\ y. THE WARBLERS OF NORTH AMERICA By FRANK M. CHAPMAN Curator of Ornithology in the American Museum of Natural History. HANDBOOK OF BIRDS OF EASTERN NORTH AMERICA. Revised Edition. With Keys to the Species, Descriptions of their Plumages, Nests, etc., and their Dis- tribution and Migrations. With over 200 Illustrations. Also in Cloth, $3.75 net. POCKET EDITION, with flexible covers, $4.25. net. BIRD-LIFE. A Guide to the Study of Our Common Birds. POPULAR EDITION in colors, Cloth, $2.25 net. BIRD STUDIES WITH A CAMERA, with introductory Chapters on the Outfit and Methods of the Bird Photographer. Illustrated with over 100 Photographs from Nature by the Author. Cloth, $2.00 net. THE WARBLERS OF NORTH AMERICA. With Contributions from other Ornitholo- gists and 24 full-page Colored Plates illus- trating every species, from Drawings by L. A. Fuertes and B. Horsfall, and Half-tones of Nests and Eggs. Cloth, $3.25 net; post- age, 20 cents additional. CAMPS AND CRUISES OF AN ORNITHOLOGIST. With 250 Photographs from Nature by the Author. Cloth, $3.25 net. COLOR KEY TO NORTH AMERICAN BIRDS. Revised Edition. With over 800 pictures. Cloth, #2.75 net. THE TRAVELS OF BIRDS. 45 cents net. D. APPLETON AND COMPANY, NEW YORK. PLATE I 1. YELLOW WARBLER, MALE. 2. YELLOW WARBLER, FEMALE. 3. MANGROVE WARBLER, MALE. (ONE-HALF NATURAL SIZE.) 4. MANGROVE WARBLER, FEMAI 5. PRAIRIE WARBLER, MALE. 6. PRAIRIE WARBLER, FEMALE. THE WARBLERS OF NORTH AMERICA BY FRANK M. CHAPMAN WITH THE COOPERATION OF OTHER ORNITHOLOGISTS WITH TWENTY-FOUR FULL-PAGE COLORED PLATES, ILLUSTRATING EVERY SPECIES, FROM DRA WINGS BY LOUIS[AGASSIZ FUERTES AND BRUCE HORSFALL, AND HALF-TONES OF NESTS AND EGGS THIRD EDITION NEW YORK D. APPLETON & COMPANY 1917 Copyright, 1907 By FRANK M. CHAPMAN All rights reserved Published, March, IQO? Reprinted, January, 1914; October, IQIJ. PREFACE THE WARBLERS have been described as "our most beautiful, most abundant, and least known birds." The knowledge that at certain seasons our woods, and even the trees of our larger city parks are thronged with an innumerable host of birds, the bril- liancy of whose plumage rivals that of many tropical species, comes to the bird student with the force of a surprising discovery. One never forgets one's first Warbler ! Highly migratory, the extended journeys of Warblers are never- theless performed with a regularity which makes their appearance in the spring a fixed calendar event. The very essence of the season is in their flitting forms and lisping voices ; without them May would seem a dreary month and the migration of birds lose half its charm. But these dainty, fascinating sprites of the tree-tops are elusive. Years of observation may be required to add to one's list of field acquaintances the last of the thirty-odd species which, in eastern North America, may be found at a single locality. In this quest the field-glass student is handicapped. The small size of Warblers, their activity, the nature of their haunts, their rapid journeys, marked seasonal changes in plumage, and the general resem- blance in the song of many species all tend to render recognition in life unusually difficult. This book has, therefore, been prepared with the cooperation of other ornithologists, to meet the demand for a fully illustrated work which will serve as an aid to the field identification of Warblers and to the study of their life-histories. F. M. C. American Museum of Natural History, New York City, January, 1907. Best gems of Nature's cabinet With dews of tropic morning wet. — Longfellow CONTENTS Page INTRODUCTORY I PLAN OF THE WORK . I LIST OF CONTRIBUTORS 5 THE WOOD WARBLERS ^. , . 7 GENERAL CHARACTERS OF WARBLERS . . . .. .... 7 PLUMAGE OF WARBLERS -, . . . 7 DISTRIBUTION OF WARBLERS . . . . , >. . . . n MIGRATION OF WARBLERS, W. W. Cooke . . . . . . . 14 SONGS OF WARBLERS . ..",.. . . . •' -\ . . . 20 NESTING HABITS OF WARBLERS .. ^ ..... 22 FOOD OF WARBLERS, Edward Howe Forbush . . . . « . 23 MORTALITY AMONG WARBLERS . v_ . . *: . -. . . . 33 THE WARBLERS OF NORTH AMERICA 37 Genus i. MNIOTILTA 38 1. Mniotilta varia, Black and White Warbler 38 Genus 2. HELINAIA 43 2. Helinaia swainsoni, Swainson's Warbler 44 Genus 3. HELMITHEROS .48 3. Helmitheros vermivorus, Worm-eating Warbler. . . 48 Genus 4. PROTONOTARIA . . . . . ' . . ' . * . 53 4. Protonotaria citrea, Prothonotary Warbler. . . . 54 Genus 5. VERMIVORA . 59 5. Vermivora chrysoptera, Golden-winged Warbler. . 60 6. pinus, Blue-winged Warbler 65 7- bachmani, Bachman's Warbler. ... 77 Peregrina, Tennessee Warbler. ... 83 9- celata celata, Orange-crowned Warbler. . 86 9a. orestera, Rocky Mountain Orange-crown. 89 9b. lutescens, Lutescent Warbler. ... 90 9c. " " sordida, Dusky Warbler. .... 91 10. rubricapilla rubricapilla, Nashville Warbler. . 92 ioa. gutturalis, Calaveras Warbler. . 97 11. Virginia, Virginia's Warbler 08 12. lucice, Lucy's Warbler. •.„ . ... . 100 Page Genus 6. COMPSOTHLYPIS 102 13. Compsothlypis americana americana, Southern Parula Warbler 103 j^a. " usnece, Northern Parula Warbler 104 14. " pitiayumi nigrilora, Sennett's Warbler. . log Genus 7. PEUCEDRAMUS no 15. Peucedramus olivaccus, Olive Warbler no Genus 8. DENDROICA . * ."' . . • .... 16. Dendroica (estiva (Estiva, Yellow Warbler. ... . 113 163. " " sonorana, Sonora Yellow Warbler. . 119 i6b. " " rubiginosa, Alaskan Yellow Warbler. . 120 i6c. '* " brewsteri, California Yellow Warbler. . 120 17. " bryanti castaneiceps, Mangrove Warbler. . . 121 i g. " magnolia, Magnolia Warbler 121 ig. " tigrina, Cape May Warbler 128 20. " carulescens carulescens, Black-throated Blue Warbler 133 2oa. " cairnsi, Cairns' Warbler. . . 140 21. " coronata, Myrtle Warbler 141 22. " auduboni auduboni, Audubon's Warbler. . . 147 22a. " " nigrifrons, Black- fronted Warbler. . 151 23. " nigrescens, Black-throated Gray Warbler. . . 151 24. " townsendi, Townsend's Warbler. . . . 154 25. " virens, Black-throated Green Warbler. . . 157 26. n chrysoparia, Golden-cheeked Warbler. . . 162 27. " occidentalis, Hermit Warbler 167 28. " cerulea, Cerulean Warbler 170 29. " fusca, Blackburnian Warbler 175 30. " dominica dominica, Yellow-throated Warbler. . 180 3Oa. " " albilora, Sycamore Warbler. . . 184 31. gratia gratia, Grace's Warbler 185 32. " pensylvanica, Chestnut-sided Warbler. . . 187 33. " castanea, Bay-breasted Warbler. . . .192 34. " striata, Blackpoll Warbler. . . . . 196 35. " vigor si vigor si, Pine Warbler. . . . . 201 36. " kirtlandi, Kirtland's Warbler. ... .206 37. " discolor, Prairie Warbler. . . .. " , . 209 38. " palmarum palmarum, Palm Warbler. . . .213 38a. " " hypochrysea, Yellow Palm Warbler. 216 Genus 9. SEIUBUS . . „•."".. . 218 39. Seiurus aurocapillus, Oven-bird. . . ... . . .219 40. motacilla, Louisiana Water-Thrush. . . . 226 41. noveboracensis noveboracensis, Northern Water- Thrush 230 4ia. " " notabilis, Grinnell's Water-Thrush. 234 Genus 10. OPORORNIS . . . . •..„... . . . 235 42. Oporornis formosus, Kentucky Warbler. . . . . 235 43- " agilis, Connecticut Warbler. . '. . . 241 Page 44. Oporornis Philadelphia, Mourning Warbler. . . 244 45. tolmiei, Macgillivray's Warbler. . . . 249 Genus n. GEOTHLYPIS 251 46. Geothlypis trichas trichas, Maryland Yellow-throat. . 251 46a. ignota, Florida Yellow-throat. . . 257 46b. occidentalis, Western Yellow-throat. 259 460. arisela, Pacific Yellow-throat. . . 260 46d. sinuosa, Salt Marsh Yellow-throat. . 261 47. beldingi, Belding's Yellow-throat. . . . 261 Genus 12. CHAM^ETHLYPIS 263 48. Chamcethlypis poliocephala poliocephala, Rio Grande Yellow-throat. 263 Genus 13. ICTERIA 263 49. Icteria virens virens, Yellow-breasted Chat. . . . 264 49a. " " longicauda, Long-tailed Chat. . . . 268 Genus 14. WILSONIA 269 50. Wilsonia citrina, Hooded Warbler 269 Si- " pusilla pusilla, Wilson's Warbler. . . . 274 5 1 a. " " pileolata, Pileolated Warbler. . . 278 Sib. " " chryseola, Golden Pileolated Warbler. . 279 52. " canadensis, Canada Warbler 274 Genus 15 CARDELLINA 285 53. Cardellina rubrifrons, Red-faced Warbler 285 Genus 16. SETOPHAGA 287 54. Setophaga ruticilla, American Redstart 287 55- " Picta picta, Painted Redstart 295 HYPOTHETICAL LIST 299 INDEX. .301 LIST OF ILLUSTRATIONS COLORED PLATES PLATE. FACING PAOE. I. YELLOW, MANGROVE, AND PRAIRIE WARBLERS. Horsfall. . Frontispiece II. BLACKPOLL AND BLACK AND WHITE WARBLERS. Horsfall. . . 38 III. BLACKBURNIAN AND PROTHONOTARY WARBLERS. Horsfall. . . 50 IV. BACHMAN'S, SWAINSON'S, AND WORM-EATING WARBLERS. Fuertes. 64 V. BLUE-WINGED, LAWRENCE'S, BREWSTER'S, AND GOLDEN-WINGED WARBLERS. Fuertes. 72 VI. OLIVE, LUCY'S, AND VIRGINIA'S WARBLERS. Fuertes. ... 98 VII. TENNESSEE, ORANGE-CROWNED, AND NASHVILLE WARBLERS. Hors- fall 86 VIII. PARULA AND SENNETT'S WARBLERS. Fuertes. ..... 104 IX. CERULEAN AND BLACK-THROATED BLUE WARBLERS. Fuertes. . . 112 X. MYRTLE AND AUDUBON'S WARBLERS. Fuertes. . . . . .118 XI. MAGNOLIA AND KIRTLAND'S WARBLERS. Horsfall 126 XII. BAY-BREASTED AND CHESTNUT-SIDED WARBLERS. Horsfall. . . 138 XIII. YELLOW-THROATED, GRACE'S, AND BLACK-THROATED GRAY WARBLERS. Fuertes • , .. . . . 152 XIV. BLACK-THROATED GREEN AND GOLDEN-CHEEKED WARBLERS. Horsfall. 162 XV. HERMIT AND TOWNSEND'S WARBLERS. Fuertes 170 XVI. CAPE MAY AND PALM WARBLERS. Fuertes 214 XVII. Rio GRANDE YELLOW-THROAT, OVEN-BIRD, NORTHERN WATER- THRUSH, LOUISIANA WATER-THRUSH. Fuertes 226 XVIII. KENTUCKY AND CONNECTICUT WARBLERS. Horsfall. . . .236 XIX. MACGILLIVRAY'S AND MOURNING WARBLERS. Horsfall. . . . 244 XX. BELDING'S AND MARYLAND YELLOW-THROATS. Fuertes. . . .252 XXI. HOODED WARBLER, YELLOW-BREASTED CHAT. Horsfall. . . . 264 XXII. WILSON'S AND CANADA WARBLERS. Fuertes. . . . . 280 XXIII. AMERICAN AND PAINTED REDSTARTS. Horsfall. . . / . 288 XXIV. PINE AND RED-FACED WARBLERS. Horsfall. . . . . " . .' 296 PHOTOGRAPHS OF NESTS AND EGGS FIGURES. FACING PAGE. 1. NEST OF PROTHONOTARY WARBLER. . "V . ' . . . . 58 2. NEST OF PARULA WARBLER. . .... -..» •' . * . . 58 3-32. EGGS OF WARBLERS. . .. .. -.,.» . 44 33. NEST OF YELLOW WARBLER. . . . . . . • • • !88 34. NEST OF CHESTNUT-SIDED WARBLER. . , " . ... .188 35-64. EGGS OF WARBLERS. . . . ' . . , . . . . 144 65-94. EGGS OF WARBLERS. . . . . , . -. . .176 95. NEST OF BLACKPOLL WARBLER. . • *. , . . . . 200 96. NEST OF OVEN-BIRD. .. -, . . . . . . v . . 200 97-126. EGGS OF WARBLERS. . .... . ' . . .' . . 258 127. NEST OF REDSTART. . . '» .. , . . . . , . 272 128. NEST OF HOODED WARBLER. . . .... . • . :. '• . . • 272 INTRODUCTORY PLAN OF THE WORK The plan on which this work was projected was outlined in 'Bird-Lore' for April, 1903 (pp. 61-63). Responding to frequent and continued requests for a book treating especially of Warblers, the writer, as editor of that magazine, asked ornithologists to assist in the preparation of the proposed volume by contributing the results of their observations of the habits of Warblers, and added : "Continued study of our birds emphasizes the absolute necessity of many observers if we are to have anything approaching adequate biographies of even a single species. Habits should be affirmed or denied only on the basis of abundant data; again, what proves true of a species in one part of its range may be incorrect in another; and we need, therefore, not only many observations from one place, but from many places throughout a bird's range before we can write its life-history with an approach to thoroughness. Cooperation, there- fore, is the watchword of the bird study of to-day. "The truth is, the best of bird biographies tell only the story of the individual rather than the species. Life is too short for a single student to acquire a thorough knowledge of more than a few species of birds, and even then his experience is apt to be limited to a small part of their range. In the writer's opinion, the bird biographies in Bendire's 'Life Histories of North American Birds' are among the best, if not the best of any which have been written. This is not solely because of Major Bendire's wide field experience and powers of observation, but also because he secured the cooperation of orni- thologists throughout the country. It was not required that they should be skilled in painting pen pictures of bird-life ; facts, not rhe- torical flights, were wanted, and the result is one of the most satis- factory books of reference of its kind. "There is an object-lesson for us here. In our enthusiastic appre- ciation of the bird as a creature of rare grace and beauty, the final touch giving life to woods and fields, let us not forget that as bird students we are here more intimately concerned with the birds' habits 2 PLAN OF THE WORK than with the part they play as the 'jewels of creation,' when, with no loss of appreciation of the esthetic side of bird-life, we may make our bird biographies a storehouse of exact and detailed observations in regard to a bird's distribution, migrations, its manner of courting, singing, nest-building, incubating, caring for its young, the relation between its structure and habit, etc." The concluding lines were then expanded into an outline bio- graphy representing the manner in which it was desired to treat each species ; and it may at once be confessed that in only a small number of instances have contributions been received which would permit of the treatment proposed. Of observations on migration, numerical abundance, local distribution, and nesting dates, there have been no lack; valuable descriptions of haunts, actions, and, particularly, of song have been sent, but the minute, intimate study revealing the bird's inner life and relation to its surroundings has, in most instances, yet to be made. Such studies result only from definitely directed and prolonged observation, and, in the development of orni- thological science in America, we are only just beginning to receive contributions from naturalists who, not content with the mere ability to name the birds of their own locality and describe their habits in a general way, have chosen some particular subject or species for thorough investigation. However, it is believed that the present volume adequately reflects existing knowledge of the North American Mniotiltidae and it is hoped, therefore, may prove a stable foundation on which to build a more complete structure. At the outset the author disclaims any special knowledge of the members of the family of which this book treats. Circumstances, some of which have been before mentioned, have induced him to undertake its preparation ; and only the generous cooperation of other workers has enabled him to complete the task. A special effort has been made to acknowledge fully all sources of assistance. Manuscript contributions have been marked as such, while information which has been previously published is, when prac- ticable, given in the words of its author. In this connection intro* ductory and transition remarks and other editorial ear-marks, which become tiresome through frequent repetition and tend to rob the matter quoted of its own distinctive character through the needless interposition of another personality, have been avoided as much as possible. While the result may be a less finished, it is, to our mind, a more effective whole. PLAN OF THE WORK 3 It should be added that in the selection of material, other things being equal, preference has been given to articles which have appeared in magazines, and in the publications of scientific societies which are comparatively inaccessible ; while those books which can be more readily purchased have been used only when other sources of infor- mation have failed. A list of the contributors, or co-authors of this volume is given on a succeeding page, but it is desired here to specify the nature of the material they have contributed, as well as to comment in a more or less explanatory way, on the book's contents. Preliminary Chapters. — The subjective matter herein contained was prepared by the writer with the exception of the article on 'Migration,' which is by W. W. Cooke, and that on 'The Food of Warblers,' which was written by E. H. Forbush. Descriptions of Plumages, etc. — The description of plumages, with remarks on genera and comments on species are by the writer. They are based on the collection of the American Museum of Natural History and the admirable series of carefully sexed Warblers in the collection of Dr. J. Dwight, Jr., which is deposited in the museum, but thanks are also due Robert Ridgway, Curator of Birds of the United States National Museum, and Dr. C. Hart Merriam, Chief of the Biological Survey, for permission to examine the birds under their charge, as well as to William Brewster and Dr. L. B. Bishop for an opportunity to study the Warblers contained in their private collections. It is a pleasure to acknowledge here, also, the assistance derived from the second volume of Ridgway's 'Birds of North and Middle America' which includes the Warblers, and Dwight's 'The Sequence of Plumages and Moults of the Passerine Birds of New York.' The measurement of 'Length' here given is taken from study 'skins', first, because a large series of measurements taken in the flesh, of all the species treated, is not available; and, second, because it is believed that the measurement of the length of a properly prepared skin gives a more nearly correct idea of the size of the living bird, than does the measurement of the recently killed, usually relaxed, and more or less stretched specimen. Range. — The paragraphs on distribution are, in the main, by W. W. Cooke with additions by the author who is responsible for the range given of the various subspecies of Warblers. Migration. — The migration tables, assuredly one of the most valuable features of the book, have been prepared entirely by W. W. 4 PLAN OF THE WORK Cooke of the Biological Survey. For the past twenty years orni- thologists throughout the country have been sending data on bird migration to the Survey. In the preparation of Bulletin No. 18 of the Survey ('Distribution and Migration of North American Warblers'), it was Professor Cooke's duty to elaborate this unequalled store of migration records, and the matter here given is based on that work, the migration records being presented in a tabular form which makes them easy of reference and comparison. The Bird and its Haunts. — Under this heading an attempt has been made to present a picture of the bird in nature; sketching its appearance and actions as well as describing its haunts, both while migrating and nesting. Here are also occasionally included remarks on the time, place, or manner of the discovery of the bird or its nest and eggs, with other pertinent historical details, and, in some instances, biographical data which seem more in place here than in any other section of the outline for treatment adopted. Especially valuable contributions to this department were made by Gerald Thayer, Frank L. Burns, Verdi Burtch, Walter K. Fisher, and Andrew Allison. Song. — Under this caption the call-notes as well as the songs of Warblers are treated. Always a difficult and unsatisfactory subject to deal with, it is particularly so in the case of the Warblers, the calls and songs of most of which lack sufficient character to be des- cribed recognizably. However, the impressions of different observers in widely separated localities are presented, not with the expectation that what they have written will give one an adequate idea of the particular song in question, but that it will lead to its identification when heard. Miss Paddock, Mrs. Farwell, Gerald Thayer, and Andrew Allison have made notable contributions to this part of the book, and Lynds Jones has permitted liberal use of his 'Songs of Warblers'. The student should also consult Matthews' 'Fieldbook of Wild Birds and their Music' (Putnams) which being readily procurable has not been quoted from. Nesting-Site and Nest. — The method of treatment of these sections requires but little comment. The abundant literature of the subject has been freely drawn on, reference showing the source ol information. The collections of the American Museum, William Brewster, and C. W. Crandall have been used, while particularly acceptable manuscript contributions were made by Andrew Allison, Frank L. Burns, and Verdi Burtch. PLAN OF THE WORK 5 The descriptions and measurements of the eggs were pre- pared by Mr. C. W. Crandall, well known as a careful, conservative oologist. Mr. Crandall possesses one of the largest private collections of eggs in the country, and his work is therefore based on abundance of material. The eggs figured are, in the main, from Mr. Crandall's collection with additions from the collections of the American Mus- eum of Natural History and of Mr. J. L. Childs. Nesting Dates. — Unless otherwise specified the dates here given are the earliest and latest at which full sets of fresh eggs were found. Most of the data here presented were contributed by the ornithologists whose names are given as authority, but the collections of the Ameri- can Museum and of Mr. C. W. Crandall as well as the literature of the subject have also been drawn on. Biographical References. — As the heading indicates this biblio- graphical matter is restricted to articles treating of the habits of the bird in question. Where quotations are made from these articles due acknowledgment is made by cross-reference in the text. Contributors. — In the preceeding comments on the plan of the book, the principal contributors to it have been mentioned. Assist- ance, however, was received from many others, in some cases merely a nesting date, in others more extended notes. Whenever used such matter is duly acknowledged and we give here an alphabetical list of all contributors of manuscript to the book. The impossibility of including in this list the names of the hundreds of observers on whose work the migration tables are based is regretted, but Professor Cooke assures us that the manner in which these data are presented makes it impossible to give credit where credit is due. To Waldron DeWitt Miller, Robert C. Murphy, and Ludlovr Griscom I am much indebted for assistance in reading proof. LIST OF CONTRIBUTORS Allison, Andrew, Ellisville, Miss. Attwater, H. P., Houston, Texas. Bagg, Egbert, Utica, N. Y. Barrows, Walter B., Agricultural College, Mich. Bishop, Louis B., New Haven, Conn. Bowles, C. W. and J. H., Tacoma, Wash. Brewster, William, Cambridge, Mass. Burns, Frank L., Berwyn, Pa. Burtch, Verdi, Branchport, N. Y. PLAN OF THE WORK Christy, Bayard H., Sewickley, Pa. Cooke, W. W., Biological Survey, Washington, D. C. Crandall, C. W., Woodside, L. I. Dille, F. M., Denver, Colo. Farwell, Mrs. John V., Jr., Lake Forest, Ills. Fisher, Walter K., Palo Alto, Cal. Forbush, E. H., Wareham, Mass. Ganier, A. F., Vicksburg, Miss. Gault, B. F., Glen Ellyn, Ills. Holmes, LaRue K., the latei Summit, N. J. Jackson, T. H., West Chester, Pa. Jacobs, J. Warren, Waynesburg, Pa. Jones, Lynds, Oberlin, Ohio. Kells, Wm. L., Listowel, Ont. Knight, O. W., Bangor, Me. Koch, August, Williamsport, Pa McDavitt, Ina Lord, Vineland, N. J. Mailliard, J. J., San Geronimo, Calif. Morgan, Albert, Hartford, Conn. Paddock, Miss I. M., St. Johnsbury, Vt. Sears, Miss Annie L., Waltham, Mass. Spaulding, F. B., Lancaster, N. H. Stephens, Frank, San Diego, Calif. Thayer, Gerald H., Dublin, N. H. Wayne, A. T., Mt. Pleasant, S. C. Widmann, Otto, St. Louis, Mo. Wood, N. A., Ann Arbor, Mich. THE WOOD WARBLERS THE GENERAL CHARACTERS OF WARBLERS The American Warblers (Family Mniotiltidae), or Wood Warblers as they are more formally called to distinguish them from the wholly different Old World Warblers (Family Sylviidae), are small insectivorous birds with generally slender, sharp-pointed, sometimes flattened, but never hooked (as in the Vireonidae) bills. The three or four outer primaries are longest and of nearly the same length, the tarsus is posteriorly ridged (not rounded as in the Tyrannidae), the hind-claw never lengthened (as in the Alaudidae or Motacillidae). The broad, bristly billed, flycatching members of the family are too brightly colored to be mistaken for most North American repre- sentatives of the true Flycatchers (Family Tyrannidse), from which they differ in other respects, and, among North American birds, the Warblers are to be confused in nature only with the Vireos and Kinglets. From the Vireos they differ in wing-formula and in lack- ing a hooked bill, while in life they may usually be distinguished from them by their greater activity. The Vireos are more deliberate in movement, they peer, while the Warblers pirouette, or flutter, turning the whole body this way then that, darting or springing here or there, the embodiment of perpetual motion among birds. The Kinglets are smaller than the smallest Warbler, except Lucy's Warbler. In the Golden-crowned Kinglet the black and orange or yellow crest is always diagnostic, while the Ruby-crown's habit of nervously twitching its wings, and wren-like call note will readily distinguish it from any Warbler. PLUMAGE OF WARBLERS Development of Plumage. — When a Warbler leaves the egg it is apparently naked, but close examination will reveal on the feather- tracts of the upper surface of the body a scanty growth of the finest down. This is the 'natal down'. (See Dwight, The Sequence of 8 PLUMAGE OF WARBLERS Plumages and Moults of the Passerine Birds of New York.') While the bird is in the nest this downy plumage is succeeded by a second plumage which has been termed both the 'first' and the 'Juvenal' plumage but which, in my opinion, among altricial birds, may best be known as the nestling plumage. Where, in the newly hatched bird, there was down, it is forced outward by the rapidly growing feathers of the nestling plumage, on the tips of which it remains for a brief period. Where there was no natal down, the nestling plumage is the first plumage to appear. When, at the age of about twelve to fourteen days, the young bird leaves the nest, the nestling plumage of its body is virtually complete, but the tail is stumpy and the wings, although they support the bird in its first uncertain flight, are not fully grown. Both wings and tail, however, belong also, as we shall see, to the first fall plumage, and the distinctive nestling plumage may therefore be said to be wholly acquired in the nest. No time intervenes between the completion of the nestling plu- mage and the appearance of the first feathers of the first fall plumage, traces of which indeed may often be detected in the feather tracts of the breast before the wings and tail are fully grown. This first fall plumage is acquired by molt of the feathers of the nestling plumage and the development of a new growth of feathers. The wing and the tail quills and the primary wing-coverts are retained, but the remaining wing-coverts and all the feathers of the body are shed. Although there may be some feather-growth during the winter, the first fall plumage remains virtually unchanged until the following spring, when, by a molt involving the feathers of various parts of the body,. but not those of the wings and tail, the first breeding plu- mage is acquired. With the exception of Vermivora bachmani, Peucedramus olivaceus, Dendroica chrysoparia, and Setophaga ruticilla, which apparently do not secure their mature plumage until their first post- breeding molt (at the beginning of their second autumn), the first breeding plumage resembles that of the mature bird, except for such minor differences as may be shown in the intensity of color of the wings and tail. Following the nesting season, in accordance with the almost universal law of molt, an entirely new set of feathers, including wing and tail quills, is gained, and this, like the plumage of the first fall, PLUMAGE OF WARBLERS 9 is unchanged until the succeeding spring when certain feathers of the body may be changed, and, thereafter, this order of molt is apparently followed by the species. Nestling Plumage. — It is difficult, if not impossible, to frame a law which shall express the relations of the nestling plumage of Warblers to their adult plumage. When, however, the adult is olive- green above, yellow or whitish below and without spots or streaks, the young is dull olive-green or olive-brown above, dusky olive or grayish below with the belly whitish or yellowish. Examples are Vermivora peregrina, V. rubricapilla, V. pinus, Dendroica ingorsi, Geothlypih trichas, Oporonis formosus, Wilsonia pusilla, W . citrina, and Icteria virens. When the plumage of the adult is varied in pattern with streaks or spots, etc., the plumage of the nestling, while it may be widely different, is generally streaked or spotted. Examples are Mniotilta varia, Dendroica coronata, D. auduboni, D. magnolia, D. Striata, D. castanea, D. fusca, D. palmar um, and the Seiuri. When the adult is gray above the nestling is gray, as in Vermi- vora luci