Snow camouflage as Hugh B. Cott have echoed his observations, adding that other animals of the Arctic such as musk ox, moose, reindeer, wolverine and raven never become white "even in the coldest parts of their range". Cott noted that both animals that hunt, like polar bear and stoat, and prey animals like ptarmigan and mountain hare, require camouflage to hide from prey or from predators respectively. There is little experimental evidence for the adaptiveness of white as camouflage, though the ornithologist W. L. N. Tickell, reviewing proposed explanations of white plumage in birds, writes that in the ptarmigan "it is difficult
Ptarmigan Traverse of the trip. Today the route is a common goal of Cascade Range mountaineers. Place names are listed from north to south: Ptarmigan Traverse Ptarmigan Traverse is an alpine climbing route in the North Cascades of Washington State. The route, from Cascade Pass to Dome Peak, is generally remote, unmarked, and challenging, traversing rugged terrain and several glaciers. The first traverse took 13 days in July 1938. The group consisted of four members of the Ptarmigan Climbing Club: Bill Cox, Calder Bressler, Ray W. Clough, and Tom Myers. The second traverse was in 1953 and consisted of Dale Cole, Bob