The Dusky Grouse 



pure white, more or less concealed; subterminal area of tail clear slaty-black; terminal 

 band ashy gray, .30-. 60 wide; comb over eye and concealed spot of naked skin on side 

 of neck, the tympanum, orange-yellow. Bill black; feet with black soles. Adult 

 female: Ground-color of male, everywhere, save on concealed webs of rectrices and 

 quills and on middle of belly, more or less mottled by ochraceous, tawny, and warm 

 browns (sudan brown to argus brown), the markings on back falling more or less into 

 bars; often also lightly washed or skirted, especially on breast and upper tail-coverts, 

 with ashy; some sector-shaped markings of white on wings, and plumage bordering 

 slaty central area of belly extensively varied by white. Young birds are much like 

 the female. Chicks are warm yellowish, clear or orange-banded below, above varied 

 in irregular pattern by ochrey, tawny, and black. Adult male, length: 508-558.8 

 (20.00-22.00), sometimes 609.6 (24.00); average of seven males: wing 232.4 (9.15); tail 

 162.6 (6.40); bill 20.3 (.80). Female, length: 431.8-482.6 (17.00-19.00) ; wing 214.9 

 (8.46); tail 130.8 (5.15); bill 19.3 (.76). 



Recognition Marks. — Crow size; dark slaty coloration; tail definitely tipped 

 with white, as compared with black tail of D. 0. richardsoni. 



Nesting. — Nest: On ground, a slight hollow lined with a few twigs, grasses, 

 and stray feathers, usually under protection of tree, bush-clump, or grass. Eggs: 

 6 to 12, 16 of record; pale cream-buff or pinkish buff, sharply and sparingly freckled 

 with reddish brown (cinnamon-brown to chestnut-brown). Av. size 52.3 x 34.5 (2.06 

 x 1.36). Season: May-June, according to altitude; one brood. 



Range of Dendragapus obscurus. — Pacific Coast and Rocky Mountain districts 

 from Alaska, southern Yukon, and southwestern Mackenzie south to Mt. Pinos (Cali- 

 fornia), western New Mexico, and central Arizona. Resident wherever found. 



Range of D. 0. fuliginosus. — Humid coastal district from Sitka south to north- 

 western California. 



Distribution in California. — Common resident of the humid coastal strip, 

 chiefly in the Douglas fir forests, east to Hayfork and Kuntz (Trinity County) and 

 south to Seaview, Sonoma County (Grinnell). 



Authorities. — Sclater (Tetrao obscurus), Proc. Zool. Soc. London, 1858, p. 1, 

 part (Trinity Mts.);Z. Kellogg, Condor, vol. xiii., 191 1, p. 119 (Hayfork, Trinity Co.); 

 Grinnell, Pac. Coast Avifauna, no. 11, 1915, p. 60 (status in Calif.). 



No. 315b Sierra Grouse 



A. O. U. No. 297c. Dendragapus obscurus sierras Chapman. 



Description. — "Differs from D. 0. fuliginosus in much paler coloration above, 

 in the heavier vermiculation of the entire upper surface, practical absence of neck- 

 tufts, whiter throat, and paler underparts." 



Status. — If we may be allowed to substitute the word perceptibly for "much" 

 in the foregoing description, this very "light" form will pass muster. The whiter 

 throat is apparently the most constant character. 



Range of D. 0. sierrce (Almost wholly included within California). — Common 

 resident in coniferous forests of the mountains from Mt. Shasta south along the inner 

 coast ranges at least to Mt. Sanhedrin, and along the Sierras south to the Piute Moun- 

 tains in Kern County, and on Mt. Pinos in Ventura County. Also found upon the 

 Warner Mountains and the White Mountains (and so presumably into Nevada). 



1590 



