236 THE ALASKA HERMIT THRUSH. 



THE more open wocicls and inure aljuiulant suns (.)f eastern Washington 

 effect tliat reduction of color in the "burnt" Thrusli, wliich henceforth charac- 

 terizes the species clear thru to the Atlantic. It would be idle to trace in detail 

 all accompanying- changes of manner and habit, but we can hardly fail to note 

 the improved qualit\' of the Olive-back's song. This is most nearly compar- 

 able to that of tlie Willow Tiirush and has something' of the same rolling 

 vibrant quality. It is. ho\ve\er, less prolonged and less vehement. It may or 

 may not retain the li(|uid I's, Ijut it discards outright the rich r"s, which the 

 Veery rolls under his tongue like sweet morsels; and the jiitch of the whole 

 rises slightly, perhaps a musical third, as the volume of S(jund diminishes 

 toward the end : irr-c-o, zvc-c-o, ivc-o zve-o zvcee. A song heard some years 

 ago at the head of Lake Chelan, ivccloo u'ccloa zvcclooec looiw seemed to have 

 all the music of perfected szcaiiisoiiii in it, yet it was not till the season of 

 1908 that Mr. Bowles established the fact of the Olive-back's presence and the 

 Russet-back's absence from the Stehekin Valley. On the other hand, Ridg- 

 way finds that both forms sometimes occur together, even during the breeding 

 season; so we are not yet prepared to make generalizations as to the relali\-e 

 distribution of these birds in Washington. 



No. 95. 



ALASKA HERMIT THRUSH. 



A. O. V. No. 759. Hylocichia guttata (Pallas). 



Synonym. — K.'\r)i.\K 13\v.\ri* TiiRusii (Ridgw.). 



Description. — .Uhilt: Upperparts plain grayish brown (hair brown to near 

 broccoli brown) changing on rumps to dull cinnamon-brown of upper tail-coverts 

 and tail ; a prominent whitish orbital ring ; sides of head mingled grayish brown 

 and dull whitish ; underparts dull white, clear only on belly, — throat and breast 

 tinged with pale creamy buff; sides and flanks washed with pale grayish brown; 

 throat in confluent chain on side and lower throat, chest and upper breast — 

 spotted with duskv or sooty, the spots narrow and wedge-shaped on lower throat, 

 broadening and deepening on chest, fading and becoming rounded on breast. 

 Liill drab brown paling on mandible basally ; feet and legs brown ; iris dark brown. 

 Winter specimens are brighter and more strongly colored thruout. Yotmg birds 

 are streaked with buffy above and the spotting of underparts inclines to bars on 

 breast and sides. Length 6.30-7.40 f 160-1S8) ; wing 3.46 (88) : tail 2.52 (64) ; 

 bill .50 (12.7); tarsus 1.14 (20). 



Recognition Marks. — Sparrow size; cinnamon of tail (and upper-coverts) 

 contrasting more or less with duller brown of remaining upperparts. 



Nesting. — Does not breed in Wasliington. Nest and Eggs as in H. g. 

 scquoicnsis. 



General Range. — Coast district of Alaska breeding northward and westward 



