470 THRUSHES, SOLITAIRES, BLUEBIRDS, ETC. 



migrates through the United States west to the Rocky Mountains and 

 south to Costa Rica. 



Nest. — In low bushes or on the ground, bulky, and compact, composed 

 largely of mosses. Eggs: o or 4, greenish blue, spotted with rusty 

 brown. 



758. Hylocichla ustulata (Nutt.). Russet-backed Thrush. 



Upper parts olii'e brown, wings and tail often browner; buffy eye ring 

 distinct ; sides of head tinged with tawny ; chest pale buff, whitish in 

 summer, marked with narrow triangular spots ; under parts white, sides 

 tinged with olive brown. Length : 6.90-7.00, wing 3.60-4.00, tail 2.80- 

 3.30, bill .50-.60. 



Bemarks. — The ustulata group is distinguished by conspicuous buffy 

 eye ring and tawny or buffy cheeks ; and ustulata and its subspecies acdica 

 and ahnce are to be distinguished from swainsoni by their brown tails, 

 that of swainsoni being olive like the back. 



Distribution. — Breeds in Boreal and Transition zones of the Pacific coast 

 region from Alaska to California ; winters in Lower California and from 

 Mexico to Guatemala. 



Nest. — In bushes or small trees, usually near water, bulky and compact, 

 made largely of mosses and shreds of bark. Eggs : 4 or 5, light greenish 

 blue, averaging decidedly paler than those of alicice, spotted with rusty 

 brown. 



Food. — Ants, caterpillars, weevils, beetles, moths, and other insects, 

 with small fruit. 



At Gray's Harbor, Washington, Mr. Lawrence says, the russet- 

 backed thrush is very common throughout the river-bottoms, and 

 common on the small prairies and in the timber. It comes about 

 the time the salmon berry bushes blossom, and goes when their 

 berries are gone. 



758a. H. U. swainsoni (Cab.). Olive-backed Thrush. 



Upper parts uniform olive or grayish olive ; buffy eye ring conspicuous ; 

 .^ides of head buffy, marked with darker ; chest bright buff, marked with 

 wide blackish streaks ; under parts white, sides olive brown. Length : 

 6.35-7.55, wing 3.80-4.10, tail 2.80-3.10, bill .50-.55. 



Bemarks. — The olive-backed is distinguished from the rest of the 

 ustulata group by having the tail of the same or nearly the same color as 

 the back, and by its darker and broader chest streaks. It is also distin- 

 guished from the gray-cheeked by its buffy cheeks and buffy eye ring. 



Distribution. — Breeds in Canadian zone in eastern North America ; 

 migrates to Cuba and through Colorado and Texas, south to Guatemala 

 and South America. 



Nest and eggs. — Like those of the russet-backed thrush. 



Food. — Among other things, caterpillars, rose hips, and the fruit of 

 smilax and hackberry. 



758b. H. U. Cedica Oberh. Monterey Thrush. 



Similar to swainsoni, but olive of upper parts somewhat tinged with 

 brown, tail and tail coverts brown, and .sides and flanks browner. Com- 

 pared with ustulata, adica is much less rufous. 



Distribution. — Breeds from the interior of southern Oregon south 

 through California, except along the northern coast ; winters in Arizona 

 and Mexico, 



