Tail of eighteen feathers, subequal. Male with inflatable air-sac on each side of neck. Two species.
D. obscurus. Male 19 1/2". Female 17". The Dusky Capercailzie. Above smoky black, mixed brownish buff; below grey. Breast not barred. Mid tail with grey band.— Female: Breast-band buff. Tail with grey terminal band on laterals. Monogamous. Known also as " Blue Grouse," "Pine Grouse." S. Rocky Mountains. Eggs (1.9 x 1.4) creamy buff, dotted all over chestnut-brown.
D. fuliginosus, a subspecies distinguished from D. obscurus by the narrower tail-bands. N.W. Rocky Mountains.
D. richardsoni. Tail uniform black.— Female: No grey tail-band, E. Rocky Mountains.