164 



by farmers, hawks generally keep away from farm buildings. In the 

 open fields, however, where rats feed in early morning and late after- 

 noon, hawks find many of the rodents. 



The species of hawks that more commonly feed on rats are the 

 buzzard hawks, including the red- tailed (Buteo borealis and sub- 

 species), the red-shouldered (B. lineatus), the broad-winged (B. pla- 

 typterus), and the Swainson (B. swainsoni}; the rough-legged hawks 

 (Archibuteo\ two species; and, to a less extent, the marsh harrier 

 (Circus hudsonius), and a few other species. 



The writer has several times found the remains of rats about the 

 nest of the red-tailed hawk. Of the 562 stomachs of this species 

 examined by Dr. A. K. Fisher, of the Biological Survey, less than 10 

 per cent contained poultry or game, while more than 70 per cent con- 

 tained injurious rodents. Most of the other species of buzzard 

 hawks made a better showing even than this, especially the Swainson 

 hawk, which had fed entirely on harmful rodents and insects. The 

 stomachs of rough-legged hawks examined nearly all contained harm- 

 ful rodents and none of them contained remains of birds of any sort. 



A few months ago, while walking on the Potomac flats near Wash- 

 ington, the writer met some boys who had just shot a red-tailed hawk. 

 Its crop was greatly distended, and later examination showed that 

 the bird had recently eaten an enormous brown rat. Although the 

 the shooting was contrary to law, when it was reported to the nearest 

 policeman, his comment was, "Oh, a hawk! Why, it's a good thing 

 to shoot a hawk." The incident illustrates the general popular 

 prejudice against all hawks. 



OWLS. 



Because they hunt by twilight and at night, owls are more efficient 

 than hawks in destroying rats. All American owls, except the more 

 diminutive species, prey on the common rat. Even the little screech 

 owl (Otus asio) feeds on young rats. 



Of all our species, the barn owl (Aluco pratincola) is preeminent as 

 a destroyer of rats. It lives commonly about farm buildings, some- 

 times even making its nest and rearing its young in the pigeon loft 

 without molesting the pigeons. In such surroundings its opportuni- 

 ties for securing rats are excellent, and no other wild bird is so useful 

 on the farm. The late Henry Newman once stated that every barn 

 owl is worth 5 a year to the British nation, and the value of the bird 

 to the American farmer is not less. 



Owls, hawks, and other birds of prey that swallow their quarry 

 whole or in large pieces do not digest the bones, fur, and feathers. 

 They eject these indigestible parts in the form of large pellets, in which 

 the fur or feathers surround the bones. The contents of these casts 



a Hawks and Owls of the United States, p. 62, 1893. 



