CHIPPING SPAEEOW 453 



crown patch (pi. 8g) does not appear until the first pre-nuptial molt, the 

 following spring. 



The Brewer Sparrow which summers in the sagebrush east of the 

 mountains is much like the chipping sparrow but never has the bright 

 brown crown patch. The Black-chinned Sparrow of the foothill chaparral 

 has a black chin and blue-gray head and hind neck. During the summer 

 season the bill of the chipping sparrow is black or nearly so, but in other 

 seasons it is light-colored. In neither of the two other species named does 

 the bill ever become black. 



An interesting instance of adventitious coloration was met with at 

 Dudley, on Smith Creek, on July 11, 1920. An adult female chipping 

 sparrow was captured which had the plumage of the whole under surface 

 of the body strongly tinged wutli a pinkish color. This was doubtless due 

 to a 'dust bath' that the bird had taken in the roadway a mile or so up 

 the valley where the soil is predominatingly reddish in color. 



Western Chipping Sparrows are notably active, ever moving rapidly 

 about from place to place. They seek much of their food on the top of 

 the ground in open spots under trees, and they must needs hunt for it 

 over a considerable area rather than dig it out in one place ; their claw^s 

 are relatively small and weak as compared with those of the ground- 

 scratchers, like towhees and fox sparrows. Their activity seems never at 

 an end, for the}^ are as busy in the heat of midday as in the chill of 

 morning or cool of evening. 



The notes of the chipping sparrow are very simple. Both sexes utter 

 a single short weak tseet, while the song of the male is nothing more than 

 a cicada-like trill or buzz, monotonous to a degree, and strongly sustained 

 throughout. It lasts several seconds (2 to 9 in instances timed by us) and 

 is repeated over and over again at short intervals. 



The Western Chipping Sparrow is one of the most notable of our 

 passerine species in respect to the wide range of its occurrence. Indeed, 

 it is exceptional for the great diversity of climatic conditions under which 

 it thrives in the Yosemite section, this being, also, an index to its great 

 degree of hardihood. Some individual birds nest in the hot, dry, almost 

 parched San Joaquin Valley, where the temperature in summer is often 

 100° F. ; and others rear their broods about the cool snow-covered alpine 

 meadows almost at timber line. Yet, within these extreme life zones, as 

 well as through all the intervening territory, it is associated with a type 

 of habitat or niche which upon analysis is seen to recur with corresponding 

 regularity. This niche is the one in which small trees dot open expanses 

 of smooth, relatively dry ground, either practically bare, or grassy. Such 

 an 'association' is illustrated by an orchard at Snelling, by a blue oak 

 hillside at Pleasant Valley, by a tract of young yellow pines adjacent to 



