Olive-backed Thrush 519 
Habits.—Henshaw found the Willow-Thrush plentiful 
near Fort Garland, among the deep swampy thickets 
along the streams, where he often heard the “ weird 
music of its beautiful song.” He also took two nests 
of this species, both built on the ground and modelled in 
and above those obviously used in the previous season. 
He described the eggs as blue, and slightly darker than 
those of Audubon’s Thrush. Gale only took one nest 
of this species ; it was placed about three feet above the 
ground, in a low evergreen bush in a shady and wooded 
cafion near Gold Hill. The nest was made up of plant 
stems, mosses and grasses, and lined with fine rootlets, 
but with no mud or clay. The eggs, four in number, 
were light blue, and averaged ‘90 x °70. This nest was 
taken June 13th, but there appears to be some little 
doubt about the identification. 
Olive-backed Thrush. Hylocichla ustulata swainsoni. 
A.O.U. Checklist no 758a—Oolorado Records—Trippe 74, p. 228; 
Henshaw 75, p. 147; Minot 80, p. 224; Allen & Brewster 83, p. 153; 
Drew 85, p. 15 ; Beckham 85, p. 140; 87, p. 127; Morrison 88, p. 70; 
Cooke 97, pp. 19, 124, 223 ; Burnett 01, p. 114 (H. u. alme) ; Henderson 
03, p. 237 ; 09, p. 241; Warren 06, p. 24; Rockwell 08, p. 179. 
Description.—Adult—Above dark brownish-olive; a conspicuous 
pale buffy orbital ring ; sides of the face, chin, throat and chest very 
pale buffy, streaked with dusky, except on the centre of the throat ; 
rest of the under-parts white, tinged with slaty-grey on the flanks, 
and with a few more or less indistinct rounded spots of the same colour 
on the lower breast; iris dark brown, bill blackish, pale brown-horn 
at the base of the lower mandible, legs pale horny. Length 6-40; 
wing 3-90 ; tail 2-80 ; culmen ‘5 ; tarsus 1-0. 
The sexes are alike ; the young birds are streaked and spotted with 
pale tawny above, while below the markings are more or less transverse 
in direction. 
Distribution.— Breeding throughout the greater part of northern 
North America, except the Pacific coast belt, from Alaska and Hudson 
Bay south at higher elevations, to California, Colorado and Virginia, 
southwards on migration through Mexico and Central America to 
Peru, Bolivia, Brazil and the Argentine. 
