WILLOW GROUS, OR LARGE PTARMIGAN. 
675 
those of the preceding species, of a muddy white, or in- 
clining to pale rufous, covered and marbled with great 
numbers of spots, of the color of clotted blood. 
It is somewhat remarkable that this species, still more 
boreal than the Common Ptarmigan in Europe and Asia, 
should constantly inhabit to the south of that species in 
North America, where it seems, as it were, to have usurp- 
ed its residence. Their general habits are very similar 
to those of the preceding. Like them, they become grega- 
rious at the setting in of winter, roaming after their food 
in flocks of as many as 266 ; living then, and at most 
seasons, on the tops, buds, and even seeds of the dwarf 
willow, and hence called Willow Partridges. They 
also subsist on most kinds of northern berries, and many 
other kinds of buds and leaves, with the tops of the 
heath, and the seeds of the birch. As food, this species 
is preferred to the smaller Ptarmigan. 
The weight of this species is 24 ounces. The length 16J inches, 
alar extent 23. Summer plumage. — Head, neck, back, scapulars, 
middle tail-feathers and their coverts, of a rufous chesnut of different 
shades, without spots on the fore part of the neck, but with black 
zig-zag lines on the other parts, and black spots on the top of the 
back; inferior part of the breast, and all below, with the greater part 
of the wing-coverts, and the quills, white. Lateral tail-feathers black, 
tipped with whitish. Cicatrice over the eye scarlet. — In icinter, 
with the exception of the lateral tail-feathers, they become wholly 
white ; and for the purpose of giving additional warmth at this in- 
clement season, the feathers, except the quills and tail, are doubled, 
a downy feather being added to the base of each; a provision com- 
mon also to the preceding species. 
