White-tailed Ptarmigan

Lagopus leucura

Description 3

The white-tailed ptarmigan is the smallest of the ptarmigans and the smallest bird in the grouse family. It is a stocky bird with rounded wings, square-ended tail, small black beak and short legs with feathering extending to the toes. Adults are 11.8 to 12.2 inches (30 to 31 cm) long, with the males being only slightly larger than the females. The average weight is 11.6 to 16.9 ounces (330 to 480 g). During the summer, the white-tailed ptarmigan is a speckled grayish brown with white underparts, tail and wings. In the fall, the plumage has turned a much more reddish-brown color and white feathers begin to grow through. By winter all the summer brown feathers are lost and the bird is completely white. A further molt in the spring precedes the breeding season and the bird returns to its summer plumage. The finely-barred greyish coloration on the back makes it easy to distinguish this species from the much browner willow ptarmigan and rock ptarmigan. Both sexes maintain white tail and wing feathers all the year and males can be identified by their reddish eyecombs (fleshy growths above the eye), also present year-long. In general this bird is silent but it sometimes makes quiet, low-pitched hoots and soft clucking noises.

Diet 3

This herbivorous bird's diet varies seasonally. Nitrogen-rich snow buttercup leaves are favored in the spring season, while willowcatkins, mountain avens flowers, and chickweed blooms, other flowers and leaves, lichens and berries form the majority of the ptarmigan's diet in the summer. Once fall and winter arrive in the region, the ptarmigan feeds on pine needles, seeds, willow and alder buds and twigs. Winter food sources have a much higher cellulose content than does summer forage, so the ptarmigan relies on bacteria-aided digestion in the cecum to extract essential nutrients. During the summer, the ptarmigan eats grit to assist in digesting plant material.

Adaptations and status 3

The white-tailed ptarmigan is well-camouflaged when on the ground. In his pioneering 1909 book on the subject, Concealing-Coloration in the Animal Kingdom, the American artist Abbott Thayer wrote:

There is perhaps no other bird which moults as gradually as the Ptarmigan, and this fact goes very far to strengthen the supposition that it has developed a peculiarly fluid and perfect system of perennial protective coloration. Figs. 8, 9, 10 and 39 show White-tailed Ptarmigans, of the Rocky Mountains, in winter and transitional plumages... Supremely beautiful and potent is the grass-pattern of this same species in summer plumage... This pattern ... is achieved by light-brown marginal bands, with a few small internal spots, on the dark feathers of the upper parts; the predominance of light and dark being gradually reversed as the lower breast is approached. The belly is entirely white, as are the quill feathers of the wings and tail.

The white-tailed ptarmigan has feathers located on its feet to serve as protection from the extreme cold often experienced in the alpine tundra environment. In addition, these birds have feathers around their nostrils to warm the air prior to entry into the respiratory tract. The most obvious adaptation is this bird's cryptic coloration, which enables it to blend in with its environment and avoid predation by golden eagles or other birds of prey. To conserve energy during the winter months, the ptarmigan avoids flight as much as possible and roosts in snowbanks.

The white-tailed ptarmigan is listed as being of "Least Concern" by the International Union for Conservation of Nature. This is because, although populations may be in slight decline, its range is too wide and the total number of birds too large to fit the criteria for being listed as "Vulnerable". This bird serves as an indicator species for the alpine tundra, and denotes overall ecosystem health. It is not a conservation concern and is abundant in alpine zones across North America, indicating that this region is not undergoing dramatic climatic, temperature, or precipitation shifts. The lack of overgrazing by cattle, the lack of human development in alpine zones, the difficulty in accessing its remote habitat, the low densities at which it occurs and the laws regarding the limits to hunting bags allow the white-tailed ptarmigan to thrive.

Sources and Credits

  1. (c) Jerry Oldenettel, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/7457894@N04/439839062
  2. (c) gailhampshire, some rights reserved (CC BY), http://farm4.staticflickr.com/3314/4574864414_d4e7521a69_o.jpg
  3. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/White-tailed_ptarmigan

More Info

Range Map

iNatCA Map

Animal Bird
Color brown, red, white
Bird Phasianidae (ptarmigans)