Arctic Fox Facts: The Fox That Changes Colour and Dives Into Snow
It is the smallest wild dog of the far north, and the toughest for its size. The Arctic fox raises pups in a world of ice, hunts prey it cannot see beneath the snow, and wears a coat that changes colour twice a year to stay invisible. Here is how a fox the size of a house cat owns the top of the world.
Watch Arctic Fox at Snack Time Zoo:
A Coat for Every Season
The Arctic fox is a master of camouflage. In winter its thick coat turns brilliant white, vanishing against snow; in summer it moults into brown and grey that match bare tundra rock and soil. A rarer 'blue' form stays dark blue-grey all year. No other young canid changes colour like this as an adult — it keeps the fox hidden from the wolves and polar bears that hunt it, and from the wary prey it stalks.
The Warmest Fur in the Arctic
Arctic foxes stay warm in temperatures down to about minus 50 degrees Celsius, and they do not even begin to shiver until it gets colder than that. Their secret is the best-insulated fur of any Arctic mammal, layered over a compact, rounded body that loses very little heat — short ears, a short muzzle and short legs all reduce exposed surface. Even their paw pads are furry, giving grip and insulation on ice, and a system of heat exchange in the legs keeps warmth in the body while the feet stay just above freezing.
The Snow Dive
Winter hunting means finding lemmings under a blanket of snow — by ear. The fox creeps forward, listening with its head cocked, then launches straight up and crashes nose-first through the snow onto prey it never saw. Researchers believe foxes may use Earth's magnetic field to line up these dives, approaching from a preferred direction that dramatically improves their success rate. A direct hit pins the lemming; a miss leaves a fox-shaped hole and a very undignified expression.
Stashing Summer for Winter
When summer brings abundance — lemmings, birds, eggs, berries like the cloudberry our cub is nibbling — the Arctic fox works overtime as a food stasher. It buries eggs and prey in scattered caches in the cold ground, a natural freezer it raids through the dark winter months; a single fox may hide thousands of eggs in one season. Families need the surplus: Arctic fox litters can be enormous, sometimes more than a dozen pups, among the largest of any wild mammal its size.
Quick Summary
The Arctic fox (Vulpes lagopus) is the Arctic's smallest canid: a colour-changing hunter with the warmest fur of any northern mammal, fur-soled paws, a spectacular snow-diving hunt, and a freezer-full of cached food for winter.
Frequently Asked Questions
How cold can an Arctic fox survive?
Arctic foxes cope with temperatures around minus 50 degrees Celsius and below. Their fur is so well insulated that they do not start shivering until extreme cold well past that point.
Why does the Arctic fox change colour?
For camouflage. White fur hides it in winter snow, and a brown-grey summer coat blends with bare tundra — hiding it from both predators and prey.
How does an Arctic fox catch prey under snow?
Mostly by listening. It pinpoints a lemming by sound, leaps high, and dives headfirst through the snow. Scientists think foxes may also use Earth's magnetic field to aim their dives.
What do Arctic foxes eat?
Lemmings are the main prey, plus voles, birds, eggs, fish, berries and carrion — including leftovers from polar bear kills, which Arctic foxes often trail in winter.