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ENVIRONMENT
SURVIVING THE BIG FREEZE Discover how animals take on the extremes and win The adaptive techniques that animals use to survive the temperature changes in their environment are nothing short of extraordinary. Some creatures such as Arctic ground squirrels or brown bears choose to while away winter in a deep slumber, while others like caribou or Arctic terns embark upon epic migrations to warmer climes the moment things start to get really chilly. Then there are the hardcore stay-putters, the animals that have evolved some truly wonderful – and some downright weird – ways to weather the storm. Take the Arctic tundra’s musk oxen, for example; this grumpy beast has a shaggy coat made of hollow hair for warmth that hangs so low to the ground that it traps a layer of warm air beneath the animal. Couple this with a whole herd of huddling musk oxen and things get very toasty indeed. Physical adaptation is a key weapon against the cold. Animals such as many rodent species will bulk up during the summer months in order to have sufficient fat reserves to see them through the winter. Other animals, like Arctic foxes or hares, have developed thick fur that actually changes colour with the seasons to provide both warmth and camouflaged protection. Metabolic changes allow survival against all odds, as well as amazing chemical adaptations, like the icefish, which has antifreeze literally running through its veins. However, surviving the chill isn’t all about adapting to seasonal changes. There are some animals in ecosystems such as the deserts that have to survive the daily extremes of day-tonight temperature fluctuations, and have developed incredible methods of coping with both extremes.
068 | How It Works
Tiny extremities Bears have very small ears and tails in order to minimise heat loss.
Energy-rich diet A diet of seals is rich in fat, providing energy for the bears to roam the Arctic all winter.
Formidable claws The polar bear’s huge claws can measure up to 5cm (2in) long, excellent for catching prey and aiding grip.
Swimming tools In the water, a bear’s huge paws act as paddles for efficient swimming.
Paw pads Small bumps called pappilae on the bear’s paw pads help to aid grip on the ice.
Furry defences During the summer when the Arctic’s snow has receded, the Arctic fox’s coat is a brownish hue. This camouflages the animal against the tundra and scrubland and allows it to blend in seamlessly with its surroundings. When the snow starts to fall, the fox’s coat moves with the seasons and transforms into a perfect icy white. These foxes have big, bushy tails to curl up under for warmth, thick, insulating fur to keep out Arctic chills, small eyes and snouts to minimise heat loss, and even furry soles on their paws to provide grip in their wintery home.
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The fox’s legs are short – keeping low to the ground avoids icy Arctic winds
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