OWLS AND FIELD MICE. 49 



low trees. Owing to its greater size, its food includes larger mam- 

 mals and birds than that of the last three species. Thus, it is able 

 to carry off a good-sized domestic fowl, and no doubt occasionally it 

 raids poultry. However, Doctor Fisher's examination of 109 stom- 

 achs of this species indicates that it is far less harmful than is gen- 

 erally supposed. Five stomachs contained poultry or game; 13, 

 other birds; 46, mice; 18, other mammals; 4, frogs; 1, lizard; 2, fish; 

 14, insects; 9, crayfish; and 20 were empty. Field mice were posi- 

 tively identified in more than half of the 46 stomachs that contained 

 mice. 



The great horned owl (Bubo virginianus) is the largest owl resi- 

 dent in the United States. Its range, including the subspecies, 

 extends from Costa Eica to the northern limit of deep forests and 

 from ocean to ocean. In South America occur a number of closely 

 related forms. 



The great horned owl has an evil reputation with most farmers 

 on account of its destruction of poultry. The bad reputation is only 

 partly merited. Doctor Fisher examined 127 stomachs of this species. 

 Of these, 31 contained poultry or game birds; 8, other birds; 13, 

 mice; 65, other mammals; 1, a scorpion; 1, a fish; 10, insects; and 

 17 were empty. About half the mice found were meadow voles and 

 the majority of the " other mammals " were rabbits. In central 

 Kansas, some years ago, I examined over a dozen nests of this species 

 in which young were being fed. The nests contained rabbits (Lepus 

 floridana mearnsi) , fox squirrels (Sciurus rufiventer), wood rats 

 (Neotoma baileyi), skunks (Mephitis), field mice, and in two cases 

 feathers of the flicker (Golaptes auratus luteus) , but in no case any 

 feathers or remains of poultry. In the few cases in which these 

 owls were observed by me to raid poultry the fowls were roosting 

 upon trees late in the fall, and hence were unnecessarily exposed to 

 attack. Where rats are abundant this owl has been known to prey 

 largely upon that rodent. O. E. Niles, in a letter to Charles Dury, 

 dated March 5, 1885, stated that at one time the remains of no less 

 than 113 rats had been counted under the nest of a great horned 

 owl.° On the whole, the great horned owl is not a very harmful 

 species, and as it is rapidly disappearing in most parts of the United 

 States warfare against it may be suspended. 



The screech owl (Ottis asio) is probably the most familiar of 

 American owls. Including its ten or more geographic races, it has 

 a wide distribution. It is too small to prey upon domestic fowls or 

 game and is beneficial. Doctor Fisher reported on the contents of 

 255 stomachs, of which 1 contained a tame pigeon; 38, other birds; 

 91, mice; 11, other mammals; 6, lizards and batrachians; 1, fish; 



« Jour. Gin. Soc. Nat. Hist, vol. 8, p. 63, 1885-86. 



