438 ANIMAL LIFE IN THE YOSEMITE 



Pine Siskin. Spinus pinus piniis (Wilson) 



Field characters. — About half size of Juiico; size and general habits of a goldfinch. 

 Sexes practically alike. Tail deeply notched at end (fig. 53d). Whole body plumage 

 both above and below, streaked brown and dull white; middle of wing and whole base 

 of tail canary yellow, these areas of bright color showing best as birds take flight. 

 Flight undulating to marked degree. Voice: A plaintive call note, swe-ah', with rising 

 inflection; also a throaty 'watch-winding' note, zwe-e-e-e-et or zree-e-e-e-eet, the inflec- 

 tion rising and the intensity increasing until the call is ended abruptly ; in summer there 

 is also a goldfinch-like song. 



Occurrence. — Common in spring, summer, and fall in Transition, Canadian, and 

 Hudsonian zones west of Sierran crest; recorded from Hazel Green eastward to Tioga 

 Pass. In winter small numbers are found in the Sonoran zones, as at Snelling. Present 

 in Yosemite Valley at least from April to December. Frequents both coniferous and 

 deciduous trees, and also often forages about meadows on flower heads close to or on 

 ground. Usually in flocks. 



In general characteristics the Pine Siskin is very much like the gold- 

 finches, but it does not wear so bright a pattern of plumage, at least as 

 regards the male sex. Indeed, its dully streaked pattern recalls more the 

 coloration of some kind of ground-dwelling sparrow. Only by a yellow 

 bar on the wing and by yellow at the base of the tail (fig. 53(i), which 

 markings are partially concealed, does its coloration suggest kinship with 

 the more brilliantly marked birds. 



In the forested region on the west slope of the Sierra Nevada from 

 Hazel Green, Chinquapin, and Yosemite Valley east to the crest line 

 of the mountains. Pine Siskins are relatively common from early spring 

 to late fall. Our earliest seasonal record for the species in Yosemite Valley 

 is for April 30 (1916) and the latest, made on the margin of the Valley, 

 at Fort Monroe, is for November 26 (1914). In January a few were noted 

 at Snelling. We saw none east of the Sierran crest at any time, nor were 

 any observed in the Yosemite Valley or its environs during the season 

 of heavy snow. It remains to be determined whether any of the siskin 

 population stays in the higher altitudes throughout the winter. The 

 numbers which occur at the lower levels to the west in that season are 

 relatively small, and some of the birds may go entirely out of the moun- 

 tains, wintering still farther west or to the southward. 



The general behavior of Pine Siskins is much like that of the gold- 

 finches. The siskin is, perhaps, more persistently flocking in habit. The 

 flocks vary in size from a half-dozen to a half-hundred or even more 

 individuals. In flight each member of the band rises and falls indepen- 

 dently of its companions yet the flock formation in this species is usually 

 more compact than is that of the goldfinches. The flight course of a 

 flock is apt to be roundabout or circling, both when the birds are leaving 



