How Arctic foxes survive on the tundra
When the going gets tough, the tough get going
For a long time it was thought that Arctic foxes (also called polar foxes) evolved in Europe when the last ice age hit around 2.6 million years ago, but a few years ago fossils were found that suggest otherwise. Fox jawbones with teeth suited to a diet almost entirely made up of meat were found high in the Tibetan mountains in rock about 3.5 to 5 million years old. The jaws didn’t match any living fox species but had a great deal in common with those of the Arctic fox (the most meat-reliant of all foxes), so it’s possible that these tough, high-altitude animals passed on their adaptations to the cold and became the ancestors of today’s Arctic species.
Wherever they came from, Arctic foxes now look completely at home on the extreme landscapes at the top of the Northern Hemisphere. While other animals snuggle up and slow down until winter passes, Arctic foxes don’t hibernate. Growing a thicker coat and slowing down their metabolism when it gets really cold allows them to use their energy efficiently and stay active all year round, while complex dens provide respite when conditions become dangerous.
Coping with the cold
Pups are born in these underground dens in spring and early summer so they have some time to grow and learn before facing the most perilous months. Fathers stick around and both parents work hard, devoting themselves to the care of their offspring to give them the best possible chance of making it to adulthood. Despite their best efforts, many pups starve, freeze or fall victim to the claws of larger Arctic animals before the end of their first winter. For those that make it through, the following winters are less risky, but life is still far from easy.
It’s hard to find food in such a desolate environment, but Arctic foxes are willing to go the extra mile: they’ve been recorded travelling as far as 4,500 kilometres (2,796.2 miles) in one winter. Sharp ears and a good sense of smell allow them to track down mammals like voles and lemmings hiding beneath the snow, and those living around water will catch fish. Hunting in spring is a little easier, with snow goose eggs and seal pups available to foxes brave enough to take them.
For more science and technology articles, pick up the latest copy of How It Works from all good retailers or from our website now. If you have a tablet or smartphone, you can also download the digital version onto your iOS or Android device. To make sure you never miss an issue of How It Works magazine, subscribe today!