OWLS 309 



Such was not the case, however, as regards the Yosemite region. Although 

 we made special search for it at several likely points in the foothill belt 

 we ourselves failed to find it there at all. 



Our only record is of a single bird seen in the golden oaks near the 

 foot of the Yosemite Falls Trail in Yosemite Valley on the evening of 

 November 20, 1915, just as our field work for the season was drawing to 

 a close. The bird was heard and momentarily seen close at hand. Within 

 a quarter of an hour there were also heard in the same vicinity, besides 

 this screech owl, 2 great horned oavIs, a pigmy owl, and a spotted owl. 



On January 13, 1916, Mr. Donald D. McLean succeeded in capturing 

 alive a screech owl at Smith Creek, east of Coulterville. 



Pacific Horned Owl. Bubo virginianiis pacificus Cassin 



Field characters. — Large size (length about 20 inclies) ; ear tufts present and con- 

 spicuous (fig. 39e) ; exceeded in size only by Great Gray Owl, which lacks ear tufts. 

 Plumage chiefly a mixture of dark and light brown, streaked on back and barred on 

 under surface; eyes yellow. Voice: A deep, reverberant, deliberate, whoo, whoo-ivhoo, 

 tvhoo, or too-icJioo, tvhoo. 



Occurrence. — Resident in moderate numbers throughout the region below Hudsonian 

 Zone; observed in Hudsonian Zone once, at Ten Lakes. Lives in open woods in 

 mountains, along wooded ravines in foothills, and in river-bottom timber in the lowlands. 



The Pacific Horned Owl is the owl which ranges most widely through 

 the Yosemite region. It is nowhere common, yet it is likely to be met with 

 anywhere from the cottonwood groves along the Merced River at Snelling 

 to the Jeffrey pine woods of the Canadian Zone. In the Hudsonian Zone 

 we found it only at Ten Lakes; its general absence from the higher zones 

 may be due to the lack there of appropriate food. On the east slope of 

 the Sierras we found the species at Walker Lake. 



Horned owls, wary birds more often heard than seen, usually will not 

 permit of close approach. It seems probable that in detecting the presence 

 of people they depend fully as much on hearing as on sight. At Lagrange, 

 Mr. Dixon tried several times to get near a horned owl heard regularly on 

 several successive evenings in a certain steep-sided, tree-clothed ravine. 

 Keeping entirely out of sight he tried to approach behind a ledge of rim- 

 rock ; but the owl, seeming to hear his footsteps, flushed while he was some 

 distance away and stilf completely out of sight. 



These owls begin to stir about at dusk and at that time are wont to 

 take commanding positions on the bare tops of dead trees whence they 

 can watch or listen for prey and detect the distant approach of enemies.. 

 Their activity extends throughout the night and until late dawn. Their 

 deep-toned reverberant hooting is most often heard in the evening and 

 morning twilight; but, as many a camper can testify, it may be uttered 



