massachusetts] about September 12, -and during the remainder of the month is ... abundant.... -The adults, however, are so very uncommon that I have -never known them [to] represent more than five per cent of the -total number of individuals. They do not seem to be more numerous -in the earlier flights than towards the close of the month, -and I am very sure that they cannot be found in this locality before -the young begin to appear." While the present samples show an -abundance of adult <i>females</i> of this species (could Brewster have -failed to recognize these as adults?) the whereabouts of the adult -males remains a mystery.</p> - -<p>(b) Another variation is displayed by the Orange-crowned Warbler -(Fig. 1, H). Here also there is an increase of adults towards -the end of migration, but this increase is marked by a growing percentage -not of females but of males. Locally this species is a late -migrant compared with most others of the Parulidae. Thus the first -sample, composed of birds taken September 25-October 1, may be -regarded as fairly early in the fall migration. Immature birds compose -84.2 per cent of this sample, there being no adult males at all. -By October 5-9 the picture has changed markedly, the sample being -composed of 44 per cent adults (82 per cent of which, in turn, -are males) and 56 per cent immatures. In view of this trend one -can not help suspecting that a still later sample would show a majority -of adults, perhaps nearly all males. This of course does not -necessarily follow; the migration of immatures could simply be -more protracted, and could have commenced earlier, than that of -adults.</p> - -<p>Little imagination is required to see how enlightening it might be -could we analyze thoroughly the patterns of all migrating species. -When the detailed facts are available, it seems likely that general -trends will emerge which may be of great significance to the study -of migration in general. A final point which must eventually be -clarified is determination of the extent of variability in the pattern -of each species from year to year and locality to locality.</p> - -<p>Once patterns of precedence in migration of different classes are -established, search into the life-histories of the species concerned -may help to explain the peculiarities discovered. In the present -case, for instance, we find a possible clue to the reason for the high -proportion of adult females of the Dickcissel late in migration, as<span class="pagenum"><a name="Page_29" id="Page_29">[Pg 29]</a></span> -shown by our sample. Gross (1921:14-15) presented evidence that -adult female Dickcissels molt considerably later than their mates, -and we have independent evidence that individuals of this species -are at times almost flightless when molting the remiges!</p> - - - -<hr class="chap" /> -<h2>Molt in Relation to Migration</h2> - - -<p><span class="smcap">General comment.</span>—The exact relationship between molt and -migration seems not to have been definitely established. The subject -has received cursory attention in the literature and conflicting -opinions have been expressed. Dwight (1900:126-128) believed -that molt is completed or nearly completed before migration in -nearly all passerine species that occur in New York save for certain -swallows and flycatchers. Molt has since been found to precede -migration of at least one of the flycatchers (<i>Empidonax virescens</i>) -considered by Dwight to be an exception to this rule (Mengel, -1952). In Great Britain the subject of molt in migration was considered -in some detail by Rintoul and Baxter (1914) and Ticehurst -(1916), who arrived at conclusions similar to Dwight's. These -workers also found certain swallows to be exceptions to the rule.</p> - -<p>The above authors and others have shown that, at least among -passerines, some body molt is frequently found in migrating individuals -but that molt of tail feathers is much less often found and -molt of remiges almost nonexistent. Baxter and Rintoul noted only -four cases of molting wing feathers among hundreds of migrants. -Among the diverse non-passerine orders the picture seems to be -more complicated, as might be expected. We do not, however, -comprehend the reasoning which led Meinertzhagen (1930:56) to -summarize: "... on the whole it can be said that though birds -seldom migrate when flight feathers are in quill, moult in general -does not influence migration." This seems to us an obvious <i>non -sequitur</i>. Meinertzhagen (<i>loc. cit.</i>) went on to say: "Males and -females of one species are believed to moult simultaneously [see, -however, Dwight, 1900:127], and there is no doubt that in some -cases the two sexes migrate at slightly different times, and occasionally -prefer different winter quarters. Birds of the year never -moult their quills previous to their first autumn migration [Consultation -of Dwight, 1900, who gives many examples of this, would -have spared Meinertzhagen this error.], and yet they frequently -follow adults on passage and sometimes precede them. There are -no grounds for believing that adults have moulted their quills before -birds of the year are prepared to migrate [but there are, in -<span class="pagenum"><a name="Page_30" id="Page_30">[Pg 30]</a></span>many cases; <i>cf.</i> Dwight, 1900:127], in the case where adults precede -the latter. Neither is there any evidence to show that adults -have not moulted their quills till after their offspring are ready for -passage, in the case where they follow their offspring. It does not, -therefore, appear that moult is an important factor."</p> - -<p>Comments interpolated above show our feeling that this summary -is inadequate and misleading. To us it seems that the extreme -rarity in migration of birds with remiges in molt is strong -evidence that molt <i>does</i> influence at least the time of migration. It -is immaterial whether this molt occurs before or after migration, -although in the majority of cases it seems to take place before. -Much more needs to be known of the migration pattern and molt -of each species before generalizations can safely be made.</p> - -<p>Analysis of samples of migrants can show only the presence and -nature or the absence of molt in birds actually migrating. In the -present instance shortage of time and manpower for preserving -some and processing all of the sample resulted in incomplete data -being kept on molt. We include this section to emphasize uncertainties -still prevalent and to stimulate further work.</p> - - -<p><span class="smcap">Molt in the Topeka sample.</span>—Our limited findings coincide with -those of Rintoul and Baxter (1914). Body molt was noted in a -number of individuals and species. When present, this molt almost -invariably was in its final stages. One immature male Rose-breasted -Grosbeak (October 1) was in heavy body molt. It is perhaps -worthy of mention here that this grosbeak evidently migrates at -times in extensive molt. An adult male (RMM 1102) taken by -Mengel near Henderson, Kentucky, on September 9, 1949, was -molting plumage of body, wings, and tail, no feather of the last -being longer than one half inch. This remarkable specimen had -only five primaries on one side and four on the other fully functional. -The outermost on the left and two outermost on the right -were from the previous plumage, not yet dropped; the three innermost -of each wing were new and full-length.</p> - -<p>In the present sample molt of remiges was noted in one specimen, -an adult female Indigo Bunting (October 1) with outer primaries -sheathed and with molt in progress in the body plumage. The one -(immature) Yellow-breasted Chat in the sample (October 1) had -all of its tail feathers nearly full-length but in quill, possibly as a -result of accident, and two feathers were being replaced also in the -tail of an immature Clay-colored Sparrow (October 6), which was -also in body molt and had some, juvenal feathers on the belly and -flanks.</p> - -<p><span class="pagenum"><a name="Page_31" id="Page_31">[Pg 31]</a></span></p> - -<p>Body molt near completion was further noted as follows: immature -male Yellow-throated Vireo (October 1), adult male Blue-headed -Vireo (October 1), immature female Leconte Sparrow (October -23), several Lincoln Sparrows (various dates).</p> - - - -<hr class="chap" /> -<h2>Size Differences according to Sex and Age</h2> - - -<p><span class="smcap">Linear measurements.</span>—Taxonomists long have recognized in -many species that males differ in size from females. Less attention, -until recently, has been paid to the relative sizes of adult and immature -birds. Many taxonomists, however, seem to have had an -uneasy suspicion that immature birds are "untrustworthy" in comparison -with adults, and immatures have often been excluded from -samples when recognizable. Since, however, there are still relatively -few reliably aged specimens in collections, for the most part -only those immature birds immediately recognizable as such by -obvious plumage differences (which are often present only in -juvenal plumage) have been excluded from series. The majority -of birds in first winter plumage so closely resemble adults that the -two ages have been included in series for measurement. In most -passerines these younger birds still bear the juvenal feathers in -wing and tail and are, in size of these important parts, quite as -"untrustworthy" as birds still in juvenal body plumage. Even if a -complete postjuvenal molt occurs we still should not assume that -first winter feathers are as long as adult winter feathers without -first determining that this is so. Although aware of this problem, -systematists until recently seemingly have been more or less content -to disregard it, or forced to do so for practical reasons. Miller -(1941:179) had little choice but to hope that size differences between -adult and immature juncos were unimportant. Behle (1942:217) -wrote of Horned Larks, <i>Eremophila alpestris</i>: "... the -plumages of first-year birds and adults seem indistinguishable, -though I have never quite satisfied myself that there are no differences -in lengths of rectrices and remiges." He added, with -logic confusing to us: "Since it is a difficult problem to determine -the ages of horned larks that have passed the postjuvenal molt, this -similarity of plumages is fortunate for the systematist."</p> - -<p>In recent years, some workers have analyzed size differences between -adults and immatures. Sibley (1950:115) showed that adult -Red-eyed Towhees (<i>Pipilo erythrophthalmus</i>) had notably longer -wings and tails than immatures, and the same was demonstrated in -Red Crossbills (<i>Loxia curvirostra</i>) by Tordoff (1952). In work -<span class="pagenum"><a name="Page_32" id="Page_32">[Pg 32]</a></span>with jays (<i>Aphelocoma</i>), Pitelka (1951:199) found that: "... -in comparisons of dimensions of sex and age groups within a given -sample, although magnitude of difference varies from one character -to another, most of the averages are successively smaller for first-year -males and adult and first-year females." He listed exceptions -and concluded: "Segregation [of sex and age classes] has proved -to be of extreme significance in an interpretation of individual and -geographic variation."</p> - -<p>Much along these lines can be learned by examination of large -random samples such as that afforded by the Topeka accident. Although -only a few species in this sample were measured, the results -secured seem to show further the need for segregation of -age classes in taxonomic work with some species.</p> - -<p>Figure 2 shows the variation in the lengths of wing and tail in -the Nashville Warbler. It is evident from the figure that in both -of these characters the four sex- and age-classes differ significantly. -An accurate idea of geographic variation in this species could not -be obtained without separating these classes in comparisons. Age -classes in spring and summer, long after the skull is completely -ossified, can be segregated only if differences in plumage can be -found. In the Nashville Warbler, such differences occur in fall -(see annotated list) but these probably are obliterated by the partial -prenuptial molt. These facts emphasize the importance, for -taxonomic studies, of aged specimens collected in late summer or -early fall on their breeding ground and in fresh winter plumage. -Figure 3 shows the variation in length of wing in the Lincoln Sparrow -in which age seems to be of much less importance than in the -Nashville Warbler. Males and females of the Lincoln Sparrow -differ significantly in wing-length, but adults and immatures are -of nearly the same size. It would seemingly not be necessary to -separate age classes in studies of geographic variation in the Lincoln -Sparrow. Size data for some other species are given in the -annotated list.</p> - - -<p><span class="smcap">Weights.</span>—Little seems to have been done to determine the correlation -of weights with sex- and age-classes. Weight may be the -best single index of over-all size and is especially useful to students -of the physiology of migration. Weight, however, is subject to the -considerable variable imposed by fat condition. In large and comparable -series, this variable is probably removed insofar as comparability -of means is concerned, but the high variability of weight -in most cases naturally results in more overlap (less separability) -between populations with means close together than is found with -most linear measurements.</p> - -<p><span class="pagenum"><a name="Page_33" id="Page_33">[Pg 33]</a></span></p> - -<div class="figcenter" style="width: 400px;"> -<img src="images/fig2.jpg" width="400" height="707" alt="" /> -<span class="caption"><span class="smcap">Fig. 2.</span> Statistics of variation in length of wing and tail in the Nashville -Warbler. The solid lines represent the observed ranges in millimeters. -The stippled boxes represent two standard errors (σm) to each side of -the means (vertical lines). The open boxes represent one standard deviation -(σ) to each side of the means.</span> -</div> - -<p><span class="pagenum"><a name="Page_34" id="Page_34">[Pg 34]</a></span></p> - -<div class="figcenter" style="width: 400px;"> -<img src="images/fig3.jpg" width="400" height="350" alt="" /> -<span class="caption"><span class="smcap">Fig. 3.</span> Statistics of variation in length of wing in the Lincoln Sparrow.</span> -</div> - -<p>Figures 4-6 show variation in weight in the samples of Nashville -Warbler, Mourning Warbler, Yellow-throat, Dickcissel, and Lincoln -Sparrow. Each figure is essentially self-explanatory. It will -be seen that in the Nashville Warbler and Lincoln Sparrow, weight -is roughly proportional to wing-length (shown in figs. 2 and 3), -giving about equally good separation of sex- and age-classes in the -latter and poorer separation in the former. Data for these and -other species indicate a generally greater weight of males than of -females, but less difference according to age. In some other species, -for example the Yellow-throat, immatures seem to be a little heavier -on the average than adults. It is unfortunate that wing-lengths are -not at present available for these.</p> - -<div class="figcenter" style="width: 400px;"> -<img src="images/fig4.jpg" width="400" height="655" alt="" /> -<span class="caption"><span class="smcap">Fig. 4.</span> Statistics of variation in weight in the Nashville Warbler and -Mourning Warbler.</span> -</div> - -<div class="figcenter" style="width: 400px;"> -<img src="images/fig5.jpg" width="400" height="677" alt="" /> -<span class="caption"><span class="smcap">Fig. 5.</span> Statistics of variation in weight in the Yellow-throat and Dickcissel.</span> -</div> - -<div class="figcenter" style="width: 400px;"> -<img src="images/fig6.jpg" width="400" height="346" alt="" /> -<span class="caption"><span class="smcap">Fig. 6.</span> Statistics of variation in weight in the Lincoln Sparrow.</span> -</div> - -<p>These comments on weight suggest an additional factor which -may play a part in rate of migration and which some day may be -profitably studied. Suppose that in some species adults and immatures -are nearly the same in weight but that immatures have -shorter wings. In such a species the immatures are relatively -shorter-winged for their weight than adults. In aerodynamic terms, -<span class="pagenum"><a name="Page_35" id="Page_35">[Pg 35]</a><br /><a name="Page_36" id="Page_36">[Pg 36]</a><br /><a name="Page_37" id="Page_37">[Pg 37]</a></span>they would have a higher "wing-loading." (Wing-loading is the -result obtained by dividing area of effective wing by total weight; -it is here assumed that in a single species wing area is directly proportional -to wing length.) This being the case, immatures with -higher "wing-loading" would require more energy (derived from -fat) to fly the same distance as adults, or with the same amount of -fat they would fly a shorter distance. Thus they might tend to be -outstripped in migration by adults starting at the same time. The -reverse, of course, would also be theoretically true, if adults possessed -a higher wing-loading than immatures. Physical factors -such as these rather than the differential "virility" postulated by -Meinertzhagen (1930:56) might account for the arrival of certain -classes of some species on the wintering grounds in advance of -others. There are, of course, many other factors which must be -taken into account before the effect, if any, of the wing-loading -factor can be evaluated. Data for illuminating calculations will -become available, however, with the accumulation of abundant information -on weights, measurements, and migration patterns.</p> -<hr class="chap" /> - -<p><span class="pagenum"><a name="Page_38" id="Page_38">[Pg 38]</a></span></p> - - - -<h2>Computations of Longevity and Survival</h2> - - -<p>Tanner (ms., and letter, April 21, 1955) recently devoted considerable -ingenuity to computing by actuarial methods the longevity -of the Oven-bird, using the adult-immature ratio in samples killed -at a ceilometer at Knoxville, Tennessee. Tanner's computations -were based on the simple assumption that</p> - - - -<div class="center"> -<table border="0" cellpadding="4" cellspacing="0" summary="formula"> -<tr><td rowspan="2">S (survival rate) =</td> - <td>Number of adults in population (or sample)</td></tr> -<tr><td class="bor_top">Total size of population (or sample).</td></tr> -</table></div> - -<p>Further application of such techniques may prove desirable and -rewarding. It would seem at present, however, to be a risky procedure, -as it has been abundantly shown (see above) that adults -and immatures often do not migrate at the same times and rates, -and the ratios of adults to immatures in samples of migrants are -likely to be far from representative of the true proportions in the -populations concerned. It should be added that Tanner is perfectly -aware of this objection.</p> - - - -<hr class="chap" /> -<h2>Processing of Samples</h2> - - -<p>Thorough processing of large samples of birds killed accidentally -is time-consuming. We were fortunate in having considerable assistance; -even so, all desirable data could not be obtained from the -1090 birds of the present sample. As aids to others conducting -studies of this kind we should mention a few points which may be -of assistance.</p> - -<p>Birds should be picked up as soon as possible after death, certainly -by the end of the day after the accident and preferably much -sooner. They should be weighed as soon as possible after collection -(weights decrease rapidly, even under refrigeration), and the -weights (in grams, to one tenth of a gram) written on tags attached -to a leg of each specimen. The sample should then be -sorted by species or groups of species of approximately equal size -(to avoid crushing of smaller birds by larger ones), placed in boxes, -paper bags, or better, air-tight containers clearly marked with date, -locality, and other necessary particulars, and relegated to a deep-freeze -compartment. For all but the smallest samples, such freezing -units are indispensable to complete study. Once frozen, the birds -may be selected for study at leisure, but time is still important, as, -even when frozen, gonads may eventually deteriorate, and birds<span class="pagenum"><a name="Page_39" id="Page_39">[Pg 39]</a></span> -eventually become desiccated which is a disadvantage if skins are -to be made.</p> - -<p>In the cases of large kills, or limited manpower, or both, it may -be impossible to process all birds, however desirable this might be. -If possible, however, all should be collected, identified, the numbers -and species recorded, and rarities saved. Further, partial analysis, -or more properly, complete analysis of a partial sample, can be -made. Analyses which for any reason require randomness of -sample pose a special problem. We think that in very large kills -the best way to solve this problem is probably to make one or more -transects across the area where dead birds are found. These -transects should cross both the areas of greatest and least density -(to allow for fast and slow flying species). Their width may be -adjusted to give the desired number of birds, that is, the number -that can be adequately processed. Another alternative would be -to decide to study certain abundant species and pick up all of these. -There are other possibilities, but in any event the method of -sampling should be thoroughly described wherever all birds have -not been processed.</p> - - - -<hr class="chap" /> -<h2>Summary</h2> - - -<p>The foregoing paper discusses accidents in which large numbers -of night-migrating birds are killed. A brief historical review of -ornithological interest in such occurrences is given, and the types -of data provided by the accidents are listed and discussed. In particular, -recent accidents occurring in early October, 1954, through -much of eastern United States are cited, and detailed analysis is -presented of a sample of 1090 birds killed one mile west of Topeka, -Shawnee County, Kansas, between September 25 and October 23, -1954.</p> - -<p>At Topeka during the period mentioned, 1090 birds representing -61 species were collected and were processed at the University of -Kansas. For all specimens, weight, sex, age, and fat condition were -recorded, and certain species were measured as well. Some notes -on molt were taken. A total of 193 birds was preserved as study -skins, and 49 as skeletons. Comments on weight, size, sex, age, -subspecific identity, and status in Kansas are presented in an annotated -list.</p> - -<p>Randomness of this and other similar samples is discussed. A -theoretical computation is given for several nights of the numbers<span class="pagenum"><a name="Page_40" id="Page_40">[Pg 40]</a></span> -of migrants passing through a plane one mile in width, from 450 -to 950 feet above ground level, and oriented to face the arriving -migrants. The computed totals give some idea of the tremendous -volume of nocturnal migration under some conditions. Potentialities -of further study of such events are discussed and a comparison -is made with lunar observations.</p> - -<p>Differential migration of sex- and age-groups as shown by the -larger samples taken at Topeka (Catbird, Red-eyed Vireo, Nashville -Warbler, Yellow-throat, Mourning Warbler, Dickcissel, Lincoln -Sparrow) is discussed and the history of theories on this subject -reviewed. It is shown that age and sex must both be taken -into account in studies of differential migration. Several patterns -of migration are displayed by the species analyzed, adults migrating -earlier than immatures in some instances, young earlier than adults -in others, but all seemingly being complicated to varying degrees -by differential migration of sexes within age groups. It is suggested -that explanations of these patterns may be sought in the -life histories of the species involved.</p> - -<p>Molt in relation to migration is discussed briefly, and it is held -that there is an important relationship between molt and time of -migration. Specimens noted to be in molt are listed.</p> - -<p>Size differences, in wing length, tail length, and weight are discussed -in relation to sex and age, and variation in one or more of -these characters is analyzed as found in the Topeka samples of -Nashville Warbler, Mourning Warbler, Yellow-throat, Dickcissel, -and Lincoln Sparrow. It seems that in some instances significant -size differences prevail between adults and immatures and that -these age classes should be separated in taxonomic work with species -where differences in size are known to exist. When the facts -are not known they should be determined, and the large samples -collected in accidents to nocturnal migrants present excellent opportunities -for ascertaining the facts.</p> - -<p>Other uses of material obtained in large migration accidents are -discussed, such as computations of longevity and the problems of -processing large, accidentally-killed samples. Care should be taken -to select samples as nearly random as possible when all birds cannot -be processed.</p> - -<p>Repeated and thorough analysis of accidental kills should provide -a mass of valuable data bearing on many questions and problems -which have thus far been little studied.</p> - -<hr class="chap" /> - -<p><span class="pagenum"><a name="Page_41" id="Page_41">[Pg 41]</a></span></p> - - - - -<h2>Literature Cited</h2> - - -<p><span class="smcap">Allen, J. A.</span></p> - -<blockquote> - -<p>1880. Destruction of birds by light-houses. Bull. Nuttall Orn. Club, -5(3):131-138, July.</p> - -<p>1896. Gätke's 'Heligoland.' Auk, 13(2):137-153, April.</p> - -<p>1901. Barrington's 'The Migration of Birds at Irish Light Stations.' [Review.] -Auk, 18(2):205-206, April.</p> - -<p>1909. An American's views of bird migration. Brit. Birds, 3(1):12-19, -June 1.</p></blockquote> - -<p><span class="smcap">Barrington, R. M.</span></p> - -<blockquote> - -<p>1900. The migration of birds as observed at Irish lighthouses and lightships -[<i>etc.</i>]. London, R. H. Porter; Dublin, Edward Ponsonby. -Pp. XXV, 285, 667. (Not seen; citation from Mullens and Swann, -Bibliogr. Brit. Orn., 1917, p. 43 and Zimmer, Cat. Ayer Coll., I, -p. 40, 1926; see also reviews, Ibis, 1900:677-679, Auk, 1901:205-206; -some sources list pagination as XXV + 667, possibly in error.)</p></blockquote> - -<p><span class="smcap">Behle, W. H.</span></p> - -<blockquote> - -<p>1942. Distribution and variation of the Horned Larks (Otocoris alpestris) -of western North America. Univ. California Publ. Zoöl., 46(3):205-316, -May 20.</p> - -<p>1950. Clines in the Yellow-throats of western North America. Condor, -52(5):193-219, September-October (September 25).</p></blockquote> - -<p><span class="smcap">Brewster, W.</span></p> - -<blockquote> - -<p>1886. Bird migration. Mem. Nuttall Orn. Club, No. I, pp. 1-22, Cambridge, -March.</p></blockquote> - -<p><span class="smcap">Carson, L. B.</span></p> - -<blockquote> - -<p>1954a. [Destruction of birds at a television tower at Topeka, Kansas.] -Topeka Aud. News, 9(1):pp. = 1-2, July, August, September [published -October]. [Unsigned, unpaged, and untitled article by -L. B. Carson, ed.]</p> - -<p>1954b. [Further destruction of birds at a television tower at Topeka, Kansas.] -Topeka Aud. News, 9(2):pp. = 5-7, October, November, December -[published December]. [Unsigned, unpaged, and untitled -article by L. B. Carson, ed.]</p> - -<p>1954c. New records for fall migrants in eastern Kansas. Kansas Orn. Soc. -Bull., 5(4):27-29, December.</p></blockquote> - -<p><span class="smcap">Dixon, C.</span></p> - -<blockquote> - -<p>1892. The migration of birds. London, Chapman and Hall. Pp. XVI + -300.</p></blockquote> - -<p><span class="smcap">Dobben, W. W. H. van</span>, and <span class="smcap">M. F. Bruyns</span></p> - -<blockquote> - -<p>1939. Zug nach Alter und Geschlecht an niederländischen Leuchttürmen. -Ardea, 28:61-79, December (not seen; see Auk, 1940:271).</p></blockquote> - -<p><span class="smcap">Drost, R.</span></p> - -<blockquote> - -<p>1935. Ueber das Zahlenverhältnis von Alter und Geschlecht auf dem -Herbst-und Frühjahrszuge. Vogelzug, 6(4):177-182, October.</p></blockquote> - -<p><span class="smcap">Dwight, J., Jr.</span></p> - -<blockquote> - -<p>1900. The sequence of plumages and moults of the passerine birds of -New York. Annals New York Acad. Sci., 13(1):73-360, October 19.</p></blockquote> - -<p><span class="pagenum"><a name="Page_42" id="Page_42">[Pg 42]</a></span></p> - -<p><span class="smcap">Ganier, A. F.</span></p> - -<blockquote> - -<p>1949. The late summer Dickcissel departure. Migrant, 20(3):52-53, -September.</p></blockquote> - -<p><span class="smcap">Gätke, H.</span></p> - -<blockquote> - -<p>1895. Heligoland as an ornithological observatory. Translated by Rudolph -Rosenstock. Edinburgh, David Douglas. Pp. X + II + -599 + 11 II. (advt.).</p></blockquote> - -<p><span class="smcap">Gross, A. O.</span></p> - -<blockquote> - -<p>1921. The Dickcissel (Spiza americana) of the Illinois prairies. Auk, -38(1):1-26, January 18 (first of two parts).</p></blockquote> - -<p><span class="smcap">Gurney, J. H.</span></p> - -<blockquote> - -<p>1923. Bird migration as observed on the east coast of England. Ibis, 11th -ser., 5(4):573-603, October 3.</p></blockquote> - -<p><span class="smcap">Howell, J. C.</span>, <span class="smcap">Laskey, A. R.</span>, and <span class="smcap">J. T. Tanner</span></p> - -<blockquote> - -<p>1954. Bird mortality at airport ceilometers. Wilson Bull., 66(3):207-215, -September [published October 29].</p></blockquote> - -<p><span class="smcap">Howell, J. C.</span>, and <span class="smcap">J. T. Tanner</span></p> - -<blockquote> - -<p>1951. An accident to migrating birds at the Knoxville airport. Migrant, -22(4):61-62, December.</p></blockquote> - -<p><span class="smcap">Laskey, A. R.</span></p> - -<blockquote> - -<p>1951. Another disaster to migrating birds at the Nashville airport. Migrant, -22(4):57-60, December.</p></blockquote> - -<p><span class="smcap">Long, W. S.</span></p> - -<blockquote> - -<p>1934. Notes from eastern Kansas. Auk, 51(2):255, April 4.</p> - -<p>1940. Check-list of Kansas birds. Trans. Kansas Acad. Sci., 43:433-456.</p></blockquote> - -<p><span class="smcap">Lovell, H. B.</span></p> - -<blockquote> - -<p>1952. Catastrophe to birds at a Louisville airport. Kentucky Warbler, -28(1):5-6, February.</p></blockquote> - -<p><span class="smcap">Lowery, G. H., Jr.</span></p> - -<blockquote> - -<p>1951. A quantitative study of the nocturnal migration of birds. Univ. -Kansas Publ., Mus. Nat. Hist., 3(2):361-472, June 29.</p></blockquote> - -<p><span class="smcap">McCabe, T. T.</span></p> - -<blockquote> - -<p>1943. An aspect of collectors' technique. Auk, 60(4):550-558, October 7.</p></blockquote> - -<p><span class="smcap">McCabe, T. T.</span>, and <span class="smcap">A. H. Miller</span></p> - -<blockquote> - -<p>1933. Geographic variation in the Northern Water-thrushes. Condor, -35(5):192-197, September-October (September 15).</p></blockquote> - -<p><span class="smcap">Meinertzhagen, R.</span></p> - -<blockquote> - -<p>1930. Nicoll's birds of Egypt. Vol. I (of 2). London, Hugh Rees Ltd. -Pp. XVI + 348.</p></blockquote> - -<p><span class="smcap">Mengel, R. M.</span></p> - -<blockquote> - -<p>1952. Certain molts and plumages of Acadian and Yellow-bellied flycatchers. -Auk, 69(3):273-283, July 7.</p></blockquote> - -<p><span class="smcap">Miller, A. H.</span></p> - -<blockquote> - -<p>1941. Speciation in the avian genus Junco. Univ. California Publ. Zoöl., -44(3):173-434, May 24.</p></blockquote> - -<p><span class="pagenum"><a name="Page_43" id="Page_43">[Pg 43]</a></span></p> - -<p><span class="smcap">Miller, A. H.</span>, and <span class="smcap">T. T. McCabe</span></p> - -<blockquote> - -<p>1935. Racial differentiation in Passerella (Melospiza) lincolnii. Condor, -37(3):144-160, May-June (May 15).</p></blockquote> - -<p><span class="smcap">Palmén, J. A.</span></p> - -<blockquote> - -<p>1876. Ueber die Zugstrassen der Vögel. Leipzig, Wilhelm Engelmann. -Pp. VI + 292 + I.</p></blockquote> - -<p><span class="smcap">Peters, J. L.</span>, and <span class="smcap">L. Griscom</span></p> - -<blockquote> - -<p>1938. Geographical variation in the Savannah Sparrow. Bull. Mus. Comp. -Zoöl., 80(13):445-478, January.</p></blockquote> - -<p><span class="smcap">Pitelka, F. A.</span></p> - -<blockquote> - -<p>1946. Age in relation to migration in the Blue Jay. Auk, 63(1):82-84, -January 25.</p> - -<p>1951. Speciation and ecologic distribution in American jays of the genus -Aphelocoma. Univ. California Publ. Zoöl., 50(3):195-464, July 20.</p></blockquote> - -<p><span class="smcap">Rintoul, L. J.</span>, and <span class="smcap">E. V. Baxter</span></p> - -<blockquote> - -<p>1914. Notes on some passerine birds found migrating in moult. Scottish -Naturalist, no. 35, pp. 245-252, November.</p></blockquote> - -<p><span class="smcap">Rowan, W.</span></p> - -<blockquote> - -<p>1926. Notes on Alberta waders included on the British list. Part II. -Brit. Birds, 20(2):34-42, June 1.</p></blockquote> - -<p><span class="smcap">Ruth, E. L.</span></p> - -<blockquote> - -<p>1952. The Bay-breasted Warbler in Kansas. Kansas Orn. Soc. Bull., -3(3):18-19.</p></blockquote> - -<p><span class="smcap">Sibley, C. G.</span></p> - -<blockquote> - -<p>1950. Species formation in the Red-eyed Towhees of Mexico. Univ. California -Publ. Zoöl., 50(2):109-194, November 24.</p></blockquote> - -<p><span class="smcap">Spofford, W. R.</span></p> - -<blockquote> - -<p>1949. Mortality of birds at the ceilometer of the Nashville airport. Wilson -Bull., 61(2):86-90, June.</p></blockquote> - -<p><span class="smcap">Stone, W.</span></p> - -<blockquote> - -<p>1906. Some light on night migration. Auk, 23(3):249-252, July.</p></blockquote> - -<p><span class="smcap">Storer, R. W.</span></p> - -<blockquote> - -<p>1951. Variation in the Painted Bunting (<i>Passerina ciris</i>), with special -reference to wintering populations. Occas. Papers Mus. Zool., -Univ. Michigan, no. 532, pp. 1-12, June 29.</p></blockquote> - -<p><span class="smcap">Thomson, A. L.</span></p> - -<blockquote> - -<p>1926. Problems of bird-migration. Boston and New York, Houghton -Mifflin Company. Pp. XV + I + 350.</p> - -<p>1936. Recent progress in the study of bird-migration: a review of the -literature, 1926-35. Ibis, 13th ser., 6(3):472-530, July 1.</p></blockquote> - -<p><span class="smcap">Ticehurst, C. B.</span></p> - -<blockquote> - -<p>1916. Notes on migrants and moult, with special reference to the moults -of some of our summer visitants. Scottish Naturalist, no. 50, pp. -29-38, February.</p></blockquote> - -<p><span class="pagenum"><a name="Page_44" id="Page_44">[Pg 44]</a></span></p> - -<p><span class="smcap">Tordoff, H. B.</span></p> - -<blockquote> - -<p>1952. Notes on plumages, molts, and age variation of the Red Crossbill. -Condor, 54(4):200-203, July-August.</p></blockquote> - -<p><span class="smcap">Wiegold, H.</span></p> - -<blockquote> - -<p>1926. Masse, Gewichte und Zug nach Alter und Geschlecht bei Helgoländer -Zugvögeln. Wissenschaftliche Meeresuntersuchungen, Abt. -Helgoland, Neue Folge, 15ter Band, Heft 3, No. 17, Lipsius & -Tischer, Kiel und Leipzig, pp. 1-73.</p></blockquote> - -<p><span class="smcap">Wolfson, A.</span></p> - -<blockquote> - -<p>1954. Weight and fat deposition in relation to spring migration in transient -White-throated Sparrows. Auk, 71(4):413-434.</p></blockquote> - -<p><i>Transmitted June 30, 1955.</i></p> - - - -<hr class="chap" /> - -<div class="transnote"> -<h2>Transcriber's Notes:</h2> - -<p>Obvious printer's errors have been repaired, other inconsistent -spellings have been kept, for example inconsistent use of hyphen (e.g. -"age-classes" and "age classes") and diacritical mark (e.g. "Zool." -and "Zoöl.")</p> -</div> - - - - - - - - -<pre> - - - - - -End of the Project Gutenberg EBook of Studies of Birds Killed in Nocturnal -Migration, by Harrison B. Tordoff and Robert M. Mengel - -*** END OF THIS PROJECT GUTENBERG EBOOK STUDIES OF BIRDS *** - -***** This file should be named 52382-h.htm or 52382-h.zip ***** -This and all associated files of various formats will be found in: - http://www.gutenberg.org/5/2/3/8/52382/ - -Produced by Judith Wirawan, Chris Curnow, Joseph Cooper -and the Online Distributed Proofreading Team at -http://www.pgdp.net - - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the United -States without permission and without paying copyright -royalties. Special rules, set forth in the General Terms of Use part -of this license, apply to copying and distributing Project -Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm -concept and trademark. Project Gutenberg is a registered trademark, -and may not be used if you charge for the eBooks, unless you receive -specific permission. If you do not charge anything for copies of this -eBook, complying with the rules is very easy. You may use this eBook -for nearly any purpose such as creation of derivative works, reports, -performances and research. They may be modified and printed and given -away--you may do practically ANYTHING in the United States with eBooks -not protected by U.S. copyright law. Redistribution is subject to the -trademark license, especially commercial redistribution. - -START: FULL LICENSE - -THE FULL PROJECT GUTENBERG LICENSE -PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK - -To protect the Project Gutenberg-tm mission of promoting the free -distribution of electronic works, by using or distributing this work -(or any other work associated in any way with the phrase "Project -Gutenberg"), you agree to comply with all the terms of the Full -Project Gutenberg-tm License available with this file or online at -www.gutenberg.org/license. - -Section 1. General Terms of Use and Redistributing Project -Gutenberg-tm electronic works - -1.A. By reading or using any part of this Project Gutenberg-tm -electronic work, you indicate that you have read, understand, agree to -and accept all the terms of this license and intellectual property -(trademark/copyright) agreement. If you do not agree to abide by all -the terms of this agreement, you must cease using and return or -destroy all copies of Project Gutenberg-tm electronic works in your -possession. If you paid a fee for obtaining a copy of or access to a -Project Gutenberg-tm electronic work and you do not agree to be bound -by the terms of this agreement, you may obtain a refund from the -person or entity to whom you paid the fee as set forth in paragraph -1.E.8. - -1.B. "Project Gutenberg" is a registered trademark. It may only be -used on or associated in any way with an electronic work by people who -agree to be bound by the terms of this agreement. There are a few -things that you can do with most Project Gutenberg-tm electronic works -even without complying with the full terms of this agreement. See -paragraph 1.C below. There are a lot of things you can do with Project -Gutenberg-tm electronic works if you follow the terms of this -agreement and help preserve free future access to Project Gutenberg-tm -electronic works. See paragraph 1.E below. - -1.C. The Project Gutenberg Literary Archive Foundation ("the -Foundation" or PGLAF), owns a compilation copyright in the collection -of Project Gutenberg-tm electronic works. Nearly all the individual -works in the collection are in the public domain in the United -States. If an individual work is unprotected by copyright law in the -United States and you are located in the United States, we do not -claim a right to prevent you from copying, distributing, performing, -displaying or creating derivative works based on the work as long as -all references to Project Gutenberg are removed. Of course, we hope -that you will support the Project Gutenberg-tm mission of promoting -free access to electronic works by freely sharing Project Gutenberg-tm -works in compliance with the terms of this agreement for keeping the -Project Gutenberg-tm name associated with the work. You can easily -comply with the terms of this agreement by keeping this work in the -same format with its attached full Project Gutenberg-tm License when -you share it without charge with others. - -1.D. The copyright laws of the place where you are located also govern -what you can do with this work. Copyright laws in most countries are -in a constant state of change. If you are outside the United States, -check the laws of your country in addition to the terms of this -agreement before downloading, copying, displaying, performing, -distributing or creating derivative works based on this work or any -other Project Gutenberg-tm work. The Foundation makes no -representations concerning the copyright status of any work in any -country outside the United States. - -1.E. Unless you have removed all references to Project Gutenberg: - -1.E.1. The following sentence, with active links to, or other -immediate access to, the full Project Gutenberg-tm License must appear -prominently whenever any copy of a Project Gutenberg-tm work (any work -on which the phrase "Project Gutenberg" appears, or with which the -phrase "Project Gutenberg" is associated) is accessed, displayed, -performed, viewed, copied or distributed: - - 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'll have to check the laws of the country where you - are located before using this ebook. - -1.E.2. If an individual Project Gutenberg-tm electronic work is -derived from texts not protected by U.S. copyright law (does not -contain a notice indicating that it is posted with permission of the -copyright holder), the work can be copied and distributed to anyone in -the United States without paying any fees or charges. If you are -redistributing or providing access to a work with the phrase "Project -Gutenberg" associated with or appearing on the work, you must comply -either with the requirements of paragraphs 1.E.1 through 1.E.7 or -obtain permission for the use of the work and the Project Gutenberg-tm -trademark as set forth in paragraphs 1.E.8 or 1.E.9. - -1.E.3. If an individual Project Gutenberg-tm electronic work is posted -with the permission of the copyright holder, your use and distribution -must comply with both paragraphs 1.E.1 through 1.E.7 and any -additional terms imposed by the copyright holder. Additional terms -will be linked to the Project Gutenberg-tm License for all works -posted with the permission of the copyright holder found at the -beginning of this work. - -1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm -License terms from this work, or any files containing a part of this -work or any other work associated with Project Gutenberg-tm. - -1.E.5. Do not copy, display, perform, distribute or redistribute this -electronic work, or any part of this electronic work, without -prominently displaying the sentence set forth in paragraph 1.E.1 with -active links or immediate access to the full terms of the Project -Gutenberg-tm License. - -1.E.6. You may convert to and distribute this work in any binary, -compressed, marked up, nonproprietary or proprietary form, including -any word processing or hypertext form. However, if you provide access -to or distribute copies of a Project Gutenberg-tm work in a format -other than "Plain Vanilla ASCII" or other format used in the official -version posted on the official Project Gutenberg-tm web site -(www.gutenberg.org), you must, at no additional cost, fee or expense -to the user, provide a copy, a means of exporting a copy, or a means -of obtaining a copy upon request, of the work in its original "Plain -Vanilla ASCII" or other form. Any alternate format must include the -full Project Gutenberg-tm License as specified in paragraph 1.E.1. - -1.E.7. Do not charge a fee for access to, viewing, displaying, -performing, copying or distributing any Project Gutenberg-tm works -unless you comply with paragraph 1.E.8 or 1.E.9. - -1.E.8. You may charge a reasonable fee for copies of or providing -access to or distributing Project Gutenberg-tm electronic works -provided that - -* You pay a royalty fee of 20% of the gross profits you derive from - the use of Project Gutenberg-tm works calculated using the method - you already use to calculate your applicable taxes. The fee is owed - to the owner of the Project Gutenberg-tm trademark, but he has - agreed to donate royalties under this paragraph to the Project - Gutenberg Literary Archive Foundation. Royalty payments must be paid - within 60 days following each date on which you prepare (or are - legally required to prepare) your periodic tax returns. Royalty - payments should be clearly marked as such and sent to the Project - Gutenberg Literary Archive Foundation at the address specified in - Section 4, "Information about donations to the Project Gutenberg - Literary Archive Foundation." - -* You provide a full refund of any money paid by a user who notifies - you in writing (or by e-mail) within 30 days of receipt that s/he - does not agree to the terms of the full Project Gutenberg-tm - License. You must require such a user to return or destroy all - copies of the works possessed in a physical medium and discontinue - all use of and all access to other copies of Project Gutenberg-tm - works. - -* You provide, in accordance with paragraph 1.F.3, a full refund of - any money paid for a work or a replacement copy, if a defect in the - electronic work is discovered and reported to you within 90 days of - receipt of the work. - -* You comply with all other terms of this agreement for free - distribution of Project Gutenberg-tm works. - -1.E.9. If you wish to charge a fee or distribute a Project -Gutenberg-tm electronic work or group of works on different terms than -are set forth in this agreement, you must obtain permission in writing -from both the Project Gutenberg Literary Archive Foundation and The -Project Gutenberg Trademark LLC, the owner of the Project Gutenberg-tm -trademark. Contact the Foundation as set forth in Section 3 below. - -1.F. - -1.F.1. Project Gutenberg volunteers and employees expend considerable -effort to identify, do copyright research on, transcribe and proofread -works not protected by U.S. copyright law in creating the Project -Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm -electronic works, and the medium on which they may be stored, may -contain "Defects," such as, but not limited to, incomplete, inaccurate -or corrupt data, transcription errors, a copyright or other -intellectual property infringement, a defective or damaged disk or -other medium, a computer virus, or computer codes that damage or -cannot be read by your equipment. - -1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right -of Replacement or Refund" described in paragraph 1.F.3, the Project -Gutenberg Literary Archive Foundation, the owner of the Project -Gutenberg-tm trademark, and any other party distributing a Project -Gutenberg-tm electronic work under this agreement, disclaim all -liability to you for damages, costs and expenses, including legal -fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT -LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE -PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE -TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE -LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR -INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH -DAMAGE. - -1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a -defect in this electronic work within 90 days of receiving it, you can -receive a refund of the money (if any) you paid for it by sending a -written explanation to the person you received the work from. If you -received the work on a physical medium, you must return the medium -with your written explanation. The person or entity that provided you -with the defective work may elect to provide a replacement copy in -lieu of a refund. If you received the work electronically, the person -or entity providing it to you may choose to give you a second -opportunity to receive the work electronically in lieu of a refund. If -the second copy is also defective, you may demand a refund in writing -without further opportunities to fix the problem. - -1.F.4. Except for the limited right of replacement or refund set forth -in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO -OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT -LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE. - -1.F.5. Some states do not allow disclaimers of certain implied -warranties or the exclusion or limitation of certain types of -damages. If any disclaimer or limitation set forth in this agreement -violates the law of the state applicable to this agreement, the -agreement shall be interpreted to make the maximum disclaimer or -limitation permitted by the applicable state law. The invalidity or -unenforceability of any provision of this agreement shall not void the -remaining provisions. - -1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the -trademark owner, any agent or employee of the Foundation, anyone -providing copies of Project Gutenberg-tm electronic works in -accordance with this agreement, and any volunteers associated with the -production, promotion and distribution of Project Gutenberg-tm -electronic works, harmless from all liability, costs and expenses, -including legal fees, that arise directly or indirectly from any of -the following which you do or cause to occur: (a) distribution of this -or any Project Gutenberg-tm work, (b) alteration, modification, or -additions or deletions to any Project Gutenberg-tm work, and (c) any -Defect you cause. - -Section 2. Information about the Mission of Project Gutenberg-tm - -Project Gutenberg-tm is synonymous with the free distribution of -electronic works in formats readable by the widest variety of -computers including obsolete, old, middle-aged and new computers. It -exists because of the efforts of hundreds of volunteers and donations -from people in all walks of life. - -Volunteers and financial support to provide volunteers with the -assistance they need are critical to reaching Project Gutenberg-tm's -goals and ensuring that the Project Gutenberg-tm collection will -remain freely available for generations to come. In 2001, the Project -Gutenberg Literary Archive Foundation was created to provide a secure -and permanent future for Project Gutenberg-tm and future -generations. To learn more about the Project Gutenberg Literary -Archive Foundation and how your efforts and donations can help, see -Sections 3 and 4 and the Foundation information page at -www.gutenberg.org Section 3. Information about the Project Gutenberg -Literary Archive Foundation - -The Project Gutenberg Literary Archive Foundation is a non profit -501(c)(3) educational corporation organized under the laws of the -state of Mississippi and granted tax exempt status by the Internal -Revenue Service. The Foundation's EIN or federal tax identification -number is 64-6221541. Contributions to the Project Gutenberg Literary -Archive Foundation are tax deductible to the full extent permitted by -U.S. federal laws and your state's laws. - -The Foundation's principal office is in Fairbanks, Alaska, with the -mailing address: PO Box 750175, Fairbanks, AK 99775, but its -volunteers and employees are scattered throughout numerous -locations. Its business office is located at 809 North 1500 West, Salt -Lake City, UT 84116, (801) 596-1887. Email contact links and up to -date contact information can be found at the Foundation's web site and -official page at www.gutenberg.org/contact - -For additional contact information: - - Dr. Gregory B. Newby - Chief Executive and Director - gbnewby@pglaf.org - -Section 4. Information about Donations to the Project Gutenberg -Literary Archive Foundation - -Project Gutenberg-tm depends upon and cannot survive without wide -spread public support and donations to carry out its mission of -increasing the number of public domain and licensed works that can be -freely distributed in machine readable form accessible by the widest -array of equipment including outdated equipment. Many small donations -($1 to $5,000) are particularly important to maintaining tax exempt -status with the IRS. - -The Foundation is committed to complying with the laws regulating -charities and charitable donations in all 50 states of the United -States. Compliance requirements are not uniform and it takes a -considerable effort, much paperwork and many fees to meet and keep up -with these requirements. We do not solicit donations in locations -where we have not received written confirmation of compliance. To SEND -DONATIONS or determine the status of compliance for any particular -state visit www.gutenberg.org/donate - -While we cannot and do not solicit contributions from states where we -have not met the solicitation requirements, we know of no prohibition -against accepting unsolicited donations from donors in such states who -approach us with offers to donate. - -International donations are gratefully accepted, but we cannot make -any statements concerning tax treatment of donations received from -outside the United States. U.S. laws alone swamp our small staff. - -Please check the Project Gutenberg Web pages for current donation -methods and addresses. Donations are accepted in a number of other -ways including checks, online payments and credit card donations. To -donate, please visit: www.gutenberg.org/donate - -Section 5. General Information About Project Gutenberg-tm electronic works. - -Professor Michael S. Hart was the originator of the Project -Gutenberg-tm concept of a library of electronic works that could be -freely shared with anyone. For forty years, he produced and -distributed Project Gutenberg-tm eBooks with only a loose network of -volunteer support. - -Project Gutenberg-tm eBooks are often created from several printed -editions, all of which are confirmed as not protected by copyright in -the U.S. unless a copyright notice is included. Thus, we do not -necessarily keep eBooks in compliance with any particular paper -edition. - -Most people start at our Web site which has the main PG search -facility: www.gutenberg.org - -This Web site includes information about Project Gutenberg-tm, -including how to make donations to the Project Gutenberg Literary -Archive Foundation, how to help produce our new eBooks, and how to -subscribe to our email newsletter to hear about new eBooks. - - - -</pre> - -</body> -</html> diff --git a/old/52382-h/images/cover.png b/old/52382-h/images/cover.png Binary files differdeleted file mode 100644 index 9dc11cf..0000000 --- a/old/52382-h/images/cover.png +++ /dev/null diff --git a/old/52382-h/images/fig1.jpg b/old/52382-h/images/fig1.jpg Binary files differdeleted file mode 100644 index a8cb0a3..0000000 --- a/old/52382-h/images/fig1.jpg +++ /dev/null diff --git a/old/52382-h/images/fig2.jpg b/old/52382-h/images/fig2.jpg Binary files differdeleted file mode 100644 index f857820..0000000 --- a/old/52382-h/images/fig2.jpg +++ /dev/null diff --git a/old/52382-h/images/fig3.jpg b/old/52382-h/images/fig3.jpg Binary files differdeleted file mode 100644 index cc4aeb8..0000000 --- a/old/52382-h/images/fig3.jpg +++ /dev/null diff --git a/old/52382-h/images/fig4.jpg b/old/52382-h/images/fig4.jpg Binary files differdeleted file mode 100644 index fae8e7d..0000000 --- a/old/52382-h/images/fig4.jpg +++ /dev/null diff --git a/old/52382-h/images/fig5.jpg b/old/52382-h/images/fig5.jpg Binary files differdeleted file mode 100644 index 68ad346..0000000 --- a/old/52382-h/images/fig5.jpg +++ /dev/null diff --git a/old/52382-h/images/fig6.jpg b/old/52382-h/images/fig6.jpg Binary files differdeleted file mode 100644 index a4043fe..0000000 --- a/old/52382-h/images/fig6.jpg +++ /dev/null diff --git a/old/52382-h/images/logo.png b/old/52382-h/images/logo.png Binary files differdeleted file mode 100644 index 63c2a9f..0000000 --- a/old/52382-h/images/logo.png +++ /dev/null |
