JUNCOS 459 



Sierra Junco. Junco oreganus thurberi Anthony-^ 



Field characters. — A small sparrow (total length about 6 inches, tail about 2^2 

 inches long). Head, neck, and breast covered by solid black (most intense in males, 

 grayish toned in females and immatures), sharply set off from white on under surface 

 of body. Bill ^Yhitish-appearing. Back and wings dark brown, unmarked; tail black 

 centrally, two outer feathers on each side pure white. Juvenile birds lack the black 

 'cowl' and have the whole head and body, both above and below, streaked. When 

 on ground, hops about rapidly in zigzag course; if flushed, rises quickly, spreading 

 tail so that white margin shows conspicuously; usually takes refuge within nearby 

 trees or large bushes. Voice: Song of male a quavering trill, metallic in quality, rapid 

 in utterance, eetle, eetle, eetle, eetle .... continued for from one to three seconds, 

 weakening in intensity toward the end; repeated at irregular intervals. Call of both 

 sexes a low seep or sharper isiclc; one of these notes often given several times in quick 

 succession as birds of a family or flock rise from ground. 



Occurrence. — Abundant summer visitant throughout the Transition, Canadian, and 

 Hudsonian zones on both sides of Sierra Nevada. Recorded in summer from 3 miles 

 east of Coulterville and from Bullion Mountain eastward across the mountains to Parker 

 Creek (at 7500 feet) and Warren Mountain. As a rule the range of this bird is 

 limited altitudinally at timber line; the highest elevation at which we saw it was 11,000 

 feet on Parsons Peak, September 6, 1915. In winter descends to below the level of 

 heavy snow, occupying the whole of foothill and lowland country; a few may remain 

 as high as Yosemite Valley. Found in numbers in winter at El Portal and 6 miles east 

 of Coulterville and from there westward to Lagrange and Snelling. In summer lives 

 in and about openings in forest or along open stream banks; in winter ranges widely, 

 but not onto open prairie. In pairs at nesting time, but in flocks of varying size during 

 other parts of year. 



The Sierra Junco or Snowbird has proved, by actual census, to be 

 the most abundant species of bird in the Yosemite section. During the 

 summer season it is common throughout the forested portions of the 

 mountains embracing the Transition, Canadian, and Hudsonian zones, on 

 both slopes, while in winter it is abundant in the Upper Sonoran foothills 

 of the west slope, and occurs in some numbers in the Transition and Lower 

 Sonoran zones as well. Because it is thus a species of wide occurrence, 

 and in addition possesses a distinctive type of coloration, we have chosen 

 it for our standard of comparison in discussing the other small birds of 

 the region. 



The whole forepart of the Sierra Junco 's body is covered by a solid 

 dark cowl, jet black in the adult males, but grayish toned in female and 

 immature birds. This black ends below abruptly against the white of the 

 belly. The back and wings lack contrasted markings of anj^ sort, but when 



28 In addition to the prevalent Sierra Junco there is present in winter in small 

 numbers another subspecies of the 'Oregon' Junco, the Shufeldt Junco, Jtmco oreganus 

 shufeldti Coale, which summers in northwestern North America interiorly. This race 

 has the wing and tail somewhat longer, the sides more dusky (less pink tinged), and 

 the back of a duller brown than has the Sierra Junco. Specimens are at hand from 

 Dudley (on Smith Creek), six miles east of Coulterville, taken December 25, 1918, and 

 January 27, 1919. 



