£-' NATIONAL ZOOLOGICAL PAE 



Issued September 26; 1911. 



U. S. DEPARTMENT OF AGRICULTURE 



BIOLOGICAL SURVEY— BULLETIN No. 39 



HENRY W. HENSHAW, Chief 



WOODPECKERS IN RELATION TO TREES 

 AND WOOD PRODUCTS 



W. L. McATEE 



Assistant Biologist, Biological Survey 



WASHINGTON 



GOVERNMENT 1 PRINTING OFFICE 



1911 



