570 BULLETIN 203, UNITED STATES NATIONAL MUSEUM 



described as follows: "Upper parts nearly uniform pale yellowish- 

 olive, with a tinge of brown on the occiput; throat, jugulum, breast, 

 anterior portion of abdomen, and under tail-coverts rich, pure yellow ; 

 sides of body warm ochraceous brown strongly tinged with yellow; 

 middle of abdomen anteriorly creamy white; a black mask on the 

 front and sides of the head bordered behind by a broad band of 

 creamy white, slightly tinged with bluish; much concealed yellow 

 on the feathers of the crown." In comparing G. trichas occidentalis 

 with G. t. trichas he states it "is somewhat larger * * * and its 

 tail is disproportionately longer. Its upper parts always paler and 

 usually yellower; the yellow of the under parts is decidedly richer 

 and purer, and extends much farther down on the abdomen, fre- 

 quently tinging nearly all of the body beneath; the flanks are paler 

 and more ochraceous; the white of the head purer and generally 

 broader." 



W. Palmer (1900) in comparing the western with the northern 

 yellowthroat states : 



The western bird, occidentalis, is a little larger than hrachidactyla, but grayer 

 in dorsal coloration with a broad white posterior edging of the facial black. 

 The yellow of the throat is more intense and the black of the forehead is 

 relatively narrower. Freshly molted adult birds are but slightly paler dor- 

 sally than eastern birds, but immature birds are fully as dark and as brown 

 above as in similar aged eastern birds. The females in summer are as a rule 

 less yellowish and paler than eastern birds. A few have decidedly yellow 

 throats but it is far from the rule. The immature females are browner and 

 duller above and beneath with a much browner tinge across the breast than in 

 either trichas or Brachidactyla, 



The wing formula and the relative length of the primaries exhibit 

 distinct differences from those of the eastern forms. 



The western yellowthroat breeds from Oregon, southern Idaho, and 

 the western portion of the Great Plains (North and South Dakota 

 and Texas) south to northern New Mexico. The distribution of the 

 western yellow-throat in California where there are also the two 

 forms G. t. sinuosa and G. t. scirpicola represented, is complicated. 

 According to Grinnell and Miller ( 1944) : "In breeding season, valleys 

 of northern California from the coast east to the Nevada line; in 

 central California south to northern Sonoma County, thence east of 

 San Francisco Bay through Solano and eastern Contra Costa coun- 

 ties to the Monterey Bay area and the Salinas Valley ; extends south 

 into central San Joaquin Valley where intergradation with scirpicola 

 takes place; similarly east of the Sierra Nevada intergradation be- 

 comes apparent in Owens Valley, Inyo County." 



In winter the western yellowthroat is found in the Sacramento and 

 San Joaquin Valleys, Calif., from Tehama County southward to south- 



