146 THE HAWKS AND OWLS OF THE UNITED STATES. 



tioned as occasionally contributing to its fare. Fully 75 per cent of 

 the stomaclis examined in the Department of Agriculture contained 

 mice. The remains of as many as six of these little mammals were 

 found in one stomach, and several contained three or four each. Prof. 

 F, E. L. Beal reported finding nothing but mice in the stomachs of a 

 pair which he killed in Story County, Iowa. They were shot in an 

 artificial grove swarming with small birds. Mr. Austin F. Park, of 

 Troy, N. T., in a report on the food of Hawks and Owls, which he 

 kindly sent to this Department, mentions mice and no other kind of 

 food as found in the stomachs of this species. 



Of the other mammals which this Owl feeds upon may be mentioned 

 shrews, gophers, and sometimes small rabbits. Shrews are not un- 

 common in the stomach contents. Dr. J. C. Merrill, in mentioning the 

 food of this bird at Fort Klamath, Oregon, says : " In one specimen a 

 pellet ready for regurgitation contained ten nearly perfect skulls of a 

 shrew, a species of which, and field mice, were nearly always found in 

 the stomachs." (Auk, vol. v, April, 1888, p. 146.) 



Unfortunately we have been unable to procure stomachs of this Owl 

 from the western plains which are infested with ground squirrels and 

 gophers, hence we do not know to what extent it feeds upon these 

 rodents. Mr. G. F. Brenninger, of Beattie, Kans., states (Ornith. and 

 Oologist, XI, 1886, 167) that the food of this species consists chiefly of 

 mice, insects and ground squirrels. It does not feed as extensively on 

 insects as either the Barred or Screech Owls, but there are reports 

 enough on the subject to show that grasshoppers, crickets, and beetles 

 at times form a considerable part of its food. It is quite exceptional 

 for this Owl to feed upon birds. Out of ninety stomachs examined by 

 us at the Department ten contained bird remains. 



A notable violation of its usual habit of feeding upon mice may be 

 quoted from Mr. William Brewster, as follows: "A small colony of 

 these birds had established itself upon a certain elevated part of the 

 island [Muskegat], spending the day in a tract of densely matted grass. 

 Scattered about in this retreat were the remains of at least a hundred 

 Terns, that they had killed and eaten. Many of these were fresh, while 

 others were in every stage of decomposition, or dried by the sun and 

 wind. In each case the breast had been picked clean, but in no in- 

 stance was any other portion disturbed. Every day at a certain time 

 these Owls sallied forth in search of fresh prey. We used regularly to 

 see them about sunset, sailing in circles over the island or beating 

 along the crests of the sand hills. They were invariably followed by 

 vast mobs of enraged Terns, which dived angrily down over the spot 

 where the Owl had alighted, or strung out in the wake of his flight like 

 the tail of a comet. The Owl commonly paid little attention to this 

 unbidden following, and apparently never tried to seize his persecutors 

 while on the wing, but on several occasions we saw a sitting bird 

 pounced, upon and borne off. Sometimes in the middle of the night a 



