How reindeer survive the cold

Most people would find a day in the Arctic difficult, but reindeer thrive there year round

Life around the North Pole is harsh and unforgiving. On the Arctic tundra, temperatures can regularly plummet below minus 50 degrees Celsius and food is  scarce. Having lived in this challenging  environment for thousands of years, reindeer –  also known as caribou – have evolved a whole  host of adaptations to help them survive in the cold.  Large hooves spread out when  caribou walk, dispersing their  weight and making walking across  deep snow much easier. Their large  surface area also comes in handy when the animals encounter water  on their long migrations. When reindeer aren’t on the move, their hooves make useful tools for  digging through ice and snow in search of  vegetation to eat. Unlike other deer species, both male and  female caribou can grow antlers. These impressive bony structures are also used to dig their antlers in autumn or early winter when the breeding season comes to an end. In subspecies where both sexes grow antlers, however, females keep theirs until spring to help them defend precious patches of food while they’re nursing young calves. Reindeer are on their feet an hour after birth and begin to eat solid food as well as their mother’s milk at just a week old. These hardy babies are weaned and independent after six months and reach full maturity around the age of four. Although they may not be constantly at their mother’s side any more, young reindeer are  rarely alone; caribou are extremely social  animals and form herds that number in the hundreds during winter and the hundreds of thousands in spring. Many of these herds remain wild, but some are herded and used by the people that call the Arctic home.

The great reindeer migration

When winter blows in, many reindeer have to travel south to find enough to eat as their breeding grounds become icy, windy and desolate. Herders gather up their animals and begin the long journey  to the winter feeding grounds, while wild caribou follow the instinctive pull towards their winter ranges. Walking, swimming and scrambling, reindeer traverse great distances in search of enough moss and lichen to see them through the coldest months. When spring arrives, the reindeer embark on another epic journey back to the calving grounds, where there are nutritious young plants and fewer predators. Currently holding the world record for the longest terrestrial migration, the Grant’s caribou’s round trip through Alaska can reach 4,800 kilometres. While some follow the same well-trodden route each year, other caribou herds vary the direction and distance of their migration to avoid using up all the available food in one place.

The Christmas story

Father Christmas hasn’t always used flying reindeer to help him deliver gifts. St Nicholas, the 3rd- and 4th-century bishop on whom the much-loved figure is based, was often depicted riding to homes on a noble white horse or a donkey. The image of the sleigh pulled by reindeer first appeared in an illustrated poem published in 1821. The 1823 poem A Visit from St Nicholas (known better as The Night Before Christmas) gave names to eight members of the team – Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Donner and Blitzen. Rudolph and his red nose didn’t take up his position at the front of the fleet until 1939, when he was invented as part of a department store chain’s festive marketing campaign.

This article was originally published in How It Works issue 119, written by Victoria Williams 

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