184 THE HAWKS AND OWLS OF THE UNITED STATES. 



mice, aud very few Owls ever visited the island. About this date the 

 house mouse (Mm mmeulus) was introduced from ships aud the Bed- 

 backed Mouse (Evotomys rutilus) in some unknown way. Twelve years 

 afterwards he found the island swarming with mice and an abundance 

 of resident Owls, affording a striking demonstration of the perfect 

 workings of nature, for with the undue increase of any one species there 

 occurs a corresponding increase of its natural enemies. 



Dr. Stejneger says: "From * * * the contents of the stomachs, 

 it would seem as if Arvicola was almost their only food. But it is only 

 fair to state that I have seen this owl chase sea ducks, especially His- 

 trionicus Mstrionicm out at the reef, very much in the same manner as 

 does the falcon." (Bull. U. S. Nat. Mus., No. 29, 1885, p. 223.) 



Mr. Thomas Mcllraith, in 'The Birds of Ontario,' mentions one which 

 made several attempts to capture a wounded duck, in which effort it 

 probably would have succeeded had it not itself been killed. On the 

 Mackenzie Biver, Bichardson relates that one of the Owls was seen to 

 fly over a cliff and carry off a full-fledged Duck Hawk in its claws, with 

 which it alighted on the opposite bank of the river. The parent Hawk 

 followed, uttering loud screams, and darting down struck the Owl, 

 killing it instantly. Wilson and Audubon, who knew the bird only 

 during its short winter visits, speak of its food as follows : 



Wilson says: "The usual food of this species is said to be hares, 

 grouse, rabbits, ducks, mice, and even carrion. * * * I met with 

 this bird on Oswego Biver, New York State, a little below the Falls, 

 vigilantly watching for fish." While according to Audubon, "Its usual 

 food, while it remains with us, consists of hares, squirrels, rats, and 

 fishes, portions of all of which I have found in its stomach. * * * 

 In one of them I found the whole of a large brown rat, in pieces of con- 

 siderable size, the head and tail almost entire." 



Although most of the Owls will occasionally eat fish, this species 

 seems to be especially fond of them, and Avhen kept in confinement will 

 eat them in preference to anything else except mice. Audubon de- 

 scribes the manner in which it catches fish, being an eye witness to 

 the occurrence several times, and the following is what he says: "At 

 the break of day one morning, when I lay hidden in a pile of floated 

 logs at the Falls of the Ohio, waiting for a shot at some wild geese, I had 

 an opportunity of seeing this owl secure fish in the following manner: 

 While watching for their prey on the borders of the pots, they invari- 

 ably lay flat on the rock, with the body placed lengthwise along the 

 border of the hole, the head also laid down, but turned towards the 

 water. One might have supposed the bird sound asleep, as it would re- 

 main in the same position until a good opportunity of securing a fish 

 occurred, which I believe was never missed ; for as the latter unwit- 

 tingly rose to the surface near the edge, that instant the owl thrust 

 out the foot next the water, and, with the quickness of lightning, seized 

 it and drew it out. The owl then removed to the distance of a few 



