296 



BRANCH CHORDATA 



ones devour many grasshoppers and other insects. They regurgitate the 

 indigestible portions of their prey in little oblong balls or pellets, which may 

 be found on the ground under the trees in which they nest. Owls nest in 

 holes in trees or banks, and lay from three to five pure white eggs. They 

 feed at night when the rats and mice are about. Thus they are of more 

 benefit than the day-feeding hawks. 



The great horned owl is the only species which is harmful to man, and 

 even it pays something for its chickens with the mice and rats it kills. 

 " Mr. O. E. Nilcs, of Ohio, once found in a nest of this bird several full-grown 



Fig. 242. Barn owl (Slrix pratin'cola). (Photograph from specimen.) 



Norway rats, and on the ground under the tree containing the nest he found 

 the bodies of 113 rats." 1 Now how many chickens would that number of 

 rats eat in a year? Probably more than one great horned owl would eat, 

 and a lot of corn besides. The investigations at Washington prove, how- 

 ever, that, although many rats and mice are eaten, so many small birds 

 and domestic fowls are destroyed by it, that one is justified in shooting the 

 great horned owl. 



Burrowing owls (see Prairie dogs) nest in the abandoned nests of prairie 

 dogs, but do not live in the same nest with them. 

 1 Hornaday, p. 223. 



