The fight to reproduce
Antlers are a reindeer’s most prominent feature, and they serve an important role in breeding. Males grow their antlers each year in preparation for the breeding season, known as the rut, which starts in September. During this time their antlers are covered in thick velvet, their necks swell, their stomachs retract and they grow a mane of long, white hair. Once all the velvet coating has been shed or rubbed off, exposing the hardened bone beneath, the rutting begins. The winner chooses five to 15 females to reproduce with and guards them fiercely from competitors. This is a stressful time for males and they can lose up to one-quarter of their body weight.
Once the mating season is over in November the males will drop their antlers. However, pregnant females will keep theirs until spring, as this puts them at the top of the feeding hierarchy, ensuring access to the best foraging sites. The mother leaves the herd in the spring and travels to a calving ground, where she usually gives birth to a single calf in the morning during the month of May, sometimes June.
Most calves are born within a ten-day period and weigh 2.5 to nine kilograms (5.5 to 19.8 pounds). They can stand after just one hour and can outrun an Olympic sprinter after only one day. The calf stays close to its mother for the first six months, relying on her rich milk until it is weaned, although it starts eating solid food after just one week.
Unlike other deer, reindeer have hair on their hooves to keeptheir feet warm. During the winter, only the rims of the hoof come into contact with the cold ground.Two large, crescent-shaped toes bear most of their weight.