THE WESTERN YELLOW-THROAT. 201 



along the shaded banks of streams, but may possibly be found along more 

 open margins, consorting with Pipits, with which it shares a restless habit of 

 jilling, or curtseying, whimsically. 



No. 81. 



WESTERN YELLOW-THROAT. 



A. O. U. Xo. 681 a. Qeothlypis trichas occidentalis Brewster. 



Description. — Adult male in spyiny and summer: Above grayish olive-green, 

 brighter (less gray) on upper tail-coverts and tail, inclining to brownish on 

 crown and hindneck : an obliquely descending facial mask of black involving 

 forehead, lores, space about eyes, cheeks and (nmre narrowlv ) sides of neck; 

 along the posterior margin of this mask a narrow sharply contrasting area of 

 clear ash or white; chin, throat and breast rich yellow (inclining to gamboge) ; 

 sides of breast and sides heavily shaded with olive-gray and breast more or less 

 washed with same ; lower breast and below between yellow and palest olive-gray ; 

 under tail-coverts and bend of wing clear yellow. Adult male in autumn: 

 Occiput more decidedly brown ; upperparts clearer olive-green. Young male in 

 first autumn: Mask of adult merely indicated by black underlying sooty-brown on 

 sides of head ; coloration of underparts duller. Adult female in spring: Like adult 

 male but without black mask and ashy edging; crown and sides of head olive 

 gray: forehead tinged with brown; region above and about eye notably paler; 

 coloration of underparts duller and paler, sometimes clearly yellow on under 

 tail-coverts alone. Young female in first autiimn: Similar to adult but under- 

 parts still duller and dingier, breast and sides heavily washed with brownish 

 olive. Length of adult about 5.00 (127): wing 2.26 (57.5); tail 2.19 (55.8); 

 bill .44 (11.3); tarsus .83 (21). 



Recognition Marks. — ^^'arbler size : black mask and white fillet of male 

 distinctive. The female is a much more difficult bird to recognize — perhaps best 

 known by peculiar sordid olive-brownish-}ellow shade of underparts. The pale 

 orbital area also assists, but one must live with these birds to know them 

 infallibly. 



Nesting. — Nest: of coarse grasses lined with fine grass and horse-hair; 

 placed 1-2 feet high in tussock of grass or rank herbage, usually near water; 

 outside 43^ wide by 33/ deep, inside 2'4 by 15^2. Eggs: 4 or 5, dotted and 

 spotted or, rarely, streaked with blackish and lavender, .^v. Size, .70 x .56 

 (17.8 X 14.2). Season: May 20-June 10; one brood. 



General Range. — Western United States and British Columbia, except 

 Pacific coast district, east to western portions of the Great Plains ; breeding 

 southward into Mexico and northern Lower California; in winter south to Cape 

 St. Lucas and western Mexico. 



Range in Washington. — Summer resident east of the Cascade Mountains; 

 found chiefly in rye-grass districts and in vicinity of water. 



