36 



stance by such an increase of grubs and grasshoppers as to 

 destroy the grass crop over large areas, and it would be very 

 unwise to allow the extirpation of this bird. 



Hawks and Owls. 



Many hawks are not only useful in nature as regulators of 

 mammal life but they are beneficial to the farmer by destroy- 

 ing grasshoppers and other large insects, squirrels, rats and 

 mice. Among the most useful of all is the rough-legged hawk 

 (Archibuteo lagopus sancti-johannis) , which very rarely has been 

 known to kill birds, and never, so far as known to me, to 

 molest poultry. The species is large, flaps and sails rather 

 slowly, and thus makes a good mark for a shotgun, or, sitting 

 upon a dead tree or stake, furnishes an excellent target for a 

 rifle. Many are shot annually in fall, winter or spring, mis- 

 taken for "hen hawks." The number of mice killed by these 

 birds is enormous, and the shooting of the species is a serious 

 detriment to agriculture. Nevertheless, farmers often boast of 

 the number that they have killed and gunners shoot them at 

 every opportunity. They would much better devote their 

 energies to shooting vagabond cats, which do far less good 

 and much more harm. 



One can hardly write of the economic relations of hawks 

 and owls in this country without referring to the work of Dr. 

 A. K. Fisher of the Biological Survey. During his researches 

 he has examined the contents of more than two thousand 

 seven hundred stomachs of these birds, with the result that 

 out of the seventy-three species investigated only six in all the 

 United States were found harmful, and all the rest were classed 

 as beneficial. Omitting the six species that feed largely on 

 poultry and game, two thousand two hundred and twelve 

 stomachs were examined, 56 per cent of which contained mice 

 and other small mammals, 27 per cent insects, and only 3j 

 per cent poultry or game birds. Of the six harmful species, 

 three are so rare that they have little effect, and in New Eng- 

 land only two, the cooper's hawk (Accipiter cooperi), and the 

 sharp-shinned hawk (Accipiter mlox), are really common and 

 generally injurious. 1 Nevertheless, individual birds of several 



1 The goshawk (Astur atricapillus atricapillus), the duck hawk (Falco peregrinus anatum), and 

 the pigeon hawk (Falco columbarius columbariua) are exceedingly destructive to birds, but are 

 uncommon in Massachusetts. 



