= ——— Se SS LABORATORY OF ORNITHOLOGY CORNELL UNIVERSITY ITHACA, NEW YORK FUERTES ROOM CORNELL LAB of ORNITHOLOGY LIBRARY at Sapsucker Woods 2 Illustration of Bank Swallow by Louis Agassiz Fuertes Cornell University Library THE BOOK OF BIRDS COMMON BIRDS OF TOWN AND COUNTRY AND AMERICAN GAME BIRDS HENRY W. HENSHAW Formerty Cuier Unirepd Srates BroLocicaL SuRVEY ILLUSTRATED IN NatrurAL Cotrors with 250 PAINTINGS BY LOUIS AGASSIZ FUERTES Wirh CwHaprers on ‘“‘EncouracinG Birps AROUND THE Home,’’ sy F. H. Kennarp; “‘THe Mysteries oF Birp Micration,’’ sy Wetits W. Cooke, anp ‘How Birps Can Take THerrR Own Porrrarts,’’ By GEORGE SHIRAS, 3RD, AND 45 ILLUSTRATIONS AND 13 CHarRts IN BLackK AND WHITE. PUBLISHED BY ‘THE NATIONAL GEOGRAPHIC SOCIETY WASHINGTON, D. C. Weems. SCG Copyright by the NATIONAL GEOGRAPHIC SOCIETY 1914, 1915, 1916, and 1918 Washington Press of Judd & Detweiler, Inc. 1918 OUR FEATHERED FRIENDS N THIS VOLUME are presented the principal articles and the most beautiful color illustrations of man’s feathered friends which have been published in the National Geographic Magazine during the last six years. The text and pictures comprise one of the most valua- ble and fascinatingly interesting contributions to popular science the National Geographic Society has devised, and the most comprehen- sive and charming handbook of avian lore that has ever been offered at a moderate price. The 250 illustrations in color of ‘the Common Birds of ‘Town and Country, of our Warblers and American Game Birds, are repro- ductions of the matchless pictures from the brush of the distin- guished artist-naturalist, Louis Agassiz Fuertes, while the descriptive text by Henry W. Henshaw, formerly Chief of the U. S. Biological Survey, sets forth concisely, entertainingly, yet with scientific accu- racy, the distinguishing characteristics of each species of bird, its pe- culiar habits, 'and its favorite habitat. Dr. Henshaw has pointed out the need for the preservation of bird life, and how the farmer without his feathered insect-destroyers would face constant disaster to his crops. Few wonders of the natural world are as compelling in interest as is the display of that mysterious impulse which is followed season after season by the birds which migrate from their winter homes to their nesting places in the spring, and then make the return journey in the fall, guided no one knows how-—an absorbing study for both layman and scientist. The article by the late Wells W. Cooke, “Our Greatest Travelers: Birds that Fly from Pole to Pole, etc.,” gives a most comprehensive and engaging digest of these mysterious migra- tions, and the text is elucidated by a series of illuminating maps and charts. t | Frederick H. Kennard’s article, “Encouraging Birds Around the Home,” accompanied by numerous illustrations in black and white, tells with the bird-lover’s enthusiasm how every reader, be he Til IV OUR FEATHERED FRIENDS proprietor of a great estate or the owner of a window-sill, can make the acquaintance and win the confidence of birds, adding them to his circle of appreciative friends and charming visitors. George Shiras, 8rd, the inventor of flashlight photography of wild animals and of methods of making animals and birds take their own portraits, gives some useful hints on the latter subject. Utility, beauty, and art are served alike when man befriends the birds. GILBERT GROSVENOR, Director and Editor. Bi a i , < Photograph by Howard H. Cleaves THE EXCITEMENT OF TOUCHING THE ECCENTRIC WOODCOCK ON THE BACK CONTENTS Page Common Birds of Town and Country. Tenry W. Hensuaw......... 0... e ee ce eee 1 Friends of Our Forests—The Warblers. Henry W. HensHaw.......0.....20. 222s 74 World Record for Feathered Friends. GiItBerr GROSVENOR. 1.00.00 06 e eee 98 How Birds Can ‘Take Their Own Portraits. Grorer Strmas, 3xp....... 2.60. eee 101 once Cana Isis Isic Wie labo connanodesvonsomoovoagocoooe deco nonod 105 lithe they Awonereain Cedi IDI Gocasds sGAdntbenunneasanS 250 pbwenudsUU DDS Son Doguaoon 158 Encouraging Birds Around the Home. Frevertck H. KENNARD........000 ee eee eee ee 160 Our Greatest Travelers—Bird Migrations. Wrtrts W. CooKE.......... se ee eee eee eee 181 Yor For For For picture description picture description see page see page see page see page Blackbird, Brewer’s............ 25 24 licker, Red-shafted........... 56 57 Blackbird Grower atetcn-aeies 17 16 Ilycatcher, Black; Phainopepla. 35 34 Blackbird, Red-winged......... 60 61 Blackbird, Yellow-headed....... 46 47 Game Birds Index............ ae 158 IS erica eerenewe mene uenese tence rene tors teat 9 8 Goldfinch, American........... 37 36 SNe = a Vag taeaer are scca reenace seuss sctenenetes 25 24 Goldtinch, Arkansas........... 37 36 LEO KWIA IS ooo poanomatongocouDS 58 59 Grosbeak, Black-headed........ 15 14 BOOMS: Eo oonnonwooenuAs oes 54 55 Grosbeak BUC isre ereesscteletene tye ae 23 D2) Bumtinte elm digo; ce = 33 32 Grosbeak, Rose-breasted........ 15 14 Bunting Woazullii sec ei ers 33 32 GROWSES RUMI ee weyers ie se = 54 55 BUS Hever eeienere cree snerertoltstoleas rei 27 26 Gull Wramklimesii ee. eee el ol 70 71 Buzzards MMUnI ih 26 Vireo, Red-eyed oo) 34 Nisha om a eccies ee eiceeleren 19 18 Vireo, Yellow-throated......... 35 34 Nuthatch, White-breasted....... 11 10 Warblers : Oriole, Baltimore.............. 29 28 Audubon’s warbler........ 85 83 Oriole, Bullock’s3 57 -. 3.0 1 25 24 Bay-breasted warbler...... 92 94 OriolemMOrchand =a reeree 29 28 Black and white warbler... 85 83 Osprey, or Fish Hawk......... 66 67 Blackburnian warbler...... 89 91 OVensDIrltsnasieueteestcustre ver svencsens 81 80 Black-poll warbler......... 89 91 Owl Barna trey vensns eertcetra 12 73 Black-throated blue warbler 88 87 Owl, Great Horned............ 44 45 Black-throated gray warbler 92 94 OES creechirwnunriud cris) 72 73 Black-throated green warbler 92 94 Blue-winged warbler....... 84 te Rewee, Woodsascess cass sss ese 21 20 Canada warbler........... 96 90 Phainopepla, or Black Flycatcher 35 34 Cape May warbler......... 88 86 Phebe ........ 21 20 Chestnut-sided warbler..... 89 90 Plover, Upland 70 71 Connecticut warbler... 96 97 Golden-winged warbler..... 84 2 Quail; Californian... c.066 44565 + 23 22) Hooded warbler........... 96 97 Kkentucky warbler......... 93 90 IVCASEAT Laesaoa deer mere atr sy aeyecrress 85 83 Louisiana water-thrush.... 93 95 Road Runner... 39 38 Macgillivray warbler...... 96 97 Robin ves. eyeprea preneensttac nase 9 8 Magnolia warbler......... 89 91 Maryland yellow-throat.... 81 80 Sandpiper, Spotted............ 44 45 Mourning warbler......... 96 97 Sapsucker, Yellow-bellied....... 64 65 Myrtle warbler........... 3 12 Shrike, Loggerhead............ 13 12 Nashville warbler...... 88 87 Sparrow, Chipping............ ant 16 Northern Parula warbler... 88 86 Sparrow, English............. 17 16 Northern water-thrush..... 93 95 Sammon IAW ooacacoucdnuad 35 34 Orange-crowned warbler.... 84 82 Sparrow, Song.. 15 14 Palmy warblerjs ens ese ae 93 95 Sparrow, Vespel!....0.-...0605 23 22 ines war bletermcscec nee 92 94 Sparrow, White-crowned....... 17 16 Prairie warbler....... 93 95 Sparrow, White-throated....... 33 3 Red-faced warbler... . ees 80 SLMS el teacyenenseel aeleh ones renee 46 47 Tennessee warbler......... 88 86 Swallow, wa arn ewer vayeperal= cee see 3 2 Wilson warbler........... 96 90 Swallow, Cliff or Eaves........ 31 30 Worm-eating warbler...... 84 82 Swallow. WEreescyecyecaiere sks + sere 31 30 Yellow palm warbler...... 93 Swill Chimneys veresi-ieerseerere yee 46 47 Yellow-rump warbler (see Myrtle warbler)........ 13 ne) Tanager, Searlet..:....0.000--+ 3 30 Yellow warbler........... 85 83 Tanager, Western............. 3 30 Whip-poor-will ............... 39 38 Tern, Black 70 71 Woodpecker, California........ 56 57 ern; COMMON ee cies =e) e) ae) 21-1 = 48 49 Woodpecker, Downy........... 62 63 Thrasher, Brown:.....-...<.5- 42 43 Woodpecker, Red-headed....... 56 57 Thrush, Louisiana Water-...... 3 95 Nine, UEKI S 6 qaaccmus daanco 11 10 For Index of American Game Birds, see page 158 Photographs by George Shiras, 3rd , ONE OF NATURES HYDROPLANES Two striking pictures showing the rising flight of a pelican. In the upper illustration the wings are seen at different angles; the lower picture shows the wings outspread, and the resemblance to a Canada goose is marked, VIL Avp YJUdAdg][a dy} UO 4SaU dy} }JoyT P4lq oY J, NAHAS UNV Ha&iDHd V AO DO WAL COMMON BIRDS OF TOWN AND COUNTRY By HENRY W. HENSHAW ForMERLY CHIEF or THE U. BIOLOGICAL SURVEY With flustrations from Paintings by Louis Agassiz Fuertes ROM very ancient times birds have appealed to the interest and imagi- nation of mankind. ‘They have furnished themes for innumerable poets, have appeared in many guises in primi- tive religions, and by their flight inspired the predictions of the soothsayers of old. Even in these modern and prosaic times birds still continue to interest mankind, and the last decade has witnessed a marked strengthening of the sentiment toward them. The present interest is direct and per- sonal, and today hundreds of thousands of men and women in various parts of the country, old as well as young, are em- ploying much of their leisure in famuil- iarizing themselves with the birds of their respective localities. In following birds afield, in studying their habits, and listening to their songs, they bring them- selves into close touch and sympathy zest, be it noted, which enriches without harm to any creature. Would that the same could be said of the sportsman who almost invariably is at heart a nature lover, though the primi- tive instinct to kill is uppermost. Many sportsmen, however, who poy fol- lowed wild creatures only to kill, have abandoned the use of rifle and shotgun, and today are finding greater | sleasure in studying and photographing ee former quarry than they did in pursuing it with murderous intent. A real interest in wild life leads naturally to a love of Nature in all her varied manifestations, and this, in all lands and under all circumstances, remains a source of lasting pleasure. A love of birds from the esthetic side, however, is of comparatively recent de- velopment and had little place among primitive peoples, who utilized birds chiefly in two ways—for food and for ornament. Feathers, especially, appealed to them for purposes of adornment, and this barbaric taste has not only survived among civilized races, but in recent years has develoy »ed to an extent which threat- ens the very existence of many of the most beautiful and notable species of birds in various parts of the world. No region is too remote, no forests too deep, no mountains too high to stay the plume- hunter, stimulated by the golden bribe offered by the tyrant Fashion. Happily, America has taken the lead in an attempt to restrict this craze for feather adornment, which means nothing less than the death of millions of beauti- ful and useful creatures. Nor are evi- dences wanting that other countries as well have recognized the gravity of the situation and are preparing to pass pro- tective laws similar to those recently enacted in this country FARMERS’ MOST ALLIES BIRDS ARE THE KFFICIENT While birds appeal to the regard and interest of man from the esthetic side as no other creatures do, there is another and even more important point of view, and it is no doubt true that of late years interest in birds has been greatly stimu- lated by the discovery that they possess an economic value. : The study of the economic side of bird life and of the relations of birds to the farmer and horticulturist has been greatly stimulated in the United States by Federal aid and supervision, and in no other country in the world have the ac- tivities of birds been so carefully investi- gated with reference to their practical bearing. Under the Biological Survey of the Department of Agriculture, for instance is a corps of trained men, who study the food of birds by careful examination of the stomachs of specimens killed for sci- entific purposes. The information thus gained 1s supplemented by observations 2 COMMON BIRDS OF TOWN AND COUNTRY in the field, and the result is a large amount of invaluable data illustrative of the economic relations of many kinds of birds. This storehouse of information has been largely drawn upon in the fol- lowing pages. OUR COUNTRY IS PARTICULARLY NATE IN THE NUMBER AND VARIETY OF ITS BIRDS FORTU- It would be strange indeed if our land, with its vast extent of territory, its diver- sified landscape, its extensive forests, its numerous lakes and streams, with its mountains, prairies, and plains, had not been provided by Nature with an abun- dant and diversified bird life. As a mat- ter of fact, America has been favored with a great variety of birds famed both for beauty and for song. America also possesses certain families, as the hum- ming-birds and wood-warblers, the like of which exist nowhere else in the world. In considering the many kinds of birds in the United States from the prac- tical side, they may not inaptly be com- pared to a police force, the chief duty of which is to restrain within bounds the hordes of insects that,if unchecked, would devour every green thing. To accom- plish this task successfully, the members of the force must be variously equipped, as we find they are. Indeed, while the 1,200 kinds of birds that inhabit the United States can be grouped in families which resemble each other in a general way, yet among the members of the sev- eral families are marked variations of form and plumage and still greater vari- ation of habits, which fit them for their diversified duties. As the bulk of insects spend more or less time on the ground, so we find that more birds are fitted for terrestrial serv- ice than for any other. Our largest bird family, the sparrows, is chiefly terres- trial, and although its members depend much upon seeds for subsistence they spend no little share of their time search- ing for insects. They are ably aided in the good work by the thrushes, wrens, certain of the warblers, and many other birds. Another group is of arboreal habits, and plays an important part in the con- servation of our forests, the true value of which we have only recently learned to appreciate. So many insects burrow into trees that a highly specialized class of birds —the woodpeckers — has been developed to dig them out. The bills, tongues, feet, and even the tails of these birds have been cunningly adapted to this one end, and the manner in which this has been done shows how fertile Nature is in equipping her servants to do her bidding. The bark of trees also forms a favorite shelter for numerous insects, and behold the wrens, nuthatches, warblers, and creepers, with sharpest of eyes and slen- derest of bills, to detect our foes and to dislodge them from crack and cranny. The air is full of flying insects, and to take care of these there are the swallows, swifts, and nighthawks, whose wings and bodies are so shaped as to endow them with the speed and agility necessary to follow all the turns and windings of their nimble insect prey. The whip-poor-wills, swift of wing and with capacious mouths beset with bris- tles, attend to the night-flying insects when most birds are asleep, while the hawks by day and the owls by night sup- plement the work of other birds and have a special function of their own, the de- struction of noxious rodents. Thus every family of birds plays its own part in the warfare against insects and other foes to man’s industry, and contributes its share to man’s welfare. Birds would fall far short of what they accomplish for man were they not the most active of living things. It is curious that the group of vertebrates which live the fastest—that is, have a higher tem- perature and a more rapid circulation than any other—should be related by de- scent to a family of such cold-blooded creatures as the reptiles and lizards, which often go without food and hiber- nate for considerable periods. Very dif- ferent is it with birds. Few realize the enormous quantity of food required to sustain the energy of these creatures, most of whose waking hours are spent in a never-ending search for food. BIRDS CHECK RAVAGES OF DISEASE- CARRYING INSECTS In satisfying their own hunger birds perform an important service to man, for notwithstanding the fact that the acreage COMMON BIRDS OF TOWN under cultivation in the United States is larger than ever before, and that the crops are greater, the cost of foodstuffs continually mounts upward. Meanwhile the destruction of farm and orchard crops by insects and by rodents amounts to many millions each year, and if any part of this loss can be prevented it will be so much clear gain. The protection of insectivorous and rodent-destroying birds is one of the most effective means of preventing much of this unnecessary loss, and the public is rapidly awakening to the importance of this form of conservation. From the farmers’ standpoint, such birds as the bobwhite, prairie- chicken, the upland plover, and the other shore birds are worth very much more as insect eaters than as food or as objects of pursuit by the sportsman. ‘This statement applies with especial force to such species as the prairie-chicken, which everywhere in its old haunts is threatened with extinction. The value of birds to the farmer is plain enough, but we do not usually think of birds as having any direct relation to the public health. To prove that they do, however, it is only necessary to state that 500 mosquitoes have been found in the stomach of a single nighthawk; that in a killdeer’s stomach hundreds of the larve of the salt-marsh mosquito have been found, and that many shore birds greedily devour mosquito larve. As mosquitoes are known to carry the germs of such serious diseases as dengue fever and malaria, it is evident that by destroying them birds are conferring an important benefit on man. It may be added that not infrequently ticks are eaten by birds, and that the tick responsible for the spread of Texas fever among cattle has been found in the stomach of the bobwhite. Since birds perform such invaluable service, every effort should be made to protect the birds we now have and to in- crease their numbers. This can be done in several ways: (a) by furnishing nest- ing boxes for certain species, as swal- lows, martins, wrens, woodpeckers, great- crested flycatchers, and others; (b) by planting berry-bearing shrubs about the farm or orchard as food for the birds in winter; (c) by the establishment of AND COUNTRY 3 bird sanctuaries, where birds may be rea- sonably safe from their natural enemies and be permitted to live and breed in ab- solute security as far as man is concerned. Here, again, the National Government, taking the lead, has set apart no less than 64 bird refuges in various parts of the United States. These for the most part are rocky, barren islands of little or no agricultural value, but of very great use- fulness in the cause of bird protection. The example thus set is now being fol- lowed by certain States, as Oregon and Wisconsin. Several private citizens also have acquired islands for the purpose of making bird preserves of them; others not only prevent the destruction of wild life on their forested estates, but go much farther, and endeavor in various ways to increase the number of their bird tenants. Efforts to protect birds on a smaller scale and to attract them about dwellings, with a view to their close companionship, are worthy of all praise, and such efforts should be far more common in this coun- try than they are at present, particularly as the means involve little trouble or ex- pense. The presence of trees and shrub- bery near the house is of itself an open invitation to birds which they are eager to accept, particularly if the shrubbery j is not too dees pruned. Birds like thick vines and tangles, in the recesses of which they feel safe from their many enemies. Suet, nuts, and other bird foods, if ex- posed in conspicuous places, can usually be depended on to attract birds in winter, and often avail to save many lives, espe- cially when snow covers the ground. Species which are not berry eaters, like the woodpeckers, nuthatches, creepers, and chickadees, can be made winter resi- dents of many farms, even in the North, by putting out at convenient places a sup- ply of suet, of which they and many other birds are very fond, even in summer. Hedges and thickets about the farm are important to furnish nesting sites and shelter both from the elements and from the numerous enemies of birds. Few are aware of the difficulty often experienced by birds in obtaining water for drinking and bathing, and a constant supply of water near the farmhouse will materially aid in attracting birds to the neighborhood and in keeping them there, 4 COMMON BIRDS OF TOWN AND COUNTRY at least till the time of migration. Shal- low trays of wood or metal admirably serve the purpose, especially as birds de- light to bathe in them. BIRDS SHOULD EVERYWHERE BE PROTECTED By supplying artificial nest-boxes the number of birds may be increased around farms and orchards where their services are most needed. ‘The average farmer's boy, if provided with a few tools, is quite equal to the task of making acceptable boxes for martins, swallows, bluebirds, wrens, woodpeckers, and other species, which are far from fastidious as to the appearance of the box intended for their occupancy. Entomologists have estimated that in- sects yearly cause a loss of upward of $700,000,000 to the agricultural interests of the United States. Were it not for our birds the loss would be very much greater, and, indeed, it is believed that without the aid of our feathered friends successful agriculture would be impossible. A knowledge of the birds that protect his crops is, therefore, as important to the farmer as a knowledge of the insect pests that destroy them. Such informa- tion is the more needful because the rela- tion of birds to man’s interests is ex- tremely complex. Thus, while it may be said that most of our birds are useful, there are only a few of them that are always and everywhere useful and that never do harm. Insec- tivorous birds, for instance, destroy, along with a vast number of harmful insects, some parasitic and predatory kinds. These latter are among Nature’s most effective agents for keeping destructive insects in check. To the extent, then, that birds destroy useful parasitic insects, they are harmful; but, taking the year round, the good they do by the destruc- tion of insects injurious to man’s interests far outweighs the little harm they do. It may be said, too, that of the birds usually classed as noxious there are very few that do not possess redeeming traits. Thus the crow is mischievous in spring and sorely taxes the farmer’s patience and ingenuity to prevent him from pull- ing up the newly planted corn. More- over, the crow destroys the eggs and young of useful insectivorous and game birds; but, on the other hand, he eats many insects, especially white grubs and cut-worms, and destroys many meadow mice; so that in much (although not all) of the region he inhabits the crow must be considered to be more useful than harmful. THEIR WINGS ENABLE BIRDS TO ACT EFFICIENTLY AS POLICEMEN Most of the hawks and owls even— birds that have received so bad a name that the farmer’s boy and the sportsman are ever on the alert to kill them—are very useful because they destroy vast numbers of insects and harmful rodents. Birds occupy a unique position among the enemies of insects, since their powers of flight enable them at short notice to gather at points where there are abnormal insect outbreaks. An unusual abundance of grasshoppers, for instance, in a given locality soon attracts the birds from a wide area, and as a rule their visits cease only when there are no grasshoppers left. So also a marked increase in the number of small rodents in a given neighborhood speedily attracts the attention of hawks and owls, which, by reason of their vora- cious appetites, soon produce a marked diminution of the swarming foe. One of the most useful groups of na- tive birds is the sparrow family. While some of the tribe wear gay suits of many hues, most of the sparrows are clad in modest brown tints, and as they spend much of the time in grass and weeds are commonly overlooked. Unobtrusive as they are, they lay the farmer under a heavy debt of gratitude by their food habits, since their chosen fare consists largely of the seeds of weeds. Selecting a typical member of the group, the tree sparrow, for instance, one-fourth ounce of weed seed per day is a conservative estimate of the food of an adult. On this basis, in a large agricultural State like Iowa tree sparrows annually eat approximately 875 tons of weed seeds. Only the farmer, upon whose shoulders falls the heavy burden of free- ing his land of noxious weeds, can realize what this vast consumption of weed seeds means in the saving and cost of labor. COMMON BIRDS OF TOWN AND COUNTRY 5 Some idea of the money value of this group of birds to the country may be gained from the statement that the total value of the farm products in the United States in 1915 reached the amazing sum of $9,108,000,000. If we estimate that the total consumption of weed seed by the combined members of the sparrow family resulted in a saving of only 1 per cent of the crops—not a violent assump- tion—the sum saved to farmers by these birds in 1915 was $91,080,000. MOST HAWKS AND OWLS BENEFICIAL The current idea in relation to hawks and owls is erroneous. ‘These birds are generally classed as thieves and robbers, whereas a large majority of them are the farmers’ friends and spend the greater part of their long lives in pursuit of in- jurious insects and rodents. The hawks work by day, the owls chiefly by night; so that the useful activities of the two classes are continued practically through- out the 24 hours. As many as 100 grasshoppers have been found in the stomach of a Swain- son’s hawk, representing a single meal; and in the retreat of a pair of barn owls have been found more than 3,000 skulls, 97 per cent of which were of mammals, the bulk consisting of field mice, house mice, and common rats. Nearly half a bushel of the remains of pocket gophers— animals which are very destructive in certain parts of the United States—was found near a nest of this species. ‘The notable increase of noxious rodents dur- ing the last few years in certain parts of the United States and the consequent damage to crops are due in no small part to the diminished number of birds of prey, which formerly destroyed them and materially aided in keeping down their numbers. A few hawks are injurious, and the bulk of the depredations on birds and chickens chargeable against hawks is committed by three species—the Cooper’s hawk, the sharp-shinned hawk, and the goshawk. The farmer’s boy should learn to know these daring robbers by sight, so as to kill them whenever possible. From the foregoing it will at once ap- pear that the practice of offering bounties indiscriminately for the heads of hawks and owls, as has been done by some States, is a serious mistake, the result being not only a waste of public funds, but the destruction of valuable servants which can be replaced, if at all, only after the lapse of years. As a rule, birds do not live very long, but, as previously stated, they live fast. They breathe rapidly and have a higher temperature and a more rapid circulation than other vertebrates. This is a fortu- nate circumstance, since to generate the requisite force to sustain their active bodies a large quantity of food is neces- sary, and as a matter of fact birds have to devote most of their waking hours to obtaining insects, seeds, berries, and other kinds of food. The activity of birds in the pursuit of insects is still further stimulated by the fact that the young of most species, even those which are by no means strictly in- sectivorous, require great quantities of animal food in the early weeks of ex- istence, so that during the summer months—the flood time of insect life— birds are compelled to redouble their at- tacks on our insect foes to satisfy the wants of their clamorous young. Field observations of the food habits of birds serve a useful purpose, but they are rarely accurate enough to be fully re- liable. ‘The presence of certain birds in a corn or wheat field or in an orchard is by no means proof, as is too often as- sumed, that they are devastating the grain or fruit. They may have been attracted by insects which, unknown to the farmer or orchardist, are fast ruining his crop. Hence it has been found necessary to ex- amine the stomachs and crops of birds to ascertain definitely what and how much they eat. ASTONISHING CAPACITY OF BIRDS’ STOM- ACHS REVEALED BY 50,000 TESTS The Biological Survey has in this way examined upward of 50,000 birds, most of which have been obtained during the last 25 years from scientific collectors, for our birds are too useful to be sacrificed when it can possibly be avoided, even for the sake of obtaining data upon which to base legislation for their protection. It is interesting to observe that hungry birds—and birds are hungry most of the Arctic zone Boreal IHudsonian i elon Canadian & 4 fina ral ‘UpperAustral eU |LowerAustralf§ Aust Region Tropi . 7 Revien Seopa YLZZZA ZONE MAP OF NORTH AMERICA After U.S. Biological Survey oO 500 1000 "Statute Miles The dotted parts of the Austral Zones east of the Great Plains indicate the extent of the humid divisions of these Zones, known respectively as the Alleghanian, Carolinian and Austroriparian Kaunas. The undotted parts of the same zones are known as the Transition, Sonoran and Lower Sonoran. 120 WS M10 10S 100 95 90 70 A} BUMSTLAD MAP SHOWING THE BIRD ZONES With their unparalleled facilities for locomotion over both land and water, birds are more widely distributed than any other vertebrates, yet their comparatively delicate organizations are highly sensitive to many conditions of life. The most important factor in determining the breeding range of birds is, of course, the one of climate, expressed mainly through tem- perature and to a lesser degree through rainfall. The zone map shows that North America is divided into three great regions—the Boreal, Austral, and Tropical—and the first two in turn are subdivided into three zones each. The boundaries of the zones follow in a general way certain isotherms, or lines of temperature, with subdivisions determined by the annual rainfall. The numerous “lakes” and “islands” noted on the zone map are brought about in most cases by the altitude of these areas. In connection with this map it is well to keep in mind C. Hart Merriam’s Laws of Tem- perature Control: First, “Animals and plants are restricted in northward distribution by the total quantity of heat during the season of growth and reproduction.” Second, “Animals and plants are restricted southward in distribution by the mean temperature of a brief period covering the hottest part of the year.” With respect to birds the reference in both instances is to the breeding range. 2 COMMON BIRDS OF TOWN AND COUNTRY A time—are not content to fill their stom- achs with insects or seeds, but after the stomach is stuffed until it will hold no more continue to eat till the crop or gullet also is crammed. It is often the case that when the stomach is opened and the con- tents piled up the pile is two or three times as large as the stomach was when filled. Birds may truly be said to have healthy appetites. To show the astonish- ing capacity of birds’ stomachs and to re- veal the extent to which man is indebted to birds for the destruction of noxious insects, the following facts are given as learned by stomach examinations made by assistants of the Biological Survey : A tree swallow’s stomach was found to contain 40 entire chinch-bugs and frag- ments of many others, besides 10 other species of insects. A bank swallow in Texas devoured 68 cotton-boll weevils, one of the worst insect pests that ever invaded the United States; and 35 cliff swallows had taken an average of 18 boll weevils each. Two stomachs of pine siskins from Haywards, Cal., contained 1,900 black olive scales and 300 plant lice. A killdeer’s stomach taken in November in Texas contained over 300 mosquito larve. A flicker’s stomach held 28 white grubs. A nighthawk’s stomach collected in Kentucky contained 34 May beetles, the adult form of white grubs. Another nighthawk, from New York, had eaten 24 clover-leaf weevils and 375 ants. Still another nighthawk had eaten 340 grass- hoppers, 52 bugs, 3 beetles, 2 wasps, and a spider.