GREAT HORNED OWL 315 



other, as though wounded. Twice the bird left the ground perching in the tops 

 of nearby trees and then the well known "hoot" was heard, which is the usual form 

 of protestation. In each instance, after a few moments' inspection, the bird 

 returned to the ground and continued the fluttering actions which lasted while I 

 was in the vicinity of the nest. 



Dr. Errington (1932a) has noticed similar behavior on three suc- 

 cessive years by what he believes to be the same owl. 



There is abundant evidence that the eyes of the great horned owl 

 are admirably adapted for effective use in either darkness or bright 

 light. Dr. Elliott Coues (1874) says of his captive owls: 



Their vision was acute at all hours. I often saw them look up and follow with 

 their eyes the motions of a grasshopper or butterfly, flickering several yards up 

 in the air. On one occasion in particular, I saw them both gazing steadfastly, 

 and on looking up to see what had attracted their attention, I was myself blinded 

 by the glare, for the direction was exactly in the sun's eye. But a few moments 

 afterward I discovered a pair of white Cranes, floating in circles half a mile high. 

 The Owl's eyes endured a glare that my own could not, and the birds certainly 

 saw the objects, for they slowly moved the head as the Cranes passed over. 

 * * * Nor was the inner eyelid drawn over the ball to shade it. I had 

 abundant evidence, on this and numerous other occasions, that the movements 

 of the bird's iris are entirely under the control of the will, instead, as commonly 

 supposed, of being automatic, depending upon the stimulus of light. I frequently 

 saw them instantaneously contract or relax the quivering iris in accommodating 

 their vision to different objects, or different distances; and moreover, they could 

 move the two irides independently of each other. 



Hearing is exceedingly acute in these and other owls. Mrs. Reed 

 (1925) says of her captive owls: "It was almost impossible to surprise 

 any one of them in the shed although the approach was made as 

 cautiously as possible and from the side where no glimpse of the 

 observer could be obtained. Not only was it possible for them to 

 hear the slightest sound but they could readily localize it. Experi- 

 ments were made where the observer, concealed, gave various sounds 

 and each time the direction was detected. A tapping on the attic 

 window when one of the captives was perched at the open side of the 

 shed invariably brought a response, the one in question focusing its 

 vision at the origin of the noise." 



She seems to agree with Frank Bolles that the sense of smell is not 

 highly developed in these owls; her birds disliked putrid meat but 

 always tasted it before rejecting it. Mr. Shelley, on the other hand, 

 says that he has seen owls caught in traps "where the meat was wholly 

 concealed by refuse and the bird could have been interested only by 

 the musky odor permeating from fresh muskrat carcass/' 



Great horned owls seldom make satisfactory pets. The one that I 

 raised from a nestling and kept for over two years never became tame ; 

 it was always sullen and ugly; it would fly in a rage at any stranger 

 that entered its cage, and often at me. Three of Mrs. Reed's owls 

 made gentle and responsive pets, though no special effort was made 



