What’s brown and black but white all winter? The ptarmigan is unique among birds for molting into snow-white plumes for half the year. In fact the three species of ptarmigan—rock, willow, and white-tailed—may be among the best-adapted birds for surviving the frigid winter temperatures of northern climes and high elevations.
Like other critters that live in snowy places, including the ermine and the Arctic fox, the ptarmigan’s gray-brown summer garb transforms into a brilliant bright white each year when the snow begins to fall. (Technically, the white-tailed and rock ptarmigan have black outer tail feathers, but they’re barely visible under most circumstances.)