Winter Snow Camouflage
Snow camouflage is the use of a coloration or pattern for effective camouflage in winter, often combined with a different summer camouflage. Summer patterns are typically disruptively patterned combinations of shades of browns and greys, up to black, while winter patterns are dominated by white to match snowy landscapes.
Among animals, variable snow camouflage is a type of seasonal polyphenism with a distinct winter plumage or pelage. It is found in birds such as the rock ptarmigan, lagomorphs such as the Arctic hare, mustelids such as the stoat, and one canid, the Arctic fox. Since these have evolved separately, the similar appearance is due to convergent evolution. This was used as early evidence for natural selection. Some high Arctic species like the snowy owl and polar bear however remain white all year round.
In military usage, soldiers often either exchange their disruptively-patterned summer uniforms for thicker snow camouflage uniforms printed with mainly-white versions of camouflage patterns in winter, or they wear white overalls over their uniforms. Some armies have made use of reversible uniforms, printed in different seasonal patterns on their two sides. Vehicles and guns are often simply repainted in white. Occasionally, aircraft too are repainted in snow camouflage patterns.