This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the white-tailed ptarmigan.
Although the range of these birds extends from Alaska to New Mexico and they are found in Archuleta County, most of us never see one. Year-round, they inhabit remote areas above treeline in alpine tundra and heath. They may move downslope in winter, but they are so well adapted to cold that temperatures above 70 degrees cause them stress.
This ptarmigan is the smallest bird in the grouse family. It is stocky with a short bill, short neck and short, all-white tail. To blend in with its surroundings, in breeding plumage, males are mottled gray and brown with red feathers above the eye that are raised and form a comb in courtship displays. Females are barred brown and black with a yellowish wash.
In breeding season, males will defend a territory generally ranging from 35 to 70 acres. Only females incubate the eggs and males play no role in caring for chicks.
White-tailed ptarmigans eat all plant parts and some insects in warm months. When the ground is covered in snow, they seek out areas where wind or snow melt uncovers plants. Buds and leaves of willows are an important part of their diet.
Both sexes molt into all white plumage for winter. To conserve energy, they avoid flight and roost in snowbanks during this season. Feathers on the feet and long claws provide a snowshoe effect and allow them to walk on snow. Day length, not temperature, triggers the change to white winter plumage. A warmer climate with later snowfalls will make this bird’s cryptic winter coloring out of sync with its environment.
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