25oofe ^tm anb Ctebietn^ 



Preliminary Census of Birds of 

 THE United States. By Wells W. 

 Cooke, Assistant Biologist. Bull. Xo. 

 187, U. S. Dept. of .\griculture. 



This Bulletin is a most encouraging 

 report of progress. It proves conclusively 

 that it is possible to make an approxi- 

 mately accurate count of not only the 

 number of species, but also of the number 

 of individual birds nesting in a given 

 area. This, in effect, shows that in time 

 we may expect to know, more or less 

 accurately, the number of birds which in 

 the summer inhabit the United States. 



Once possessed of data of this kind, and 

 we shall for the first time be in a position 

 to determine whether a given species of 

 bird, or bird-life in general, is decreasing 

 or increasing. Hitherto there have been 

 but few and limited areas in this country 

 where observations have been made which 

 would permit of a satisfactory comparison 

 of present with past conditions. 



As Mr. Abbott H. Thayer showed in 

 Bird-Lore for August, 1914, statements 

 based on the memory of early experiences 



are worthless. What we need are facts 

 such, for example, as are presented by 

 Mr. F. L. Burns in his comparative cen- 

 suses made as Berwyn, Pa., in 1899-1901 

 and 1914, and published in this number of 

 Bird-Lore. In reports of this kind, we 

 have not 'opinions' or 'impressions,' but 

 authentic and reliable statistics gathered 

 by experts. 



It is information of this nature which 

 the Biological Survey proposes to gather 

 in its census of the birds of the United 

 States. The undertaking is an enormous 

 one, and it can succeed only through the 

 cooperation of every bird student who 

 has the experience and opportunity to 

 take part in it. 



Professor Cooke's summary of the work 

 accomplished during the season of 19 14 

 contains some exceedingly interesting 

 and suggestive material. Mr. Burns' 

 observations show 588 pairs of native 

 birds breeding on 640 acres; while the 

 returns from the Survey census of 1914 

 give an average of 583 pairs for a similar 

 area. These essentiallv similar results 



PL.\CES FROM WHICH BIRD CENSUS REPORTS WERE RECEIVED IN 1914 

 Courtesy of the Biological Survey 



(136) 



