The Bird Study Book

by T. Gilbert Pearson

CIVILIZATION'S EFFECT ON THE BIRD SUPPLY

Twelve hundred kinds of wild birds have been positively identified in North America. About one-third of this number are called sub-species, or climatic varieties. To illustrate the meaning of "sub-species," it may be stated that in Texas the plumage of the Bob-White is lighter in colour than the plumage of the typical eastern Bob-White, which was first described to science; therefore, the Texas bird is known as a sub-species of the type. Distributed through North America are nineteen sub-species of the eastern Song Sparrow. These vary from the typical bird by differences in size and shades of marking. In a similar way there are nine climatic variations of Screech Owls, six Long-billed Marsh Wrens, and fourteen Horned Larks. It is difficult to explain why this variation in colour and size is so pronounced in some species and yet is totally absent in others of equally wide range. The Mourning Dove breeds in many localities from the southern tier of Canadian Provinces southward throughout the United States and Mexico, and yet everywhere over this vast range the birds are the same in size and colour. Nowhere do the individuals exhibit any markings suggestive of climatic influences.

Some birds are very rare and are admitted to the list of North American species because of the fact that during the years a few stragglers from other parts of the world have been found on our continent. Thus the Scarlet Ibis from South America, and the Kestrel and Rook from western Europe, are known to come to our shores only as rare wanderers who had lost their way, or were blown hither by storms. Eighty-five species of the birds now listed for North America are of this extra-limital class. Among those naturally inhabiting the country, some are, of course, much more abundant than others, thus every one knows that Bald Eagles are comparatively rare, and that Robins and Chipping Sparrows exist by millions.

The Number of Birds in Different States.—The number of kinds of birds found in any one State depends on the size of the State, its geographical situation, and the varieties of its climate as affected by the topography in reference to mountains, coastlines, etc. The number of bird students and the character of their field studies determine the extent to which the birds of a State have been catalogued and listed. The following list indicates the number of kinds of birds that have been recorded in forty-three of the States and the District of Columbia. The authority for the statement in each instance and the year in which the figures were given is also stated:

Alabama, 275 (Oberholser, 1909).
Arizona, 371 (Cooke, 1914).
Arkansas, 255 (Howell, 1911).
California, 541 (Grinnell, 1916).
Colorado, 403 (Cooke, 1912).
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Connecticut, 334 (Sage and Bishop, 1913).
Delaware, 229 (Rennock, 1908).
District of Columbia, 293 (Cooke, 1913).
Florida, 362 (Thurston, 1916).
Idaho, 210 (Merrill, 1898).
Illinois, 390 (Cory, 1909).
Indiana, 321 (Butler, 1898).
Iowa, 356 (Anderson, 1907).
Kansas, 379 (Bunker, 1913).
Kentucky, 228 (Garman, 1894).
Louisiana, 323 (Byer, Allison, Kopman, 1915).
Maine, 327 (Knight, 1908).
Maryland, 290 (Kirkwood, 1895).
Massachusetts, 369 (Howe and Allen, 1901).
Michigan, 326 (Barrows, 1912).
Minnesota, 304 (Hatch, 1892).
Missouri, 383 (Widmann, 1907).
Nebraska, 418 (Swenk, 1915).
Nevada, 250 (Hoffman, 1881).
New Hampshire, 283 (Allen, 1904).
New Jersey, 358 (Stone, 1916).

New Mexico, 314 (Ford, 1911).
New York, 412 (Eaton, 1914).
North Carolina, 342 (Pearson and Brimley, '16).
North Dakota, 338 (Schmidt, 1904).
Ohio, 330 (Jones, 1916).
Oregon, 328 (Woodcock, 1902).
Pennsylvania, 300 (Warren, 1890).
Rhode Island, 293 (Howe and Sturtevant, 1899).
South Carolina, 337 (Wayne, 1910).
Tennessee, 223 (Rhoads, 1896).
Texas, 546 (Strecker, 1912).
Utah, 214 (Henshaw, 1874).
Vermont, 255 (Howe, 1902).
Virginia, 302 (Rives, 1890).
Wellington, 372 (Dawson, 1909).
West Virginia, 246 (Brooks, 1913).
Wisconsin, 357 (Kumlien and Hollister, 1903).
Wyoming, 288 (Knight, 1902).

For the five remaining States no list of the birds has as yet been issued.

Increase of Garden and Farm Birds.—The effect of civilization on the bird life of North America has been both pronounced and varied in character. Ask almost any one over fifty years of age if there are as many birds about the country as there were when he was a boy, and invariably he will answer "No!" This reply will be made, not because all birds have decreased in numbers, but because there has come a change in the man's ideas and viewpoint; in short, the change is chiefly a psychological one. The gentleman doubtless does not see the birds as much as he did when he was a boy on a farm, or if he does, they do not make the same impression on his mind. It is but another example of the human tendency to regard all things as better in the "good old times." Let us turn then from such well-meant but inaccurate testimony, and face the facts as they exist. I have no hesitation in saying that with many species of Finches, Warblers, Thrushes, and Wrens, their numbers in North America have greatly increased since the first coming of the white men to our shores.