446 ANIMAL LIFE IN THE YOSEMITE 



as none were added by the following morning the set was believed to be 

 complete. When this nest was again visited, on June 4, it was found to 

 have been raided; one egg was gone and another lay broken outside the 

 nest. Neither of the birds was seen on this last visit. The nature of 

 the enemy was not determinable but it seemed likely that he had been 

 frightened away before his meal was completed, as even the egg which 

 was broken open still held some of its contents. 



During the fall and winter months the lark sparrows gather into flocks 

 which are usually small. But at El Portal, in December, at least 25 of 

 the birds were seen together in a live oak standing out by itself in an open 

 field. The species habitually forages upon the ground among grasses and 

 other low vegetation ; but when the individuals are alarmed they seek 

 perches a few feet above the ground, whence, when further pressed, they 

 fly off in an open course to a distance. They do not as a rule dive into the 

 brush as do the White-crowns ; nor do they run aside through the grass, 

 as do the Savannahs. 



Although these birds are permanent residents west of the mountains, 

 they are probably only summer visitants in the elevated Mono Lake 

 country. The first lark sparrow observed in the latter region was seen in 

 the garden at Farrington's ranch, near Williams Butte, May 2 (1916). 

 Others were encountered later the same month at this ranch, and also at 

 Mono Lake Post Office. 



White-crowned Sparrows. Zonotrichia leucophrys (Forster)^^ 



Field characters. — Slightly larger than Junco (length about 7 inches). Sexes alike. 

 Top and back of head with three white and four black stripes alternating, the middle 

 stripe over the crown being white (pi. 8a, c) ; upper surface of body streaked with 

 brown on a gray ground; tail plain brown; some small white spots forming two rows 

 on wing; under surface of body grayish white, unstreaked. Immature birds have black 

 and white on head replaced by reddish brown and dull buff, respectively. (See pi. 86.) 

 Voice: Males have a clear set song; both sexes utter a sharp call or alarm note, peenk. 



Occurrence.— Common summer visitant to Hudsonian Zone (subspecies leucophrys) ; 

 common fall visitant to Transition Zone and winter visitant to Sonoran Zones on west 

 side of Sierras, and fall and spring migrant east of the mountains in vicinity of Mono 

 Lake (subspecies gam'beli).^'^ 



27 Two subspecies of the White-crowned Sparrow occur in the Yosemite region, namely : 

 (1) The Hudsonian White-crowned Sparrow, Zonotrichia leucophrys leucophrys 

 (Forster), which summers in the northeastern and mountainous parts of North America 

 east of the Pacific humid coast strip, and which is distinguished j^rincipally by the 

 small area between bill and eye (technically, the lores) being black (pi. 8a), is a sum- 

 mer visitant to the Hudsonian Zone of the Yosemite section of the Sierra Nevada. It 

 was found established for the summer from near Mono Meadow and Porcupine Flat east- 

 ward to the vicinity of Williams Butte ; it passes through the lower levels on both sides 

 of the mountains during the spring migration. One case of nesting in Yosemite Valley 

 has been reported (Dawson, 1916, p. 28). It arrives in Yosemite region by early May 

 at least and departs about the end of September. It frequents willow thickets, in pairs 

 or family parties. 



(2) The Intermediate White-crowned Sparrow, Zonotrichia leucophrys gambeli 

 (Nuttall), which is found in summer in the interior of northwestern North America from 



