OWLS 



303 



Unlike the nest found in Yosemite Valley, all of those near Williams 

 Butte were clean and almost altogether free of animal remains, so that 

 little was to be learned concerning the food habits of the Long-eared Owls 

 there. In one instance, a freshly killed White-footed Mouse {Peromyscus 

 sp.) was found beneath an occupied nest. 



The pellets from the Yosemite nest (fig. 40) upon examination proved 

 to contain chiefly remains of the Yosemite Meadow Mouse. One long pellet 

 contained practically the entire 

 skeleton and hair of a mouse 

 of this species, together with 

 numerous feathers aud bones of 

 a Spurred Towhee. One pellet 

 contained bones from the hinder 

 portion of a Yosemite Pocket 

 Gopher (Thomomys alpinus 

 awahnee). The materials in all 

 of the pellets were consoli- 

 dated into surprisingly compact 

 masses. Often the long bones 

 of the rodent skeletons are 

 thrust into the open parts of a 

 skull; only rarely do they pro- 

 trude from the surface of a 

 pellet. The hair is felted down 

 so that the whole mass has a 

 smooth exterior, not likely to 

 scratch the owl's gullet. 



Hunting almost exclusively 

 at night, this owl does not cap- 

 ture many birds. The Spurred 

 Towhee here recorded as being captured is notable for being especially 

 active at dusk, just when the Long-eared Owl begins its nightly forays. 

 The Long-eared Owl, although roosting and nesting in dense thickets, does 

 its foraging in the open, and small birds are not as available there, at least 

 at night, as they are in the trees and bushes through which certain other 

 species of owls, known to capture birds, are wont to hunt. The meadow 

 mice and gophers are most active in the early hours of the night, when 

 presumably this owl does most of its foraging. 



Pig. 40. Pellets and bones picked up under 

 nest of Long-eared Owl in Yosemite Valley, 

 July 31, 1915. About % natural size. See text 

 for analysis. 



