Arctic fox: The double-wardrobe survivor of 50 below

The Arctic fox is a small fox of the Arctic tundra. It owns two completely different "coats": snow-white in winter, grey-brown in summer. Both colours help it hide perfectly in its surroundings. Let's meet this cold-proof expert.

Its body

The winter coat is pure white — warm, and camouflage in the snow; in summer the fox puts on grey-brown fur that melts into tundra rock and lichen. Its fur is among the best insulation in the mammal world, shrugging off fifty degrees of frost. It also has a big, thick tail — perfect as a quilt when it curls up to sleep. Small ears and a short muzzle reduce heat loss, and its rounded paws are like built-in snow boots.

Where it lives and what it eats

The Arctic fox is a carnivore and a clever scavenger: it often follows polar bears at a distance and eats what they leave behind. It also leaps and dives head-first into snow to catch lemmings — a move that looks both comical and impressive. Its hearing is superb, able to pick up lemmings moving beneath the snow.

Where it is found

Arctic foxes live in the tundra near the Arctic Circle, including the far north of Eurasia and North America. To cope with such a harsh world, their numbers rise and fall with the abundance of prey such as lemmings.

A note for grown-ups

You could play a "change your coat" game with a child: white in winter, grey-brown in summer — guess why. The answer is to hide in a different place. Moving from "changing colour" to "hiding" is a lovely way to understand how animals adapt.