448 ANIMAL LIFE IN THE YOSEMITE 



that the Intermediate Sparrow does not winter in the vicinity of Mono 

 Lake, although it is common there during the last half of September ; prob- 

 ably it moves still farther south when the snow comes. On the west slope 

 of the mountains some of the birds which arrive first appear in the Tran- 

 sition Zone, as in Yosemite Valley. Then, with or before the coming of 

 the snow, they drop down to the foothill country where they remain 

 throughout the winter and spring. They evidently do not move up the 

 mountains again after the snow has gone but tarry at the lower levels until 

 read}' to depart directly to their nesting grounds in the north. On May 6, 

 1919, near Lagrange, about a dozen Intermediate Sparrows were seen 

 and one was collected. The fact that some of the birds linger late in spring 

 should not lead anyone into believing that this subspecies nests in Cali- 

 fornia. 



The two white-crowned sparrows may be readily distinguished in adult 

 plumage from all other sparrows in the Yosemite region by the striping 

 on their heads. Of the only two species which approach these birds in 

 coloration the Golden-crowned Sparrow has a broad, golden-yellow patch 

 on the middle of its crown and entirely lacks any pure white about its head, 

 and the Lark Sparrow has at all ages, a brown-striped head. The latter 

 has a conspicuously white-marked tail, as well. 



White-crowned sparrows are thicket-dwelling birds at all seasons. (See 

 pi. 18a and text fig. 21.) Often they may be seen on open level ground 

 or grassland but never far from some hedge or bush to which they can 

 resort if frightened. Their preference is for isolated or scattered shrubs 

 rather than for broad areas of solid chaparral. When frightened they 

 always seek shelter in brush instead of making off in the open, and when 

 resting between periods of foraging they perch in the tops of thickets. 



If a flock of White-crowns is come upon while it is foraging on the 

 ground, the birds get up quickly and dart into the shelter of some nearby 

 thicket, each pursuing a separate course. There they remain for a short 

 time, silent and motionless, but peering furtively at the intruder. After 

 a short period of quiet, if there be no further cause for fright, they become 

 active again, giving voice to faint seeps and, individually, they begin to 

 hop up in the brush where they can see about before venturing into the 

 open again. 



The general demeanor of the White-crown is almost sedate, just oppo- 

 site to that of the Song Sparrow; every movement is made with seeming 

 deliberation. As the White-crowns hop about on the ground they present 

 a trim appearance, due in part to their long legs and manner of standing 

 more nearly in an upright posture than most ground-feeding birds. Prac- 

 tically all of their foraging is done on the ground, but they do not habit- 

 ually scratch like the heavier bodied and stouter clawed Fox Sparrows and 

 towhees. 



