The eggs of this species vary considerably in length and breadth; they average about 1.85 inches in length and 1.20 in breadth, and are oval in shape, one end a little less obtuse than the other. They are all beautifully variegated and marked with bold confluent blotches of a dark claret color, upon a ground of a deep cream tinged with a reddish shading.
Lagopus mutus, var. rupestris, Leach.
ROCK PTARMIGAN.
Tetrao rupestris, Gmelin, Syst. Nat. I, 1788, 751 (based on Rock Grouse of Pennant).—Latham, Ind. Orn. II, 1790, 312.—Sabine, Supplem. Parry’s First Voyage, page cxcv.—Richardson, Append. Parry’s Second Voyage, 348.—Aud. Orn. Biog. IV, 1838, 483, pl. ccclxviii. Lagopus rupestris, Leach, Zoöl. Misc. II, 290.—Bon. List, 1838.—Aud. Syn. 208.—Ib. Birds Amer. V, 1842, 122, pl. ccci.—Baird, Birds N. Am. 1858, 635.—Elliot, Monog. Tetraon. pl.—Gray, Cat. Brit. Mus. V, 1867, 92.—Dall & Bannister, Tr. Chicago Ac. I, 1869, 287. Tetrao (Lagopus) rupestris, Swains. F. Bor. Am. II, 1831, 354, pl. lxiv. Attagen rupestris, Reich. Av. Syst. Nat. 1851, page xxix. Rock Grouse, Pennant, Arctic Zoöl. II, 312. Lagopus islandorum, Fab. Prod. der Island. Orn. page 6.—Gray, Gen.—Ib. Cat. B. Brit. Mus. III, 47, 1844. Tetrao lagopus islandicus, Schleg. Rev. Crit. des Ois. d’Eur. p. 76. Tetrao islandicus, Brehm, Eur. Vog. II, 448. Lagopus reinhardti, Brehm. Lagopus groenlandicus, Brehm, Vögelfang, p. cclxiv, note. ? Tetrao lagopus, Sabine, E. Suppl. Parry’s First Voyage, p. cxcvii.—Sabine, J. Franklin’s Jour. 682.—Rich. App. Parry’s Second Voyage, 350. Tetrao (Lagopus) mutus, Rich. F. B. A. II, 1831, 350. Tetrao mutus, Aud. Orn. Biog. V, 1839, 196. Lagopus mutus, Gray, Cat. B. Brit. Mus. 1867, 91 (Ft. Resolution and Ft. Simpson). Lagopus americanus, Aud. Syn. 1839, 207, B. Am. V, 1842, 119, pl. ccc.—Baird, Birds N. Am. 1858, 637.
Sp. Char. Bill slender; distance from the nasal groove to tip (.35) greater than height at base (.27). In summer the feathers of back black, banded distinctly with yellowish-brown and tipped with white. In winter white, the tail black; the male with a black bar from bill through eye. Size considerably less than that of L. albus. Length, about 14.50; wing, 7.50; tail, 4.50.
Female in summer (44,582, Barren Grounds, June 29, 1864; R. MacFarlane). Wings (except upper coverts) and legs white; tail (except intermediæ), black, narrowly tipped with white. Rest of plumage light ochraceous or buff, some feathers tipped with white, and all with broad transverse bars of black, this color prevailing on the dorsal region. On the lower surface the buff bars exceed the black ones in width. Wing, 7.20; tarsus, 1.15; middle toe, .90; bill, .35 by .27.
Hab. Arctic America.
The L. mutus of Europe appears to differ only in its summer and autumnal plumages from the present form, and is then only distinguished by the uniformly black feathers on the breast in the former, and the bluish cast in the latter stage. Those in the winter plumage that we have examined are absolutely identical in size, proportions, and color with the American birds.
Habits. According to Hutchins, this Ptarmigan is numerous at the two extremes of Hudson’s Bay, but does not appear at the middle settlements of York and Severn except in very severe seasons, when the Willow Grouse are scarce; and Captain Sabine informed Richardson that they abounded on Melville Island, latitude 75°, in the summer. They arrived there in their snow-white winter dress about the 12th of May. By the end of the month the females had begun to assume their colored plumage, which was completed by the first week in June, when the change in the plumage had only just commenced in the males. Some of the latter were found as late as the middle of June in their unaltered winter plumage. This Grouse was also found on the Melville peninsula and the Barren Grounds, rarely going farther south, even in the winter, than latitude 53° in the interior, but, on the coast of Hudson’s Bay, descending to latitude 58°, and in severe seasons still farther to the southward. In its general manners and mode of living it is said to resemble the albus, but does not retire so far into the wooded country in the winter. At that season it frequents the more open woods on the borders of lakes, especially in the 65th parallel, but the bulk of this species remains on the skirts of the Barren Grounds. They incubate in June.
Mr. MacFarlane found this species breeding about Fort Anderson, and on the Barren Grounds east of the Horton River. They nest, in a similar manner to L. albus, on the ground, placing the materials in a depression on the ground, and using hay, withered leaves, and a few feathers, and making a rather loose, ill-arranged nest. This is usually placed on an open common, sometimes near the banks of a small stream. They were more early in their breeding than the albus, as young Ptarmigans of a goodly size are mentioned as having been seen June 30. The eggs ranged from four to eight in number.