A list of some animals that change their colour in the winter.
Last week we looked at the cutest hibernators, but let's talk about a strategy that is used by some creatures that don’t hibernate in the winter. All of these species are found in the northern part of the northern hemisphere. This means that during winter, the environment is covered in snow. With everything suddenly covered in a layer of white, the animals, with their summer coat, would no longer be camouflaged. To fix this, these animals change their coat colour every winter to better match the surroundings, so let's jump into it.
Found in North America, the snowshoe hair is brown over the summer and turns white over the winter. It is called a snowshoe hare because of the long, stiff hairs on the hind legs that prevent it from sinking into the deep snow, much like a set of snowshoes. The fur has the added benefit of keeping the feet warm and creating a barrier between the skin and the frozen snow. Snowshoe hares mainly feed on twigs and bark during the winter, which is a lot harder to digest than the green leaves and new shoots that they get to munch on during the summer. Being camoflaged during the winter helps protect the snowshoe hair from its main predator, the Canadian Lynx.
The short-tailed weasel
Perhaps better known as the ermine, the short-tailed weasel is a small, elongated predator. It is related to badgers and wolverines, but not anywhere near as large. It is found in the northern parts of North America and Eurasia, where it hunts rodents in their burrows. It was hunted extensively in the 15th century, when the fur was used to line royal capes and clothing. During the summer, the ermine has a reddish brown coat with a white underbelly, which changes to all white with a black tail tip during the winter. An interesting thing about ermine reproduction is that they are not monogamous and that pups in a litter can even have different fathers.
Image by Paul Gierszewski, used with permission
An interesting addition to this list, as not all caribou change colour in the winter. Instead, it is just a subspecies found in northern Canada and Greenland, which is also the smallest subspecies of caribou. They are silver in the summer and change to white in the winter. The hair of the caribou winter coat is hollow, much like that of a polar bear. This helps trap air in the coat, which acts as insulation between the body and the cold arctic blast. Due to the fact that they are the only subspecies that change colour, they were originally thought to be their own species, but genetic testing has put them as a subspecies.
Image by Bjorn Christian Torrisen, used with permission
The only bird on this list, the rock ptarmigan, is part of the grouse family. It is found throughout the arctic and subarctic climates of North America and Europe, including Japan. The Rock Ptarmigan has a brown coat in the summer and moults its feathers in the winter and grows white feathers instead. They are found mainly in the tundra and are also found along rocky mountain sides. Because of its remote locations, it usually isn’t very fearful of humans and can be approached fairly easily.
There are many other animals that change their colours during the winter to help provide protection from predators. Which ones stand out in your mind that we missed?