White-tailed ptarmigan 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
Climate of the Arctic twice as much as the global mean temperature has. In 2009, NASA reported that 45 percent or more of the observed warming in the Arctic since 1976 was likely a result of changes in tiny airborne particles called aerosols. Climate models predict that the temperature increase in the Arctic over the next century will continue to be about twice the global average temperature increase. By the end of the 21st century, the annual average temperature in the Arctic is predicted to increase by , with more warming in winter ( than in summer. Decreases in sea-ice extent and thickness are