THE GIFT OF FLORENCE V. V. DICKEY TO THE UNIVERSITY OF CALIFORNIA AT LOS ANGELES THE DONALD R. DICKEY LIBRARY OF VERTEBRATE ZOOLOGY USEFUL BIRDS AND THEIR PROTECTION CONTAINING BRIEF DESCRIPTIONS OF THE MORE COMMON AND USEFUL SPECIES OF MASSACHUSETTS, WITH ACCOUNTS OF THEIR FOOD HABITS, AND A CHAPTER ON THE MEANS OF ATTRACT- ING AND PROTECTING BIRDS. EDWARD HOWE FORBUSH, ORNITHOLOGIST TO THE MASSACHUSETTS STATE BOARD OF AGRICULTURE. ILLUSTRATED BY THE AUTHOR, C. ALLAN LYFORD, CHESTER A. REED, AND OTHERS. PUBLISHED UNDER DIRECTION OF THE MASSACHUSETTS STATE BOARD OF AGRICULTURE, BY AUTHORITY OF THE LEGISLATURE. 1908. APPROVED BY THE STATE BOARD OF PUBLICATION. PRINTED BY WRIGHT & POTTER PRINTING COMPANY, STATE PRINTERS, BOSTON, MASSACHUSETTS. 0* * $% Commonroealtlj of |Ha30aclju0eit5, Resolves of 1905, Chapter 51. A RESOLVE TO PROVIDE FOK PREPARING AND PRINTING A SPECIAL 11EPORT OX THE IURDS OF THE COMMONWEALTH. Resolved, That there be allowed and paid out of the treasury of the Commonwealth a sum not exceeding three thousand dollars for prepar- ing and printing, under the direction of the state board of agriculture, in an edition of five thousand copies, a special report on the birds of the Commonwealth, economically considered, to include the facts relating to the usefulness of birds and the necessity for their protection already ascertained by the ornithologist of the state board of agriculture, to be distributed as follows: — Two copies to each free public library in the Commonwealth; two copies to each high school, and two copies to such schools in towns which have no high school as the school committee may designate ; one copy to the library of congress, and one copy to each state or territorial library in the United States ; twenty-five copies to the state library ; five copies to the governor ; two copies to the lieu- tenant governor and each member of the council ; two copies to the secretary of the Commonwealth ; two copies to the treasurer and re- ceiver general : two copies to the auditor of accounts ; two copies to the attorney-general, and one copy to each member of the present general court applying for the same ; the remainder to be distributed under the direction of the state board of agriculture. [Approved April 14, 1.905. 505192 Commonrotaillj af lHa00adju0eft0. Resolves of 1907, Chapter 77. RESOLVE TO PROVIDE FOR PRINTING ADDITIONAL COPIES OF THE REPORT OX THE BIRDS OF THE COMMONWEALTH. Resolved, That there be allowed and paid out of the treasury of the Commonwealth, a sum not exceeding twenty-five hundred dollars for printing five thousand additional copies of the report on the birds of the Commonwealth. From the copies so printed each member and each elective officer of the general court for the year nineteen hundred and seven shall receive ten copies, and each assistant clerk of the general court, the doorkeepers, messengers and pages shall receive one copy. Copies may be sold by the secretary of the state board of agriculture at a price not less than the cost thereof, and additional copies may be printed for sale at the discretion of the secretary, the expense thereof to be paid from the receipts from such sales. Any amount received from sales shall be paid into the treasury of the Commonwealth. \Approved May 8, 1907 . PREFACE. In preparing and submitting this report the fact has been kept in mind that the material prosperity of the state and nation depends very largely on agricultural pursuits. An attempt has been made, therefore, to make the volume ser- viceable to both agriculturist and horticulturist. The author of this report believes, with Townend Glover, that an ac- quaintance with the useful birds of the farm is as important to the farmer as is a knowledge of the insect pests which attack his crops. Those who open this volume expecting to find within its covers a guide to the birds, a manual for the collector, or a systematic account of the birds of Massachusetts, will be disappointed, for its scope is chiefly economic. The plan of the report as outlined before the legislative committees has been followed to the letter. In undertaking the work, the author has attempted to counteract in some measure the effects of some phases of modern civilization and intensive farming which operate to destroy or drive out the birds ; and it is hoped that the book will be of some service as a source of useful information for the bird protectionist. As no report prepared with such a purpose can exert much influence unless widely read, it has been written in a popular style, with little scientific verbiage. A part of the material was prepared between the years 1891 and 1900, during the author's experience as field di- rector for the State Board of Agriculture in the work of destroying the gipsy moth. Chapters I. and II. are partly composed of revised and rewritten portions of papers pub- lished during that time. Chapter III. is based largely on observations made during that period by two faithful, capable workers, — Messrs. C. E. Bailey and F. H. Mosher. Owing PREFACE. to Mr. Bailey's untimely death and Mr. Mosher's occupation in a new field, it was deemed best to publish some of the field notes of these observers with little editing, in order to avoid any possible distortion of their evidence. In presenting in Chapter I. some of the evidence, given by the earlier writers, regarding the utility of birds as protectors of crops and trees, it has been necessary to use such material as was obtainable. No carefully guarded experiments or observations in this direction were made until the latter part of the nineteenth century, and it is only recently that scien- tific investigators have been employed in this little-known field. It is not an alluring task for the scientist, in which his work brings him neither material reward, credit, nor honor. That portion of the final chapter which treats of the means of attracting birds is drawn mainly from six years' experience at the author's home at Wareham, Mass. The first three chapters were mainly written there. Most authors quoted or cited in these chapters are given full credit. The remaining chapters, which are largely based on the author's own investigations and observations, were written and the proof was read while he was away from home, in the woods, or travelling from place to place, often at a distance from any ornithological library. Under such circumstances it was impossible to quote verbatim, but in most cases authors are named when facts have been gathered from their writings. The averages of the components of the food of each species are taken mainly from the publications of the Bureau of Bio- logical Survey of the United States Department of Agricul- ture, except where credit is otherwise given. Thanks are due to Dr. L. O. Howard, who has read critically that part of the introduction devoted to insects, and the author is greatly indebted to him for information ; also, more than he can tell, to Mr. William Brewster for counsel and suggestions ; and especially to Mr. J. A. Farley, who read a large part of the manuscript. The limited time at the author's disposal has prevented such painstaking revision and abridgment of the manuscript PREFACE. vii as would be required to attain the highest literary excellence ; but both manuscript and proof were critically read by Mrs. A. Drew, whose work has added much to the appearance of the volume, and whose suggestions have been very valuable. Mr. F. H. Fowler has placed the author under great obli- gations by doing a large amount of clerical work, and giv- ing much assistance in his official position as first clerk and librarian of the State Board of Agriculture. The scientific ornithological nomenclature is that of the American Ornithologists Union. The grouping of birds according to their habitats (as birds of woodland, etc.) is based more on their food habits than on their choice of nesting sites. This classification is of necessity arbitrary, and not always consistent, for it is sometimes influenced by other considerations, such as are evident in the inclusion of the Whip-poor-will among birds of the air. The nomenclature of plants is mainly that used by Britton and Brown in their Flora of the Northern United States, Canada, and the British Possessions, except in some cases where Dr. Judd or other authors are quoted. That of insects has been derived from various sources at different times, and for this reason some of the scientific names are not the latest. In the original plan of the report no descriptions of species were included ; but the suggestion was made by Mr. J. A. Farley that it would be useless to descant to a man on the usefulness of the Chickadee if he did not know the bird. The brief, un technical descriptions of bird, nest, eggs, and bird notes, and the illustrations of the species, are all in- tended as helps to identification. The descriptions of birds are calculated merely to call attention to the principal colors and marks that serve to identify birds afield. Brief descrip- tions of haunts, habits, and manners are also given, as guides to identity. A species that is found throughout the year within the limits of the State is denominated a resident. Xo attempts have been made to give fixed dates of arrival and departure, for these vary somewhat in different parts of the State, as PREFACE. well as in different seasons ; but the months in which each species is most commonly seen are given. For example, the season for the Tree Swallow is given as April to Septem- ber ; but no mention is made of the fact that it sometimes appears in small numbers in March ; neither is it stated that this bird has been seen in flocks in southeastern Massachu- setts in late October and even in November, for such occur- rences are unusual. It may be taken for granted that most of the insect-eating birds that arrive in March or April come in the latter part of those months, while most of those that depart for the south in September or October leave in the earlier weeks of their respective months. Our attempts to represent the songs of birds in printed syllables are not often of much assistance to the beginner, for they lack the variation, quality, and expression of bird songs, and birds do not sing in syllables. Also, the imagi- nation of the writer often greatly affects these syllabic rendi- tions, as may be seen by comparing the various sentences attributed by different people to the White- throated Sparrow. Nevertheless, some such imitations of bird songs which are now accepted and are quite generally considered helpful are given in this report; in other cases the author's own inter- pretations of well-marked bird notes are given. The line cuts of birds, nesting boxes, appliances, etc., are mainly reproductions of the author's pen and ink sketches and drawings. The attitudes have been caught by sketch- ing the living birds afield ; but as most of the drawings were necessarily made in winter, the measurements and the details of markings were taken mainly from bird skins. While this method does not give so good results as does the use of the dead bird, it obviates the necessity of killing1 birds for the pur- pose. The sketches for Figs. 19, 22, 23, and 25 were sug- gested by half-tone plates in American Ornithology. Figs. 1, 27, 53, 71, 73, 71), 109, 113-117, 142, and 143 were made from pen drawings by Lewis E. Forbush. The wood-cuts of insects were taken chiefly from Harris's Insects Injurious to Vegetation, Flint's Manual of Agriculture, and various papers published by Dr. A. S. Packard while serving as ento- mologist to the Massachusetts State Board of Agriculture. PREFACE. IX Mr. C. Allan Lyford has given valuable assistance in taking photographs illustrating bird feeding, nesting boxes, etc. The author is also greatly indebted to Messrs. C. A. and C. K. Reed for the use of half-tone plates from American Ornithology ; to Mr. Frank M. Chapman, the Massachusetts Commission on Fisheries and Game, Mr. A. C. Dike, and others, to whom credit is given in the text or captions, for the use of photographs, half-tone plates, or cuts ; and to Messrs. William Brewster and Ralph Holman for the use of bird skins. Plates VI. and VII. are from E. A. Samuels. The credit for the publication of this volume rightly be- longs to the State Board of Agriculture, which, through its secretary, introduced and advocated the resolve providing for preparing and printing ; to the Massachusetts Audubon Society, which supported the resolve before the Legislature ; to the various associations, officials, and friends who upheld the resolve ; and to those members of the House and Senate who were instrumental in securing the appropriation which made possible the production of the report. For its many shortcomings the author alone is responsible. CONTENTS, INTRODUCTORY. — THE UTILITY OF BIRDS IN NATURE, .... 1 CHAPTER I. — THE VALUE OF BIRDS TO MAN, . . . . ; 23 Primitive Man's Relations to Nature, 23 Changed Relations produced by Agriculture, ...... 24 Man at War with Nature in the New World, .25 The Increase of Insect Pests, 27 The Number of Insects, 28 The Reproductive Capacity of Insects, 28 The Voracity of Insects, 30 The Great Loss to American Agriculture by Insect Ravages, . . .31 Losses by Insect Ravages in Massachusetts 36 The Capacity of Birds for destroying Pests 40 The Digestion of Birds, 40 The Growth of Young Birds, 42 The Amount of Food required by Young Birds, .... 44 The Time required for Assimilation of Food, 49 The Number of Insects eaten by Young Birds in the Nest, . . 51 The Amount of Food eaten by Adult Birds 57 Birds save Trees and Crops from Destruction, 63 The Increase of Injurious Insects following the Destruction of Birds, . 72 The Destruction of Injurious Mammals by Birds, 76 The Value of Water-birds and Shore Birds, 80 The Commercial Value of Birds, 81 The ^Esthetic, Sentimental, and Educational Value of Birds, . . 85 CHAPTER II. — THE UTILITY OF BIRDS IN WOODLANDS, .... 90 The Relations of the Bird to the Tree, 91 The Forest Planters, 92 The Influence exerted by Birds and Squirrels on the Succession of Forest Trees, ....'. 96 The Tree Pruners, 99 The Guardians of the Trees, 100 CHAPTER III. — BIRDS AS DESTROYERS OF HAIRY CATERPILLARS AND PLANT LICE, Ill CHAPTER IV. — THE ECONOMIC SERVICE OF BIRDS IN THE ORCHARD, . 149 CHAPTER V. — SONG BIRDS OF ORCHARD AND WOODLAND, . . . 155 Woodland Thrushes 155 Kinglets, 160 Nuthatches and Tits ... 163 CONTENTS. CHAPTER V. — SONU BIKDS OF ORCHARD AND WOODLAND — Con. PAQE Creepers, 177 Thrashers and Mockingbirds, 178 Warblers, 185 Vireos 203 Waxwings, 209 Tanagers, 211 Finches, Grosbeaks, and Towhees 215 Blackbirds, Grackles, Orioles, etc., 224 CHAPTER VI. — SONGLESS BIRDS OF ORCHARD AND WOODLAND, . . 229 Flycatchers, 229 Hummingbirds, . 240 Woodpeckers 245 Cuckoos, Kingfishers, etc., 2(i2 Grouse, Partridges, etc., 266 CHAPTER VII. — THE UTILITY OF BIRDS IN FIELD AND GARDEN, . . 275 CHAPTER VIII. — BIRDS OF FIELD AND GARDEN, 282 Thrushes and their Allies, 282 Wrens " 292 Sparrows, 294 Blackbirds, Grackles, etc 312 Pigeons and Doves 323 Grouse, Partridges, etc. 325 Pheasants, 332 Snipe, Sandpipers, Woodcock, etc., 334 CHAPTER IX. — BIRDS OF THE AIR, ........ 339 Swifts, 340 Nighthawks, Whip-poor-wills, etc* 341 Swallows, 343 CHAPTER X. — BIRDS OF MARSH AND WATERSIDE, 349 Perching Birds 349 Rails 350 Herons, 351 Water-fowl, 353 CHAPTER XI. — CHECKS UPON THE INCREASE OF USEFUL BIRDS, . . 354 The Destruction of Birds by Man, 35(5 The Natural Enemies of Birds, 361 Introduced Four-footed Enemies, 302 Cats, 362 Native Four-footed Enemies, ......... 364 Squirrels, ............ 364 Rats and Mice, 366 Feathered Enemies, . . . , . . . . . . 366 Hawks 3(5(; Owls, 367 Crows and Jays, 368 CONTENTS. Xlll CHAPTER XI. — CHECKS UPON THE INCREASE OF USEFUL BIRDS — Con. PAO« Feathered Enemies — Con. The House Sparrow, .......... 370 Shrikes, 370 Other Bird Enemies, 371 Reptilian Enemies, 371 Fish, 371 CHAPTER XII. — THE PROTECTION OF BIRDS, 372 Methods of attracting Birds, 373 Feeding and Assembling the Winter Birds 377 Attracting the Summer Birds, 384 Providing Nesting Places about Buildings, 386 Bird Houses and Nesting Boxes, ....... 388 Furnishing Nesting Material, 398 Feeding the Summer Birds, 399 Attracting Water-fowl, 402 The Protection of Birds against their Natural Enemies, . . . .403 The Protection of Farm Products from Birds, 410 To protect Grain from Crows and Other Birds, 411 To protect Small Fruits, 412 To protect Chickens from Hawks and Crows, 412 General Protective Measures, 413 Game Protection 414 Measures and Legislation necessary for the Protection of Game and Birds 415 Artificial Propagation of Game Birds, 417 The Movement for Bird Protection, 418 Papers on Ornithology, published by the Massachusetts State Board of Agriculture, 421 INDEX, 423 LIST OF ILLUSTRATIONS. PACK FIGURE 1. — The Archaeopteryx, 5 FIGURE 2. — Ground Beetle, 9 FIGURE 3. — Cutworm, 11 FIGURE 4. — Xoctuid Moth, 11 FIGURE 5. — Fly and its Larva, 14 FIGURE 6. — Chestnut Beetle or Weevil, . 14 FIGURE 7. — Caterpillars, the Larvae of Butterflies, 14 FIGURE 8. — Pupae or Chrysalids, 15 FIGURE 9. — Predaceous Beetle, the Lion Beetle or Caterpillar Hunter, . 18 FIGURE 10. — Predaceous Beetle, a Tiger among Insects, . . . .18 FIGURE 11. — Hymenopterous Parasite, 18 FIGURE 12. — Host Caterpillar with Cocoons of a Parasite upon its Back, . 19 FIGURE 13. — Tiger Beetle, 19 FIGURE 14. —Chinch Bug, 27 FIGURE 15. — Colorado Potato Beetle, 29 FIGURE 1(5. — Hessian Fly, 33 FIGURE 17. — Alimentary Canal of Bluehird, 41 FIGURE 18.— Young Cedar Bird on its First Day, 42 FIGURE 19. — Young Cedar Birds less than Three Weeks old, . . . 43 FIGURE 20. — Young Grouse, 43 FIGURE 21.— Young Woodcock, 44 FIGURE 22. — Young Robins, . 44 FIGURE 23. — Young Crows, 49 FIGURE 24. — Passenger Pigeon feeding by Regurgitation, . ' . . .52 FIGURE 25. — Chipping Sparrow feeding Young, 55 FIGURE 26. — Yellow-throat catching Birch Aphids, 63 FIGURE 27. — Western Cricket, 65 FIGURE 28. —Gulls saving Crops by killing Crickets, 66 FIGURE 29. — Warblers destroying Plant Lice, 71 FIGURE 30. —The Winged Seed of White Pine, 92 FIGURE 31. — A Forest Planter, . . 94 FIGURE 32.— Ruffed Grouse, "budding," . 99 FIGURE 33. — The Diligent Titmouse 101 FIGURE 34.— Winter Tree Guards, 104 FIGURE 35. — Destructive Bark Beetle, 107 FIGURE 36. — Wood pecker hunting Borers 107 FIGURE 37. — Larva of the Cecropia Moth, 110 XVI LIST OF ILLUSTRATIONS. FIGURE 38. — Woolly Bear Caterpillar, 120 FIGURE 39. — Yellow Bear Caterpillar, 120 FIGURE 40. — Caterpillar of the White-marked Tussock Moth, . . .121 FIGURE 41.— Web of the Brown-tail Moth Caterpillar 130 FIGURE 42. — Nashville Warbler, 133 FIGURE 43. — Caterpillar of the Brown-tail Moth, 133 FIGURE 44. — Warblers feeding on Young Caterpillars of the Gipsy Moth, . 135 FIGURE 45. — Egg Cluster of the Gipsy Moth, 148 FIGURE 46. — Wilson's Thrush, 157 FIGURE 47. — Wood Thrush, 158 FIGURE 48. — Golden-crowned Kinglet, 101 FIGURE 49.— Chickadee, 164 FIGURE 50. — Eggs of the Tent Caterpillar Moth, 167 FIGURE 51.— Codling Moth, Parent of the Apple Worm, . . . .168 FIGURE 52. — Fall Cankerworm Moth 169 FIGURE 53. — Apple Twig with Eggs of the Cankerworm Moth, . . . 169 FIGURE 54. — AVhite-breasted Nuthatch, 172 FIGURE 55. — Nuthatches, 173 FIGURE 5(5. — Wood-boring Beetle, 175 FIGURE 57. — Red-breasted Nuthatch, 176 FIGURE 58. — Brown Creeper, ......... 177 FIGURE 59. — Brown Thrasher, 180 FIGURE 60. — Catbird, . 182 FIGURE 61.— Northern Yellow-throat, 187 FIGURE 62. — Oven-bird and Nest, 189 FIGURE 63. — Black and White Warbler, 191 FIGURE 64. — Chestnut-sided Warbler, 193 FIGURE 65. — Yellow Warbler, 195 FIGURE 66. — American Redstart, 197 FIGURE 67. — Black -throated Green Warbler liKi FIGURE 68. — Pine Warbler, 201 FIGURE 69.— Myrtle Warbler 202 FIGURE 70.— Woolly Apple Tree Aphis, 202 FIGURE 71. — Red-eyed Vireo, 204 FIGURE 72. — Warbling Vireo, 206 FIGURE 73. — Yellow-throated Vireo, 208 FIGURE 74. — Cedar Bird, 209 FIGURE 75. — Passing the Cherry, 210 FIGURE 76. — Good Work in the Orchard, 211 FIGURE 77. — Scarlet Tanagers and Gipsy Moth Caterpillars, . . .212 FIGURE 78. — Rose-breasted Grosbeak, Male, 216 FIGURE 79. — Rose-breasted Grosbeak, Female 217 FIGURE 80. — Towhee, 219 FIGURE 81. — Purple Finch, 221 FIGURE 82. — American Goldfinch, . ... 222 LIST OF ILLUSTRATIONS. XV11 PACE FIGURE 83. — Baltimore Oriole, 225 FIGURE 84. — Pea Weevil, 226 FIGURE 85. — Tent Caterpillars, Eggs, and Cocoon 220 FIGURE 86. — Click Beetle, 227 FIGURE 87. — Cucumber Beetle and Curculios, 227 FIGURE 88. — Gipsy Moth, Male, 230 FIGURE 89. — Cankerworm, 231 FIGURE 90. — Wood Pewee, 232 FIGURE 91.— Tortricid Moth, 232 FIGURE 92. — Tussock Moth, 232 FIGURE 93. — Phoebe, 233 FIGURE 94. — Moth of Spring Cankerworm, 234 FIGURE 95. — Wood-boring Click Beetle, 234 FIGURE 96. — Brown-tail Moth, .234 FIGURE 97. — Kingbird, 23(5 FIGURE 98. — Cetonia Beetle, 238 FIGURE 99. — May Beetle, . . 238 FIGURE 100. — Hummingbirds about Two Weeks old, 242 FIGURE 101. — Hummingbird feeding Young, 243 FIGURE 102. — Young Hummingbirds nearly fledged, 244 FIGURE 103. — Skull and Tongue of Woodpecker, 246 FIGURE 104. — Spearlike Tongue-tip of Downy Woodpecker, . . . 246 FIGURE 105. — Pine Borer, 247 FIGURE 106. — Pales Weevil, 248 FIGURE 107. — Cocoon of Codling Moth pierced by Woodpecker, . . .251 FIGURE 108. — Apple Tree Borer, 251 FIGURE 109. — Section of Young Tree saved by Downy Woodpecker, . . 253 FIGURE 110. — Downy Woodpecker and his Work, 253 FIGURE 111. — Bark pierced by Downy Woodpecker, .' . . . 254 FIGURE 112. — The Same, showing the Channels made by Bark Beetles, . 254 FIGURE 113. — Pine Top killed by Pine Weevil, 255 FIGURE 114. — Tree ruined for Timber by Pine Weevil, . . . .255 FIGURE 115. — Section of Red Maple tapped for Sap, 257 FIGURE 116. — A Similar Section, 257 FIGURE 117. — Hairy Woodpecker, 258 FIGURE 118. — Flicker, 261 FIGURE 119. — Black-billed Cuckoo 264 FIGURE 120. — Caterpillar of the lo Moth, 264 FIGURE 121. — Spiny Elm Caterpillar, 264 FIGURE 122. — Fall Web Worm, 265 FIGURE 123. — Red-humped Caterpillar, 272 FIGURE 124. — Tree Hoppers, 273 FIGURE 125. — American Robin 282 FIGURE 126. — White Grub, 288 FIGURE 127. — Bluebird, 291 XVlll LIST OF ILLUSTRATIONS. PAGE FIGURE 128. — The Bluebird's Bread 292 FIGURE 129. — Indigo Bunting, Male, 298 FIGURE 130. — Indigo Bunting, Female, 298 FIGURE 131. — Song Sparrow 299 FIGURE 132. — Slate-colored Junco, 301 FIGURE 133. — Field Sparrow, 302 FIGURE 134. — Chipping Sparrow 303 FIGURE 135. — Moth of the Tent Caterpillar 304 FIGURE 136. — Chipping Sparrows hunting Beet Worms 304 FIGURE 137. — Tree Sparrow, 306 FIGURE 138. — White-throated Sparrow, 307 FIGURE 139. — Vesper Sparrow 311 FIGURE 140. — Crow Blackbird, 314 FIGURE 141.— Meadowlark, 317 FIGURE 142. — Red-winged Blackbird, Male, 319 FIGURE 143. — Red-winged Blackbird, Female, 320 FIGURE 144. — Bobolink, Male, and Army Worm, 322 FIGURE 145. — Bobolink, Female, 323 FIGURE 146. — Bob-white 325 FIGURE 147. — The Morning Call, . . 327 FIGURE 148.— Ring-necked Pheasant, 332 FIGURE 149. — Purple Martin, Male, 347 FIGURE 150. — Purple Martin, Female, 348 FIGURE 151. — Salt-marsh Caterpillar, 349 FIGURE 152. — Army Worm, 349 FIGURE 153. — Swamp Sparrow, 350 FIGURE 154. —Italian Sportsman and his Decoy Owl, 359 FIGURE 155. — Blue Jay, 369 FIGURE 156.— Northern Shrike, 370 FIGURE 157. — Seed Catkins of Gray Birch, 374 FIGURE 158. — Fruit of Virginia Juniper or Red Cedar, .... 377 FIGURE 159. — Downy Woodpecker feeding on Suet, 380 FIGURE 160. — The Birds' Christmas Tree, 381 FIGURE 161. — The Birds' Tepee 382 FIGURE 162. — Design for a Sparrow-proof Shelf, 383 FIGURE 163. — Mr. Chapman's Bird Bath, 386 FIGURE 164. — Phoebe's Nest in Box, 388 FIGURE 165. — Sparrow-proof Box, 389 FIGURE 166. — Birch-bark Nesting Box for Chickadees, . . . .391 FIGURE 167. — Shingle Box for Bluebirds 392 FIGURE 168.— Chickadees feeding Young in Observation Box, . . .395 FIGURE 169. —A Martin Box, 396 FIGURE 170. — A Martin Barrel, 397 FIGURE 171. — Zinc Bands to prevent Cats or Squirrels from climbing Trees or Poles t 410 LIST 'OF ILLUSTRATIONS. XIX WOOD DUCK (Colored Plate) , Frontispiece PLATE I. — The American Silkworm Moth, .... faces page 31 PLATE II. — The Destructiveness of the Gipsy Moth, between pages 38 and 39 PLATE III. — Expensive Work of destroying the Eggs of the Gipsy Moth in Woodland Parks, .... between pages 38 and 39 PLATE IV. — Red-eyed Vireo feeding Young, .... faces page 51 PLATE V. — Chickadee, with Insects in its Beak, . . . faces page 54 PLATE VI. — Field or Meadow Mouse, ' faces page 76 PLATE VII. — White-footed or Deer Mouse, .... faces page 76 PLATE VIII. — A Useful Mouse-eating Owl, .... faces page 78 PLATE IX. — Regurgitated Owl Pellets, .... . . faces page 80 PLATE X. — The Same Pellets, dissected, faces page 80 PLATE XI. — Albatrosses on Laysan Island, H. I., . . faces page 82 PLATE XII. — The Cecropia Moth, faces page 109 PLATE XIII. — Web of Tent Caterpillar, which had been attacked by Birds, faces page 118 PLATE XIV. — Various Stages of the Brown-tail Moth, . . faces page 137 PLATE XV. — Various Stages of the Gipsy Moth, . . . faces page 142 PLATE XVI. — General View of Georgetown Woodland, . . faces page 144 PLATE XVII. — Pines, Oaks, and Other Trees, stripped by the Omnivorous Caterpillars of the Gipsy Moth, . . . faces page 144 PLATE XVIII.— Luna Moth, faces page 214 PLATE XIX. — Least Flycatcher on Nest, faces page 229 PLATE XX. — Downy Woodpecker at Nest Hole, . . . faces page 249 PLATE XXI. —Ruffed Grouse on Nest, faces page 267 PLATE XXII. — Ruffed Grouse, One Day old, .... faces page 268 PLATE XXIII. — Ruffed Grouse, Four Months old, . . . faces page 268 PLATE XXIV. — Ruffed Grouse, strutting, .... faces page 270 PLATE XXV. — Robin's Nest in Hollow Tree, .... faces page 283 PLATE XXVI. — Robin on Nest, . faces page 289 PLATE XXVII. — Wren at Nest Hole, faces page 293 PLATE XXVIII. — Chipping Sparrows feeding their Young, . faces page 304 PLATE XXIX. — American Woodcock, . . . . faces page 336 PLATE XXX. — Nighthawk, faces page 341 PLATE XXXI.— Whip-poor-will, faces page 341 PLATE XXXII. — A Swallow Roost, faces page 343 PLATE XXXIII. — Nest Robbers faces page 359 PLATE XXXIV. — Work which drives out the Birds, . . faces page 360 PLATE XXXV. — Cat with Young Robin, faces page 362 PLATE XXXVI. — Barred Owl, faces page 367 PLATE XXXVII. — Blue Jay's Nest in Author's Grove, . . faces page 369 PLATE XXXVIII. — Fruits that are valuable as Bird Food, . faces page 375 PLATE XXXIX. — A Bountiful Repast, faces page 378 PLATE XL. — A Scratching Shed, faces page 378 PLATE XLI. — Chickadee seen through Window, at Author's Home, faces page 380 LIST OF ILLUSTRATIONS. PLATE XLII. — Chickadees on Pork Rind, .... faces page 380 PLATE XLIII. — Eniest Harold Baynes taming a Chickadee, . faces page 381 PLATE XLIV. —Chickadee feeding from the Hand, . . . faces page 381 PLATE XLV. — Chickadees seen on a Frosty Morning, through Author's Window, faces page 382 PLATE XLVI. — A Red-breasted Nuthatch at the Window, . faces page 382 PLATE XLVII. — Bird Houses and Nesting Boxes, . . . faces page 391 PLATE XLVIII. — Inexpensive Nesting Boxes faces page 392 PLATE XLIX. — Chickadee about to enter its Nest, in an Old Varnish Can, faces page 392 PLATE L. — Owl Box, at Author's Home, . . between pages 394 and 395 PLATE LI. — Owl on Nest, between pages 394 and 395 PLATE LII. — Chickadee's Nest, madet>f Cotton, in Box on Author's Window, between pages 400 and 401 PLATE LIII. — Chickadee on Nest, . . . between pages 400 and 401 PLATE LI V. —Mother Chickadee bringing Food to Young, between pages 400 and 401 PLATE LV. — Mother Chickadee cleaning Nest, between pages 400 and 401 PLATE LVI. — Domesticated Canada Goose on Nest, . . faces page 417 USEFUL BIRDS AND THEIR PROTECTION. INTRODUCTORY. THE UTILITY OF BIRDS IN NATURE. There is no subject in the tield of natural science that is of greater interest than the important position that the living bird occupies in the great plan of organic nature. The food relations of birds are so complicated and have such a far-reaching effect upon other forms of life that the mind of man may never be able fully to trace and grasp them. The migrations of birds are so vast and widespread that the movements of many species arc still more or less shrouded in mystery. We do not yet know, for instance, just where certain common birds pass some of the winter months. Some species sweep in their annual flights from Arctic America to the plains of Patagonia, coursing the entire length of the habitable portion of a hemisphere. Many of the birds that summer in northern or temperate America winter in or near the tropics. Some species remain in the colder or temperate regions only long enough to mate, nest, and rear their young, and then start on their long journey toward the equator. The annual earth-wide sweep of the tide of bird life from zone to zone renders the study of the relations of birds to other living forms throughout their range a task of the utmost magnitude. This vast migration at once suggests the question, Of what use in nature is this host of winged creatures that with the changing seasons sweeps over land and sea? Our first concern in answering this question is to deter- mine what particular office or function in the economy of nature birds alone are fitted to perform. The relations USEFUL BIRDS. they may bear to the unnatural and semi-artificial conditions produced by the agriculturist may then be better under- stood. The position occupied by birds among the forces of nature is unique in one respect at least ; their structure fits them to perform the office of a swiftly moving force of police, large bodies of which can be assembled at once to correct disturbances caused by abnormal outbreaks of plant or animal life. This function is well performed. A swarm of locusts appears, and birds of many species congregate to feed upon locusts. An irruption of field mice, lemmings, or gophers occurs, and birds of prey gather to the feast from far and near. This habit of birds is also serviceable in clearing the earth of decaying materials, which otherwise might pollute both air and water. A great slaughter of animals takes place, and Eagles, Vultures, Crows, and other scavengers hasten to tear the flesh from the carcasses. A dead sea monster is cast upon the shore, and sea birds promptly assemble to devour its wasting tissues. The gathering of birds to feed is commonly observed in the flocking of Crows in meadows where grasshoppers or grubs abound, the assembling of Crows and Blackbirds in cornfields, and in the massing of shore birds on flats or marshes where the receding tide exposes their food. A study of the structure and habits of birds shows how well fitted they are to check excessive multiplication of injurious creatures or to remove offensive material. Birds are distinguished from all other animals by their complex, feathered wings, — the organs of perfect flight. The tremendous muscular power exhibited by birds is only such as might be expected in creatures provided with such perfect respiratory, circulatory, and assimilative organs. The strength of birds as compared with that of man is enormously out of proportion to their size ; but it is largely concentrated in the muscles that move the wings, for it is by flight that the bird is enabled to live. Xo other animals have such sustained power of flight or such perfect command over themselves while in the air. Even the bat, which is a most skillful flyer, being remarkably quick in aerial evolutions, UTILITY OF BIRDS IX NATURE. cannot at its best equal the bird. I once saw a bat make seven attempts to catch a moth fluttering along the still sur- face of a moonlit river. A Swallow could have seized it at once with no perceptible effort. Xo creature can equal the soaring of the Eagle or Vulture, or that of the Man-o'-War Bird as it sails on high above the storm ; while the speed that the Hummingbird attains is such that the eye can scarcely follow its most rapid flight. Birds are provided with wings to enable them ( 1 ) to pro- cure food, (2) to escape their enemies, (3) to migrate. All birds have wings, though a few, like the Apteryx, have them only in a rudimentary form. Others, like the Penguin and the Ostrich, have small wings, but cannot raise them- selves in the air. All birds that cannot fly, however, are reminders of a past age, and are not fitted to live on the same earth with man. Such birds are either already extinct or in a fair way to become so, either at the hands of man or at the teeth or claws of the dogs, cats, or other animals that man introduces. Flight alone might save the few that remain. The Great Auk, using its wings only in pursuing its prey under water, disappeared before the onslaught of the white man ; while the Loon, flying both under water and above it, still sur- vives. Birds are pursued by many enemies. Water-fowl fly to the water and dive to escape the Hawk or Eagle, and fly to the land to escape the shark, alligator, or pike. Sparrows fly to the thicket to elude the Hawk, and to the trees to avoid the cat. Evidently this great power of flight was given to birds to enable them not onby to concentrate their forces rapidly at a given point, but also to pursue other flying creatures. Birds can pursue bats, flying squirrels, flying fish, and insects through the air. Bats and insects are their only competitors in flight. Comparatively few insects can escape birds by flight, and this they do mainly by quick dodging and turning. The speed at which birds can fly on occasion has seldom been accurately measured. The maxi- mum flight velocity of certain wild-fowl is said to be ninety miles an hour. Passenger Pigeons killed in the neighbor- USEFUL BIRDS. hood of New York have had in their crops rice probably taken from the fields of the Carolinas or Georgia, which indicates that within six hours they had flown the three or four hundred miles intervening, at about the rate of a mile a minute.1 The rate of flight of a species must be sufficiently rapid to enable it to exist, and so perform its part in the economy of nature. Birds find distant food by the senses of sight and hearing mainly. The sense of smell is not highly developed, but the other perceptive powers are remarkable. The perfection of sight in birds is almost incomprehensible to those who have not studied the organs of vision. The keen eye of the Hawk has become proverbial. The bird's eye is much larger in proportion to the size of its owner than are the eyes of other vertebrates. It is provided with an organ called the pecten, by which, so naturalists believe, the focus can be changed in an instant, so that the bird becomes nearsighted or farsighted at need. Such provision for changing the focus of the eye is indispensable to certain birds in their quick rush upon their prey. Thus the Osprey or Fish Hawk, flying over an arm of the sea, marks its quarry down in the dark water. As the bird plunges swiftly through the air its eye is kept constantly focussed upon the fish, and when within striking distance it can still see clearly its panic-stricken prey. Were a man to descend so suddenly from such a height he would lose sight of the fish before he reached the water. The Flycatcher, sitting erect upon its perch, watch- ing passing insects that are often invisible to the human eye, in like manner utilizes the pecten in the perception, pursuit, and capture of its prey. Most of the smaller birds will see a Hawk in the sky before it becomes visible to the human eye. The Vulture, floating on wide wings in upper air, discerns his chosen food in the valley far below, and as he descends toward it he is seen by others wheeling in the dis- tant sky. As they turn to follow him they also are seen by others soaring at greater distances, who, following, are pur- 1 American Ornithology, Wilson and Bonaparte, Vol. IV, pp. 319, 320. Evi- dently a quotation from Audubon's Ornithological Biography. UTILITY OF BIRDS IN NATURE. sued from afar by others still, until a feathered host con- centers from the sky upon the carrion feast. Birds are lower in the organic scale than the class of mammals which includes man, the four-footed animals, and even the seal and the whale. Birds are closely allied in structure to reptiles. The earliest bird known, the Archa?- opteryx, had teeth, two fingers on each wing, and a long rep- tilian tail adorned with feathers. Still, notwithstanding the comparat i vely 1 o w place which is given by the systematists to birds, their physical organiza- tion excels in some respects that of all otheranimals. They s u r pass all other vertebrate animals in breathing power or lung capacity, as well as in muscular strength and activ- ity. The tempera- Fig. I.— The Archseopteryx, a bird with teeth. Re- tllTe of the blood is stored from the Jurassic epoch. About one-fifth natural size; after Chapman. higher in birds than in other animals, and the circulation is more rapid. To maintain this high temperature, rapid circulation, and great activity, a large amount of food is absolutely necessary. Food is the fuel without which the brightly burning fires of life must grow dim and die away. Birds are, therefore, fitted for their function of aerial police not only by their powers of flight and perception, but also by their enormous capacity for assimilating food. When food is plentiful, birds gorge themselves, accumulating fat in quantities. Shore birds frequently become so fat during the fall migra- 6 USEFUL BIRDS. tions that, when shot, their distended skins burst open when their bodies strike the ground. This accumulation of fatty tissue may aid to tide the birds over a season of scarcity, but the moment they need food they must seek it far and wide, if need be, as they cannot live long with- out it. Birds are not always the ethereal, care-free creatures of the poet's dream. In time of plenty, the joys of flight, of sunshine, of singing, of riding swinging boughs, or toss- ing to and fro on flashing waves, are theirs to the full ; but in times of scarcity, or when rearing their helpless young, their daily lives are often one continued strenuous hunt for food. Food, therefore, is the mainspring of the bird's existence. Love and fear alone are at times stronger than the food craving. The amount of food that birds are capable of consuming renders them doubly useful in case of an emergency. The utility of birds in suppressing outbreaks of other an- imals by massing at threatened points is of no greater value in the plan of nature than is the perennial regulative influ- ence exerted by them individually everywhere as a check on the undue increase of other forms of life. He who studies living birds, other animals, or plants, and the relations which these living organisms bear to one another, will soon learn that the main effort of each plant or animal is to preserve its own life and produce seed or young, and so multiply its kind. He will see, also, that the similar efforts of other organisms by which it is surrounded tend to hold its increase in check. The oak produces many hundreds of acorns ; and were each acorn to develop into a tree, the earth eventually would be full of oaks, for all other trees would be crowded out. But many animals feed on the acorns or the young seedlings ; other trees crowd out the young oaks ; caterpillars feed on the foliage ; other insects feed on the wood and bark, de- stroying many trees ; so, on the average, each oak barely succeeds in producing another to occupy its place. Certain moths deposit hundreds of eggs in a season ; and were each egg to hatch and each insect to come to maturity and go on producing young at the same rate, the entire earth UTILITY OF BIRDS IN NATURE. in a few years would be carpeted with crawling caterpillars, and the moths in flight would cover the earth like a blanket of fog. But under natural conditions the caterpillars that hatch from the eggs of the moth are destroyed by birds, mammals, insects, or other animals, by disease or the action of the elements, so that in the end only one pair of moths succeeds another. If every Robin should produce five young each year, and each Robin should live fifteen years, in time every square foot of land on this continent would be packed with Robins ; but the surplus Robins are killed and eaten by various other birds or by mammals, each striving to maintain itself; so that, eventually, the number of Robins remains about the same. Thus we see that, while birds, insects, other animals, and plants arc constantly striving to increase their numbers, the creatures that feed upon them operate continually to check this undue multiplication . The Hawk preys upon the smaller birds and mammals. The smaller birds and mammals feed on insects, grass, seeds, leaves, and other animal and vege- table food, each virtually endeavoring to gain strength and increase the numbers of its race at the expense of other living organisms. There is a competition among various dissimilar organisms, also, in seeking certain kinds of food. Grazing mammals, such as cattle, sheep, and deer, eat grass. Grass is eaten also by birds, mice, and insects. If any one kind of these creatures should be left without check, and become too numerous, it might consume the food supply of all. In the great struggle for existence, each perpetuating form of life that we call a species is really an expansive force, that can be restrained and kept in its proper place only bjr the similar expansive forces (other species) by which it is surrounded. It is as if the whole field of ani- mal and vegetable life consisted of a series of springs, each exerting a pressure in all directions, and each held in place only by the similar expansion of the springs .surrounding it. This action and reaction of natural forces constitute what is known as the balance of nature. Any serious disturbance of this balance is always fraught with serious consequences. USEFUL BIRDS. All animals and plants are sustained and nourished by air, water, and food. Food supplies the material for growth and development. Its abundance increases the energy and fertility of a species, — its ability to produce young abun- dantly. The study of the food and food habits of birds and other animals is of the utmost importance, for by this study alone we are enabled to trace their life relations to each other, to plants, and to man. Some progress has already been made in this study. We know in a general way the character of the food of some of the common birds of the United States ; but we know so little as yet of the food of the smaller mammals, the reptiles, batrachians, many insects and other lower animals, that it is impossible to tell what may be the ultimate effect of the destruction of any one of these animals by birds. On the other hand, no one can tell what grave and far- reaching results might follow the extermination of a single species of bird ; for it is probable that the food preferences of each species are so distinctive that no other could fill its place. Birds are guided by their natural tastes in selecting their food, unless driven by necessity. Of the food which suits their tastes, that which is most easily taken is usually first selected. In the main, species of similar structure and habits often choose similar food, but each species usually differs from its allies in the selection of some certain favorite insects. Were a species exterminated, however, its place might be taken eventually by the combined action of many species, for nature always operates to restore her disturbed balances. The complexity of the food relations existing between birds and other organisms may be indicated hypothetically by a brief illustration. The Eagles, larger Hawks, and Owls feed to some extent on Crows, and probably the nocturnal, tree-climbing, nest-haunting raccoon also robs them of eggs and young ; otherwise, they seem to have very few natural enemies to check their increase. Crows feed on so many different forms of animal and vegetable life that they are nearly always able to find suitable food ; therefore they are common and widely distributed. UTILITY OF BIRDS IN NATURE. The general fitness of the Crow is admitted by all. Un- doubtedly it has a useful work to perform in the world ; but a careful study of its food habits shows so many apparently harmful traits that it may well leave the investigator in some doubt as to the Crow's value in the general plan. Crows rob the nests of Robins, eating very many eggs and young birds ; they therefore constitute a serious check on the in- crease of this species. Robins feed largely on common black beetles, called ground beetles (Carabidne), which run about on the ground, hiding under stones and other rubbish. As these beetles are not quick to fly by day, and are easily caught, they form a consid- erable part of the food of many ground- frequenting birds. But ground beetles feed, to a greater or less extent, on other insects. The question then arises, Is not the Robin doing harm in killing ground beetles, and does it not merit the destruc- tion of its eggs and young by the Crow? Fig. 2._Ground If the Robin's habit of eating these beetles beetle, is harmful, is not the Crow rendering a service by destroy- ing a bird so apparently destructive as the Robin ? Perhaps, if there were too many Robins, they might eat too many ground beetles, and thus become the indirect cause of the destruction of much vegetation, by saving the lives of the caterpillars and other harmful insects that the ground beetles, had they been left to themselves, might have destroyed.1 Many ground beetles that are eaten by the Robin feed much on vegetable matter.2 This makes these beetles doubly useful in one respect, for they can maintain their numbers 1 These questions can be answered only by one having a thorough knowledge of the food of our ground beetles, — a knowledge which no living man yet pos- sesses ; but enough has been learned to throwr some light on their food habits. Insects that feed promiscuously on other insects are generally classed as bene- ficial in so far as they take insect food, even though they may destroy some so-called useful insects ; for, as the so-called injurious insects far outnumber the useful ones, it is considered safe to regard the habit of feeding on insects a bene- ficial one. 2 The ground beetles of the genus Calosoma and those of some closely allied genera are believed to feed entirely on animal food, as their structure fits them for that alone. They feed ravenously upon both beneficial and injurious insects, and when too numerous they devour one another. These are not the beetles that are generally eaten by the Robin, however, but rather by the Crow. 10 USEFUL BIRDS. when insect food is not plentiful, and so be ready to check any increase of insects which may occur. On the other hand, if they become too numerous, they may create serious disturbances by destroying grass, grain, or fruit. I have witnessed attacks made by certain of these beetles on grain and strawberries; and were they not held in check by birds, it is probable that they would soon become serious pests. Their destruction by Robins and other birds tends to keep these beetles within those normal bounds where they will do most good and least harm ; while the check kept by the Crow on the increase of the Robin may pre- vent the latter from destroying too many ground beetles. If certain low-feeding caterpillars became so numerous as to be injurious, ground beetles and Robins would feed largely on them. The caterpillars would then largely take the place of the beetles in the Robin's food. The beetles, therefore, would increase in numbers, and the force of both bird and beetle would be exerted to reduce the caterpillars to their normal limit. This accomplished, the Robin would again attack the ground beetles, and thus tend to reduce them to normal numbers. Let us now go back to the beginning of our chain of destruction. The Eagles, Hawks, Owls, and raccoons may indirectly allow an increase in the number of Robins by preventing too great an increase of the Crow. But Hawks and Owls also prey on the Robin, and, by dividing their attention between Robin and Crow, assist in keeping both birds to their normal numbers. Whenever Crows became rare, Robins as a consequence would become very numerous, were it not that the Hawks also eat Robins. (Hawks and Owls eat also some species of insects that are eaten by both Robin and Crow.) There are compensations in the apparently destructive career of the Crow. An omnivorous bird, it seems inclined to turn its attention to any food which is plentiful and readily obtained. It is a great feeder on May beetles (miscalled "June bugs"), the larvae of which, known as white grubs, burrowing in the ground, sometimes devastate grass lands and also injure the roots of many plants, including trees. UTILITY OF BIRDS IN NATURE. 11 The Crow is also a destroyer of cutworms. These are the young or larvae of such noctuid moths or "millers" as are commonly seen fluttering from the grass by any one who disturbs them by walking in the fields. Robins also feed largely on cutworms, as well as on the white Fig. 3. — Cutworm. grub of the May beetle. When these insects are few in number, a part of the usual food supply of both Robin and (Vow is cut off. This being the case, the hungry Crows are likely to destroy more young Robins and other young birds than usual, in order to make up the supply °f anmial food for themselves and their ravenous nestlings. In a few years this Fig. 4.-xoctuid moth. WQuld decrease perceptibly the number of Robins and other small birds, and would be likely in turn to allow an increase of May beetles and cutworms. As these insects became more plentiful, the Crows would naturally turn again to them, paying less attention to the young of Robins and other birds for the time, and allowing them to increase once more, until their multiplication put a check on the insects, when the Crows would of necessity again raid the Robins „ The Blue Jay may be taken as another instance of this means of preserving the balance of nature. Hawks and Owls kill Blue Jays, Crows destroy their eggs and young ; thus the Jays are kept in check. Jays are omnivorous feeders. They eat the eggs and young of other birds, par- ticularly those of Warblers, Titmice, and Vireos, — birds which are active caterpillar hunters. But Jays are also extremely efficient caterpillar hunters. Thus the Jays compensate in some measure for their destruction of cat- erpillar-eating birds, by themselves destroying the cater- pillars which they unconsciously have allowed to increase in numbers by destroying these birds. Like the Crow, they virtually kill the young of the smaller birds, and eat them, that they (the Jays) may eventually have more in- sect food for their own young. When this object has been attained, the Jays may again, perhaps, allow an increase of 12 USEFUL BIRDS. the smaller birds, the survivors of which they have unwit- tingly furnished with more insect food, thus making con- ditions favorable for the increase of the smaller birds. These oscillations or alternate expansions and contractions in the numbers of birds or insects are usually so slight as to escape common observation. It is only in those cases where they are carried to extremes that they result disas- trously. Under nature the checks on the increase of birds are essential, else they would increase in numbers until their food supply had become exhausted, when they would starve, and other consequences even more grave and much more complex would then follow. While these examples of the way in which the balance of nature is preserved may be regarded as somewhat hypothet- ical, they probably approximate what actually takes place, although the feeding habits of birds undoubtedly produce far more complicated results than are here outlined. It is a law of nature that the destroyer is also the protector. Birds of prey save the species on which they prey from overproduction and consequent starvation. They also serve such species in at least two other ways: (1) the more powerful bird enemies of a certain bird usually prey upon some of its weaker enemies ; (2) these powerful birds also check the propagation of weakness, disease, or unfitness, by killing off the weaker or most unfit individuals among the species on which they prey, for these are most easily captured and killed. TTe have seen already that Jays, which are enemies of the smaller birds, are preyed upon by the more powerful Crows, Hawks, and Owls. These latter also destroy skunks, weasels, squirrels, mice, and snakes, all of which are also enemies of the smaller birds. Xo doubt these animals would be much more injurious to the smaller birds were they with- out these wholesome feathered checks on their increase. In a state of nature, albino birds or those that are rendered conspicuous to their enemies by any unusual mark or color are soon captured by some bird of prey, and seldom live to perpetuate their unfitness. UTILITY OF BIRDS IN NATURE. 13 Aii experience with domestic Pigeons, related to me by Mr. AVilliam Brewster, will serve as proof of this state- ment. He had kept a flock of twenty-five or thirty Pigeons in confinement at Cambridge for many years. Under such protective domestication the individuals of the flock had assumed a variety of shades and colors. There were blue Doves, white Doves, and many pied individuals varying between the two extremes. He removed the flock to his farm in Concord, where they were at liberty to roam at will during the day. Here they were attacked by Hawks, and in five years' time the white and pied birds were practically all weeded out, and the flock consisted of blue rock Doves alone. The preservation of birds by the weeding out of sickly or wounded individuals did not escape the notice of Prof. Spencer F. Baird, who wrote : — It has now been conclusively shown, I think, that Hawks perform an important function in maintaining in good condition the stock of game birds, by capturing the weak and sickly, and thus preventing reproduc- tion from unhealthy parents. One of the most plausible hypotheses explanatory of the occasional outbreaks of disease amongst the grouse of Scotland has been the extermination of these correctives, the disease being most virulent where the game keepers were most active in de- stroving what they considered vermin.1 It appears, then, that under natural conditions the birds of prey destroy merely the unfit and surplus individuals of the species on which they prey, and do not, on the whole, reduce their numbers below what the land will support. The relations of birds to insects merit the most profound thought and study. Xo one can study intelligently the effect produced by birds upon insect life unless he first acquires some knowledge of the habits and transformations of insects, and is able to distinguish the so-called injurious and benefi- cial groups. A brief explanation here of the transformations of insects will better enable the reader to understand the terms used later in describing them as food for birds. 1 Letter from Prof. Spencer F. Baird to Mr. J. W. Shorton. published in the Journal of the Cincinnati Society of Natural History, 1882, Vol. V, pp. 69, 70. 14 USEFUL BIRDS. Most insects emerge from eggs, which ordinarily are de- posited and fixed by the female parent in positions where the young will find suitable food in readiness i — jjLgp for them when the eggs hatch. Some insects f ^yfj^ bring forth their young alive, but this is an Fig. 5. -Fiy and exception to the general rule. The young its larva. insect that emerges from the egg is called the larva (plural, larvae). Some larva; are provided with short legs or feet, others have none that can be seen ; but all are without wings, and move about mainly by crawling. Their principal occupation is to feed. Some species, such as the Fig. 6. — Chestnut beetle or weevil, enlarged, a, larva or grub, enlarged; b, young larva in chestnut, natural size. leaf-eating caterpillars, rest during certain parts of the day ; others, like the larvae of flesh-feeding flies, apparently feed constantly. As all eat enormously and grow rapidly, they are capable, when in great numbers, of doing much harm or good, as the case may be. The larvae of flies are commonly called maggots or slugs, those of beetles are called grubs, and those of butterflies and moths are called caterpillars. Much of the injury done by insect pests is attributable to the larVJB ; although Figt 7- ~~ CaterPillar8> the larvae of butterflies. some, like certain leaf-eating beetles, are injurious in the per- fect form. During the rapid growth of a larva the skin is shed several times, until full size is reached, when the next transformation is effected, and the larva becomes a pupa or chrysalis. Among the butterflies and moths (Lepidoptera) the insect often spins from within itself a thread, which it weaves into a case or cocoon which encloses it while in the UTILITY OF BIRDS IX NATURE. 15 pupal form. This stage it passes without food and while fixed to some object. The pupre or nymphs of some other insects, however, move about freely, as is the case with locusts, grasshoppers, and like insects (Orthoptera).1 The pupa finally throws oft' its outer shell, and emerges a full}7 developed or perfect insect or imago with wings ; although some insects which, like some birds, have lost the use of their wings, never fly.2 After the union of the sexes the female insect eventually deposits the eggS for the FI*. 8.-P«P.-eorehryB«lld8. next generation. Thus we have four forms which insects assume : (1) the egg, (2) the larva, (3) the pupa or nymph, (4) the imago or perfect winged insect. Practically all living animals of appreciable size, as well as most plants that are visible to the unaided eye, furnish food for certain insects. Other insects feed on dead animals, dead trees, or other decaying animal or vegetable matter. A certain larva has been known even to tunnel into marble. Those insects which feed on live vegetation or living animals are capable of doing great harm if they increase unduly ; while those that feed only on dead animals or dead and decaying vegetation can do only good in nature, although they may be injurious to man by destroying hides, furs, pre- served meats, or clothing. It is difficult to perceive the usefulness of those so-called injurious species which feed on the different parts of plants ; still, the larvse that eat the buds, the caterpillars that feed 1 In the Orthoptera the transformations are imperfect; the larvae of grass- hoppers, for example, are provided with well-developed legs, and much resemble the imago or perfect insect, but are without wings. In this stage they are usually called nymphs. As they approach maturity they enter what is virtually an im- perfect pupal stage, but retain their shape, limbs, and activity. They now show rudimentary wings, but it is only at maturity that they are capable of flight. 2 The Thysanura, or lowest order of insects, including " bristle tails," " spring tails," " fish moths," and the like, never become winged or develop any trace of wings. 16 USEFUL BIRDS. on the leaves, the borers that attack the twigs, and the insects that destroy the blossom or the fruit, all probably, when in normal numbers, exert a useful influence by a healthful and necessary pruning, which at least does no injury to the tree. It is only when these insects increase abnormally in numbers that they seriously injure or destroy many vigorous plants and trees. During such outbreaks birds often come to the rescue of the trees. Birds feed very largely on such insects, and by keeping down their excessive multiplication perform a great service in the economy of nature. Here the keen senses and remarkable flight powers pos- sessed by birds aid them in concentrating their forces imme- diately when and where they are most needed. The rule will bear repetition here that, other things being equal, birds will take such suitable food as is most plentiful and most easily obtained. This is especially true of the feeding of birds on insects, although there are some insects that are so protected by prickly spines or acrid secretions that few birds will eat them. Such are the caterpillars of the mourning- cloak butterfly (Euvanessa anttopa) and the imagoes of the Colorado potato beetle (Doryphora decemlineata) . Birds are quick to assemble wherever in the woods the disappearing foliage denotes the presence of great numbers of destructive caterpillars, or where patches of dead and dying grasses indicate that grubs are destroying the grass roots on meadow or prairie. Birds flock to such places to feed on the easily procured insects, and so take a prominent part in repressing such insect outbreaks. This is so well known as to be worthy of only passing mention here, were it not to inquire whether the birds that assemble in such locali- ties do not neglect their normal and special work of hold- ing in check certain species elsewhere. If the Robin, for example, which feeds normally on such ground-frequenting insects as white grubs, cutworms, grasshoppers, March flies, and ground beetles, goes to the woods to feed on caterpillars, as is sometimes the case, does it neglect to devour any one of the insects on which it usually feeds, and so give this insect a chance to increase? If so, it would be merely sup- pressing one outbreak and permitting another. But birds UTILITY OF BIRDS IN NATURE. 17 do not neglect any one element of their ordinary food in such cases. They neglect them all, both animal and vegetal, for the time being, and turn to the now abundant insect food that is more readily accessible. This I have observed in studying outbreaks of canker worms, and Professor Forbes records a similar experience with birds feeding on canker- worms.1 This apparently agrees with the experience of the forest authorities in Bavaria during the great and destructive out- break of the nun moth (Liparis monacha) which occurred there from 1889 to 1891. The flight of Starlings collected in one locality alone was credibly estimated at ten thousand, all busily feeding on the caterpillars, pupa?, and moths. Enormous flights of Titmice and Finches were similarly engaged. The attraction of Starlings to such centers be- came so great that market gardeners at a distance felt their absence seriously.2 Evidently in such cases the birds, changing their usual fare entirely for the time being, remove their restraining influence from both useful and injurious insects, leaving one to exert its full force as a check on the other, until the urgent business of the serious outbreak of grasshoppers, caterpillars, or some other pest has been attended to ; then the birds return to their usual haunts and food, and exert the same repressive influence as before. Although the insects which are potentially injurious are greatly in the majority, there are many species which per- form a very apparent useful function in nature. Such are the bees and some of their allies of the order Hymenop- tera, — insects which travel from flower to flower in search of sweets, and, becoming loaded with pollen, fertilize the blossoms, rendering the trees fruitful. Other insects seem especially adapted to hold the potentially injurious species in check. Some which are called predaceous insects attack other insects and devour them, as do the ground beetles 1 The Regulative Action of Birds upon Insect Oscillations, by S. A. Forbes. Bulletin No. 6, Illinois State Laboratory of Natural History, 1883, p. 21. 2 Protection of Woodlands, by Herman Fiirst. English edition, translated by John Nisbet, 1893, p. 126. 18 USEFUL BI11DS. (Carabidse) already mentioned, the tiger beetles (Cicinde- lidge), the ladybirds (Coccinellidse), and many of the true bugs. Such insects are often miscalled parasites, but they do not merit this misnomer. The predaceous beetles are the wolves, lions, and tigers of the insect world. They hunt down their prey, pouncing upon it and killing it when found . Often these insects are so ravenous that they con- tent themselves with drawing the life blood and other juices from their quarry, leaving the rest to be devoured by ants Fig. 9. -Predaceous beetle; the lion or other scavengers. While beetle or caterpillar hunter. the larger predaceous beetles attack many of the larger insects, smaller species, such as ladybirds, assail other minute insects, such as the aphids or plant lice. The bugs are the vampires of the insect world. Armed with a strong proboscis, the bug pursues its prey, pierces it and sucks its juices, leaving it drained and lifeless ; but the so-called parasitic insects feed in a manner entirely different. Certain families of the Hymenoptera and Diptera contain parasitic genera and species. These insects range in size from that of a large wasp down to that of a small midge. Most of them have the habit of depositing their eggs on, or in, the bodies of other living insects. Each ichneumon fly is armed with a long ^"1\\ Xx/) ovipositor, which operates somewhat like a hollow sting, by means of which it is en- abled to pierce the skin of the larvfe of other insects and pass its eggs through the 1% . 11. — Hymenop- puncture, depositing: them in the body tis- terous parasite. J imago, natural size sues beneath the skin. These eggs soon hatch, and the young larvae, emerging from IO.-ITB- daceous beetle; a tiger among insects. UTILITY OF BIRDS IN NATURE. lit them, feed first upon the fatty portions of the caterpillar in which they find themselves. The caterpillar thus unwill- ingly becomes their host, furnishing them with food and lodging from and within its own substance. When they have made their growth, and it is nearly time for them to pupate, they attack the vitals of their host, killing it, and then pupating either within or upon its body. Soon they emerge as perfect flies, the females again seeking other caterpillars as hosts for their progeny. Often these parasites do not kill their ^ . . Fig. 12. — Host caterpillar, with host Until it has SOUght Some place cocoons of the parasite upon its of safety and pupated. Every cat- erpillar or pupa thus destroyed nourishes one or many of these parasites, to emerge and attack surviving caterpillars. The parasites themselves, however, are often attacked in the same manner by a secondary parasite, which destroys them precisely as they destroyed the caterpillar. The larger pri- mary parasites may deposit a single egg or only a few in each caterpillar, while the smaller ones may deposit the entire brood in the body of a single caterpillar. Birds eat both predaceous and parasitic insects. We have seen that they eat ground beetles, many of which are pro- vided with acrid secretions that are supposed to render them disagreeable and offensive to the taste, and so give them a certain immunity from their ene- mies. Evidently, however, it takes a very strong flavor to take the edge off a bird's appetite, for birds eat bugs ; and any child who has ever eaten berries from the bushes, and inadvertently put one of the berry-eating bugs in his mouth, knows how disgusting their Fig. is.-Tiger flavor is. There are some useful insects that fTrm aUe8a1eUn ai'6 Seld°m eaten b7 birds- The VerJ Smallest by very few are beneath the notice of most birds. The tiger beetles and some of the useful flies are so quick that birds find it difficult to catch them. Wasps and bees, though eaten by some birds, can protect themselves very well with their stings. Probably, however, 20 USEFUL BIRDS. birds eat a great many caterpillars containing parasites, though birds will reject any caterpillars that show signs of weakness or disease. The question then arises, Is the bird doing harm by eating caterpillars or other larvae containing parasites? The bird certainly ends the destructive career of the larva at once. The parasites would have ended it eventually ; but had it been left to them, it might have gone on for some time in its destructive career, doing as much injury as if not parasitized ; the parasite merely destroys it in time to prevent it from propagating its kind. So far the evidence is in favor of the bird. The question remains, however, whether the bird and its young would eventually destroy more caterpillars than would the progeny of the parasites had they not been eaten by the bird. This question evidently is unanswerable. Birds act as the primary check on the increase of destructive insects ; parasitic insects are the secondary check provided by nature to operate in con- junction with the birds, or to supplement the regulative action of birds where the number of birds is insufficient to check the increase of insects. Birds sometimes kill many of the imagoes of parasitic insects in flight, where such insects are numerous. At first sight, this would seem to condemn the birds ; on further study, it seems probable that this is often a harmless habit. Where parasitic insects are found in great numbers, it is probable that the birds destroy mainly the surplus flies, which otherwise, failing to find hosts for their young, would merely live out their time and die without issue were they not killed by the birds. Such harm as birds do in killing primary parasites may be offset by the killing of secondary parasites by birds, for this acts as a protection to the pri- mary parasites. Certain predaceous bugs feed not only on insects but also on vegetable food. They also attack other predaceous or useful insects. Birds, by preventing their undue increase, may prevent excessive injury to both useful plants and insects. All reasoning from known premises leads to one conclusion UTILITY OF BIRDS IX NATURE. 21 regarding the utility of birds in nature. It may be stated confidently, as a general rule (not without exceptions, how- ever), that, in the natural order of things, the species that is kept within normal numbers without great fluctuations, whether beast, bird, reptile, batrachian, or insect, will serve a useful purpose ; while the species that increases undulv will devour too much animal or vegetable food, and, by dis- turbing the balance of nature, become a pest. It is the abnormal increase of the gipsy and brown-tail moths and the " English " Sparrow in this Commonwealth that has been responsible for the injury they have done. If birds do well their part in holding in check native insects, small mammals, reptiles, batrachians, and other forms of life on which they feed, they have fulfilled their mission, even if in doing this they destroy some individuals of some species that are classed as useful. This, then, is the chief mission of the birds in organic nature : to fill their peculiar place in preserving the balance of nature's forces, — a place that cannot be filled by any other class of animals. In much of the foregoing it appears that the birds are engaged in checking the increase of insects and other ani- mals, exerting that check constantly when and where it is most needed. The vegetable food of birds is perhaps of less importance, but here also they exercise a restraining influence by destroying seed as well as in other ways. They also exert a beneficial influence by planting seed. Birds also play a great part in the distribution of plants, the upbuilding and fertilizing of barren islands, and a minor part in the distribution of insects. Wild-fowl and Herons may sometimes carry small seeds for many miles embedded in particles of mud which adhere to their feet. AVhere this mud drops from their feet, the seeds may sprout and grow. The fruit-eating birds are among the most valuable of tree planters, distributing the seeds far and wide. Certain insects which cling to the feet or feathers of birds are sometimes distributed in this way. The part taken bv birds in forest planting and fertilizing barren lands will be taken up far- 22 USEFUL BIRDS. ther on, in connection with their relations to forestry and agriculture. Taken all in all, the relations of birds to the natural world are beneficent. Evidently birds are an essential part of nature's great plan. This being the case, they must be serviceable to man also, for man, the animal, is a mere inte- gral part of nature. VALUE OF BIRDS TO MAN. 23 CHAPTER I. THE VALUE OF BIRDS TO MAN. Birds are classed as useful or injurious only as they affect man or his property. In an uninhabited country birds can- not be ranked as beneficial or harmful, good or bad, for there is no agriculture. There the earth, untroubled by man, brings forth vegetation, and animals after their kind. Nature's laws, working in harmony, need none of man's assistance. The condition of the earth before man appeared is typified in the Biblical account of the garden of Eden. PRIMITIVE MAN'S RELATIONS TO NATURE. TTe have seen that under such natural conditions all birds are essential to the general welfare, each filling well its appointed place. But trouble and discord come to Eden. Man appears, and becomes the dominant power on the earth. He sets up artificial standards of his own, and bids nature conform to them. He is constantly at war with nature. He classes wild creatures as injurious, provided they either in- jure his person, or cause him loss by destroying or harming any of his property or any of the wild animals or plants which he regards as useful. He considers all wild creatures beneficial that contribute directly or indirectly to his own welfare, or to the increase in value of his property. He is often in error, even from his own standpoint, in thus classifying animals, owing to an insufficient knowledge of their food habits ; but the principle holds good, and stand- ards change with the acquisition of knowledge. Man in a savage state lived, like other animals, in harmony with nature. At first he practised no agriculture and domes- ticated no animals. He made war mainly upon his fellows and the larger beasts of prey, killing them in self-defence or for food. (It seems probable that primitive man was a cannibal.) Otherwise, he fed altogether upon the wild 24 USEFUL BIRDS. products of forest, meadow, sea, lake, or river. The only creatures that he then could regard as injurious were those that attacked his own person or the persons of his family. Any irruption of animals, such as vast herds of deer, bison, or antelopes, hordes of monkeys or rats, flights of birds or locusts, outbreaks of caterpillars or other creatures, was about as likely to benefit as to injure him. For instance, when locusts became so numerous as to destroy a part or all of his vegetable food, he followed the example of other creatures, and, by feeding for the time on the superabundant locusts, exerted an influence toward restoring the balance of nature. (There are still savage tribes in various parts of the earth that eat monkeys, rats, locusts, grubs, or caterpillars. ) In times of plenty primitive man feasted, as did other animals ; and in times of want, like them, he starved. But usually he was indifferent to any ordinary injury done to the animal or vegetable life around him, as he owned no prop- erty, and could readily move his camp from a region of want to one of plenty. CHANGED RELATIONS PRODUCED BY AGRICULTURE. With the beginning of agricultural practice, however, all this was changed. When man began to domesticate animals, he faced immediately a host of enemies. Wild animals and birds attacked his cattle, horses, sheep, goats, and hogs, or devoured their young. Tormenting insects stampeded his herds, or carried disease and death among them. His poul- try were decimated by scores of rapacious animals. When he began to plant seed and raise grain, both his growing and his garnered crops were attacked by a host of ene- mies ; for noAV he had begun to disturb nature's balance, and nature asserted herself in the effort to resume her inter- rupted sway. This was the beginning of a war with nature which will never cease so long as man inhabits the earth ; for the agriculturist does not work altogether with nature, but largely against her. Most of the animal and vegetable forms that he produces are at variance with those produced by nature, and must be continually fostered and protected VALUE OF BIRDS TO MAN. 25 if they are to maintain their artificial characters and excel- lences. Left to themselves, the various breeds of domesti- cated Pigeons would all disappear, merging into the original Dove from whence they sprang. All artificial varieties of animals, plants, and fruits would, under nature, become, in time, like the wild stock from which they originated. Hence man must wage war continually against organic nature, in order to maintain his artificial standards against her inex- orable laws. The beginning of agriculture was the first step toward civilization as well, for the necessity of remaining near his crops to guard them from their enemies compelled the prim- itive farmer to erect a permanent habitation. This took his attention from war and the chase, for much of his time was now occupied in tilling the soil and caring for his crops and animals. The slow growth of primitive agriculture in the older civilized countries gave time for a gradual adjustment of the forces of nature to the new conditions established and main- tained by man. The gradual or partial clearing away of the forests occupied centuries. The planting of crops merely kept pace with the natural increase of population, while the destruction of wild animals and their replacement with domesticated species were similarly gradual and progressive. So, although in the older countries agriculture suffered much from the pests to which its operations must always give rise, it remained for the peopling of newer lands to develop the greatest difficulties in the path of the farmer. Agriculture produces an increased food supply. The population increases correspondingly, and the overflow seeks new fields. In these new lands, of which America is the most prominent example, the conditions of civilization and agriculture have replaced with marked rapidity those of savagery and primeval nature. MAN AT WAR WITH NATURE IN THE NEW WORLD. All the greater changes that were effected gradually by man in Europe, where, in the course of centuries, civiliza- tion was slowly evolved from savagery, — all these stupcn- 26 USEFUL BIRDS. dous changes, — were wrought here in a few years by the tide of immigration from the eastern world. In many communities only a score of years elapsed be- tween the subjugation of the unbroken wilderness and the building of a farming town or growing city. In Massachu- setts the settlers cut down the forest ; killed off most of the larger mammals and birds ; imported and bred horses, cattle, and poultry ; cleared and planted much of the arable land ; introduced many new plants ; and rapidly changed the ap- pearance of the country from that of a Avilderness to that of an agricultural colony. Thirty years after the landing of the Pilgrim Fathers at Plymouth, eastern Massachusetts was well colonized ; with several growing seaport towns ; with prosperous farms, fertile fields and green pastures ; with flocks and herds grazing on many a hill, where the wild Indian and the red deer formerly roamed. All these changes, taking place so rapidly, produced great disturbances in the economy of nature. As the wolf, lynx, puma, and bear were killed or driven away, the smaller animals on which they had formerly preyed increased in numbers and attacked the crops. Crows, Blackbirds, and many insects, finding in the grain crops new sources of food supply, swarmed upon them and multiplied exceedingly. Birds and insects attacked the cultivated fruit. Thousands of acres of cleared meadow land were producing crops of grass. Given this increased food supply, locusts and other grass-eating insects increased in numbers. The settlers, meantime, were destroying the Heath Hen, Quail, Plover, Blackbirds, Hawks, and Crows, the natural enemies of the locusts. As time went on, many new plants were introduced from Europe, and in some cases insect pests unwittingly were brought with them. The two succeeding centuries brought about a tremendous immigration from Europe. As settlement extended into the western States, great fields of wheat and other grains were established, covering the plains in some instances as far as the eye could see. Hundreds of thousands of acres were planted to orchards and vineyards ; great areas near the cities were devoted to garden vegetables ; north and south, corn, wheat, and cotton clothed the land. VALUE OF BIRDS TO MAX. 27 THE INCREASE OF INSECT PESTS. Insects introduced from foreign lands found here a para- dise, in which to multiply, in the great areas planted year after year to the same crops. Having escaped their native enemies, they had come to an abundance of food in a land where many of the insect-eating birds and other insectivo- rous animals had been much reduced in number by the unwise policy of the settlers. Hence the rate of increase of im- ported insect pests in America has far exceeded that of the same insects in their native lands. Certain native American insects, finding their food plants destroyed by the cutting down of the forests or the break- ing up of the prairie, turned their attention to the crops of the farmer, and became important pests. Such are the cutworms (Xoctuidae) ; their name is legion. Others, having been reached in their desert or mountain homes by the advance of civilization, left their natural food for the more succulent plants raised by man, and so spread over the country from farm Fig. 14 _cllim.h to farm. Such are the chinch bug and the bue. much en- Colorado potato beetle, which, as civilization advanced westward, met it and spread toward the east. The enormous losses which have occurred in the United States from the destruction of growing crops by insects must seem incredible to those who do not realize how vast are the numbers of insects, how stupendous their power of multi- plication, how insatiable their voracity. When we fully appreciate the consuming powers of insects, they assume an economic importance greater than can be accorded to the ravening beast of prey. Let us consider briefly, then, the potency for evil that lies hidden in the tiny but innumerable eggs of injurious insects, which require only the warmth of the summer sun to release from confinement their destructive energies. 28 USEFUL BIRDS. THE NUMBER OF INSECTS. The number of insect species is greater by far than that of the species of all other living creatures combined. More than three hundred thousand have been described. There are many thousands of undescribed species in museums. Dr. Lintner, the late distinguished State entomologist of New York, considered it not improbable that there were a million species of insects. The number of individual insects is beyond human comprehension or computation. Dr. Lintner says that he saw at a glance, in a small extent of roadway near Albany, more individuals of a single species of snow flea, as computed by him, than there are human beings on the entire face of the earth. A small cherry tree ten feet in height was found by Dr. Fitch to be infested with an aphid or plant louse. He estimated (first counting the number of these insects on a leaf, the number of leaves on a branch and the number of branches on the tree) that there were twelve million plant lice on the tree ; and this was only one tree of a row similarly infested. To give the reader an approximate idea of the number of insects on the tree, it was stated that, were a man to count them singly and as rapidly as he could speak, it would require eleven months' labor at ten hours a day to complete the enumeration.1 In the days of their abundance the Rocky Mountain locusts in flight filled the air and hid the sun. From the high peaks of the Sierra Nevada they were seen filling the valleys below and the air above as far as a powerful field glass could bring the insects within focus. The chinch bug in countless mil- lions infests the grain fields over towns, counties, and States. The army worm moves at times in solid masses, destroying the crops in its path. THE REPRODUCTIVE CAPACITY OF INSECTS. Insects are enormously productive, and, were the progeny of one pair allowed to reproduce without check, they would cover, in time, the entire habitable earth. 1 Our Insect Enemies, by J. A. Lintner. Sixteenth Annual Report, New Jersey State Board of Agriculture, 1888-89, pp. 293, 294. VALUE OF BIRDS TO MAN. 29 The rapidity of propagation shown by some insects is per- haps without a parallel in the animal world. In order to give some idea of the powers of multiplication of the Colorado potato beetle, the Canadian Entomologist states that all its transformations are effected in fifty days ; so that the result of a single pair, if allowed to increase Avithout molestation, would in one season amount to over sixty millions.1 beetle- Speaking of the great power of multiplication shown by plant lice or aphids, Dr. Lintner says that Professor Rilev, in his studies of the hop vine aphis (PJiorodon humuti), has observed thirteen generations of the species in the year. Xow, if we assume the average number of young produced by each female to be one hundred, and that every individual attains maturity and produces its full complement of young (which, however, never occurs in nature), the number of the twelfth brood alone (not counting those of all of the preceding broods of the same year) would be 10,000,000,000,000,000,000,000 (ten sextillions) of indi- viduals. Where, as in this instance, figures fail to convey any adequate conception of numbers, let us take space and the velocity of light as measures. Were this brood mar- shalled in line with ten individuals to a linear inch touching one another, the procession would extend to the sun (a space which light traverses in eight minutes) , and beyond it to the nearest fixed star (traversed by light only in six years), and still onward in space beyond the most distant star that the strongest telescope may bring to our view, — to a point so inconceivably remote that light could only reach us from it in twenty-five hundred years. The remotest approach to such unchecked multiplication on the part of this insect might paralyze the hop-growing industry in one season. While the aphids may represent the extreme of fecundity, there are thousands of insect species the unchecked increase of any one of which would soon overrun a continent. Mr. A. H. Kirkland has com- 1 Report of Townend Glover, entomologist, in Annual Report of the United States Commissioner of Agriculture, 1871, p. 74. 30 USEFUL BIRDS. puted that the unrestricted increase of the gipsy moth would be so great that the progeny of one pair would be numerous enough in eight years to devour all the foliage in the United States. THE VORACITY OF INSECTS. Many insects are remarkably destructive because of the enormous amount of food which they must consume to grow rapidly to maturity. Many caterpillars daily eat twice their weight of leaves ; which is as if an ox were to devour, every twenty-four hours, three-quarters of a ton of grass.1 This voracity and rapid growth may be shown by the statement of a few facts. A certain flesh-feeding larva will consume in twenty-four hours two hundred times its original weight ; a parallel to which, in the human race, would be an infant consuming, in the first day of its existence, fifteen hundred pounds of food. There are vegetable feeders, caterpillars, which during their progress to maturity, within thirty days, increase in size ten thousand times. To equal this remarkable growth, a man at his maturity would have to weigh forty tons. In view of such statements, need we wonder that the insect world is so destructive and so potent a power for harm ? 2 Mr. Leopold Trouvelot, who introduced the gipsy moth into this country, was occupied for some time in raising silkworms in Medford, Mass. He made a special study of the American silkworm ( Telea polyphemus) . Regarding its food and growth he says : — It is astonishing how rapidly the larva grows, and one who has had no experience in the matter could hardly believe what an amount of food is devoured by these little creatures. One experiment which I made can give some idea of it. When the young worm hatches out, it 1 A probable cause for this voracity in the case of herbivorous larvae is that the stomachs do not have the power of dissolving the vegetable matter received into them, but merely of extracting from it a juice. This is proved both by their excrement, which consists of coiled-up and hardened particles of leaf, which, when put into water, expand like tea, and by the great proportion which the excrement bears to the quantity of food consumed (Kirby and Spence's Ento- mology, p. 259) . 2 Our Insect Enemies, by J. A. Lintner. Sixteenth Annual Report, New Jersey State Board of Agriculture, 1888-89, p. 295. VALUE OF BIRDS TO MAN. 31 weighs one-twentieth of a grain ; when ten days old, it weighs one-half a grain, or ten times the original weight; when twenty days old, it weighs three grains, or sixty times the original weight ; when thirty days old, it weighs thirty-one grains, or six hundred and twenty times the original weight ; when forty days old, it weighs ninety grains, or eight- een hundred times the original weight ; and when fifty-six days old, it weighs two hundred and seven grains, or forty-one hundred and forty times the original weight. When a worm is thirty days old, it will have consumed about ninety grains of food ; but when fifty-six days old it is fully grown, and has consumed not less than one hundred and twenty oak leaves, weighing three-fourths of a pound; besides this, it has drunk not less than one- half an ounce of water. So the food taken by a single silkworm in fifty-six days equals in weight eighty-six thousand times the primitive weight of the worm. Of this, about one-fourth of a pound becomes excrementitious matter, two hundred and seven grains are assimilated, and over five ounces have evaporated. What a destruction of leaves this single species of insect could make, if only a one-hundredth part of the eggs laid came to maturity ! A few years would be sufficient for the propagation of a number large enough to devour all the leaves of our forests.1 When we consider the dangers arising from the immense numbers, fecundity and voracity of insects, the fact that insects new to cultivated crops are continually appearing becomes a source of grave apprehension. THE GREAT LOSS TO AMERICAN AGRICULTURE BY INSECT RAVAGES. Economic entomologists, who are constantly increasing our knowledge regarding insect pests, discover every year new species attacking important crops or trees. Dr. Lintner made a list of the insects injuring apple trees in the United States, which was published in the appendix to his first report as entomologist of New York State. It contained one hundred and seventy-six species, while large though lesser numbers have been found on the plum, pear, peach, and cherry. The study of the insect enemies of the forest trees of the United States has not yet progressed far enough to deter- 1 The American Silkworm, by L. Trouvelot. American Naturalist, Vol. I, p. 85. 32 USEFUL BIRDS. mine with approximate accuracy the numbers of insects that infest our forest trees. The forest insects of some sections of Europe have been studied longer, and the numbers of in- sects found injuring the principal trees are surprising. Kal- tenbach enumerates five hundred and thirty-seven species of insects, from central Europe, injurious to the oak ; to the elm he ascribes one hundred and seven. The poplars feed two hundred and sixty-four species ; the willows harbor three hundred and ninety-six ; the birches, two hundred and seventy ; the alder, one hundred and nineteen ; the beech, one hundred and fifty-four ; the hazel, ninety-seven ; and the hornbeam, eighty-eight. Among the coniferous trees, the pines, larch, spruce, and fir, collectively, are attacked by two hundred and ninety-nine species of insects.1 Dr. Packard enumerated over four hundred species which prey upon our oaks, and believed it not improbable that ultimately the number of species found on the oaks of the United States would be from six hundred to eight hundred or even one thousand.2 The list of insects which feed on grasses, cereals, field and garden crops is very large and constantly growing, for it is continually receiving accessions from both native and foreign sources. The destructiveness of some of these insects is so enormous and widespread that the financial loss resulting therefrom amounts to a heavy annual tax on the people of the United States. Hence since the first settlement of the country the amount of this annual tax has been increasing. In 1854 the loss in New York State alone from the ravages of the insignificant wheat midge (Diplosis tritici), as esti- mated by the secretary of the New York State Agricultural Society, was fifteen million dollars. Whole fields of wheat were left ungarnered. So destructive was this insect in the following years as to stop the raising of white wheat, and reduce the value of all wheat lands forty per cent.3 1 Die Pflanzenfeinde aus der Klasse der Insekten. 2 Insects Injurious to Forest and Shade Trees, by A. S. Packard. Fifth Report of the United States Entomological Commission, 1886-90, p. 48. 3 Report on the Rocky Mountain Locust, by A. S. Packard. Ninth Annual Report of the United States Geological and Geographical Survey of the Territo- ries, 1875, p. 709. VALUE OF BIRDS TO MAN. 33 Iii 1850, in Livingston County, New York, two thousand acres on flats which would have yielded thirty bushels of wheat per acre were not harvested because of the destruc- tive work of this insect.1 Dr. C. L. Marlatt, of the Bureau of Entomology of the United States Department of Agriculture, who has made careful calculations of the loss still occasioned by the Hessian fly ( Cecido- myia destructor} in the wheat-growing States, says that in comparatively few years does it cause a loss of less than ten per cent, of the crop. On the val- uation of the crop of 1904 this would amount to over fifty million dollars. Dr. Marlatt states that in the year 1900 the loss in the wheat-growing States Fig ia. — Hessian tiy. from this tiny mido-e undoubtedly ap- About Uvelve time8 nat- 0 > ural size. proached one hundred million dollars.2 The chinch bug (UUssus leucoptei*us) attacks many staple crops, and has been a seriously destructive pest in the Mississippi valley States for many years, where it injures chiefly wheat and corn. Dr. Shimer in his notes on this insect estimates the loss caused by it in the Mississippi valley in 1804 at one hundred million dollars,3 while Dr. Riley gives the loss in that year as seventy-three million dollars in Illinois alone.4 These are only a few of the extreme losses. Year after year the injuries from the depredations of this bug have amounted to many millions of dollars. The cotton worm (Alabama argillacea) has been known as a serious pest to the cotton crop for more than a century. The average loss in the cotton States from this caterpillar 1 First Annual Report on the Injurious and Other Insects of the State of New York, by J. A. Lintner, 1882, p. 6. 2 The Annual Loss occasioned by Destructive Insects in the United States, by C. L. Marlatt. Yearbook, United States Department of Agriculture, 190i, p. 467. 3 Report on the Rocky Mountain Locust, by A. S. Packard. Ninth Annual Report of the United States Geological and Geographical Survey of the Territories, 1875, p. 697. 4 First Annual Report on the Injurious and Other Insects of the State of New York, by J. A. Lintner, 1882, p. 7. 34 USEFUL BIRDS. for fourteen years following the civil war was estimated at fifteen million dollars per year.1 In 1873 the injury to the cotton crop reached twenty-five million dollars, and later averaged from twenty-five million to fifty million dollars annually.2 Now a new enemy, the Mexican cotton boll weevil (Anthonomus grandis}, threatens equal destruction. The Rocky Mountain locust (Melanoplus spretus} began to destroy crops as soon as the country it inhabits was set- tled, and is still injurious. From time to time its enormous flights have traversed a great part of the Mississippi valley. It reached a maximum of destructiveness from 1874 to 1877, when the total loss from its ravages in Kansas, Nebraska, Iowa, Missouri, and neighboring States, including injury by depression of business and general ruin, was estimated at two hundred million dollars.3 In those years this devastating insect swept over the Missis- sippi valley. Wherever its vast flights alighted or its young developed, they destroyed nearly all vegetation, ruining great numbers of farmers, causing a famine in the land, and driving many people to emigration. This was an extreme calamity, such as is not likely to occur again. A still larger but more widely distributed loss from insect pests, however, is still borne annually by the American people. Dr. Lintner states his belief that the annual and periodical injury caused by cutworms in the United States is greater than that caused by the Rocky Mountain locust. In September, 1868, Prof. D. B. Walsh, editor of the American Entomologist, estimated that the country then suffered to the amount of three hundred million dollars annually from the depredations of noxious insects. By the census of 1875 the agricultural products of this country were valued at two billion, five hundred million dollars. Of this 1 Fourth Report of the United States Entomological Commission, by C. V. Riley, 1885, p. 3. 2 Report on the Rocky Mountain Locust, by A. S. Packard. Ninth Annual Report of the United States Geological and Geographical Survey of the Terri- tories, 1875, p. 591. 3 Report on the Rocky Mountain Locust, by Riley, Packard, and Thomas. First Report of the United States Entomological Commission, 1877, pp. 115-122. VALUE OF BIRDS TO MAN. 35 amount, Dr. Packard says that in all probability we annually lose over two hundred million dollars from the attacks of injurious insects. In the report of the Department of Agri- culture for 1884 (p. 324) the losses occasioned by insects injurious to agriculture in the United States, it is said, are variously estimated at from three hundred million to four hundred million dollars annually. Prof. C. V. Riley, in response to a letter of inquiry, in 1890, stated that no very recent estimate of the injury done by insects had been made; but that he had estimated, some time previously, that the injury done to crops in the United States by insects exceeded three hundred million dollars annually. Dr. James Fletcher, in his annual address as president of the Society of Economic Entomologists, in Washington, in 1891, stated that the agricultural products of the United States were then estimated at about three billion, eight hun- dred million dollars. It was believed that a sum equal to about one-tenth of this amount, or three hundred and eighty million dollars, was lost annually through the ravages of injurious insects. It is evident that, in spite of the improved methods of fighting insects, the aggregate loss from this source increases in proportion as the land under cultivation increases. The most recent estimate of the loss occasioned by insect injury in the United States which has come to my notice is that of Dr. C. L. Marlatt, who by careful estimates approxi- mates the percentage of loss to cereal products, hay, cotton, tobacco, truck crops, sugars, fruits, forests, miscellaneous crops, animal products, and products in storage. Dr. Marlatt attributes an annual loss of eighty million dollars to the corn crop alone, and approximates the loss to the wheat crop at one hundred million dollars each year. The injury to the hay crop is estimated at five hundred and thirty thousand dollars, while the codling moth alone is be- lieved to injure fruit crops to the amount of twenty million dollars annually. This statement, based on the value of farm products as given in the reports of the Bureau of Statistics of the United 36 USEFUL BIRDS. States Department of Agriculture for 1904, gives the loss from insect depredations for that year as seven hundred and ninety-five million, one hundred thousand dollars ; and this is believed to be a conservative estimate of the tax now im- posed by injurious insects on the people of the United States, without reckoning the millions of dollars that are expended annually in labor and insecticides in the fight against insects.1 LOSSES BY INSECT RAVAGES IN MASSACHUSETTS. The proportion of this loss that Massachusetts is called upon to bear has not received the attention that it deserves. Some figures, however, may be given. In 1861 the army worm (probably Heliophila unipuncta) swept eastern Mas- sachusetts. The damage done to crops, according to Dr. Packard, exceeded five hundred thousand dollars.2 We have no estimates of the loss occasioned by more recent invasions of this insect. Prof. C. H. Fernald 3 estimates that an amount of cranberries equal to one-third the possible crop of the Cape Cod region is annually destroyed by insects. Thus a sum not less than five hundred thousand dollars is yearly lost to the people of that region. In 1890 Dr. Henry H. Goodell, president of the Massa- chusetts Agricultural College, stated that it was costing the farmers of the United States two million dollars, and the farmers of Massachusetts eighty thousand dollars, each year, to hold the Colorado potato beetle in check by the use of Paris green.4 In 1901 Hon. J. W. Stockwell, then secretary of the Massachusetts State Board of Agriculture, asked me to esti- mate the annual loss to the Commonwealth through the rav- ages of insect pests. My estimate, which seemed to me at 1 The Annual Loss occasioned by Destructive Insects in the United States, by C. L. Marlatt. Yearbook, United States Department of Agriculture, 1904, p. 464. 2 First Report on Injurious and Beneficial Insects of Massachusetts, by A. S. Packard. Annual Report of the Massachusetts State Board of Agriculture, 1870, Part I, p. 353. 3 In Bulletin No. 19 of the Hatch Experiment Station of the Massachusetts Agricultural College, Professor Fernald gives statistics of the cranberry crop, and evidence from which his estimate is made. 4 Agricultural Education, by H. H. Goodell. Sixth Annual Report of the Rhode Island State Board of Agriculture, 1891, p. 186. VALUE OF BIRDS TO MAN. 37 the time a most safe and conservative one, was three million, one hundred thousand dollars. Mr. Stockwell also asked Dr. II. T. Fernald and Mr. A. H. Kirkland, both expert economic entomologists, to make, independently, a similar estimate. Their replies follow, showing how they made up their figures. These gentlemen had every facility for obtain- ing knowledge of insect injury in the Commonwealth. It will be seen that their approximations considerably exceeded my own. Dr. H. T. Fernald says : l — Years ago a number of experts, figuring independently, came to the conclusion that for farm, market-garden and orchard crops the loss by the attacks of insects in an average year would represent one-tenth of the value of the crop, or about two million, six hundred thousand dollars for Massachusetts. Recently, however, prominent entomologists have expressed the opinion that this per cent, is too low. Three factors have caused this change : first, the concentration of crops of the same kind into large contiguous acreage ; second, the introduction of over one hundred pests from foreign countries, which have been here long enough to make their presence seriously felt ; and third, the great reduction in the number of insectivorous birds. I believe it will be entirely safe to take fifteen per cent, of the crop valuation of Massachusetts, and that you will be sufficiently conserva- tive in using that amount as representing part of the damage. I have never seen a cherry tree killed by plant lice, yet I have often seen lice so abundant on cherry trees as to much reduce the crop, which is true of a large proportion of our crops ; and it is loss of this kind which is covered by the fifteen per cent, estimate, . . . but how are we to place a money value on the defoliation of an elm tree unless it be repeated year after year until the tree dies ? I would be inclined to add, to the fifteen per cent, estimate already given, two hundred and fifty thousand dollars for labor, apparatus, poison, etc., used in the fight against insects, and another two hundred and fifty thousand dollars to cover damage actually done, but which cannot be reduced to figures, making a total yearly damage of four million, four hundred thousand dollars for Massachusetts. Mr. Kirkland says : The best figures available for estimating the loss caused by pests in this State are those of the 1895 census. From the report of this census I have taken figures giving the value of certain crops notably attacked 1 Report of Secretary J. \V. Stockwell, Annual Report of the Massachusetts State Board of Agriculture, 1901, pp. xiii, xiv. 38 USEFUL BIRDS. by insects, and have estimated in each case the probable average yearly reduction in value caused by these pests. The data used are given be- low. I have tried to make a conservative estimate in the case of each product, since, to have any value, such an estimate should fall below rather than above the actual amount. Even then the figures afford material for serious reflection on the part of agriculturists. PRODUCT. Value of Product. Percentage damaged by Insects. Amount of Damage. $1,749,070 10 $174 907 00 Hothouse and hotbed products, . 97,227 182906 5 15 4,861 35 27 435 90 o 780 314 20 556 06l> 80 Cereal products, Fruits, berries, and nuts, 1,104!578 2,850,585 12,491,090 5 25 10 55,228 90 712,6477 <)06 60 Tobacco, Property : — Fruit trees, vines, etc., . 544,968 7,924,878 10 10 54,496 80 792,487 80 Totals, $36,115,149 - $4,905,142 40 Assuming the accuracy of these data, and exclusive of the damage wrought by insects to our woodlands, street trees, parks, etc., we have in round figures five million dollars as the average annual damage from insects to agricultural products and property in this Commonwealth. While the cost of insect injury is enormous, the expense of fighting injurious insects in the attempt to protect crops and trees from their ravages is proportionately great. In recent years Massachusetts has had, and is still having, a costly experience in attempting to control or suppress an imported insect. The gipsy moth (.Porfketria dispar^, a well-known pest of European countries, was introduced into Medford, Mass., by Mr. Leopold Trouvelot, in 1868 or 1869. Twenty years later the moths had increased in numbers to such an extent that they were destroying the trees and shrubbery in that section of Medford where they were first liberated. They swarmed over the houses of the inhabitants, invaded their gardens, and became such a public nuisance that in 1890 the Legislature appropriated fifty thousand dollars for their extermination. It was learned within the next two years that the moths had spread over thirty towns. The State VALUE OF BIRDS TO MAN. 39 Board of Agriculture was given charge of the work in 1891, and over one million dollars were expended within the next ten years in the attempt to exterminate the insect. As at the expiration of that time all the larger moth colonies had been destroyed, the Legislature, deeming further expendi- ture unwise, gave up the work, despite the protest of the Board of Agriculture, and its prediction that a speedy rise of the moth would follow the cessation of concerted effort against it. This prediction has been abundantly fulfilled, and the policy of the Board has been fully justified. Dr. Marlatt, who in 1904 visited the region infested by the moth, reported to the Bureau of Entomology at AVashington that the people of the infested district were then fighting the insect at a greater annual cost than that formerly assumed by the State. Since the State gave up the work, a single citizen, Gen. Samuel C. Lawrence of Medford, has expended over seventy-five thousand dollars to protect the trees and plants on his estate. Finally, in 1905 the Legislature was obliged to renew the fight, and appropriate the sum of three hundred thousand dollars for work against both this insect and another im- ported pest, — the brown-tail moth (Euproclis chrysorrkea) , which had been introduced into Somerville some time in the latter part of the nineteenth centmy. The State has also been obliged to call on municipalities and individuals to assist in the work of suppressing these moths, at an annual expense to those concerned which ex- ceeds all previous yearly expenditures for this purpose. These insects have gained a much larger territory than ever before, and thousands of acres of woodland have been attacked by them during the present }'ear (1905), and many pine and other trees have been killed. The gipsy moth has been found in Rhode Island, Connect- icut, and New Hampshire, and the brown-tail moth is also spreading into other States. The prospect now seems to be that our protective expenses against these two insects, as well as the injury done by them, will increase constantly : and that other States also will be put to similar expense, with no prospect of permanent relief 40 USEFUL BIRDS. save by such checks as may come, in time, through natural causes. In view of the dangers threatened by insect increase and voracity, how fortunate it is for the human race that so many counter-checks are provided against the multiplication of these destructive creatures. If we could increase by so much as one per cent, the efficiency of the natural enemies of insects, a large proportion of the loss occasioned by insect injury might be saved. Hence the importance of the study of these natural enemies, among which birds hold a high place. THE CAPACITY OF BIRDS FOR DESTROYING PESTS. When we realize the losses that insects are capable of in- flicting, we see at once that birds, in their capacity of insect destroyers, continually operate to prevent the destruction of some of our most important industries. If birds are present in sufficient numbers, they will prevent the excessive increase of any kind of a pest which they will eat. The number of birds required to accomplish this highly desirable end need not be very large in comparison with the number of insects ; for each bird can devour an incredible number of insects, and the young birds in the nests require more of this food, in proportion to their size, than do their parents. The Digestion of Birds. The digestive organs of birds are so constructed and equipped that they can both contain and dispose of a very large quantity of food. The stomachs of many species quickly separate the indigestible portions of the food from the digestible parts, and the former are thrown out of the mouth, thus relieving the stomach of much worthless mate- rial, and enabling the bird immediately to consume more food. The alimentary canal (including the crop, gullet or oasophagus, the first division of the stomach or proventricu- lus, the gizzard, gigerium or second division of the stomach, the intestine and the cloaca) consists of a tube reaching from mouth to anus, conveying the food. The nutritious qualities of the food are drawn off by the lacteals as it passes ; the VALUE OF BIRDS TO MAN. 41 refuse is voided. This is digestion. The food is often manip- ulated, crushed, or divided by the beak. It then receives saliva from the mouth, and passes through the pharynx into either the gullet (a muscular and membranous tube) or crop (a pouch) , as the case may be, organs capable of great distention, and connecting with the first division of the stomach. Here, then, is the first receptacle of the food. Birds of prey, Herons and some other large birds sometimes fill the gullet to the very mouth, while awaiting the digestion of the food in a stomach already full. The Pelicans have also another great receptacle or pouch, ex- ternal and beneath the beak, where a store of food can be carried. Many of the smaller birds also are able, after filling the stomach, to stow away a still larger supply of food in the gullet. The stomach is large, and usually capable, bv distention, of contain- ing a considerable quantity of food. The food passes from the gullet or the crop to Fig i7._Aiimen- the proventriculus or glandular portion of the stomach. This is where the process of digestion begins. Mixed with salivary, ingluvial, and proventricular secretions, the food next passes to the gizzard or muscular division of the stomach, where the food grist is ground fine. Among seed-eating birds the heavy, powerful muscles of this portion of the stomach are, with the rough, calloused stomach lining, assisted in their work by sand and gravel which are swallowed. This mineral matter takes the place of teeth in grinding the food. In vegetable-feeding birds the intestine is very long and much coiled, while the digestive tract is generally shorter and simpler in the flesh-eating and fish-eating species. All the processes of digestion are remarkably rapid. The sali- vary glands, the liver and the pancreas all quickly pour their copious secretions into the alimentary canal ; the food is chylified after impregnation with the biliary and pancreatic tary canal of Blue- bird, reduced; after Audubon. a, b, gul- let or oesophagus; c, proventriculus; d, gizzard; e, f, h, in- testine; », cloaca. 42 USEFUL BIRDS. fluids ; the chyle is drawn off by the lacteals, and the residue is excreted. The vigor, perfection, and rapidity of these processes in insect-eating birds are such as might be expected among animals of such high temperature, perfect respiration, and rapid circulation. The various dilations of the digestive tract serve well their purpose of enabling the bird to consume the large amount of food necessary for its maintenance. Digestion is partic- ularly rapid in the growing young of most birds, for they require not only food sufficient to sustain life, but an extra supply as well to enable them to increase daily in size, and to grow, in a few days, those wonderful appendages that we call feathers. The Growth of Young Birds. The growth of many birds from the egg to the hour of flight requires less time than is needed by some insects to reach the flight stage. It is most significant that young birds can develop as rapidly as can many in- sects on which they feed, for it shows how readily, under favorable conditions, the increase of birds might keep proportion- ate pace with that of insects. Weed and Dearborn, in their interesting manual, en- titled "Birds in their Relations to ^n," naked, blind, and help- state that they watched four young Sons: less, with mouth open o , , ' ,. , , for food. Reduced; Sparrows that were out of the nest on the after iierrk-k. eighth day. Mr. Owen records another instance where a brood of young Song Sparrows were fledged and left the nest within the same period.1 Probably this is exceptional ; but many of the smaller birds rear their young from the egg to the first flight within two or three weeks. Mr. Owen found that on one particular day this family of five young Song Sparrows increased in average weight forty-eight per cent., while the smallest bird gained fifty-five per cent, in a single day. The young of perching birds (Insessores) come into the world tiny creatures, either naked or covered Avith down, 1 A Family of Nestlings, by D. E. Owen. The Auk, Vol. XVI, No. 3, July, 1899, pp. 221-225. VALUE OF BIRDS TO MAN. 43 blind, and helpless ; yet in a few days, or at most a few weeks, they have grown to nearly the size of their parents, and produced a perfect suit of feathers, including the strong quills of wings and tail. In a few weeks more they are able to begin a journey of hun- dreds or thousands of miles over land and sea, in their first migration. The young of prsecocial birds, such as Grouse, S n i p e and Plover, are able to run about soon after they are hatched. Young GrOUSe learn tO fly pig. 19. — Young Cedar Birds, less than three when quite small, but they weeks old' develop more slowly than do the young of the smaller altricial birds. It is difficult, therefore, to determine the amount of food they require, as they leave the nest at once and wander from place to place, picking up their own food. The young of the altricial perching birds, however, re- main quite helpless in the nest until nearly fledged, affording an Fig. 2O. — Young Grouse, just from the egg, but able excellent Opportunity towalk- for the investigator to determine the amount and character of their food, and to watch the progress of their development. We can learn how much food such young birds require by feeding them in confinement. 44 USEFUL BIRDS. The Amount of Food required by Young Birds. It seems necessary to the health and comfort of the nest- ling bird that its stomach be filled with food during most of the day. Nearly half a century ago Prof. D. Treadwell called attention to the great food requirements of the young Robin. TAVO young birds from the nest were selected for his experiment. One soon died of starvation, as the supply of food given them at first was much too small. The food of the re- maining bird was gradually Fig. 21. - A young Woodcock, ready to increased from day to day, leave the nest. J *] until on the seventh day it was given thirty-one angleworms ; but there was no increase in its Aveight until, on the fourteenth day, it received sixty- eight worms, Aveighing, all told, thirty-four pennyweights.1 Later the same bird ate nearly one-half its own Aveight of beef in a day. A young man eating at this rate Avould consume about seventy pounds of beefsteak daily. The Robin even when full grown required one-third of its weight of beef (J.iily Fig. 22. — Young Robins, in the nest. Mr. Charles "W. Nash fed a young Robin from fifty to seventy cutworms and earthworms a day for fifteen days. While experimenting to see hoAV many cutworms the bird would eat in a day, he fed it five and one-half ounces of this food, or one hundred and sixty-five cutworms. As the Robin Aveighed but three ounces in the morning, it must 1 The Food of Young Robins, by D. Treadwell. Proceedings of the Boston Society of Natural History, Vol. VI, pp. 396-399. VALUE OF BIRDS TO MAN. 45 have eaten, during the day, a quantity one and five-sixths times its own weight.1 Three voung liobins, about ten days old, fed by their parents, were watched by Weed and Dearborn. By an in- genious method of weighing and calculating, the observers arrived at the conclusion that apparently there was eaten a daily amount equal to more than half the birds' own weight.2 Mr. Daniel E. Owen kept a young Hermit Thrush, which ate regularly half its weight of raw steak daily, and would, he says, probably have eaten as much more had it been fed oftener.3 In 1895 two young Crows were kept and fed by Messrs. A. H. Kirkland and H. A. Ballou, then my assistants, from August 7 to September 2, when one bird was killed by accident. The survivor was kept until September 14, when it wras killed to determine some points regarding digestion. These birds were confined in a large cage or enclosure in an insectarv, and were also allowed access during the dav to an enclosed yard, which they reached through the window. This gave them considerable exercise. A careful record was kept of most of their food. Never- theless, they occasionally picked up some sprouted grain in the yard, and probably a few insects that could not be re- corded or weighed. For this reason the quantity of the daily food supply recorded is probably, on the average, too low, or, in other words, on the safe side. Some of the smaller animals fed to the birds (toads, frogs, and salamanders) were not always weighed, but they were measured and could be compared with others of known weight, so that the weight was approximated closely. The birds were well grown when they were first received ; but the amount of food at first given them probably was not sufficient for their needs, as their weight did not increase, although they were fed a variety of both vegetal and animal 1 Birds of Ontario in their Relation to Agriculture, by Charles W. Nash. Toronto, Department of Agriculture, 1898, p. 22. 2 Birds in their Relations to Man, by Clarence M. Weed and Ned Dearborn, 1903, p. (35. 3 Notes on a Captive Hermit Thrush, by Daniel E. Owen. The Auk, Vol. XIV, No. 1, January, 1897, pp. 1-8. 46 USEFUL BIRDS. food. They were designated by number. On August 20 No. 1 weighed seventeen ounces and No. 2 fourteen ounces. That day the two birds had two ounces of tomato, five ounces of sweet corn, fifty grasshoppers (about three-fourths of an ounce), — in all, nearly eight ounces, — and they also had free access to some grain in the yard. As their weight remained the same, they were fed the next day one-half ounce of tomato, one ounce of corn, one ounce of muskmeloii, five ounces of meat, one ounce of beets, and fifty grasshoppers, — in all, fully nine ounces. An apple also was eaten to some extent, and there was still some grain in the yard. Nevertheless, each bird lost about an ounce in weight that day. They were fed at about the same rate the following day, and, as they were losing weight, they were given on the 23d two ounces of melon, all the grasshoppers that could be collected near their place of confinement, four frogs, a sala- mander, two ounces of tomato, and five ounces of corn. On this diet the Crows regained some of the weight they had lost, Aveighing the next morning sixteen and one-half and thirteen and one-half ounces respectively. On the 24th they were fed more than twelve ounces, and the larger bird lost half an ounce and the smaller gained about the same weight. On the 25th they received over seventeen ounces of food, the smaller bird gaining another half ounce and the larger bird remaining the same. No. 1 now weighed sixteen ounces and No. 2 fourteen and one-half ounces. The next day, with twelve ounces of food, the smaller bird lost one-half ounce and the larger bird made no gain. Evidently Avhere any gain was made by one bird on this amount of food the bird either got more than its share, or found some food in the yard. On August 28 nearly twenty-seven ounces of food were given. This was all vegetal matter except thirty grass- hoppers (one-third of an ounce). It was all eaten, and apparently all needed, for neither bird increased in weight, No. 1 losing half an ounce. It seemed evident throughout the experiment that the birds required much animal food, and when vegetal food alone was given, a larger amount VALUE OF BIRDS TO MAN. 47 than usual was needed. The next day about twenty ounces of food, containing a large proportion of animal matter, were given ; and on August 30 the larger bird had again regained its weight of seventeen ounces, while the other held its own. So far the experiment seemed to show that when they were fed from twenty to twenty-five ounces of a ration containing both animal and vegetable food the birds held their own or gained slightly ; but if fed less than twenty ounces of this ration, one or both of the birds fell off in weight. After the death of one bird the other and all its food were weighed daily. All opportunity to secure scattered grain or other food than that weighed was denied. The greatest weight reached by this bird was eighteen and one-half ounces on September 13, on which date it was fed as much corn, cucumber, and tomato as it cared to eat, also a frog, two toads, twenty-seven grasshoppers, thirty-one borers, eight beetles, and eighteen crickets. The record of the twelve days during which this bird was alone seems to show that less than eight ounces of food daily was hardly sufficient for its needs, as on a less amount it tended to lose in weight, while when the amount was increased to ten ounces or more the tendency toward a daily gain in weight was marked. When the quantity of food given these birds was largely reduced in any one day, there was a corresponding reduction in their weight. On September 13 the larger Crow was given only two ounces of tomato, fifty-six grasshoppers, twelve crickets, and a little grain, — in all, not much over three ounces of food. The next morning it had lost one and one-half ounces in weight. The fact that a bird, while in confinement and without a great amount of exercise, could lose nearly ten per cent, of its weight in a single day, even when fed a quantit}r of food equal to about one-sixth its weight, shows how dependent birds are upon their supply of food. If this single experiment can be regarded as conclusive, we may assume that young Crows, when fledged, absolutely require a daily amount of food equal to about one-half their own weight ; and it is evident that they will consume much more than this to their own advantage if they can get it. It 48 USEFUL BIRDS. seems quite probable that a young bird at liberty, depend- ing largely on its own exertions to procure food, and thus exercising more than in confinement, would require still more food to repair the consequent extra waste of the tissues. Others have made similar experiments with Crows in con- finement. Samuels says that he has kept specimens in cap- tivity, and has proved by observation that at least eight ounces of such food as frogs, fish, etc., are eaten daily by our common Crow. He says that a Crow can live on a very limited allowance, but believes eight ounces to be a reasonable amount. He leaves us to infer that he is speaking of adult Crows, which undoubtedly require less food than their grow- ing young.1 Weed and Dearborn kept a wounded adult Crow in a small box, twelve by thirteen by twenty inches. In these cramped quarters, where the bird could hardly stretch its wings, it ate fish for three days in succession at the rate of four and eighty-three hundredths ounces per day, — more than a quarter of its own weight, or about half what our young Crows ordinarily required.2 Probably the amount of food eaten by this captive bears about the same proportion to the quantity eaten by a vigor- ous Crow at liberty that the food taken by a prisoner in solitary confinement, or that consumed by a sedentary clerk, bears to the amount required by a strong man at hard labor, or by a prize-fighter in training. The amount of food taken by young birds could not be disposed of by such limited powers of digestion as are given to other animals. What a wonderful contrast is presented between the quantity of food required by the hot-blooded, quick-pulsing, active bird, and that needed by the cold- blooded vertebrates. Many reptiles can live for months without food. Even some of the mammals do not eat at all during their hibernation. 1 Birds of New England, by Edward A. Samuels, 1870, p. 359. 2 Birds in their Relations to Man, by Clarence M. Weed and Ned Dearborn, 1903, p. 61. VALUE OF BIRDS TO MAN. 49 The Time required for Assimilation of Food. If we assume that the stomach and oesophagus of a young Crow can contain but an ounce of food, then the bird would be required to digest from eight to twelve meals a day, according to its appetite and opportunity. The question at once arises, How can any digestive system complete such a task? Experiments were made with our young Crows to determine the time required for digestion. The birds were kept without food until the stomach and intestines were empty . They were then fed insects' eggs, in the belief that some parts of the shells would escape the grind- ing processes of the stomach and be voided in the excreta. Sub- sequent occurrences justified this belief. Ten experiments of this kind were made with the two birds. From the time Avhen the birds began to feed until the time when the first eggshells were dropped in the excreta there elapsed, on the average, one hour, twenty-nine minutes and forty-five seconds. The shortest time was forty-eight minutes, and the longest one hour and fifty-four minutes. This, it should be noted, was not merely the time that the food remained in the stomach, but the full interval occupied in digesting and assimilating it, for within this period at least a part of the food had passed the entire digestive tract. In most cases all evidence of the food used in the experi- ment had disappeared from the excreta in from two to two and one-half hours. If we contrast this with the slower digestion of man, we shall see how birds readily dispose of more meals each day than a man is capable of digesting. To learn how long food remains in a Crow's stomach, it would be necessary to kill a large number of Crows, each being killed at a longer or shorter interval after it had filled its empty Fig. 23. — Young Crows, well fledsred. 50 USEFUL BIRDS. stomach. I am not aware that this has ever been done, but have no doubt that the majority of the farmers of Massachu- setts would not object to the destruction of a considerable number of young Crows for this purpose, or any other. The Crow which was accidentally killed had fed freely upon grasshoppers for twenty minutes, and died ten minutes after the close of the feeding period. An examination of the alimentary canal showed the stomach to be quite full, but less than fifty per cent, of its contents, consisting mainly of the hard parts of wings, thoraces, and legs, was in a con- dition to be recognized. The strongly chitinized pronota and hind femora of the grasshoppers offered the most resist- ance to the digestive processes. The other fifty per cent, of the stomach contents had been so finely divided, in the very brief time that it had been in that receptacle, that one would hardly have cared to express a positive opinion as to its identity. This condition of stomach contents is not unusual. In examining the contents of birds' stomachs we often find more than fifty per cent, of the food so finely comminuted and mixed as to be practically unrecognizable. The presence of insects in a bird's stomach is sometimes made known by a mere mandible or some other recognizable por- tion, which has resisted for a time the grinding of this remark- able digestive organ. It is significant, however, that, in the thirty minutes intervening between the beginning of a feeding period and death, the stomach had thoroughly pulverized half the food eaten. This experiment was carried further with the second Crow. On September 14 the only food materials given the bird were six crickets and eleven grasshoppers. These it ate within four minutes, and thirty minutes later it was killed. Only about twenty-five per cent, of the stomach contents was recognizable, but this is not all. The alimentary canal was thirty-six inches in length, and in the intestine at a distance of from twelve to fifteen inches from the stomach, and again at twenty-five to twenty-eight inches from that organ , were found a few small pieces of the fore wings of the grasshoppers. As the bird had not been fed since 4 o'clock in the afternoon of the previous day, these remains probably PLATE IV. — Red-eyed Vireo feeding Young. (Photograph by C. A. Eeed.) VALUE OF BIRDS TO MAN. 51 came from the insects fed to it not more than thirty-three minutes before it was killed. In summing up the results, Mr. Kirkland says : "I think, from what we have seen, that we might expect to find the gizzard empty in from one to one and one-half hours." Such an experiment should be carried further, but enough was learned to show that the stomach of a young Crow prob- ably can be filled with food and emptied of the digested material from eight to twelve times a day during the long days of midsummer, when their appetites are at their best. Digestion in some of the smaller birds is doubtless even more rapid, for they are enabled to dispose of a still larger amount of food in proportion to their size. Mr. Owen in- forms us that the time required for a blueberry to traverse the digestive tract of his Hermit Thrush was practically an hour and a half. Mr. C. J. Maynard once told me that in a similar experiment a Cedar Bird passed the residue of food within thirty minutes after the food was taken. Weed and Dearborn found that a blackberry was digested by a young Cedar Bird in half an hour. The Number of Insects eaten by Young Birds in the Nest. The remarkable appetites of young birds keep their de- voted parents very busy supplying food most of the time from morning till night. The mother bird spends practically all her time either in searching for food, brooding, protect- ing, and feeding the young, or cleaning the nest (for all the smaller birds that nest openly are obliged to dispose of the excreta of their young, that it may neither befoul the nest nor betray its location to their enemies). Most of the visits made by the old birds to the nest during the day are for the dual purpose of feeding the young and keeping the nest clean. Eecords kept of the number of these visits show the industry of the parent birds and the food capacity of the young. My assistant, Mr. F. H. Mosher, watched a pair of Red- eyed Vireos feeding their young on June 13, 1899. There were three nestlings, about one day old. At this early age the young of most small birds are fed mainly by regur- 52 USEFUL BIRDS. gitation. The parent birds swallow the food, and probably soften or partly digest it, ejecting it afterwards through their own mouths into the open mouths of the young. No attempt was made, therefore, in this case, to determine the character or amount of the food, for fear of disturbing the parents and interrupting the regularity of the feeding. The birds were fed between 7 and 8 A.M. four- teen times; between 8 and 9, nine times ; between 9 and 10, twelve times ; between 10 and 11, seven times; between 11 and 12, sixteen times ; between 12 and 1, nine times ; between 1 and 2, twelve times ; between 2 and 3, fifteen times ; between 3 and 4, thirteen times ; and be- tween 4 and 5, eighteen times. It will be seen that one or the other parent came to the nest Avith food one hundred and Fig. 24. -Passenger Pigeon feeding twenty-five times in ten hoUl'S, by regulation. From Samuels. eyen when the observei. was Avatching near by ; but this leaves four hours unaccounted for, to fill out the long June day, from daAvn to evening. The feeding periods averaged less than six minutes apart dur- ing the time the birds Avere watched ; so it seems probable that, had the entire record for the day been kept, at least one hundred and fifty visits to the young Avould have been recorded. Young birds are fed oftenest at morning and even- ing, or during the hours Avhen these Vireos Avere not watched. Mr. Mosher Avatched a pair of Rose-breasted Grosbeaks feeding their young on June 12, 1899. The young Avere nearly ready to leave the nest, as one of them stood on a branch near its edge. The nest Avas situated about fifteen feet from the ground, in the top of a slender Avhite birch in the Avoods. The ground Avas Avell covered with hazel bushes about three and one-half feet high, which nearly concealed the observer. During the first half hour he made no record, as the birds were alarmed by his presence. As they com- VALl'E OF HI LIDS TO MAX. menced bringing food regularly, he began the record at (j A.M. Between (5 and 7 they came to the nest fifty-two times ; between 7 and 8, forty-seven times ; between 8 and 9, forty- three times; between 9 and 10, thirty times; between 10 and 11, thirty-six times ; between 11 and 12, twenty-seven times; between 12 and 1, thirty -two times; between 1 and 2, thirty-eight times ; between 2 and 3, forty-one times ; between 3 and 4, twenty-two times ; between 4 and f), fifty- eight times. The majority of the larvae seemed to be leaf rollers from the oak trees. The female came on the average about three times to each two visits of the male ; he was occupied much of the time in keeping other birds away from the vicinity of the nest. When the young of most insect-eating birds are well grown, the parents feed them whole insects just as they are picked up. With a glass, therefore, the insects brought by these Grosbeaks could be seen in the birds' beaks. Their lusty youngsters were fed almost entirely on insect larva; or cater- pillars taken from the forest trees. On only four visits did either parent bird bring less than two larva; each. In eleven hours, then, they made four hundred and twenty-six trips, and must have fed their nestlings at least eight hundred and forty-eight larvte or caterpillars, and possibly more, as a bird has been observed to carry as many as eleven small cater- pillars on one visit to its young. In comparing the records of the two nests as given above, it is noticeable that the Grosbeaks fed the young much oftener than did the Yireos. This difference is due mainly to the fact that about the time the young birds are read}' to fly, as were these Grosbeaks, they require much more food than when first hatched, as was the case with the Vireos. This, of course, is mainly owing to their increased size. The dif- ference in the number, age, and size of the young probably accounts largely for the great variation in the number of visits made to them by the parent birds, as recorded by dif- ferent observers. I have published some notes on the feeding of young Chickadees by the parent birds. Six visits were made to these young within thirteen minutes. In each case the bills 54 USEFUL BIRDS. of the parent birds were filled with a mass of small insects, mainly ants and plant lice, to which were added a few spiders. These young were also fully fledged.1 The number of young in the nests of the smaller perch- ing birds is usually from three to five. In the case of the Chickadees mentioned above there were seven, and in another case that I have recently observed there were nine. Chick- adees and AVrens, because of their insectivorous habits and the large broods they rear, probably reach the maximum in the number of insects brought to their young. Dr. Judd gives an account of the feeding of some young House Wrens by the mother bird alone. These young Wrens were about three-fourths grown, and were visited one hun- dred and ten times in four hours and thirty-seven minutes. They were fed, during this time, one hundred and eleven insects and spiders. Among these were identified one white grub, one soldier bug, three millers (Xoctuidaj), nine spiders, nine grasshoppers, fifteen May flies, and thirty-four cater- pillars. On the following day, in three hours and five min- utes, the young were fed sixty-seven times.2 Professor Aughey states that during a locust year in Nebraska he saw a pair of Long-billed Marsh Wrens take thirty-one small locusts to their nest in an hour. It is inter- esting to note that a pair of Rock Wrens that he watched took just thirty-two locusts to their nest in another hour.3 Another observer is reported by Dr. Barton to have seen a pair of Wrens coming from their box and returning with insects from forty to sixty times an hour. In an exceptional hour they carried food seventy-one times. He estimates that at that time they took from the garden six hundred insects per day.4 Few people, unfortunately, who are qualified for the task, 1 Two Years with the Birds on a Farm. Annual report of the Massachusetts State Board of Agriculture, 1902, p. 129. 2 The Birds of a Maryland Farm, by Sylvester D. Judd. Bulletin No. 17, United States Department of Agriculture, Division of Biological Survey, pp. 45, 46. 8 Notes on the Nature of the Food of Nebraska Birds, by S. A. Aughey. First Report of the United States Entomological Commission, 1877, Appendix, p. 18. 4 Fragments of the Natural History of Pennsylvania, by Dr. B. S. Barton, Part I, 1799, p. 22. PLATE V. — Chickadee. Female, with mass of insects in her beak, entering nesting box at author's window. (From Ameri- can Ornithology.) VALUE OF BIRDS TO MAN. 55 have both the time and patience to watch the feeding of young birds for an entire day. Dr. C. M. Weed and Mr. W. F. Fiske, however, have accomplished this feat. They watched the nest of a Chipping Sparrow from 3.40 A.M. to 7.49 P.M. on June 22, 1898. The valuable record of these observations Fig. 26.— Chipping Sparrow feeding young. shows that these two birds, having only three young in the nest, visited it at least one hundred and eighty-two times during that day ; and Dr. Weed says that they made almost two hundred trips, although some of the trips evidently were made to furnish grit for grinding the food. The birds were busy from daylight to dark, with no long intermission. The food, so far as identified, consisted largely of caterpillars. Crickets and crane flies were seen, and it was believed that a great variety of insect food was brought. l A committee on useful birds, selected from the Pennsyl- vania State Board of Agriculture, reported that an observer had watched the nest of a pair of Martins for sixteen hours, from 4 A.M. until 8 P.M., to see how many visits the parent birds made to the young. One hundred and nineteen visits were made by the male and one hundred and ninety-three by the female.2 1 The Feeding Habits of the Chipping Sparrow, by C. M. Weed. Bulletin No. 55, New Hampshire College Agricultural Experiment Station, 1898. 2 C. C. Musselman, in Agriculture of Pennsylvania, 1887, p. 105. 56 USEFUL BIRDS. The number of insects consumed daily by young birds in their nests is difficult of estimation, because of the variation in size among insects and the great difference in size between the mature insect and the newly hatched larva. Five hun- dred of the young larvre of a moth might occupy less space in the stomach of a bird than would the moth itself ; while a thousand aphids might take no more room than a full-grown caterpillar. Nevertheless, many estimates have been made, based on known data, as to the number of insects fed to young birds. The introduced House Sparrow (Passer domesticus), com- monly called the English Sparrow, undoubtedly eats fewer insects, here, in proportion to the rest of its food than any of our smaller native birds. The young are fed very largely on grain and other non-insectivorous food. Still, a Sparrow's nest in the city of Paris is said to have contained seven hun- dred pairs of chafer wing-cases.1 Mons. P. Pelicot gives a table of the estimates, made by several foreign authors, of the numbers of insects eaten by Sparrows in a given time. These approximations vary from that of Blatin, who estimates that two Sparrows will destroy twelve hundred chafers in twelve days, to that of Tschudi, who believes that a single Sparrow will destroy fifteen hun- dred larvte within twenty-four hours.2 Bradley mentions watching a bird's nest and discovering that five hundred caterpillars were consumed in one day.3 He says (according to Samuels) that a pair of Sparrows will destroy thirty-three hundred and sixty caterpillars for a week's family supplies. A single pair of Sparrows is reported to have carried to the nest five hundred insects in an hour. These statements may be exaggerated, but if they approx- imate the facts, what immense numbers of insects must be 1 Notes on Recent Progress of Agricultural Science, by David A. Wells. Re- port (on Agriculture) of the United States Commissioner of Patents, 1861, p. 323. 2 A Favorable View of the English Sparrow, a Review of "Un Passereau a Prote'ger," Insect Life, Riley and Howard, Vol. IV, 1891, p. 153, published by the United States Department of Agriculture. 3 Birds and Bird Laws, by J. R. Dodge. Annual Report of the United States Commissioner of Agriculture, 1864, pp. 436, 437. VALUE OF BIRDS TO MAN. 57 consumed by the young of native Massachusetts birds that are fed almost entirely upon insect food. Weed and Dearborn watched three young Cedar Birds in the nest for the fifteen days they remained there, and found that they each devoured not less than ten ounces of food in that time, or more than ten times their weight on the day they left the nest. The Amount of Food eaten by Adult Birds. There is no way of determining how much food is required daily by the adult bird, except it be kept in confinement ; in that case, the food taken can be weighed or measured. This has been done. Dr. Stanley mentions sixteen Canaries which ate one hundred grains of food per day, or an amount equal to about one-sixth of their weight, which is probably much less than wild birds of the same species would eat.1 Seed- eating birds, like the Canary, however, require less food than the insectivorous species, as their food is more con- centrated. Mr. Robert Ridgway, the distinguished ornithol- ogist of the Smithsonian Institution, makes the statement in the American Naturalist for August, 1869, that a Western Kingbird (Tyrannus verticalis}, which he kept in a cage, devoured one hundred and twenty locusts in a single day. Compared with the wild bird, the specimen that is caged or confined is a poor, weak thing at best, short of breath, low in vitality, and lacking the vigorous assimilative powers of the free bird. Keepers of cage birds, who know well the capacity of their pets, find it difficult to believe that wild birds can possibly consume the amount of food that actually has been found in their stomachs by economic ornithologists. When the reader is told that thirty grasshoppers were found in the stomach of a single Catbird, he conjures up a mental photograph of the full-grown grasshopper (the imago) that he sees in the field in late summer, and fails to remember, perhaps, that grasshoppers come from eggs, and in their growth to maturity may be found of all sizes, between that of the newly hatched insect and the full-winged hopper. 1 History of Birds, p. 225. 58 USEFUL BIRDS. While the Catbird's stomach might not be large enough to contain thirty full-grown locusts, it would easily contain more than thirty small ones. The statement that thirty grasshop- pers were found in the Catbird's stomach might also need modification in another way. The least fragment of an in- sect found in a bird's stomach is usually considered good proof that the bird has eaten that insect. There might be found in the stomach of a bird a mass of unrecognizable material, from which the expert would be able to sort out and recognize enough of the harder parts of different grass- hoppers to prove that thirty of these insects, of consider- able size, had been eaten within a certain time, even though a greater part of those first swallowed had already disap- peared from the stomach. Prof. F. E. L. Beal writes me as follows regarding the methods used at the United States Department of Agri- culture in counting the insects found in the stomachs of birds : — In the case of grasshoppers and caterpillars it is the jaws (mandi- bles) that are counted. Birds when not sleeping appear to eat all the time when not occupied in other duties, such as nest-making or feeding their young. The process of digestion is continuous. The more easily digested parts pass out of the stomach very quickly, but the hard parts remain somewhat longer. In this way when a bird is feeding upon grasshoppers the jaws of those first eaten remain after the rest of the body has passed on. When the stomach is opened the jaws are counted, and for every two we estimate at least one grasshopper killed. In cases where only a few insects were involved I have taken the pains to pair the jaws, and in this way have often found that the number that had been eaten was more than half the number of jaws. In this work each head that appears to be whole is carefully examined, to see that it has not lost one or more of its jaws ; were it not for this precaution, the insect might be counted twice. Caterpillars, like grasshoppers, are easily broken up, and so the heads are counted when whole ; other- wise the jaws are counted. The variation in size of different species of insects should also be considered. While the caterpillars of some species of moths reach three or four inches in length, others never grow to be half an inch long. These and other similar considerations, well known to VALUE OF BIRDS TO MAX. 59 the economic ornithologist, lead him to accept as facts the extreme statements made by competent investigators. It will be seen from the foregoing explanations that, while a large number of injurious insects found in a bird's stom- ach may indicate its usefulness, it may not always mean that it has eaten a great bulk or quantity of such food. The question which most interests the farmer, however, is, not so much what birds require to sustain life, as how much they will eat if they can get their fill. If in times of plenty birds will eat more than they really need, then thev become more useful or injurious, as the case may be, than they would be if they ate only enough to live. The amount of food that has been found in birds' gizzards indicates that they will eat until surfeited. Professor Beal, who has examined the contents of over twenty thousand stomachs, says, regarding this habit: — The majority of people have no idea of how much these insects can be compressed in the stomach of a bird. It is often the case that when a stomach has been opened, and the contents placed in a pile, the heap is two or three times as large as the original stomach with the food all in it. Moreover, in the cases where remarkable numbers of insects have been found, the crops or gullets usually have been full, as well as the stomach itself. It is a fact, perhaps not generally known, that with birds that have no special enlargement of the gullet in the nature of a crop, the whole gullet is used for the purpose ; and when favorite food is abundant, the bird will till itself to the throat. 1 have seen a Snow- bird so full of seeds that they were plainly in sight when the beak was opened, and from the bill to the stomach was a solid mass of seed. The stomachs of birds are often packed so hard and tight witli food that it is a wonder how the process of digestion can go on : but it does, nevertheless. In giving the maximum amounts of food found in birds' stomachs, I shall be obliged to refer to the publications of the Bureau of Biological Survey of the United States De- partment of Agriculture ; and it is but just to say here that the world owes much to Dr. Merriam, chief of the Bureau, for his indefatigable labors in behalf of science and agriculture. In connection with the work of the survey, the contents of more than thirtv-tive thousand bird stomachs have been 60 USEFUL BIRDS. examined, and much has been done in observing the feed- ing habits of birds in the field. The work in economic orni- thology performed by Merriam, Fisher, Barrows, Beal, and Judd is of great value. Its results rank above those of all other similar investigations, and must be considered as authoritative. Professor Beal found in the stomach of a Yellow-billed Cuckoo two hundred and seventeen fall webworms, and in another two hundred and fifty American tent caterpillars. Two Flickers were found to have eaten respectively three thousand and five thousand ants. Sixty grasshoppers were found in the stomach of a Xighthawk. Professor Harvey found five hundred mosquitoes in a Nighthawk's stomach. In this case the insects must have been fully grown, as the larvse of the mosquito are found mainly in water, and the Nighthawk takes its food on the wing. The stomach of this useful bird is much larger in pro- portion to its size than that of most other birds ; but sev- enty-five hundred seeds of the yellow Avood sorrel had been eaten by a Mourning Dove, sixty-four hundred by another, and ninety-two hundred seeds, chiefly of weeds, were found in another. Here we have twenty-three thousand one hun- dred seeds, mostly those of weeds, eaten at a meal by three birds. Probably where these large numbers are given, the result is approximate, and is arrived at by counting a part of the contents for a measure, and from this estimating the rest in bulk. Dr. Judd says that the stomachs of four Bank Swallows contained, all together, just two hundred ants, and that a Xighthawk has been known to eat one thousand at a single meal. He speaks of seventeen hundred seeds of weeds hav- ing been taken at one feeding by a Bob-white ; three thou- sand leguminous seeds were found in the stomach of another, and no less than five thousand seeds of pigeon grass were taken from a third. Dr. Warren has taken twenty-eight cutworms from the stomach of a Red-winged Blackbird. Stomachs of Snowflakes have each contained from five hundred to fifteen hundred seeds of amaranth. Professor Forbes found in the stomachs of seven Cedar Birds a number VALUE OF BIRDS TO MAN. 61 of cankenvorms varying from seventy to one hundred and one each, the number found in most cases averaging nearly one hundred for each bird. A Ruffed Grouse, killed in winter, had in its crop twelve leaves of sheep laurel and four hundred and thirty-five buds and bits of branches, all taken for its morning meal. The crop of another contained over five hundred buds and twigs. As these birds eat such food both at morning and at night, it would seem that they must require daily, for these two meals alone, between eight hundred and one thousand buds and twigs.1 The following notes, received from Professor Beal since the above was written, are of great interest : — From the stomach of a Franklin's Gull (Larus franklinii) there were taken seventy entire grasshoppers and the jaws of fifty-six more ; from another, ninety grasshoppers and one hundred and two additional jaws ; from another, forty-eight grasshoppers and seventy more jaws ; and still another contained sixty-seven grasshoppers. Another stomach of this species contained sixty-eight crickets. These grasshoppers and crickets were each more than one inch in length. We examined the stomach of a Franklin's Gull which contained three hundred and twenty-seven entire nymphs of dragon flies, each three-fourths of an inch in length. In the stomach of a Cliff Swallow were found one hundred entire beetles (Aphodius inquinatus) , with remains of others. These insects are a little more than three-eighths of an inch in length. AVe are now examining birds' stomachs from Texas, and from the stomach of a Yel- low-billed Cuckoo were taken the remains of eighty-two caterpillars that originally were from one to one and a half inches in length. From another stomach were taken eighty-six, and from forty to sixty from several others. All evidence acquired by observation as to the amount of food eaten by wild birds at liberty must perforce be frag- mentary, for such observation is necessarily limited to brief periods. The difficulties attending such work make its re- sults somewhat uncertain and unsatisfactory ; nevertheless, some information as to the quantity of food eaten by wild birds may be obtained in this way. Vultures are said to so gorge themselves that they are unable to fly. I have known 1 Birds in their Relation to Man, by Clarence M. Weed and Ned Dearborn, 1903, p. 62. 62 USEFUL BIRDS. a Goshawk in winter to kill a domestic Cock of more than its own weight, and devour the greater part at two meals. I have learned, by following certain Warblers and Titmice through the woods, that their search for and consumption of insects are almost continuous during most of the forenoon. As the noon hour approaches they become less active, and on warm days devote some time to resting and bathing. In the afternoon their activity increases, until toward night their quest for food is almost as strenuous as in the early morning. They are, therefore, actually engaged for the larger part of the day in capturing and eating insects. In feedino- wild birds in winter I have noticed that Chickadees O come to the food supplied for them about three times an hour all day long, and that in the intervals they are mainly occu- pied in finding their natural food. On May 28, 1898, Mr. Mosher watched a pair of Northern Yellow-throats eating plant lice from the birches in the Middlesex Fells Reserva- tion, where these insects swarmed. He was equipped with a good glass, and concealed close to the spot where the birds were feeding, and so was able to count in turn the number of times each bird picked up an insect. One of these War- blers apparently swallowred eighty-nine of these tiny insects in one minute. The pair continued eating at this rate for forty minutes. Mr. Mosher states that they must have eaten considerably over seven thousand plant lice in that time. It would seem impossible for the birds to crowd that number of insects into their stomachs ; but we must remember that the insects were infinitesimal in size, soft-bodied, easily com- pressed in the stomach, and quickly digested, so that by the time a part were eaten those first taken would be well dis- posed of, leaving room for more. Mr. Mosher is a very careful, painstaking, and trustworthy observer ; undoubtedly his statement is accurate ; but, to eliminate any possibility of error, we will assume for purposes of calculation that they ate only thirty-five hundred in an hour. A pair of Yellow- throats (presumably the same) were seen to come daily and many times each day to the birch trees which were infested with these aphids. Probably they spent at least three hours each day feeding on these insects. If VALUE OF BIRDS TO MAN. 63 the two birds ate only thirty-five hundred an hour for three hours a day, they would consume ten thousand five hundred aphids each day, or seventy-three thousand five hundred in a week. It requires no draft on the imagination to see how such appe- tites may become useful to the farmer if they are satiated on his insect enemies. Two Scarlet Tanagers were seen eating very Fig. 26. — Yellow-throat catohing birch aphids. small caterpillars of the gipsy moth for eighteen minutes, at the rate of thirty-five a minute. These birds spent much time in that way. If we assume that they ate caterpillars at this rate for only an hour each day, they must have consumed daily twenty-one hundred caterpillars, or fourteen thousand seven hundred in a week. Such a number of caterpillars would be suffi- cient to defoliate two average apple trees, and so prevent fruitage. The removal of these caterpillars might enable the trees to bear a full crop. It is easily possible, therefore, for a single pair of these birds in a week's time to save the fruit of two average apple trees, — a crop worth from two to five dollars or more, according to the productiveness of the trees and the price paid for apples. BIRDS SAVE TREES AND CROPS FROM DESTRUCTION. Since birds evidently operate to check insect outbreaks, it follows that in their capacity of insect destroyers they must in many instances have saved trees and crops from destruc- tion by insect pests. If, however, we turn to the literature of agriculture, entomology, and ornitholog}r, we shall not find it replete with such instances. Still, there are enough on record to show that conspicuous services of birds have been noted occasionally ; and I am convinced by my own experi- ence that such checks to insect increase occur commonly, but escape both observation and record. Some brief but striking accounts of this class of occur- 64 USEFUL BIRDS. rences may be gleaned from European records. Samuels writes that in Pomerania in 1847 an immense forest that was in danger of being utterly ruined by caterpillars was very unexpectedly saved by Cuckoos, which, though on the point of migrating, established themselves there for some weeks, and so thoroughly cleared the trees that the next year "neither depredators nor depredations were to be seen." l He also speaks of a European outbreak of the gipsy moth (Bombyx dispar} in 1848, saying that the hand of man was powerless to work off the infliction, but that on the approach of winter Titmice and Wrens paid daily visits to the infested trees, and before spring had arrived the eggs of dispar were en- tirely destroyed. This account agrees with the following translation from Altum : — In the year 1848 endless numbers of the larvae of Bombyx dispar had eaten every leaf from the trees of Count Wodzicki, so that they were perfectly bare. In the fall all the branches and limbs were covered with the egg clusters. After he had recognized the impracticability of it, he gave up all endeavor to remove them by hand, and prepared to see his beautiful trees die. Towards whiter numerous flocks of Titmice and Wrens came daily to the trees. The egg clusters disappeared. In the spring twenty pairs of Titmice nested in the garden, and the larva plague was noticeably reduced. In the year 1850 the small feathered garden police had cleaned his trees, so that he saw them during the entire summer in their most beautiful verdure.2 According to Reaumur, these larvae were so extremely numerous on the limes of the Alle verte at Brussels in 1826 that many of the great trees of that noble avenue were nearly defoliated. The moths swarmed like bees in the summer. They were also very numerous in the park, and if one-half the eggs had hatched in the following spring, probably scarce a leaf would have remained in these favorite places of public resort. Two months later, however, he could scarcely dis- cover a single egg cluster. This happy result was attributed to the Titmice and Creepers, which were seen busily running up and down the tree trunks.3 1 Agricultural Value of Birds, by E. A. Samuels. Annual Report of the Massachusetts State Board of Agriculture, 1865-66, pp. 116, 117. 2 Translated from Forstzoologie, II, 1880, p. 324. 8 Reau. i 387. Cited by Kirby and Spence in their Introduction to Entomology, 1857, pp. 117, 118. VALUE OF BIRDS TO MAN. 65 The value of birds has already been recognized at the antipodes. Australian fanners have suffered greatly from inroads of locusts upon their crops and pastures. The Australian correspondence of the Mark Lane Express of March 7, 1892, had a paragraph relating to the value of the Ibis to fanners during the locust incursions of that year and the year previous. In the Glen Thompson district several large flocks, one said to number fully five hundred birds, were seen eating the young locusts in a wholesale manner. Other insectivorous birds were flourishing upon the same diet. Xear Ballarat, Victoria, a swarm of locusts was noted in a paddock ; and just as it was feared that all the sheep would have to be sold for want of grass, flocks of Starlings, Spoonbills, and Cranes made their appearance, and in a few days made so complete a destruction of the locusts that only about forty acres of grass were lost.1 American farmers have had many similar experiences. When the Mormons first settled in Utah their crops were almost utterly destroyed by myriads of crickets that came Fig. 27. — Tlie western cricket that destroyed the settlers' crops at Salt Lake. Natural size; after Glover. down from the mountains. Hon. Geo. Q. Cannon, as tem- porary chairman of the third irrigation congress, told how it happened. The first year's crop having been destroyed, the Mormons had sowed seed the second year. The crop prom- ised well, but when again the crickets appeared, the people were in danger of starvation. In describing the conditions in 1848 Mr. Cannon says : — 1 Insect Life, Riley and Howard, 1891-92, Vol. IV, p. 409. 66 USEFUL BIRDS. Black crickets came down by millions and destroyed our grain crops; promising fields of wheat in the morning were by evening as smooth as a man's hand, — devoured by the crickets. . . . At this juncture sea Gulls came by hundreds and thousands, and before the crops Avere entirely destroyed these Gulls devoured the insects, so that our fields Avere entirely freed from them. . . . The settlers at Salt Lake regarded the advent of the birds as a heaAren-sent miracle. . . . I have been along the ditches in the morning and have seen lumps of these crickets A'omited up by the Gulls, so that they could again begin killing. These "lumps of crickets" were probably pellets com- posed of indigestible portions of the insects, regurgitated by the birds. These crickets (Anahrus purpurascens} trav- Pig. 28. — Gulls saving crops by killing crickets. elled in enormous hordes, stopping at no obstacle, even crossing rivers. Several times afterward the crops of the Mormons were attacked by them, and were saved by the Gulls.1 Dr. A. K. Fisher is authority for the statement 1 This account of the deliverance of the Mormons by the Gulls is vouched for by many witnesses. See Irrigation Age, 1891, p. 188 ; also, Insect Life, Vol. VII, p. 275; Annual Report of the Massachusetts State Board of Agriculture, 1871, p. 76; Annual Report of the United States Commissioner of Agriculture, 1871, p. 79; and Second Annual Report of the United States Entomological Commission 1878-79, p. 166. VALUE OF BIRDS TO MAX. 67 that the bird referred to is undoubtedly Franklin's Gull (Lams franklinii) , which occurs in enormous flocks about the small fresh- water lakes of the northwest, and feeds in great companies on Orthoptera of all sorts. The Gulls wrere practically canonized by the grateful Mormons, and protected by both law and public sentiment, as a recognition of their worth. Similar services were performed by birds during the great locust ravages which followed the settlement of the Missis- sippi valley. When large swarms of locusts appeared, nearly all birds, from the tiny Kinglet to the great Whooping Crane, feel on them. Fish-eating birds, like the Great Blue Heron, flesh-eating birds, like the Hawks and Owls, shore birds, Ducks, Geese, Gulls, — all joined with the smaller land birds in the general feast. Prof. Samuel Aughey learned this by dissecting birds and observing their feeding habits in Nebraska. In a paper published by him in 1877, but not often quoted, he gives some of the practical results of the work done by birds in protecting crops from the mighty swarms of locusts which were devastating most of that region. He says : — In the spring of 1865 the locusts hatched out in countless numbers in northeastern Nebraska. Very few fields of corn and the cereal grains escaped some damage. Some fields were entirely destroyed, while others were hurt to the amount of from ten to seventy-five per cent. One field of corn northwest of Dakota City was almost literally covered with locusts, and there the indications were that not a stalk would escape. After, and about the time the corn was up, the Yellow-headed Blackbirds in large numbers made this field their feeding ground. Visiting the field frequently, I could see a gradual diminution of the number of the locusts. Other birds, especially the Plovers, helped the Yellow-heads ; and, although some of the corn had to be replanted once, yet it was the birds that made the crop that was raised possible at all. During the same season I visited Pigeon Creek valley, in this county, and I found among the eaten-up wheat fields one where the damage done was not over five per cent. The Irishman who pointed it out to me ascribed it to the work of the birds, chief among which were the Black- bird and Plover, with a few Quail and Prairie Chickens. Professor Aughey speaks of a locality where, on several old fields, locusts hatched to the number of about three hun- 68 USEFUL BIRDS. dred to the square foot. Birds soon found them, and the ground was frequented by Blackbirds, Plover, Curlews, Prairie Chickens and small land birds. Long before the middle of June most of the locusts had disappeared. In 1886 locusts, he says, invaded Cedar and Dixon counties in swarms that darkened the sun. Nevertheless, at one point under observation the great number of birds that attacked these insects very materially lessened their numbers. In 1869 more than ninety per cent, of the locusts in one neighborhood were destroyed, apparently by birds, in one week. Other experiences are given, and several interesting letters from farmers are published, one of which follows : — DEAH SIR : — In answer to your question about the birds and the locusts, I must say this : every farmer that shoots birds must be a fool. I had wheat this last spring on new breaking. The grasshoppers came out apparently as thick as the wheat itself, and indeed much thicker. I gave up that field for lost. Just then great numbers of Plover came, and flocks of Blackbirds and some Quail, and commenced feeding on this field. They cleaned out the locusts so well that I had at least three-fourths of a crop, and I know that without the birds I would not have had any. I know other farmers whose wheat was saved in the same way. S. E. GOODMOKE. FREMONT, NEB. Another farmer wrote that the locusts hatched in immense numbers in his corn fields, but flocks of Blackbirds came and destroyed the insects, so that he raised a good crop. In an- other case, related by State Senator Crawford, a wheat field was swept clean by the locusts when the wheat was about two inches high; but flocks of Blackbirds came and de- voured the locusts, and the wheat sprang up again and made a good crop. The members of the United States Entomo- logical Commission were much impressed with the value of birds as locust destroyers. They said that the ocular dem- onstration of the usefulness of birds as insect destroyers was "so full and complete that it was impossible to entertain any doubt on this point." In one instance a farmer took one of the members of the commission out into the field, to show him how numerously the young locusts were hatching VALUE OF BIRDS TO MAX. 69 When they arrived, the insects had disappeared from the place where they had been so abundant in the morning. The statement by the family that a flock of Blackbirds had been there during the farmer's absence solved the mystery. In another instance a garden was attacked by an innumer- able host of little locusts. The owner battled bravely- with them for awhile, but at last, giving up in despair, sat down to watch the destruction of his vegetables and flowers, when suddenly a flock of Blackbirds alighted on the young cot- tonwoods he had planted in his yard. Having chirped a song, as if to cheer him, they flew into the garden ; when they left, an hour or so later, the dreaded " hoppers " were gone, and his garden was saved.1 A severe outbreak of the forest tent caterpillar (Mdlaco- soma disstn'a) occurred in Xew York and some of the Xew England States in 1897—98. Thousands of acres of wood- land were devastated, great damage was done to the sugar- maple orchards of Xew York and Vermont, and the injury extended into Massachusetts. Birds and other natural ene- mies attacked the caterpillars vigorously in many localities, and by the year 1900 the plague had been reduced so that the injury was no longer seen. Miss Mary B. Sherman of Ogdensburg, X. Y., wrote on May 18 of that year that the town was then full of birds which were feeding on the cater- pillars. There had been numerous Warblers in the maples, and the Orioles, Sparrows, Robins, Cedar Birds, several species of Warblers, and probably the House "Wren, were killing caterpillars. Birds were reported in large numbers in the county. On May 26 she wrote again, stating that there were practically no caterpillars left, cold weather hav- ing killed many, and the birds apparently having destroyed the remainder.2 The good accomplished by birds in quelling great insect in- vasions should be patent to all, but very few people realize what the birds are doing. Many Xebraskans failed to notice 1 First Report of the United States Entomological Commission. Riley, Pack- ard, and Thomas. 1877, pp. 335, 336, 338-344. 2 Report on the Injurious and Other Insects of the State of New York, by E. P. Felt, 1900, p. 1019. 70 USEFUL BIRDS. that birds were feeding on the locusts until Professor Aughey called their attention to this fact by articles published in the press. Birds are doing the same kind of work in Massachusetts to-day, in repressing smaller outbreaks of common insects. Had we more observing people to record such services, their amount and variety probably would astound us. Professor Beal saw a family of Rose-breasted Grosbeaks clear the potato beetles from a potato patch of about one-fourth of an acre. Mr. P3. W. Wood of West Newton, a well-known horticultur- ist, informed me that during one season, when the spring can- kerworms (Paleacrita vernata) became quite numerous in his orchard, a pair of Baltimore Orioles appeared, built a nest near by, and fed daily upon the cankerworms. This they continued to do assiduously ; by the time the young birds were hatched, the numbers of the worms were considerably reduced. The birds then redoubled their diligence, carry- ing ten or eleven worms to the nest at once. Soon the cankerworms had disappeared, and there has been no trouble from them for many years. Instances were recorded during the first State campaign against the gipsy moth, from 1890 to 1895, where small isolated moth colonies appeared to have been suppressed and even annihilated by birds. A serious outbreak was discovered in Georgetown, Mass., in 1899. It had been in existence for a long time, but its spread had evidently been limited by the great number of birds that were feeding there on all forms of the moth. Several months later the State abandoned the work against the moth, and little hope was entertained that anything more than a severe check had been given the insect in Georgetown. Nevertheless, in the six years that have since elapsed coniparativelv few moths have been found in that locality. The most feasible explanation of this seems to be that up to 1906 the birds have kept the numbers of the moths below the point where they can do appreciable injury. I have had several opportunities, within the last fifteen years, to watch the checking of insect uprisings by birds. One morning in the fall of 1904 I noticed in some poplar VALUE OF BIRDS TO MAN. 71 trees near the shore of the Musketaquid a small flock of Myrtle and Black-poll Warblers, busily feeding on a swarm of plant lice. There were not more than fifteen birds. The insects were mainly imagoes, and some of them were flying. The birds were pursuing these through the air, but were also seeking those that remained on the trunks and branches. I watched these birds for some time, noted their activity7, and then passed on, but returned and ob- served their move- ments quite closely at intervals all day. Toward night some of the insects had scattered to neigh- boring trees, and a few of the birds were pursuing them there ; but most of the latter remained at or about the place where the aphis swarm was first seen, and they were still there at sundown. The swarm decreased rapidly all day, until just before sunset it was difficult to find even a few specimens of the insect. The birds remained until it was nearly dark, for they were still finding a few insects on the higher branches. The plant lice I had secured for identification were destroyed or lib- erated during the night, probably by a deer mouse which frequented the camp ; so the next morning at sunrise I went to the trees to look for more specimens. The birds, how- ever, were there before me, and I was unable to find a single aphis on the trees. The last bird to linger was more suc- cessful than I, for it was still finding a few ; but it soon gave up the effort, and left for more fruitful fields. Probably a few insects escaped by flight ; but in examining the locality in 1905 I could not find one. The apparently complete Fig. 29. — Warblers destroying a swarm of plant lice. 72 USEFUL BIRDS. destruction of these insects may have been due in part to the hard winter that ensued, but the effect produced by the birds was most obvious. Such instances of the quelling of insect outbreaks by birds are noticeable, but the regulative influence steadily and perennially exerted by them, which tends to keep hundreds of species of injurious insects below the point where their injury to trees and plants would become apparent, is very seldom appreciated. THE INCREASE OF INJURIOUS INSECTS FOLLOWING THE DESTRUCTION OF BIRDS. Many cases have been noted where the destruction of birds has been followed by an immediate increase in the numbers of injurious insects. Frederick the Great, king of Prussia, being particularly fond of cherries, was annoyed to see that the Sparrows were destroying his favorite fruit. An edict was issued ordering Sparrow extermination. All the re- sources of the fowler were brought to bear, and the cam- paign was so successful that not only were the Sparrows destroyed, but many other birds were either killed or driven away by the extraordinary measures taken against the Spar- rows. Within two years cherries and most other fruits were wanting. The trees were defoliated by caterpillars and other insects, and the great Frederick, seeing his error, imported Sparrows at considerable expense to take the place of the birds that had been killed.1 In the year 1798 the forests in Saxony and Brandenburg were attacked by a general mortality. The greater part of the trees, especially the firs and pines, died as if struck at the roots by some secret malady. The foliage was not de- voured by caterpillars ; the trees perished without showing any signs of external disease. This calamity became so gen- eral that the regency of Saxony sent naturalists and skillful foresters to find out the cause. They soon found it in the multiplication of one of the lepidopterous insects, which in its larval state fed within the tree upon the wood. When- 1 Agricultural Value of Birds, by E. A. Samuels. Annual Report of the Mas- sachusetts State Board of Agriculture, 1865-66, pp. 116, 117. VALUE OF BIRDS TO MAN. 73 ever any bough of the fir or the pine was broken this insect was found within it, and had often hollowed it out even to the bark. The naturalists reported that apparently the extraor- dinary increase of the insect was owing to the entire dis- appearance of several species of Woodpecker and Titmouse, which had not been seen in the forest for some years.1 In 1858 Kearly wrote to the Entomologists' Intelligencer that a friend who had been spending a short time in Belgium informed him that in the previous year Sparrows and other birds had appeared in the park at Brussels in unusual num- bers. These birds probably were attracted by an unusual supply of insect food ; but complaint was made of the Sparrows as a nuisance, and their destruction was ordered. r'But," says Kearly, '"it now turns out that in exterminat- ing the birds the park goers have got rid of one evil only to entail upon themselves a greater. Throughout the past summer the place has swarmed with insect pests." He says also that the larva of the gipsy moth stripped nearly all of the trees of their foliage, and was one of the chief offenders. He adds that, had the authorities known what Kirby and Spence say on this subject (regarding the destruction of this insect by birds in Brussels in 1826), they would have remained guiltless of killing their feathered protectors. During the year 1861 the harvests of France gave an un- usually poor return, and a commission to investigate the cause of the deficiency was appointed at the instance of the Minister of Agriculture.2 The commission took counsel of experienced naturalists, St. Hilaire, Prevost, and others. By this commission the deficiency was attributed in a great degree to the ravages of insects which it is the function of certain birds to check. It seems that the French people had been killing and eating not merely the game birds, but the smaller birds as well. Insect-eating birds had been shot, snared, and trapped throughout the country. Fruit-eating and grain- eating species especially had been persecuted. Birds' eggs 1 Utility of Birds, by Wilson Flagg. Annual Report of the Massachusetts State Board of Agriculture, 1861, pp. 66, 67. 2 Notes on the Progress of Agricultural Science, by David A. TVells. Report of the United States Commissioner of Patents, 1861, pp. 322, 323. 74 USEFUL BIRDS. had been taken in immense numbers. A single child had been known to come in at night with a hundred eggs, and the number of birds' eggs destroyed in the country each year was estimated at eighty to one hundred millions. Before such persecution the birds were actually dying out. Some species had already disappeared, and others were rapidly diminishing. As an apparent result of the destruction of birds, the vines, the fruit trees, the forest trees, and the arrain in the fields, had suffered much from the attacks of O destructive insects, that had increased as a result of the dis- turbance of nature's balance caused by the decrease of birds. In one department of the east of France the value of the wheat destroyed by insects in a single season was estimated at five million francs. It was concluded that by no agency save that of little birds could the ravages of insects be kept down. The commission called for prompt and energetic remedies, and suggested that the teachers and clergy should endeavor to put the matter in its proper light before the people. In 1895 I received a letter from Mons. J. O. Clercy, secretary of the Society of Natural Sciences, Ekaterinburg, Russian Siberia, in which he stated that the ravages of two species of cutworms and some ten species of locusts had con- tributed (together with the want of rain) to produce a famine in that region. One of the evident causes which permitted such a numerous propagation of insect pests was, he said, the almost complete destruction of birds, most of which had been killed and sent abroad by wagonloads for ladies' hats. A law for the protection of birds was then enacted, and, said M. Clercy, "The poor little creatures are doing their best to reoccupy their old places in the woods and gardens." The reoccupation, however, did not go on as rapidly as did the destruction.1 Mr. R. E. Turner, in an important paper upon insects, read before an agricultural conference at Mackay, Queens- land, stated that he considered that the decrease of insectiv- orous birds, owing to their indiscriminate shooting by the Kanakas on the plantations, had a great deal to do with the 1 The Gipsy Moth, by E. H. Forbush and C. H. Fernald, p. 206. Published by the Massachusetts State Board of Agriculture, 1896. VALUE OF BIRDS TO MAN. 75 increase of the sugar-cane insects, particularly white grubs, which were then so abundant.1 A similar effect was observed by the early settlers of America to follow the shooting of the birds which attacked their crops. Kalm states, in his Travels in America, that in 1749, after a great destruction among the Crows and Blackbirds for a legal reward of three pence per dozen, the northern States experienced a complete loss of their grass and grain crops. The colonists were obliged to import hay from England to feed their cattle. The greatest losses from the ravages of the Rocky Mountain locust were coincident with, or followed soon after, the de- struction by the people of countless thousands of Blackbirds, Prairie Chickens, Quail, Upland Plover, Curlew, and other birds. This coincidence seems significant, at least. Professor Aughey tells how this slaughter was accom- plished. He says that the Blackbirds and many other birds decreased greatly in Nebraska in the twelve years previous to 1877. He first went to the State in 18(54. He never saw the Blackbirds so abundant as they were during 1865 over eastern Nebraska. Vast numbers of them were poisoned around the corn fields in spring and fall during the twelve years, so that often they were gathered and thrown into piles. This was done in the belief that the Blackbirds were damaging the crops, especially the corn. Great numbers of birds of other species were destroyed at the same time. A single grain of corn soaked with strychnine would suffice to kill a bird. In one autumn, in Dakota Count}' alone, not less than thirty thousand birds must have been destroyed in this way. Regarding this slaughter he wrote : — Supposing that each of these birds averaged eating one hundred and fifty insects each day, we then have the enormous number of one hun- dred and thirty-five million insects saved in this one county in one month that ought to have been destroyed through the influence of birds. When we reflect, further, that many of these birds were migratory, and that they helped to keep down the increase of insects in distant regions, the harm that their destruction did is beyond calculation. The killing of such birds is no local loss ; it is a national, a continental loss.2 ' Insect Life, by Riley and Howard. 1894, Vol. VI-, No. 4, p. 333. 2 First Report of the United States Entomological Commission. Riley, Pack- ard, and Thomas. 1877. pp. 343, 344. 76 USEFUL BIRDS. Professor Aughey gathered statistics regarding the killing of Quail and Prairie Chickens for the market during this period, and concluded that in thirty counties the average yearly slaughter of these birds must have been at least five thousand Quail and ten thousand Prairie Chickens for each county, or four hundred and fifty thousand birds in all. We can only conjecture as to how great was the destruction of other game birds. The poisoning of birds in the west permitted an increase of many other insects besides the locusts. A farmer from Wisconsin informed me that, the Blackbirds in his vicinity having been killed off, the white grubs increased in number and destroyed the grass roots, so that he lost four hundred dollars in one year from this cause. THE DESTRUCTION OF INJURIOUS MAMMALS BY BIRDS. The injury to trees and crops by insects is not the only evil that has followed the destruction of birds and other animals by man. Rapacious birds hold a chief place among the forces which are appointed to hold in check the gnawing mammals or rodents, which breed rapidly, and, unless kept within bounds, are very destructive to grass fields, crops, and trees. The great swarms of lemmings which have appeared from time to time upon the Scandinavian peninsula are his- torical. Their migrations, during which they destroy the grass or grain in their path, until finally they reach the sea and perish in a vain attempt to cross it, have been recorded often. A similar increase of rodents may take place any- where whenever their natural enemies are unduly reduced in numbers. Such cases are on record in England and Scot- land. In Stowe's Chronicle, in 1581, it is stated : — About Hallontide last past (1580) in the marshes of Danessey Hun- dred, in a place called South Minster, in the county of Essex, there sodainlie appeared an infinite number of mice, which overwhelming the whole earth in the said marshes, did sheare and gnaw the grass by the rootes, spoyling and tainting the same with their venimous teeth in such sort, that the cattell which grazed thereon were smitten with a murraine and died thereof ; which vermine by policie of man could not be de- stroyed, till at the last it came to pass that there nocked together such PLATE VI. — Field or Meadow Mouse. A prolific and destructive species, held in check by Hawks and Owls. PLATE VII. — White-footed or Deer Mouse. A destructive wood mouse, the increase of which is controlled by Hawks and Owls. VALUE OF BIRDS TO MAN. a number of Owles, as all the shire was able to yield, whereby the marsh-holders were shortly delivered from the vexation of the said mice. The like of this was also in Kent. This reads a little like a fable or legend, and we must be permitted to doubt the statement as to the cause of the "murraine ;" but the accuracy of the story, in the main, is corroborated by the records of later occurrences of a similar nature in the same region. Childrey also records this occur- rence in his Britannia Baconica, 16(50, p. 14. Similar tf sore plagues of strange mice " were experienced in Essex again in 1(548, near Downham Market, Norfolk, in 1745, and again in Gloucestershire and Hampshire in 1813- 14. l With regard to Norfolk, the following extract is of interest : — Once in about six or seven years, Ililgay, about one thousand acres, is infested with an incredible number of field mice, which, like locusts, would devour the corn of every kind. Invariably there follows a pro- digious llightof Norway Owls, and they tarry until the mice are entirely destroyed by them.2 Notwithstanding that both the cause and remedy of these frequent outbreaks of field mice were apparent, the de- struction of their natural enemies by man still goes on. In 1875—76 a noted outbreak of mice occurred in the borders of Roxburghshire, Selkirkshire, and Dumfriesshire, also in parts of Yorkshire. The abundance of the mice attracted Hawks, Owls, and foxes in unusual numbers. In 1892 an alarming increase of these field mice again occurred in the south of Scotland. In Roxburgh and Dumfries alone the plague was estimated to have extended over an area of eighty thousand to ninety thousand acres.3 A preponderance of opinion among farmers was reported, tracing the cause of this outbreak to the scarcity of Owls, Hawks, weasels, and other so-called vermin. All these animals, and Crows also, are to be ranged among the natural enemies of mice. The state- 1 See Journal of the Royal Agricultural Society, 1892, p. 223, and papers there cited. 2 Gentleman's Magazine, 1754, Vol. 24, p. 215. 3 Report to the Board of Agriculture on the Plague of Field Mice or Voles in the South of Scotland, 1892. 78 USEFUL BIRDS. ment made by Childrey as to the assemblage of Owls when the field mice swarmed in Essex in 1580 received confirma- tion during 1892. Local observers reported that, after the great increase of voles was noticed, the Short-eared Owl ( Otus brachyotus} became much more numerous on the hill farms, and that many pairs, contrary to precedent, remained to breed. Dr. W. B. Wall expresses the opinion, from his experience with the pests, that their chief enemies are the Owl and the Kestrel (a Hawk), which do more to reduce their ranks than all the traps of the farmers and the "microbes of the scien- tists" combined. Both farmers and game keepers in England and Scotland are inclined to regard these birds as vermin, to be shot at sight. In some parts of the United States the destruction of the natural enemies of rodents by man has been so complete that these animals have greatly increased in numbers. Prairie hares, or Jack rabbits, as they are called, became so numer- ous in some States at times that they could not be kept in check by ordinary hunting, and the people of whole town- ships congregated to drive them into great pens, where thousands were killed with clubs. Gophers or spermophiles have so increased in numbers that they have become pests. Farmers have been obliged to resort to extraordinary meas- ures to destroy them. In Montana such large sums were paid out in six months of 1887 in bounties for the destruc- tion of ground squirrels or gophers and prairie dogs, that a special session of the Legislature was called to repeal the law, lest it should bankrupt the State. In New England our common hares (miscalled rabbits) are kept in check in thickly settled regions by hunters ; but the field mice, which are not subject to this check, have increased so rapidly in many localities that during the hard winters of 1903-04 and 1904-05 thousands of young fruit trees in the New England States were attacked by them and ruined. These mice have become so numerous that in some places young trees cannot be grown unless protected from them. They also destroy a great quantity of grass and grain , some small fruit, and vegetables. Unfortunately, the food habits of these little animals have never been fully studied. Screech Owl PLATE VIII. — A Useful Mouse-eating Owl. (From Wan-en, after Audubou.) 80 USEFUL BIRDS. small Owls I have almost invariably found that the food consisted very largely of field mice and wood mice, with a few shrews, and rarely a bird or two. Several species of Hawks seem to feed almost entirely on field mice, small reptiles, batrachians, and insects. The young of Hawks and Owls remain a long time in the nest, and require a great quantity of food. They probably tax the resources of the parent birds excessively in the effort to find enough food for them ; hence some species are forced to commit depredations on the poultry yard, while a few kill birds and poultry from choice. But most of these birds are, on the whole, useful to the farmer. Dr. Fisher, having ex- amined the contents of two thousand six hundred and ninety stomachs of Hawks and Owls from various parts of the United States, and collected the evidence of many observers, con- cludes that Owls are among the most beneficial of all birds ; and that Hawks, with possibly one or two exceptions, are in some degree beneficial to the farmer. THE VALUE OF WATER-BIRDS AND SHORE BIRDS. Many shore birds are to some extent insectivorous. Many Gulls and Terns might be reckoned among the friends of the farmer, were they fully protected by law and public senti- ment, as they now are in some countries and in some west- ern localities in our own country. But here they have been so persecuted that they usually keep well away from the vicinity of field and farm. Even as it is, however, they ren- der some service to man. Certain water-birds are useful to navigators, fishermen, and pilots. In thick summer weather the appearance of Terns or Gulls in numbers, or the sound of their clamorous voices, gives warning to the mariner that he is nearing the rocks on which they breed. Shore fisher- men enshrouded in fog can tell the direction of the islands on which the birds live by watching their undeviating flight homeward with food for their young. The keen senses of sea birds enable them to head direct for their nests, even in dense mist. Fishermen often discover schools of fish by watching the sea birds, that, like the larger fish, pursue the small fry. ^o^r^ k ^&i£^ PLATE IX. — Regurgitated Owl Pellets. These pellets, composed of bones and fur, also feathers of a Robin, were left near authors house bv Screech Owls. PLATE X. — The Same Pellets, dissected. The fur is shown in a pile on the right, and, on the left, portions of skulls and other bones of mice, shrews, and moles, eaten by the Owls. VALUE OF BIRDS TO MAN. 81 Navigators approaching their home port during seasons of bird migration welcome the appearance of familiar land birds which are seen while land is still far out of sight. Mr. Frank M. Chapman has shown, in an interesting paper on the ornithology of the first voyage of Columbus, that we possibly owe the discovery of America by Columbus to the fact that he happened to approach the land at the right time and place to cross the line of the fall flight of land birds that were going from the Bermudas to the Bahamas and Antilles. The discouraged seamen were on the verge of mutiny, and might have compelled Columbus to return to Spain, had not small land birds come aboard unwearied and singing. The course of the vessel was changed to correspond with the direction of their flight, and the voyage was thus shortened two hundred miles and pursued to its end.1 The well-known services of Vultures, which destroy gar- bage and carrion in the tropics, have no real counterpart in the north. Crows are of some use, but Gulls and other water-birds are most valuable to man in this respect, in that they devour the garbage and refuse that are cast into harbors and arms of the sea, thus undoubtedly preventing the pollu- tion of many bays and beaches by floating filth and refuse from great cities. Sea birds must be reckoned among the chief agencies which have rendered many rocky or sandy islands fit for human habitation. The service performed by birds in fertilizing, soil-building, and seed-sowing on many barren islands has entitled our feathered friends to the gratitude of many a shipwrecked sailor, who must else have perished miserably on barren, storm-beaten shores. THE COMMERCIAL VALUE OF BIRDS. In all the foregoing we have considered mainly " the good offices that birds voluntarily take upon themselves in our service." We have yet to take into account the tax which we impose upon them for our own revenue of profit or pleasure, — a tax which we collect unsparingly, and with the strong hand of force. 1 Papers presented at the World's Congress on Ornithology, 1896, pp. 181-185. 82 USEFUL BIRDS. This tribute of flesh, blood, and feather is levied largely upon those orders of birds which in domestication become poultry, and in the wild state are known as game birds ; but many small land birds have become victims of man's greed, and the sea birds have been forced to contribute to his food supply. The eggs of certain Gulls, Terns, Herons, Murres, and Ducks that breed in large colonies find a ready sale in the market, or furnish a part of the food supply of the people who live near these breeding places. Wholesale egging was carried on along the coast of Massachusetts and other New England States, until the Gulls and Terns were in most cases driven away from their breeding places. The inhabitants along the shores of the southern States, as well as those on the Pacific coast, gathered the eggs of the sea birds by boatloads for many years. For nearly fifty years Murres' eggs were collected on the Farallone Islands and shipped to the San Francisco market. It is said that in 1854 more than five hundred thousand eggs were sold there in less than two months. This must have been an important item in the food supply of the young and growing city. Mr. H. W. Elliot mentions that on the occasion of his first visit to Walrus Island in the Behring Sea six men loaded a badarrah, carrying four tons, to the water's edge with Murres' eggs. On Laysan, one of the Hawaiian Islands, there is a great breeding place of an Albatross (Diomedea immutabilis) . Such immense quantities of their eggs have been gathered that cars have been loaded with them.1 All this egg collect- ing, however, should be stopped, for it tends to exterminate the birds, and all the eggs needed for human consumption can be produced by poultry. Sea birds which breed on isolated islands or barren shores feed mainly on animal food, which they get from the sea. Guano consists of the excreta and ejecta of sea birds, mixed with the remains of birds, fish, and other animals. It is found on the gathering places of these birds. In the rainless lati- 1 A Review of Economic Ornithology in the United States, by Dr. T. S. Palmer. Yearbook, United States Department of Agriculture, 1899, pp. 271, 272. See this paper also for an account of the guano trade. VALUE OF BIRDS TO MAN. 83 tudes of the Pacific, near the equator, guano once accumulated in tremendous deposits. It dried quickly, and where there were no rains to wash it away it was preserved with most of its fertilizing constituents intact. The guano found on islands outside the dry latitudes is of less value, as its nitrogen is quickly washed out or dissipated. The importance of guano as a fertilizer was recognized in Peru by the Indians more than three centuries ajjo. Under the Incas the birds on the Chincha Islands were carefully protected, and the deposits of guano jealously guarded. It is said that the penalty of death was inflicted on any one who killed birds near these rocks in the breeding season. Humboldt, returning from his travels in tropical America in 1804, carried some samples of guano to Europe, and first called attention to the value of the deposits of this substance on the Chincha Islands ; but it was nearly forty years later that guano became a stimulus to intensive agriculture, and furnished a source of revenue to civilized nations. The vast deposits on these three islands covered the rocks in some places to a depth of ninety or one hundred feet. The amount still undisturbed in 1853 was estimated by the official sur- veyors of the Peruvian government as twelve million, three hundred and seventy-six thousand, one hundred tons. Its use was first attempted in England in 1840 ; at that time the beds seemed inexhaustible. The guano trade soon became so important as to be a source of diplomatic correspondence between nations. It is said to have brought Peru and Chile to the verge of war. By 1850 the price of Peruvian guano had advanced in the United States to fifty dollars a ton, and American enterprise began to seek guano elsewhere. Americans have since filed with the government claims to about seventy-five guano islands in the South Pacific or in the Caribbean Sea. The vast deposits on the Chinchas are nearly exhausted, and fertilizers are now manufactured to supply the demand. Undoubtedly, however, the discovery and use of guano marked the beginning of the present enor- mous trade in commercial fertilizers. The manurial value of the phosphoric acid and nitrogen contained in fish has now become quite generally recognized, and fleets of small 84 USEFUL BIRDS. vessels are employed in seining menhaden and other fish for use in the manufacture of fertilizers. Notwithstanding the value of birds to man as destroyers of insects and vermin, they are killed and utilized by him in various ways. The destruction of game birds has been so great in Mas- sachusetts, and the demand so much in excess of the supply, that birds are now imported from other States and from other countries. It is becoming a serious question, with those most interested, how we shall so regulate the shooting of game birds that the supply may be kept up. The game birds of America have a great intrinsic value as game. The flesh of many is considered to rank high among delicacies. The pursuit of these birds has formed a large part of the occupation of many members of the rural population during the shooting seasons, and a vast business has grown out of the traffic in birds' flesh. An enormous game business has been carried on by provision dealers in this country, and the demand for game is continually increasing. Few accurate statistics of the amount of game sold are obtainable ; but Mr. D. G. Elliot, writing in 1864, states that one dealer in New York was known to receive twenty tons of Prairie Chickens in one consignment, and that some of the larger poultry dealers were estimated to have sold from one hun- dred and fifty thousand to two hundred thousand game birds in the course of six months.1 The killing of birds for sport has a certain economic affin- ity with market hunting, in that it supports a large trade in guns, ammunition, boats, dogs, and all the tools, appliances, and impedimenta of the sportsman . It furnishes employment to guides, dog breakers, and boatmen, and helps support many country hostelries and seaside hotels. The manufac- ture of firearms and ammunition for sportsmen has become a great industry. Altogether, many thousands of men are dependent for a part of their livelihood on the killing of game for sport or food, while a still larger army finds its chief outdoor recreation in the pursuit of game birds. The 1 Report of the United States Commissioner of Agriculture, 1864, pp. 383, 384. VALUE OF BIRDS TO MAN. 85 value of game birds to the farmer, epicure, marketman, and sportsman should insure them the most stringent protection. Nevertheless, some of the migratory species, through lack of effectual protection, have already been so reduced in num- bers that they are no longer of any commercial importance. The domestication of birds probably was coincident with that of animals, and grew from the desire of the primitive agriculturist to have always at hand a fresh supply of deli- cate and nutritious animal food. Xo other animals can ever be so adapted to the environments of civilization as to fur- nish us with a similarly valuable supply of both meat and eggs- The poultry business of this country has grown to such importance that the total value of the annual poultry prod- uct has reached nearly three hundred million dollars. Mas- sachusetts imported probably about eighteen million dollars' worth of poultry products in 1903. When we consider that in all the centuries the w^ork of domestication has included but a few species, it is evident that the possibilities in this direction have not been exhausted. Within the last half-century fashion has been responsible for the killing of millions of birds for the millinery trade. This trade is now limited by laws making it illegal to kill or use most native birds, except game birds, for this purpose. Instances of the destruction of birds for millinery purposes will be given in another chapter. The American demand for feathers for ornamental uses is now largely met by articles manufactured from the feathers of domestic fowls and game birds. The demand for Ostrich plumes has re- sulted in the establishment of a new industry in America, — the raising of Ostriches. There has been a growing demand for American song birds for cage purposes ; but this traffic is now prohibited by law. THE AESTHETIC, SENTIMENTAL, AND EDUCATIONAL VALUE OF BIRDS. Thus far I have written solely from the standpoint of "enlightened selfishness," entertaining no consideration of the aesthetic, humane, sentimental, or educational. I have 86 USEFUL BIRDS. attempted to look at birds solely from the utilitarian point of view, and to demonstrate the fact that their contributions to man's welfare have at least a material value. Xow let us turn for a moment from the contemplation of such utility of birds as money can measure to " some of the higher and nobler uses which birds subserve to man." In so doing we step at once from the beaten path of economic ornithology into a boundless realm, sacred to art, letters, sentiment, and poetry on the one hand, while on the other lie the fair fields in which we may take up, if we will, the fascinating study of birds, which may end merely in delightful experi- ences, or lead to the class room, the museum, the laboratory, or the closet of the systematist. Wherever it may lead us, this phase of our subject is of the highest importance, and demands the most serious consideration . Although presented last, its benefactions should perhaps come first among the items which go to make up the sum of our indebtedness to birds. The beauty of birds, the music of their songs, the weird wildness of their calls, the majesty of their soaring flight, the mystery of their migrations, have ever been subjects of absorbing interest to poets, artists, and nature lovers every- where. Prominent among the und}ring memories of men are mental pictures of the birds of childhood, their coming in the spring, their nesting, and their chosen haunts. Many an exiled emigrant longs in vain to hear again the outpour- ing melody of the Skylark, as it soars above the fields of England. Many a New England boy, shut in by western mountains, yearns for the bubbling, joyous song of the Bob- olink in the June meadows. The characters and traits of birds, their loves and battles, their skill in home building, O" their devotion to their young, their habits and ways, — all are of human interest. Birds have become symbolic of cer- tain human characteristics ; and so the common species have come to be so interwoven with our art and literature that their names are household words. What biblical scholar is not familiar with the birds of the Bible ? Shakespeare makes over six hundred references to birds or bird life. Much of the best literature would lose half its charm were it shorn of poetic allusions to birds. VALUE OF BIRDS TO MAN. 87 Birds often have inspired the poets. Bryant's lines " To a Water-fowl," and Shelley's " Skylark," each exhibit a phase of such inspiration. These are but instances of the stimu- lating power exerted on the mind of man by the bird and its associations. Some of the grandest poems ever written have been dependent on their authors' observation of birds for some touch of nature which has helped to render them immortal. Thus Gray, in his famed " Elegy written in a Country Churchyard " : — The breezy call of incense-breathing morn, The Swallow twittering from the straw-built shed, The Cock's shrill clarion, or the echoing horn, Xo more shall rouse them from their lowly bed. Who, reared in a country home, can fail, as he reads these lines, to recall the twittering of the Swallows under the spreading rafters in the cool of early morning? The mental contemplation of that peaceful pastoral scene, the train of tender recollections of the time of youth and inno- cence, all tending toward better impulses and higher aspira- tions, are largely due to the mention of the familiar bird in its association with the home of childhood. Is not literature the richer for the following lines of Longfellow in his "Birds of Passage"? Above, in the light Of the star-lit night, Swift birds of passage wing their flight Through the dewy atmosphere. I hear the beat Of their pinions fleet, As from the land of snow and sleet They seek a southern lea. How much of life and color the presence of birds adds to the landscape ! The artist appreciates this. What marine view is complete without its Gulls in flight? How much a flock of wild-fowl adds to a lake or river scene ! Birds are a special boon to child life, and a never-ending source of entertainment to many children who live upon isolated farms, where the observation of birds' habits adds greatly to the rational enjoyment of existence. It is not a far cry from the poet to the philosopher, and 88 USEFUL BIRDS. he also sees a value in birds for the opportunity they afford for the culture of the intellect. Every page of the book of nature is educational. But, as Dr. Coues says, there is no fairer or more fascinating page than that devoted to the life history of a bird. The systematic study of birds develops both the observational faculties and the analytical qualities of the mind. The study of the living bird afield is rejuve- nating to both mind and body. The outdoor use of eye, ear, and limb, necessitated by field work, tends to fit both the body and mind of the student for the practical work of life, for it develops both members and faculties. It brings one into contact with nature, — out into the sunlight, where balmy airs stir the whispering pines, or fresh breezes ripple the blue water. There is no purer joy in life than that which may come to all who, rising in the dusk of early morning, wel- come the approach of day with all its bird voices. The nature lover who listens to the song of the Wood Thrush at dawn — an anthem of calm, serene, spiritual joy, sounding through the dim woods — hears it with feelings akin to those of the devotee whose being is thrilled by the grand and sacred music of the sanctuary. And he who, in the still forest at even- ing, harkens to the exquisite notes of the Hermit, — that voice of nature, expressing in sweet cadences her pathos and her ineffable mystery, — experiences amid the falling shades of night emotions which must humble, chasten, and purify even the most upright and virtuous of men. The uplifting influence that birds may thus exert upon the lives of men constitutes to many their greatest value and charm. A growing appreciation of the sesthetic and the edu- cational value of birds has sent many cultured folk to the woods, fields, and shores. People are turning toward nature study, and the observation of birds in the field is one of the most popular manifestations of an increased and abiding in- terest in nature. To the utilitarian this movement has an economic aspect. Students who have become familiar with the common birds of their own vicinity long for new fields and new birds. Let a well-known writer describe in print any locality in Massachusetts where rare or interesting birds are to be found, and soon some of his readers will be upon the VALUE OF BIRDS TO MAN. 89 ground . This travelling about of those in search of birds bids fair eventually to assume considerable proportions, and can- not fail to be of some pecuniary importance to transportation companies, as well as to those who minister to the wants of man and beast. Many people prefer to spend their vacations in localities where both the larger and smaller birds are plen- tiful. Thus the aesthetic value of the soaring Hawk or the wading Heron becomes of practical importance to the farmer and hotel keeper who are looking for summer boarders. People of means are fully sensible of the many advantages of life in the country, and are making homes for themselves on our farms. But a merchant prince who established such a home found his enjoyment of the place greatly abridged by the scarcity of birds. With the growing interest in birds, towns or localities where birds are plentiful will have an added value as places of residence. Possibly, however, the greatest boon that the study of birds can confer upon man is seen in the power of the bird lover to keep his spirit young. One who in his early years is attracted to the study of birds will find that with them he always renews his youth. Each spring the awakening year encompasses him with a flood of joyous bird life. Old friends are they who greet him, and they come as in the days of childhood, bringing tidings of good cheer. Thus it is ever. Years roll on, youth passes, the homes and woods of our childhood disappear, the head becomes bowed with sorrow and frosted by the snows of time, the strong hand trembles, the friends of youth pass away ; but with each returning spring the old familiar bird songs of our childhood come back to us, still unchanged by the passing years. The birds turn back, for us, the flight of time. Their songs are voices from our vanished youth. Let us, then, teach our children to love and protect the birds, that these familiar friends of their childhood may remain to cheer them with song and beauty, when, toward the sunset of life, the shadows will grow long upon the pathway. 90 USEFUL BIRDS. CHAPTER II. THE UTILITY OF BIRDS IN WOODLANDS. Massachusetts contains very little land that can be digni- fied by the name of forest. She has practically no forests such as are cared for by European States, nor has she any extensive primeval wilderness of trees such as still exist on some western mountain ranges ; nevertheless, a large area of the State is forested with coppice growth or seedling trees, which are usually allowed to grow from thirty to fifty years, and are then cut for either firewood or lumber. While this large area of woodland produces comparatively little valuable timber, its aggregate value, as estimated in the census of 1895, is twenty-three million, nine hundred and thirty-six thousand, three hundred and sixty- two dol- lars. It is no exaggeration to say that for the preservation of this great woodland estate from the ravages of insects we are largely indebted to birds. The service that birds per- form in protecting woodland trees is more nearly indispen- sable to man than any other benefit they confer on him ; for the money value of forest trees, while large in the aggre- gate, is not ordinarily great enough to pay the owners to protect them against their many enemies, even if this were possible. The little things of life are the most difficult for man to control. The wild animals and venomous serpents of the woods he may exterminate ; but insects, which are even more dangerous to human life or property, will still possess the land. Were the natural enemies of forest in- sects annihilated, every tree in our woods would be threat- ened with destruction, and man would be powerless to prevent the calamity. He might make shift to save some orchard or shade trees ; he might find means to raise some garden crops ; but the protection of all the trees in all the woods would be beyond his powers. Yet this herculean task ordinarily is accomplished as a matter of course by birds and UTILITY OF BIRDS IN WOODLANDS. 91 other insectivorous creatures, without trouble or expense to man, and without appreciable injury to his great woodland interests. Birds attain their greatest usefulness in the woods, mainly because the conditions there closely approach the natural, and organic nature has an opportunity to adjust her balances without much human interference. Man may be supreme in the garden, field, or orchard, but in the woods nature reigns. There her laws, unhampered, operate for the good of her children. THE RELATIONS OF THE BIRD TO THE TREE. A mere glance at the economy of the forest shows us a series of interrelations and interdependences existing be- tween the bird and the tree. Mr. Frank M. Chapman thus indicates tersely and clearly the nature of these relations : — Between birds and forests there exist what may be termed primeval, economic relations. Certain forest trees have their natural insect foes, to which they furnish food and shelter ; and these insects, in turn, have their natural enemies among the birds, to which the trees also give a home. Here, then, we have an undisturbed set of economic relations : (1) the tree ; (2) the insect, which lives in the tree, preys upon it, and may assist in the fertilization of its blossoms ; (3) the bird, which also finds a home in the tree, and, feeding upon insects, prevents their un- due increase. Hence it follows that the existence of each one of these forms of life is dependent upon the existence of the other. Birds are not only essential to the welfare of the tree, but the tree is necessary to the life of the bird. Consequently, there has been established what is termed "a balance of life," wherein there is the most delicate adjust- ment between the tree, the insect, the bird, and the sum total of the conditions which go to make up their environment. The more trees, the greater the number of insects, and hence an increase not only in food supply for the birds, but an increase in the number of nesting sites.1 Nearly all the wood birds are dependent upon trees. Destroy the trees, and some of the insects might find new food in the crops of the fanner, but the birds lose their home 1 The Economic Value of Birds to the State, by Frank M. Chapman. Sev- enth Annual Report of the Forest, Fish and Game Commission of New York State, 1903, p. 6. 92 USEFUL BIRDS. when the tree falls. Lacking the nesting sites, protection, and shelter once afforded them among the trees, they must find other shelter, or perish. The interests of birds and trees are identical, and each must protect the other for the good of all. Birds are conspicuously useful in distributing the seed, and in planting, pruning, and protecting the trees. THE FOREST PLANTERS. If we take a white pine cone, containing seeds, break it open and examine a seed, we find that it is enveloped in a membrane with a wing-like appendage. Xow take the seed and toss it into the air, and it will descend to the ground with a rotary motion, like that of a pickerel spoon when drawn through the water. As the seed descends, its wing in rotat- .— The winged seed ing forms a spiral plane at an angle with of the white pine. ,, j. .. f ., j the direction 01 its descent, serving as a parachute to sustain it in the air. If there is the slightest breeze, the seed floats off upon it and descends diagonally to the ground. The phenomenon is much the same as that observed in falling seeds of the ash and some other deciduous trees. Such seeds are winged, like the pine seed, for dis- tribution. Although they will not float on a gentle breeze, like thistle or dandelion seeds, still, in a strong wind they are carried fifteen or twenty rods, or more. When pine seeds fall to the ground they soon separate from their wings. A heavy washing rain or the foot of some animal may bury them with earth mould, or falling leaves may cover them, and the planting is done. Should they fall upon the surface of a lake, the gentle breeze would waft them along over the surface, like a fleet of little boats, to islands or distant shores ; should they fall upon a stream, they would float away with the current. Although the seeds of many forest trees do not grow their own wings, we find them as widely distributed as the seeds of the pine. Notice the distribution of the wild cherry along the roadsides. In spring we see here and there, on bushes or trees, the webs of the tent caterpillar. They are usually found upon the apple and wild cherry ; and if, late in May, UTILITY OF BIRDS IN WOODLANDS. 93 we search woods and fields, along walls and on bushy hill- sides, we may be surprised in certain years to find wild cherry trees everywhere. When they are rendered conspic- uous by the caterpillar webs they bear, we see how they are scattered through the woods, where birds that fed upon the fruit dropped the stones as they flew. It is a law of nature that the destroyer of the fruit is also the distributer of the seed. When first I found the nest of the Wood Thrush, some thirty-fiVe years ago, I noticed that after the young had flown, a little heap of cherry stones, polished clean and white, was left in the nest. I did not know at the time how the birds were able to do this. On Oct. 21, 1890, Mr. Thomas Proctor wrote me that he had seen similar collections of cherry stones in the nests of the Wood Thrush, and that by keeping individuals of the species in captivity he had learned that they swallowed cherries whole, taking several in suc- cession and at almost regular intervals ; and that, prior to the next feeding, they expelled the polished stones by the mouth. This is a provision of nature for the distribution of the cherry tree. The pits found in the nest were prob- ably left there by the young birds just before leaving the nest ; but after the birds have flown it is not probable that many pits are left together in the same place except when the birds are at roost. The cherry stones found by Mr. Proctor in the nest were, he said, probably such as are known to botanists as "escapes," or varieties which have escaped from cultivation. Much of the planting of such trees is due, no doubt, to birds ; but wild cherry pits are oftener planted by their agency. Mr. Proctor wrote that he had kept several hundred birds of different species, and that he had come to the conclusion, from observation of their feeding habits, that other Thrushes and Warblers in general reject the larger indigestible portions of their food in this way. Mr. Proctor has since then published in The Auk the results of his observations on this subject. The seeds of berries are often expelled or excreted with their vitality unimpaired. Thus birds arc instrumental in extending the growth of the woodlands and thickets in which they dwell. 94 USEFUL BIRDS. One day I noticed a young pine growing some ten feet from the ground in the fork of a maple by the roadside. There Avere no other pines near. What planted it there? This was merely an illustration of the fact that tree seeds are furnished with transportation by the wings or legs of animals that feed upon them. The Jays alight in the tree top ; each Jay breaks off an acorn with his feet, hammers it open with his beak, and eats the kernel on the spot, or carries it off to some hiding place, Pig. 31. — A forest planter. The Blue Jay lends wings to the acorn. sometimes dropping it from the tree or while flying, appar- ently by accident or for no purpose except perhaps to hear it strike the earth. A sudden fright will cause a bird to drop whatever food it may be carrying. Such acorns are usually left where they happen to fall. We cannot study the relations of birds to the forest with- out noting also the important part that squirrels take in tree planting. In the autumn of 1897 the mast crop was light in some sections of eastern Massachusetts, but here and there an oak tree was found which bore a good crop. Such trees were soon discovered by the Jays and squirrels, several of which might be seen gathering the acorns from each tree. The ground squirrels work in pairs, as do the squirrels of UTILITY OF BIRDS IN WOODLANDS. 95 the Pacific coast, one climbing the tree and throwing the acorns down to the other. Jays, Crows, and squirrels seem to have a mania for distrib- uting and hiding things. I recall an old shellbark hickory by a farmhouse door, the crevices of its ragged bark orna- mented with walnuts, tucked in here and there all over the trunk. Any one watching the Jays and squirrels in the fall will find them filling crevices with nuts or seeds, dropping nuts, acorns, corn, and other things into cavities and hollows in the trees, or burying them in the leaf mould on the ground. I once watched a Crow killing a large, brightly colored beetle, probably Calosoma scrutator, which it buried care- fully beneath a tuft of grass. Returning a few moments later, the sable bird unearthed the brilliant insect, carried it away and buried it in another place. In a pine wood in Medford, on April 16, 1897, several Crows flew from the ground. Here, under the pines, an interrupted feast was found. Crows, Jays, and squirrels had been digging out stores of acorns which probably had been buried there the previous fall. The interrupted diggers had left six acorns which they had dug from one hole ; others were partly unearthed. It is said that squirrels bite off the germ ends of the acorns before burving them. This habit has never come under my observation. These acorns not only had their germ ends intact, but seven of them had sprouted. One had sent the tap root down four inches into the mould. They had been carefully set with the points downward, as if by a squirrel, and at just the right depth for planting. A man could not have done it better. They were deeply covered with light mould and pine needles. Some of the digging looked like the work of squirrels, but marks on some of the acorns were apparently made by the beak of a bird. A gray squirrel was seen near by. Had its feast been interrupted by the Crows, or had all been at work together? How could the Crow know that the acorns lay buried just there? Did he remember that he planted them ? Had he seen the disturb- ance of the pine needles, caused by the young sprout? Or 96 USEFUL BIRDS. had he watched the squirrel, and descended to rob it of its stores ? Who is wise enough to interpret the workings of a Crow's mind? Who can tell how far its perceptive faculties will serve, or mark the boundary between instinct and reason ? We may say that some creature had been merely storing up food against a season of want, and that may be true, but it is only half the truth. Many of the seeds which are dropped or hidden by birds and squirrels are never found by them again. There is an immense amount of vitality in these animals, which must be expended in some way. When the red squirrel is not eating, sleeping, providing food for itself, or getting into some abominable mischief, it is usually scold- ing or chattering in profane squirrel language at some in- truder, or busy burying something or digging it up. The squirrel makes its journeys back and forth, burying acorns, pine seeds, chestnuts, beech nuts, and hickory nuts in secret places. One day, however, as it is going its accustomed way up the walnut tree, a Hawk swoops down, and the squirrel is no more. That squirrel has stored up a supply of food which it will never gather. As Thoreau says, it has planted "a hickory wood for all creation." That Hawk has protected the planted seed. The part ordinarily taken by birds in forest planting is not so conspicuous as that of the squirrels, but it results in a wider distribution of seed. The birds and squirrels destroy a large part of the seed crop, but the trees produce a great surplus, and the wild creatures plant an abundance of good seed which they leave to germinate. Thus it is that the destroyer of the seed disseminates it, and so perpetuates the tree which furnishes him sustenance. The Influence exerted by Birds and Squirrels on the Succession of Forest Trees. When we cut down an oak or chestnut wood that is com- posed of old and heavy timber, a pine wood is likely to spring up in its place, particularly if there are pines near by ; while if we cut off pines, they are usually succeeded by a wood composed mainly of deciduous trees, mostly hard woods, or the nut-bearing or acorn -bearing kinds. Such a UTILITY OF BIRDS IN WOODLANDS. 97 succession of trees has long been considered by farmers to be the rule. In other words, in some way there often comes rotation of crops when wood lots are cut off. This is be- lieved by some people to be due to the springing up of seed Avhich has been buried in the ground for many years. When an oak wood springs up where a pine wood has been cut away, there is no doubt that it has sprung from seed in the ground; probably, however, it has not come from seed which has been buried for many years, but from seed sown by birds and squirrels within a few years, and which has been given a new lease of life by the sun's rays let in by the removal of the dense foliage from above. All through the autumn months, when nuts and acorns are plentiful, Jays, Crows, and squirrels are gathering and storing away the seed among the pines, where they resort for shelter. Thousands of Crows will roost in a pine wood for months during the winter, when the leaves are off the deciduous trees. The pines then offer the best hiding places for all woodland creatures. In some of the large Crow roosts among the pines extensive deposits of various seeds and other mate- rial ejected by Crows are found. When a pine wood is sur- rounded by oak and nut trees, when squirrels and Jays are plentiful, and the trees bear well, quantities of acorns and nuts will be carried into the pine wood by these crea- tures and buried beneath the dead " needles" or hidden away in crevices. Many of these nuts and acorns are dug up during the winter months, especially by the red squirrel, but many others are never found. Note an opening in the pines made by cutting away a few trees. Here young oaks spring up, and we find oaks and walnuts in such openings quite as often as we find pines. Examine the ground under the pines in summer, and you may find many little oak, walnut, and maple trees coming up from beneath the pine needles, and you will also find young pines here and there. All these young trees soon die in the dense shade of the larger pines.1 But let the pine 1 If the lot is not favorably situated, if the woods are very dense, if birds and squirrels are not plentiful, and, above all, if the crop of mast has been light the year before, there may be no young walnuts and oaks springing up. 98 USEFUL BIRDS. wood be cut off, and if the conditions are favorable, the young hard-wood trees spring up and flourish. But why do not pines spring up where pines are cut off ? For this there are several reasons : (1) pines do not sprout from the stump ; (2) there is not a crop of pine seed each year, therefore, when the pine wood is cut there may be little good seed in the ground ; (3) young pines need some shade and pro- tection, and if the larger trees are all cut down, many of the young pines may die when exposed to the sun. Those who, with a knowledge of this fact, plant pines on unshaded ground, usually sow rye or some other cereal with the pines, so that the quick-growing grain may shade the young plants for the first year. The shaded trees grow, and in time fur- nish shade for others, and so the wood extends. Now let us see why pines sometimes appear where hard woods have been cut off. This kind of succession is not common. The trees growing on most wood lots are cut for cord wood as soon as they are of sufficient size. Immedi- ately on the opening of the season , sprouts shoot up rapidly from the hard- wood stumps, choking many young pines. Still some will live and flourish, and so there comes a mixed growth of pines and hard- wood trees. This is the character of much of the wooded region near Boston. But if an oak or walnut wood is allowed to grow until the trees are old, and is cut when the roots have lost their vigor, the sprouts, if they come up at all, are not so vigorous, and the young pines have a better opportunity. Where birds and squirrels are numerous, a considerable part of the fruitage of the pine is removed by them, and cones or detached seeds are buried or scattered about, not only among the pines, but among the hard-wood trees. The winds also scatter pine seed far and wide among deciduous trees ; so, if there are pines near hard- wood lots, young pines usually sprout among the hard- wood trees. When an old growth of deciduous woods is cut off, these young pines, having had a start in the shade, flourish and afford some shade for still younger seedlings, which quickly germinate from the seed in the ground ; thus occa- sionally the pines succeed the broad-leaved trees. UTILITY OF BIRDS IN WOODLANDS. 99 V THE TREE PRUNERS. If the young tree escapes or survives the assaults of its many enemies, and grows vigorously, it is prone to an over- production of fruit or leaves. Orchardists and some foresters practise pruning, and believe that when it is judiciously done it is good for the tree. Xature has many ways of pruning. Superfluous buds are nipped off by birds and squirrels, or destroyed by insects. When the sun lies warm in February and March on wooded hillsides, the Ruffed Grouse or Partridge may be seen "budding*' on the wild apple trees, alders, pop- lars, and birches. In Mav the Rose-breasted Grosbeak and the Purple Finch attack both buds and blossoms, scattering snowy petals far and wide. We have seen that all trees have numer- ous insect enemies, which live upon them ; but most of these insects, when occurring in nor- mal numbers, are either harm- less or beneficial rather than injurious. Their interests, like those of the birds, are iden- tical with those of the tree which supplies them with suste- nance. A few leaf-eating caterpillars may be a benefit to the tree, by removing surplus foliage, and thus checking a too vigorous development, which otherwise might be injuri- ous. Other insects, if not too numerous, may destroy the surplus fruit or seed, and thus direct the energies of the tree toward perfecting larger and better fruit. Certain insects cut off the twigs ; others destroy branches. The numbers of these insects are regulated by birds. In 1896 oak pruners (Elapliidion vittosum) were numerous in eastern Massachu- setts. They attacked several species of oaks, hickories, and maples. They also assailed the apple trees. Their occur- rence in numbers seems to be periodical, and thus the trees Fig. 32. — Ruffed Grouse, ding." 1 bud- 100 USEFUL BIRDS. are subject to a more or less regular periodical pruning. Large quantities of twigs and small branches fell from the oaks and other trees in 1896, and it appeared as if the oak pruners might do considerable injury to these trees ; but birds and other natural enemies attacked the insects, and the trees were not injured, — very likely in most cases they were even benefited by this removal of the twigs from the upper branches. Jays, Crows, and Hawks break off strong twigs and small branches to use in their nest build- ing. Squirrels gnaw off many twigs while gathering nuts and acorns, or while building their nests. When branches are injured by insects or overshading to such an extent that they die, they are removed later (when weakened by decay) by the action of the wind, or are broken off in winter by ice and snow. Thus the pruning of the trees is effected. THE GUARDIANS OF THE TREES. Birds guard the Trees the Year round. — We know that trees are subject to many injuries by reason of the undue multiplication of animals that feed upon them. The foliage is devoured by insects and other animals ; the fruit and seeds by insects, birds, and squirrels; the twigs are killed by borers or girdlers ; the bark is eaten by mice, hares, squir- rels, or porcupines ; the trunks are attacked by wood borers ; the roots have insect enemies ; even the very life blood, the sap, is sucked out by aphids. When we consider well the fecundity, voracity, and the consequent great possibilities for mischief possessed by their enemies, we wonder that trees survive at all. Still, trees spring up and grow apace. In a wooded country a few years' neglect of field and pasture suffices to clothe them with a growth of bushes and saplings, and in time a wood lot succeeds the cleared land. That trees are able thus to spring up and grow to maturity with- out man's care is sufficient evidence that they are protected by their natural friends from the too injurious inroads of their natural enemies. Among these friends birds hold a high place. It is generally believed that there are few birds in deep woods. Travellers often have remarked the scarcity of birds UTILITY OF BIRDS IN WOODLANDS. 101 in the forest. It is true that usually there are fewer birds, both in numbers of species and individuals, in most northern forests than in more open or cultivated lands. This is par- ticularly true of coniferous forests, for such woods harbor fewer insects than deciduous forests, and so furnish a more meager food supply for birds. Those birds that live and breed in the deep woods, however, are especially fitted to destroy the trees' enemies. This care of the trees is kept up throughout the year by the ebb and flow of the tide of bird life. In the chill days of March and early April, when sunshine and shadow fleck the lingering snow, in silent, leafless woods and along swol- len streams, the lusty Fox Sparrow searches for seeds and for dormant insects, which only await the warmer sun of April or May to emerge from their hiding places and attack the trees. This Sparrow and its companions, the Tree Sparrow and the Junco, soon pass on to the north, making way for the White-throats and Thrushes, which continue the good work, to be followed in their turn by other Thrushes and the Towhees. Birds are not plentiful in the woods in early April, but nevertheless diligent Titmice, Woodpeckers, Jays, Nuthatches, and Kinglets are there and at work. In the warm days of Ma}-, when nature has awakened from her long winter's sleep ; when the little, light-green oak leaves are just opening; when the bright young Fig. 33. -The diligent birch leaves decorate, but do not hide, the twigs ; when every leaflet vies with the early flowers in beauty, and every branch upholds its grateful offering ; when insects which were dormant or sluggish during the earlier days of the year become active, and their swarming offspring appear on bud and leaf, — then the south wind brings the migratory host of birds which winter near the equator. Unnoticed by men, they sweep through the woods, they encompass the trees; flight after flight passes along on its way to the north, all resting daily in the woods and gleaning insects ere they go. No one who has not watched these beautiful birds hour after hour and day after day, and 102 USEFUL BIRDS. who has not listened to their multitudinous notes, as, night after night, they have passed overhead, can realize the num- bers that sweep through the woods in the spring and fall migrations. Those who watched the great flights of War- blers during the season of 1905 could but marvel at their vast and changing procession. One must be in the woods most of the time, during both spring and autumn, to form any adequate conception of these movements ; and even then he may be mystified by the sudden changes he will observe. While at Amesbury, Mass., on May 11, 1900, I went out at daybreak with a few friends who were interested in bird study. As we walked through the streets of the village many male Blackburnian Warblers Avere seen among the street trees. A little later we saw them all about us in the orchards, their brilliant orange breasts flashing in the sunlight. As we approached the woods it was everywhere the same. The night had been very cold, and other insect-eating birds were seeking benumbed insects on or near the ground. There were four bright Redstarts flitting about on the upturned sod of a newly plowed garden. These and other species of Warblers were to be seen in every orchard, wood, and thicket. The Blackburnian Warblers had come in during the night, and were busy hunting for their breakfasts until 7 o'clock, when we went to ours. At 8 o'clock not a single Blackburnian was to be seen. I scoured the country until nearly noon, finding alt the other Warblers as at daybreak, but not a Blackburnian could be found. They had done their share in the good work, and had passed on. A later riser would have missed them. Had we not been afield that morning, the flight might have been unrecorded. In May most of the smaller birds that pass the summer in our northern woods — Thrushes, Warblers, Vireos, Cuckoos, Towhees and their kin — arrive, mate, and build their nests. In June the growing insect hosts increase, and the activities of the parent birds in procuring food for their young are at their height. Each occupied nest is a sepulchre for worms, spiders, and insects ; each young bird's mouth is an open door, yawning for their destruction. The parent birds are UTILITY OF BIRDS IN WOODLANDS. 103 ever hunting, hunting, hunting, to find the wherewithal to stop those insistent, hungry cries ; for hunger is not good for young birds, and their cries may betray them to their enemies. This continual search for food for the callow young goes far towards checking the uprising host of in- sects in June and July, and preventing the absolute destruc- tion of the trees. When the young birds are out of the nest, their parents lead them to some spot where insects are most plentiful, and there continue to feed them for a time. When the fledge- lings are strong and well able to fly about and find their own sustenance, the old birds usually drive them away from the vicinity of the home, and they scatter in search of food, drifting here and there, wherever food is most plentiful, until they find themselves moving southward, with the receding tide of bird life, toward that land where frost and snow are never known. Some of the Warblers are ready to leave for the south by midsummer. Such of the summer residents as still remain wander through the woods in late summer and early fall, in search of insect outbreaks, wild fruit, and seeds, feeding as thev move along. They are now slowly migrating. The chill of autumn evenings accelerates their southward move- ment, and on clear, still nights their call notes and even their beating wings may be heard as they fly southward. The birds are now without home attachments, and gather wherever food is most plentiful. Those that have found insects in plenty call to others that are fly ing by or overhead, bidding them also to the feast. So the tide of bird life sweeps back through the woods of the temperate zone toward the equator. In late October bird songs are heard no more. A few Thrushes, Woodpeckers, Chickadees, Kinglets, Creep- ers, and Nuthatches flit here and there ; Blue Jays mourn- fully call ; a Crow caws now and then ; but otherwise the woods seem deserted. Still, at this season of the year and all through the winter and early spring months the few birds that remain are accomplishing the greatest good for the forest ; for now the development and increase of all insects are arrested, while their destruction by birds goes on. In 104 USEFUL BIRDS. winter the smaller wood birds that remain in the north must subsist largely on the hibernating eggs of insects, for many insects pass the colder months in the egg ; the bird that eats these eggs can destroy at least a hundred times as many insects in this minute, embry- onic form as it could in the summer, after the caterpillars had hatched and grown toward maturity. The Jays, Titmice, Nuthatches, and Woodpeckers, which remain through the win- ter in the northern woods, give months more of service to our trees than do the majority of birds that come here as sum- mer residents or migrants only. These all-the-year-round birds, with the Creepers and Kinglets, are the most valuable guardians of the wood. Millions upon millions of insects and their eggs are destroyed by them during the long winter months. In this work they are assisted to some extent by certain of the winter Finches and Sparrows. Birds guard All Parts of the Tree. — Even insects which feed upon the roots are dug out of the ground by birds, or attacked by these feathered enemies whenever they appear above the surface. Sparrows, Thrushes, and Towhees search among the dead leaves for caterpillars which drop from the trees and crawl on the ground, and for those which pupate among the litter of the forest floor. Woodpeckers, tapping the trunks, find and bring forth injurious ants, bark beetles, and wood-boring insects. Creepers, Kinglets, Titmice, and Nuthatches search the bark and cavities of the trunk and limbs for insects' eggs, scale insects, bark lice, borers, bark beetles, and other insects which hide there. Jays, Warblers, Tanagers, Wrens, Titmice, Vireos, Cuckoos, and other tree- loving birds pry about among the leaves and branches in search of caterpillars of all sorts. Even the hidden leaf- Figf. 34. — Winter tree guards, a Creeper and a Nuthatch. UTILITY OF BIRDS IN WOODLANDS. 105 rollers are sought out. The gall insects are dragged from their hiding places by Jays and Grosbeaks. Titmice get the bud worms, and Woodpeckers search out the fruit worms. When the spanworms, disturbed by the movements of the caterpillar-hunting Warblers, Vireos, and Sparrows among leaves and twigs, spin down on their gossamer threads, and so escape one class of enemies, they are marked by Fly- catchers sitting on the watch or hovering in the air ready to dart upon them. When the mature insects, gaining wings, attempt to escape by flight, they are snapped up by these same Flycatchers, that sit waiting on the outer limbs of the trees ; or, escaping these, they are pursued by Swallows and Swifts in the upper air. Those whose flight is noc- turnal must run the gauntlet of the Screech Owl, Xight- hawk, and Whip-poor-will. Each family of birds seems exactly fitted for the pursuit and capture of insects that feed on a certain part of the tree, while nearly all species can so adapt themselves, at need, as to feed readily on insects not ordinarily taken by them. While living in the woods, much of the time alone, for several seasons, I have been greatly impressed by both the vast yearly uprising of insect pests and the strong repressive influence exerted by birds upon their increase. When the buds open in spring, broods of tiny, hungry caterpillars emerge, only to be preyed upon by the constantly increasing flights of birds that peer, swing, flutter, or hop from twig to twig through all the woods. At this time these caterpil- lars are not at all noticeable, and are very difficult to find ; still, the great majority of them are readily found and eaten by birds, and therefore never become apparent to ordinary observation. As summer conies and the caterpillars grow in size, each brood is reduced in number, until, as they ap- proach full size, a band which erstwhile numbered hundreds of little crawlers has shrunk to a score or two, a "baker's dozen," or even less. When the survivors pupate they are still attacked by birds, and the moths or butterflies as they emerge and try their wings are pursued by their swifter feathered enemies. In studying the increase of the gipsy moth it was found 106 USEFUL BIRDS. that during the first few years after its introduction into a locality its inroads on the foliage were not noticeable ; nearly all the insects resulting from each egg cluster fell victims to their natural enemies. This is true to a still greater extent of most of our native insects. As the season advances the few large caterpillars that are left from each brood injure the leaves a little, so that on close inspection in July the foliage appears somewhat ragged and riddled, but at a distance, or to the casual observer, the trees seem in fine foliage. He who watches the birds feeding from day to day can only wonder how they can possibly find so many caterpillars ; for birds do find them continually, by going over the same ground day after day. When it is difficult for us to see even a single specimen on the leaves, the birds continue to find them until summer wanes and the leaves begin to fall. The value of the service performed in woodlands by birds that eat caterpillars is far greater than it seems at first sight, for wherever the foliage of a tree is destroyed by insects the fruit of that tree cannot mature, and the tree also suffers a serious check in growth. There is much woodland in Massa- chusetts that pays very little in excess of the taxes. A leaf- less tree makes no wood growth ; therefore, whenever trees that are grown for wood or lumber are stripped of their leaves by caterpillars, the size of the annual wood ring is so much below the normal that the owner realizes no profit, and may even suffer a loss on his wood lot that year. But this is the least danger that is threatened by the attacks of caterpillars. Most people know that the tree "breathes through its leaves," and when for a long period these organs are prevented from developing, it must inevitably die. Most coniferous trees, like the pine and hemlock, die when stripped of their foliage for one season ; and deciduous or broad- leaved trees, such as the oak, ash, and maple, often succumb if deprived of their leaves for a considerable length of time each year for even two or three years in succession. Most trees would soon be killed in this way were it not for the birds, for there is a succession of many species of caterpillars that feed upon the trees all summer, and, were they not held in check by birds, they would destroy the foliage month UTILITY OF BIRDS IN WOODLANDS. 107 after month. The consequent weakened condition of the trees would invite the bark beetles and other borers which attack such trees, and, multiplying exceedingly, cut channels beneath the bark until all the vital tissues are destroyed. I have seen many trees defoliated by the gipsy moth that afterward succumbed to the attacks of these insidious borers, which are probably the ultimate cause of the death Fig. 35. -De- j? j e v j. i i. structive bark of many defoliated trees. bee tie .eaten The destruction of these larvae in their re- bayr