White-tailed ptarmigan wings, square-ended tail, small black beak and short legs with feathering extending to the toes. Adults are long, with the males being only slightly larger than the females. The average weight is . 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
Arctic Cordillera moss campion, bilberry, and Arctic white heather. The conditions here are far too severe for reptiles and amphibians to survive, and insects are also rare in the region. Muskoxen and barren-ground caribou are the only large herbivores in this environment, while polar bears and the Arctic wolf are the only large carnivores to be found in the region. Smaller herbivores include the Arctic hare and the collared lemming. Arctic foxes and stoats are some of the smaller carnivores found in the region. Marine mammals include narwhals, beluga whales, walrus, and ringed and bearded seals. The furry-legged rock ptarmigan is a