Coloration evidence for natural selection J. Bowler wrote that Darwin's theory In his 1889 book "Darwinism", the naturalist Alfred Russel Wallace considered the white coloration of Arctic animals. He recorded that the Arctic fox, Arctic hare, ermine and ptarmigan change their colour seasonally, and gave "the obvious explanation", that it was for concealment. The modern ornithologist W. L. N. Tickell, reviewing proposed explanations of white plumage in birds, writes that in the ptarmigan "it is difficult to escape the conclusion that cryptic brown summer plumage becomes a liability in snow, and white plumage is therefore another cryptic adaptation." All the same, he notes, "in spite
Ptarmigan (sternwheeler) piper, and lifted him unharmed over to the foredeck of "Ptarmigan" while the piper reportedly never missed a note. "Ptarmigan" passed "Gian" and thereafter Cantlie steered clear of the big steamer. "Ptarmigan" was dismantled in 1909. "Ptarmigan"'s engines, which had been under water at least twice when the vessels they powered sank (once with "Ptarmigan", once with the first "Duchess") were installed in another vessel, the "Nowitka". Ptarmigan (sternwheeler) Ptarmigan was a sternwheel steamboat that operated in British Columbia on the Columbia River from 1903 to 1909. "Ptarmigan" was built at Golden, BC and was the last vessel built for