White-tailed Ptarmigan 149 
was first taken in Colorado by Dr. Anderson, attached to Captain 
Marcy’s party when marching from Fort Bridger in Utah to Santa 
F6, probably on the Cochetopa Pass, in January, 1858. It has been 
found nesting near the Chicago Lakes by Trippe and Evan Lewis 
(Brewer, Trippe and Bendire), near Breckenridge by Carter, near 
Crested Butte by Warren, in Saguache co. by Anthony (Bendire), 
and in the San Juan Mountains, San Juan, co., by A. D. Wilson 
(Coues), and appears to be generally distributed. 
Habits.—This bird, generally known in Colorado as 
the “‘Mountain Quail,” is with the Leucostictes the 
highest-ranging and most alpine of all the birds in the 
State. It is, where not molested, very tame and easily 
approached, and is chiefly met with among the rock- 
slides and bare, almost vegetation-free country lying above 
timber line. It is with difficulty flushed, and even where 
this is accomplished it flies but a short distance, and 
generally tries to escape by running and squatting among 
the rocks which it so closely resembles. Its food consists 
chiefly of leaves, stalks and flowers of alpine plants, 
and grasses, especially of Caltha leptocephala, the Rocky 
Mountain marsh-marigold. During the winter it feeds 
on the buds and needles of pines and willows. Its note 
is a loud cackle ; and it is somewhat gregarious, keeping 
in flocks of twenty up to one hundred individuals 
throughout most of the year, except in the breeding 
season. 
The white plumage begins to change in March, but 
the summer-dress is seldom complete until the end of 
May or beginning of June. After the breeding is over 
the complete post-nuptial moult, common to nearly all 
birds, takes place, and the white wing- and. tail-feathers 
are replaced ; later on, in October, a special moult of 
the dusky and grey feathers of the back commences, and 
the birds gradually assume the pure white winter-dress. 
The nest is generally near the summit of a ridge, and 
ig merely a depression among the rocks, lined with a 
