Oliv-e-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 

 canon 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— Colorado 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. almce) ; 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 ; cuhnen -5 ; tarsus 1-0. 



The sexes are alike ; the yoimg 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 Cahfomia, Colorado and Virginia, 

 southwards on migration through Mexico and Central America to 

 Peru, Bolivia, Brazil and the Argentine. 



