OWLS 311 



range the owl turns its head so as to keep the passerby under constant 

 surveillance; should the observer circle about the bird, the latter seem- 

 ingly finds no difficulty in rotating its head, even so as to look directly 

 over its own back. The dexterity of the bird in this respect has given rise 

 to the popular beUef that it can twist its head entirely around several times 

 without inconvenience! A curious mannerism of this owl is a profound 

 bow executed at irregular intervals. 



Nests of the Burrowing Owl are situated in squirrel burrows, at varying 

 distances from the entrances, but usually far beyond arm's length. The 

 birds make use of damp horse manure almost exclusively in making the 

 nest proper, hence a scattering of this material seen during the spring 

 months at the entrance to a squirrel hole may be counted on as an indi- 

 cation that a pair of Burrowing Owls has a nest within. 



Burrowing Owls are more prolific than tree-nesting species of owls, 

 doubtless because they are more subject to enemies than the latter species. 

 Late in summer family groups of as many as a dozen individuals are 

 occasionally seen within the radius of a few yards. 



California Pigmy Owl. Glaucidium gnoma calif ornicum Sclater 



Field characters. — Size very small (smallest of our owls) ; total length only about 

 7 inches, expanse HYo inches; head round, without ear tufts (fig. 39a); eyes yellow. 

 Color of plumage above grayish brown, relieved by small white spots; below white, with 

 sharp blackish streaks. Voice: Different from that of any other owl, and frequently 

 heard during the day; a single mellow whoot, repeated at intervals; or a prolonged 

 slow trill, followed by two or three isolated whoots: too-too-too-too-too-too-too-too-too; 

 ichoot; whoot; whoot. 



Occurrence. — Apparently a common permanent resident of the Transition Zone, and 

 perhaps also of the upper margin of the Upper Sonoran Zone. Inhabits sparse woods. 

 Definite stations: Yosemite VaUey, 3900-4200 feet; El Portal, 2000-2500 feet; Smith 

 Creek, on Coulterville Eoad, 2800 feet. 



In Yosemite Valley, the voice of the California Pigmy Owl was heard 

 more frequently than that of any other nocturnally active bird. The first 

 indication of the presence of this owl was a regular concert beginning at 

 early dark and lasting until dark, given on the evening of October 10, 1914, 

 in the strip of pine, cedar, and fir woods between the road and the cliff-wall 

 below LeConte Lodge. Two birds about 300 yards apart were answering 

 one another, and at one time a third was heard in the distance. The calls 

 consisted of a slow trill, rather mellow, but not so mellow nor of such full 

 quality as in the call of the California Screech Owl — more like the slow 

 roll of the flicker. This trill would continue some seconds, then came a 

 pause, then one note, an equal pause, and a second note. In one instance 

 a third note was added. The striking characteristic was the pause after 

 the trill, followed by the two detached notes. Once three far-separated 



