170 
The summer male is decidedly barred with dark and ochre with little white inter- 
mixed, the dark being predominant. In autumn plumage the same colours are present 
but generally lighter and vermiculated with a fine pepper and salt effect, the ocnre pre- 
dominating and with more white than in summer which gives a greyish overcast. 
Females are coarsely barred, showing much more light colours than the male. The 
autumn plumage has the barring reduced and is somewhat less finely vermiculated than 
the male. It may be double phased; one phase being predominantly ochre, the other 
being more greyish. 
Distinctions. A small Grouse. Feet feathered to end of toes (Figure 193) and white 
wings distinguish it as a Ptarmigan. The black tail separates it from the White-tailed 
Ptarmigan, and in winter the black streak through the eye, sometimes reduced, occasion- 
ally obsolete, from the Willow. The greatest difficulty of separation will be from summer 
Willow Ptarmigan. The male is recognizable by colour in either summer or autumn 
plumage by the lack of any mass of red and the presence of pronounced crossbarring. 
In the autumn plumage both sexes show a pronounced, fine vermiculation foreign to the 
Willow. Females in summer plumage are difficult to separate from similar plumage of 
the Willow Ptarmigan by colour characters, and size, especially of the bill which is lighter 
and slenderer as well as smaller, makes the most reliable criterion (compare Figures 195 
and 194). The bill may be quite variable, but no Willow Ptarmigan ever has the bill 
quite as slight as the heaviest of this species. 
Figure 195 
Specific details of Rock Ptarmigan; natural size. 
Field Marks. Considerably smaller than the Willow Ptarmigan, and with more 
slender bill. With few exceptions recognizable by a black area in front of eye. 
Distribution. A more Arctic form than the Willow or the White-tailed. Northern 
North America and Greenland. In America, across the continent farther north than the 
Willow and seldom if ever coming down into civilization even in winter. Occurs on some 
of the mountain tops as far south as central British Columbia. 
SUBSPECIES. A number of subspecies are recognized, several being credited to 
Alaska. Throughout western Canada but one race, the Arctic Ptarmigan, the typical 
form Lagopus rupestris rupestris, is recognized by the American Ornithologists’ Union. 
304. White-tailed Ptarmigan (Including Northern and Southern White-tailed 
Ptarmigan). Lagopus leucurus. L, 12-50. The smallest of the Ptarmigan. In winter 
all white, including face and tail (Figure 196). A scarlet comb over eye is prominent in 
spring and may persist to a less degree at other seasons. 
