CHAPTER VII 



FRIENDS AMONG THE BIRDS AS DESTROYERS 

 OF INSECT PESTS 



THE practical value of birds to man, whether 

 helpful or harmful, depends chiefly on their food 

 habits. Some of their food consists of things injuri- 

 ous to man, such as insect pests, weed seeds, and 

 rodent pests, while some consists of things valuable 

 to man, such as fruit and grain: so that the exact 

 economic status of a bird is determined by a careful 

 study of its food habits. 



The United States Bureau of Biological Survey. 

 The first systematic and thorough study of the food 

 habits of birds began in 1885, when the National 

 Government established a section of economic orni- 

 thology whose purpose was to investigate the food 

 habits, distribution, and migration of North Ameri- 

 can birds and mammals in relation to agriculture, 

 horticulture, and forestry. This was later given the 

 title of Bureau of Biological Survey. Its work upon 

 the economic value of birds has been along three 

 lines: (1) to determine as accurately as possible the 

 food of birds of economic importance; (2) to act as 

 a court of appeal to investigate complaints concern- 

 ing depredations of birds on crops; (3) to diffuse 



