THE RELATIONS OF BIRDS TO MAN 379 



species) are chiefly beneficial ; that seven species are as bene- 

 ficial as they are harmful ; and that only the gyrfalcons, duck 

 hawk, sharp-shinned hawk, Cooper's hawk, and goshawk are 

 harmful. 



As examples of beneficial birds of prey may be mentioned (i) 

 the rough-leg hawk, which feeds almost entirely on meadow mice 

 during its six months' sojourn in the United States, (2) the red- 

 tailed hawk, or " hen hawk," sixty-six per cent of whose food 

 consists of injurious mammals and only seven per cent of poul- 

 try, and (3) the golden eagle, which is highly beneficial in cer- 

 tain localities because of the noxious rodents it destroys. The 

 Cooper's hawk is the real " chicken hawk " ; its food is made up 

 largely of poultry, pigeons, and wild birds, but it also includes 

 the harmful English sparrows. 



The beneficial qualities of birds are well shown by Dr. S. D. 

 Judd from a seven years' study of conditions on a small farm 

 near Marshall Hall, Maryland. Modern methods of investi- 

 gation led Dr. Judd to the following conclusions : 



" At Marshall Hall the English sparrow, the sharp- shinned, 

 and Cooper hawks, and the great horned owl are, as everywhere, 

 inimical to the farmers' interests and should be killed at every 

 opportunity. The sapsucker punctures orchard trees exten- 

 sively and should be shot. The study of the crow is unfavorable 

 in results so far as these particular farms are concerned, partly 

 because of special conditions. Its work in removing carrion 

 and destroying insects is serviceable, but it does damage to game, 

 poultry, fruit, and grain that more than counterbalances this 

 good, and it should be reduced in numbers. The crow blackbird 

 appears to be purely beneficial to these farms during the breeding 

 season and feeds extensively on weed seed during migration, 

 but at the latter time it is very injurious to grain. More de- 

 tailed observations are necessary to determine its proper status 

 at Marshall Hall. 



" The remaining species probably do more good than harm, 

 and except under unusual conditions should receive encourage- 



