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 (sternwheeler) surface). Captain Armstrong was able to raise "Ptarmigan" and return her to service. However "Ptarmigan" caught fire later in 1907, and her upper works were destroyed. Again, "Ptarmigan" was salvaged, her upper works were rebuilt and she was returned to service. The gasoline engine was a new development in the early 1900s. Captain Northcote Cantlie, who has gone down in history as "an eccentric Scot" purchased a gasoline-engined launch, "Gian", and placed her on the upper Columbia. Unlike Armstrong, Cantlie came from a wealthy background, drank champagne for breakfast, and kept a bagpiper as his personal attendant. Cantlie, knowing that