Townsend describes the eggs as numerous, of a cinereous-brown color, blunt at both ends, and small for the bird. The actions of the female, when the young are following her, are said to be exactly similar to those of the Ruffed Grouse, employing all the artifices of that bird in feigning lameness, etc., to draw off intruders.
Canace obscurus, var. richardsoni, Douglas.
RICHARDSON’S DUSKY GROUSE.
Tetrao obscurus, Aud. Orn. Biog. IV, 1838, 446, pl. ccclxv.—Ib. Syn. 1839, 283.—Ib. B. Am. I, 1842, 89.—Nutt. Orn. I, 1840, 609.—Swains. F. B. A. II, 1831, 344, pl. lix, lx. Tetrao richardsoni, Dougl. Linn. Trans. XVI, 141.—Lord, Pr. R. A. I. IV, 122 (between Cascade and Rocky Mountains).—Gray, Cat. B. Brit. Mus. V, 1867, 86. Dendragapus richardsoni, Elliot, P. A. N. S. 1864, 23.—Ib. Monog. Tetraon, pl.—Wilson, Illust. 1831, pl. xxx, xxxi.
Sp. Char. Tail-feathers broad and nearly truncated; tail almost perfectly square, and black to the tip, with the terminal band either only faintly indicated or entirely wanting; in all other respects exactly like var. obscurus. Male (18,397, Browns Cut off. N. Rocky Mountains; Lieutenant Mullan). Length, about 20.00; wing, 9.00; tail, 7.30; tarsus, 1.70; middle toe, 1.85. Female (18,398, forty miles west of Fort Benton; Lieutenant Mullan). Wing, 8.60; tail, 6.00; tarsus, 1.60; middle toe, 1.60.
Hab. Rocky Mountains of British America, south to the Yellowstone and Hellgate region of the United States.
No. 18,377, Hellgate, and others from localities where this form and var. obscurus approach each other, have the terminal zone of the tail of the usual width, and even sharply defined; but it is so dark as to be scarcely distinguishable from the ground-color.
Habits. In regard to distinctive peculiarities in habits and manners, of this form of Grouse, if it possesses any, our information is quite limited. In its external markings and in size it appears to be readily distinguishable from the T. obscurus either specifically or as a well-marked interior race. Mr. J. K. Lord refers to it in his account of the obscurus, where he states that between the Cascades and the Rocky Mountains the Dusky Grouse appears to be replaced by a well-marked variety, if not a distinct species. In size it is a trifle smaller, but the great mark of distinction is the entire absence of the white band at the end of the tail. In their habits, in their periods of arrival and departure, or rather of appearance and disappearance, the two varieties are pronounced to be, in every respect, similar. In regard to their unexplained disappearance and reappearance, Mr. Lord is of the opinion that these birds do not migrate, but only retire into the thickest trees, and, living on the buds, pass the winter thus sheltered in the tree-tops.
Captain Blakiston thinks that this species is the form that inhabits the interior of British North America, and refers the figure of the male in Richardson’s Fauna to the richardsoni,—the Black-tailed and smaller species. In his wanderings he met with these birds only in or near the pine woods on the slopes of the Rocky Mountains; but, having killed only females, he could not feel certain of the species. These Grouse range towards the Pacific as far as the Cascade Mountains of Oregon and British Columbia, and along the Rocky Mountains from the head-waters of the Platte to the Liard River, a tributary of the Mackenzie. When the ranges of the two species are fully defined, he thinks the T. richardsoni will be found the more northern bird.
The eggs of Tetrao richardsoni are very similar, except in size, to those of the obscurus, resembling them closely in their ground-color, as well as in their markings. In the specimens in the cabinet of the Boston Natural History Society the spots are smaller, a little less distinct, and less numerous. The eggs are 1.75 inches in length, and from 1.35 to 1.36 inches in breadth.