Range. - Chiefly in the interior of British America, from the southern portions to Alaska and the Arctic Ocean.
A species with a smaller bill and in summer a grayer plumage, more finely barred with black. Its nesting habits are the same as the other species, it nesting on the ground in such localities as would be frequented by the Ruffed Grouse. Its eggs cannot be positively distinguished from those of the Willow Ptarmigan. Size 1.70 x 1.20.
Willow Ptarmigan. Rock Ptarmigan.
Range. - Labrador and Greenland; an eastern variety of the preceding species. Its habits, nesting habits and eggs are just the same as those of Rock Ptarmigan.
Range. - Unalaska, of the Aleutian chain. An abundant species in its restricted range, making its nest on the ground in the valleys. Eggs like the others.
Range. - Atka Island, of the Aleutian chain. Nests and eggs not distinctive.
Range. - Kyska Island of the Aleutian group.
On account of the constantly changing plumage of these birds, while interesting, they are very unsatisfactory to study, and it is doubtful if anyone can identify the different sub-species of the Rock Ptarmigan, granting that there is any difference, which is doubtful.
Range. - Attu Island, of the Aleutian group.
This is, in summer, the darkest of the Ptarmigans, having little or no rufous and much blackish. The nesting habits and eggs are the same as those of the Rock Ptarmigan.