ALBERT R. MANN LIBRARY New York State Colleges OF Agriculture and Home Economics AT Cornell University Library Burrau Cal. No. 1137 Library Cornell University QL 673.B4 an^ function The bird, its form 959 3 1924 000 149 Hes|ifruniis, — a wingless, toothed, diving liinl, aliout live feet in length, wliieh inhabited tlie great se;is during tlie Cretaceous period, some four millions of years ago. antfrican jl5aturc g>mc6 Group II. The Functions of Nature THE BIRD ITS FORM AND FUNCTION C. WILLIAM BEEBE Curator of Ornitliology of the New York Zoologiaal Park and Life Member of the A'ew York Zoological Society ; Member of the American Ornilhologiiti' Union and Fellow of tlie New York Academy of Sciences Author of "Two Bird- Lovers in Mexico" WITH OVER THREE HUNDRED AND SEVENTY ILLUSTRATIONS CHIEFLY PHOTOGRAPHED FROM LIFE BY THE AUTHOR NEW YORK HENRY HOLT AND COMPANY 1906 Copyright, 190« BY HENRY HOLT AND COMPANY Published September, 1906 ROBERT DRPMMOND, PRINTER, NE'W YORK DEDICATED IN GRATITUDE AND ESTEEM TO professor IbciuB ffalrficl? ©sborn BY HIS FORMER PUPIL THE AUTHOR — PREFACE We find to-day some thirteen or fourteen thousand different forms, or species, of birds upon the earth. For many years ornithologists have laboured to name, and to arrange in some rational order, these multitudinous forms of bird life. Some such arrangement is, of course, a neces- sity —without a handle we should indeed be handicapped in studying a bird; but let us not forget that classification is but a means to an end. Far too many students of birds follow some such mode of procedure as this: When a new bird is found, it is shot, labelled, preserved in a collection and forgotten; or, if studying the bird with a glass, all efiort is centred in finding some characteristic by which it can be named, and, succeeding in this, search is at once made for still another species, whose name can in turn be added to a list. Observing the habits, the courtship and nest-building, and memorizing the song, is a third phase of bird-study the best of all three methods; but few indeed have ever given a moment's thought to the bird itself. 1 have lectured to an audience of teachers, every one of whom was able to identify fifty birds or more, but not one among them knew the significance of the scales on viii Preface a bird's foot. It is to bridge this gap that this book is intended—an untechnical study of the bird in the abstract. This, it seems to me, is the logical phase of bird life, which, with an earnest nature-lover, should follow the handbook of identification—the study of the physical life of the bird itself preceding the consequent phase of the mental life, with its ever-varying outward ex- pression. Far from considering this treatment exhaustive, one must remember that any chapter subject could easily be elaborated into one or more volumes. I have intended the book more as an invitation than aught else: for each to observe for himself the marvellously fascinating drama of evolution; to pass on from the nature stories of ideal- ized composite animals and birds to the consideration of the evolution of all life; to the tales of time and truth which have been patientl}' gleaned by the life-long labours of thousands of students. Whenever possible I have illustrated a fact with a photograph from a preparation or from a living bird, believing that, where verbal exposition fails, pictorial interest will often fix a fact in the memory. First of all we must consider a few of the more important and sig- nificant of the bird-forms of past ages; because no one who is interested in living birds from any standpoint should be entirely ignorant of a few facts concerning the ancestors of these creatures. Otherwise it is as if one entirely ignoring the rest of the plant, studied certain leaves and flowers, knowing not whether they came from tree or vine. Preface ix In my treatment of the various phases of the bird's phj^sical life I have been considerably influenced by the many questions which I have heard asked by visitors to the New York Zoological Park. The short list of books in the Appendix will indicate the sources whence much more detailed information may be obtained by those who desire it. Some two dozen of the illustrations are from outside sources, and for permission to use these I am indebted to Dr. William T. Hornaday, the American Museum of Natural History, Prof. A. Smith-Woodward, Prof. R. S. Lull, A. E. Brown, Esq., Mr. R. H. Beebe, Mr. T. H. Jackson, Mr. Harold AVhealton, and Mr. E. H. Baynes; and for the use of specimens to Dr. F. A. Lucas, Dr. Robert Ridgway, and Dr. .Jonathan Dwight, Jr. Unless otherwise indicated, the illustrations were taken by the author. The work of Mr. Walter King Stone in the paint- ing for the frontispiece and a number of text cuts is gratefully acknowledged; and for the skilful printing of many of the photographs my thanks are due to Mr. E. R. Sanborn. To my wife, for constant and valuable help, criticism, and suggestion in all departments of the book, I render my sincere appreciation. To take a few dead facts and clothe them with the living interest which will make them memorable and full of meaning to any lover of birds, and at the same time to keep them acceptable in tenor and truth to the most critical scientist—this has been my aim. X Preface A few chapters of this volume have akeady appeared in print in "Outing," "Bird-Lore," and the "New York Evening Post." C. W. B. New York Zoological Park, May, 1906. CONTENTS CHAPTER PAGE 1. Ancestors 1 II. Feathers 19 III. The FR.iMEWORK of the Bird 62 IV. The Skull 103 V. Org.^ns of Nutrition- 116 VI. The Food of Birds 142 VH. The BRE.iTH of .\ Bird 16.5 VIII. Muscles and Nerves 188 IX. The Senses 203 X. Be.\.k.s and Bills 223 XI. Heads and Necks 2.52 XII. The Body of .a Bird 2S.5 XIII. Wings 319 XIV. Feet and Legs 3.53 XV. Tails 398 XVI. The Eggs of Birds 427 XVII. The Bird in the Egg 462 Appendix—Brief List of Useful Books 483 Index 485 THE BIRD CHAPTER I ANCESTORS ITH the exception of Astronomy, the science which most powerfully dominates our imagina- tion is Palaeontology, or the study of the life of bygone ages. Of all things in Nature, the stars symbolize absolute immensity, their distances stretching out beyond our utmost calculation. So the revelations of Palaeon- tology take us far beyond the sciences of life on the earth to-day, and open vistas of time reaching back more than five-hundred-fold the duration of the sway of mankind. Fossil bones—philosophically more precious than any jewels which Mother Earth has yielded—are the only certain clews to the restoration of the life of past ages, millions of years before the first being awakened into human consciousness from the sleep of the animal mind. Until recently, Palseontolog}' has been popularly con- sidered one of the dryest and most uninteresting of the 'ologies, but now that the fossil collections in our museums are being arranged so logically and so interestingly, the most casual lover of Nature can read as he runs some of — 2 The Bird the "poems hidden in the bones." As Professor Huxley once said, " Palseontology is simply the biology of the past, and a fossil animal differs only in this regard from a stuffed one, that the one has been dead longer than the other, for ages instead of for days." A great many more fossil mammals and reptiles have been discovered than birds, and the reason may perhaps be conjectured. The bones and bodies of birds were in former times as now very light, and if death occurred on the water, the body would float and probably be de- voured by some aquatic reptile. Then, again, when some cataclysm of nature or change of climate obliterated whole herds and even races of terrestrial creatures, the birds would escape by flight, and when death eventuall}^ came, they would be stricken, not in flocks, but singly and in widely scattered places as to-day. For perhaps a million years in the past, birds have changed scarcely at all, —the bones of this period belong- ing to the species or at least genera of living birds. But in the period known as the Cretaceous, when the gigantic Dinosaurs flourished and those flj^ing reptile-dragons the Pterodactyls—flapped through the air, a few remains of birds have been found. Some of these are so com- plete that almost perfect skeletons have been set up, enabling us vividly to imagine how the bird looked when swimming through the waters of our globe, or flying through the air, perhaps four millions of years ago. The most remarkable peculiarity of these l)irds was the possession of teeth. Two of the most well-known examples are called Ichthyornis and Hespcrornis. The Ancestors 3 bones of these birds were discovered by Professor Marsh imbedded in the roclcs of western Kansas, and the}' are now preserved in the museum of Yale University. Pro- fessor Marsh tells us that Hesperornis, the Bird of the Fig. 1. —Restored skeleton of Ichthyornix (after Marsh). 1/2 natural size. West, "was a tv'pical aquatic bird, and in habit was doubtless very similar to the loon, although, flight being impossible, its life was probal^ly passed entirely upon the water, except when visiting the shore for the purpose of breeding.