The Hermit Warbler 



No. 91 



Hermit Warbler 



A. O. U. No. 669. Dendroica occidentalis (Townsend). 



Synonym. — Western Warbler. 



Description. — Adult male in breeding plumage: Forehead, crown and sides 

 of head and neck, broadly, rich lemon-yellow, sharply defined below by black of chin, 

 throat and upper chest, less sharply above by black of occiput or hind-neck; this in 

 turn shading through mingled olive and black into gray of remaining upperparts; 

 upper plumage more or less tinged with olive-green and streaked more or less broadly 

 with black; wings and tail black with grayish edgings; middle and greater coverts 

 tipped with white forming two conspicuous wing-bars, — outermost pair of tail-feathers 

 chiefly white on both webs, next pair white on terminal half of inner web, and third 

 pair marked with longitudinal spot near tip; black of chest with convex posterior 

 outline sharply defined from white of remaining underparts. Bill blackish; legs 

 and feet dark brown; iris brown. Adult male in fall and winter: Yellow of crown 

 veiled by olive-green, sooty olive or blackish; black of throat veiled by whitish tips; 

 black streaking of upperparts less conspicuous. Adult female in spring: Like male 

 but much duller; the black of throat and chest wanting, or else heavily veiled, — upon the 

 throat with yellow, upon the breast with sordid buffy; the yellow of head duller, pale 

 yellow; the feathers of crown generously tipped with sooty olive or blackish; the black 

 of cervix wanting; remaining upperparts dull bluish gray, glossed with olive-green; 

 black streaks obsolete; remaining underparts sordid white or dull buffy. Immature 

 birds resemble the adult female, but the olive-green element in the upper plumage 

 much strengthened, nearly pure warbler green on cervix; the pileum chiefly olive- 

 green with mesial streaks of black; the black also more or less present in broad wedge- 

 shaped streaks on back (most abundant in males ?) ; underparts more strongly buffy, 

 with throat often buffy-white rather than yellow. Length about 130.8 (5.15). Av. of 

 10 adult males in M. V. Z. colls.: wing 67 (2.64); tail 50.8 (2.00); bill 9.8 (.39); tarsus 

 18.9 (.74). Av. of 5 adult females: wing 63.3 (2.49); tail 49 (1.93); bill 9.6 (.38); tarsus 

 17.8 (.70). 



Recognition Marks. — Warbler size; yellow mask of male outlined against black 

 of throat and hind-neck distinctive. Female and young more difficult, but essential 

 yellowness of head contrasting with gray and sordid white usually suggestive. 



Nesting. — Nest: Saddled on horizontal branch of fir tree at considerable height; 

 a compact structure of fir-twigs, mosses, and vegetable down; lined with fine grass and 

 horsehair; measures outside 4 inches wide by 2^4 deep; inside, 2 wide by 1% deep. 

 Eggs: 4 or 5; dull white, heavily spotted and blotched with shades of reddish brown and 

 vinaceous gray. Av. size, 17 x 13.2 (.67 x .52). Season: c. June 1st; one brood. 



General Range. — Pacific Coast district and Sierra-Cascade system with its 

 outliers, north to British Columbia; Nevada and Arizona in migrations; Mexico and 

 Guatemala in winter. 



Distribution in California. — Fairl}' common breeder in the Transition zone 

 of the Sierras from Mt. Whitney north to Shasta; doubtfully a breeder in the San 

 Bernardino Mountains; common migrant through southern California and on both 

 sides of the Sierras; less common or sporadic spring migrant through west central 



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