BULLETIN OF THE 



No. 187 



Contribution from the Bureau of Biological Survey, Henry W. Henshaw, Chief 

 February II, 1915. 



PRELIMINARY CENSUS OF BIRDS OF THE 



UNITED STATES. 



By Wells W. Cooke, Assistant Biologist. 

 INTRODUCTION. 



During the summer of 1914 the Biological Survey took initial 

 steps toward a census of the birds of the United States for the pur- 

 pose of ascertaining approximately the number and relative abun- 

 dance of the different species. In view of the recognized value of 

 birds to agriculture, such information can not fail to be of great 

 value. 



An added reason for this census was that the Congress has recently 

 placed the Department of Agriculture in charge of migratory game 

 and insectivorous birds, so that it is necessary that exact informa- 

 tion be secured in regard to their present numbers as a basis for 

 determining the adequacy of the present laws for their protection 

 and whether the several species are increasing or diminishing, 



The census will need to be repeated for several years and on a 

 much larger scale before a satisfactory basis can be obtained for safe 

 generalizations. It is hoped that all who can aid in the work will 

 notify the Biological Survey in order that later necessary instruc- 

 tions and report blanks may be furnished. It will be understood 

 that the bureau has no funds to pay for this work, and it must 

 therefore depend upon volunteer observers. Bird observers in the 

 West and the South are particularly requested to cooperate, as 

 these sections have not been sufficiently covered in past observa- 

 tions. The circular of instructions for 1915 will be sent out early 

 enough in the spring to allow ample time for making well-considered 

 plans. 



Note.— This bulletin is a preliminary report on the number and relative abundance of wild birds. It 

 is for the information of those interested in the protection and increase of birds. 

 76541°— Bull. 187—15 



