DESTROYERS OF RODENT PESTS 97 



The result proves that a class of birds commonly looked 

 upon as enemies to the farmer, and indiscriminately de- 

 stroyed whenever occasion offers, really rank among his 

 best friends, and with few exceptions should be preserved 

 and encouraged to take up their abode in the neighbor- 

 hood of his home. Only six of the seventy-three species 

 and subspecies of hawks and owls of the United States 

 are injurious. Of these, three are so extremely rare that 

 they need hardly be considered, and another (the fish 

 hawk) is only indirectly injurious, leaving but two (the 

 sharp-shinned and Cooper's hawks) that really need to be 

 taken into account as enemies to agriculture. Omitting 

 the six species that feed largely on poultry and game, 

 2212 stomachs were examined, of which 56 per cent con- 

 tained mice and other small mammals, 27 per cent in- 

 sects, and only 3i per cent poultry and game-birds. In 

 view of these facts the folly of offering bounties for the 

 destruction of hawks and owls, as has been done by 

 several States, becomes apparent, and the importance of 

 an accurate knowledge of the economic status of our 

 common birds and mammals is overwhelmingly demon- 

 strated. 



Money value of hawks and owls. Mr. H. W. 

 Henshaw, chief of the Bureau of Biological Sur- 

 vey, estimates that Swainson's hawk saves the 

 Western farmers one hundred thousand dollars a 

 year through the destruction of injurious insects and 

 small rodents. 



Dr. C. Hart Merriam, former chief of the Bureau 

 of Biological Survey, estimates the value of a hawk 

 or owl as follows: 



It is within bounds to say that within the course of a 

 year every hawk and owl destroys at least a thousand 



