LETTER OF TRANSMITTAL. 



IT. S. Department of Agriculture, 



Division of Biological Survey, 



Washington, D. C, May 22, 1900. 

 Sir: I have the honor to transmit herewith for publication as Bul- 

 letin No. 13 a report on 'The Food of the Bobolink, Blackbirds, and 

 Grackles,' by Prof. F. E. L. Beal, assistant biologist. This report is 

 based on a careful examination of the contents of more than 4,800 

 stomachs, representing nine species and several subspecies of Amer- 

 ican blackbirds. The family of orioles and blackbirds, to which the 

 bobolink, cowbird, blackbirds, and grackles belong, is one of much 

 economic importance. The ravages of the bobolink in the rice fields 

 of the South, and of some of the blackbirds in the grainfields of the 

 Upper Mississippi Valley at planting and harvesting time, are matters 

 of common knowledge, but the other food of these and other species 

 is not so well known. The present bulletin is devoted mainly to the 

 food of the various blackbirds during the summer months; several of 

 the species consume insects in such quantities at this time as to com- 

 pensate in great measure for the grain they destro}^. 

 Respectfully, 



C. Hart Merriam, 

 Chief, Biological Stirvey. 

 Hon. James Wilson, 



Secretary of Agriculture. 



3 



