Page:Auk Volume 13-1896.djvu/56

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20 Baker, A Factor in Western Bird-life. [^ AN IMPORTANT* FACTOR IN THE STUDY OF WESTERN BIRD-LIFE. BY CARL F. BAKER. Probably no better instance of the progressiveness of the American can be offered than that of the settlement of the arid lands of the Western States. Through the magic touch of irriga- tion a desert has been made to support a vegetation of almost tropical richness. Where once was but a barren plain, now spread broad fields of luxuriantly growing crops, fine orchards, and green meadows. It would seem that in this wonderful transformation, brought about in so short a time, the zoologist would find a field of sur- passing interest for study, and one promising varied and valuable results. How it has affected the buffalo, antelope, elk, and badger are familiar facts. But its effects on the smaller mammals and birds have never been traced, although they must in many instances be nearly as marked as on those species mentioned. Compare for an instant the two sets of conditions. Then, a treeless, uninhab- ited tract (except along the streams which were few and far between) covered with a very scant herbaceous vegetation, upon which fell but very little rain. Now, covered with farms having ornamental trees and orchards in abundance, the face of the country not gray brown, but green, and water everywhere. These changes have been effected over immense tracts within a very few years, and are going on rapidly to-day. It seems as if here was an opportunity such as occurs but once in an age. It is true that similar changes are in progress in all inhabited countries, but in no instance have changes on so grand a scale been brought about in so short a time. With a single exception, in none of the literature at my command can I find that such studies have been carefully prosecuted. This exception is an article by Dr. H. H. Behr (Proc. Calif. Acad. Sci., Vol. I), entitled ' Changes in Fauna and Flora of California.' Ornitho- logical literature is full of specific instances of variation of habit produced by the settlement of the country, such as those of the Phcebe, Martin, Barn Swallow, and others. But I cannot find