THE BIRDS 



203. 



habits of different species birds, especially by the Biological 

 Survey of the United States Department of Agriculture, 

 which has issued numerous bulletins upon the subject. A 

 large part of the data on the food of birds has been ac- 

 cumulated by the examination of the contents of stomachs. 

 By the laborious counting of the different kinds of insects, 

 grains, weed seeds and other bodies which are found in 



FIG. 157. California valley quail. (From Rep. of Calif. Fish and Game 

 Commission.) 



the stomachs of many thousands of birds of all sorts a 

 great many very valuable facts have been discovered 

 concerning the utility or harmfulness of various species. 

 Were it not for the destruction of insects by birds it would 

 be difficult for man to raise many of his crops. The 

 common bob-white, or quail, of the eastern and middle 

 states lives mainly on insects and weed seed, and is 



