Reindeer (Rangifer tarandus tarandus)

Reindeer is a semi-domesticated animal that reminds wild reindeer by its anatomy and behaviour. The male height at the withers is around 110 cm and it weighs 90-180 kg. A female reindeer’s height at the withers is about 90 cm and it weighs 60-100 kg.

Reindeer are well adapted to the arctic climate

Both female and male reindeer grow solid bone antlers that drop once a year and grow again. Reindeer are the only species in which the females also grow antlers. The male reindeer drop their antlers after the rutting season ends and female, after calving in the spring. Reindeer antler is the fastest growing antler in the world: it can grow 2 cm per day.

Reindeer in falling snow. As proof of good insulation of the fur the snow on the back of the reindeer does not melt. Image: Tarja Konstig.

The antlers affect the reindeer’s status in the herd. If a male reindeer loses its antlers or they are cut, its status weakens. Reindeer use antlers in their mutual bickering, but the main purpose is to use the antlers in the fights during the rutting season. When fighting with large carnivores, reindeer kick instead of using their antlers.

Calves start growing antlers during the first summer reaching 20 cm by autumn. The antlers are not as branchy as the grownups have – instead they look like two sticks. The age of a reindeer cannot be estimated on the basis of the antlers, but when reindeer grow old, the size is smaller. Reindeer living in the mountainous areas have lighter-coloured and broader antlers, whereas reindeer in the forest areas have darker and narrower antlers, which makes it easier to walk around trees.

The Colour of a Reindeer

The colouring of a reindeer varies from almost black to white. There are dozens of different names for these colours. For example, a dark reindeer is “musikki”, a light coloured is “suivakko” and white is “valkko”.

Reindeer have traditionally been different coloured and sized around the reindeer husbandry area. T.I.Itkonen said in 1916:

“The reindeer in Enontekiö are slightly smaller than the average and rather dark. … In Russian Lapland, there are plenty of white reindeer, but also in Karasjoki, Norway, one can see many reindeer white as snow. In the eastern parts, reindeer are lighter and bigger than in the western parts.”

Bigger and long-legged reindeer are found in Kainuu due to the existence of the wild forest deer in the area. It is likely that the its genes have moved to reindeer due to interbreeding.

Reindeer in Numbers

  • Length from muzzle to tail 150-210 cm
  • Tail 10-15 cm
  • Ear 9-12 cm
  • Front leg 55-56 cm
  • Female live 18-20 years
  • Male live over 10 years
  • New born calf weighs 4-6 kilos

Moving in the Snow

Reindeer has well adapted to the cold, snowy climate

Reindeer is a long-legged, four toed herbivore and has well adapted to the harsh Arctic climate. The nails of the toes are long, broad and the shape of a half circle. In soft snow, reindeer supports itself with the whole hoof and an additional toe in each hoof makes it even easier to move. Due to this the surface pressure that reindeer cause is only 85-100 grams, whereas the corresponding number for a wolf is 90-110 grams and for an elk even 1200 grams per square centimeter. Moving in deep, soft snow is very heavy for reindeer. Hence, it tries to avoid these kinds of areas.

 The body of a reindeer is very warm under the fur, but its feet are exposed to cold air. They stay warm due to efficient circulation and the “oleic acid” in the bone marrow. The circulation in the feet is intensified by the vein-artery system that keeps the warmth that blood circulation brings to the feet. When the outdoor temperature drops below zero degrees Celsius, the temperature of a reindeer foot is only a few degrees above zero degrees Celsius. The oleic acid in the bone marrow helps the circulation as it works like antifreeze liquids. Most of the oleic acid works on the bottom part of the leg to prevent it from freezing when the weather is very cold.

The delicate feet of reindeer. On soft surface the hooves spread and carry the reindeer. Image: Helena Rännäli.

Reindeer Fur – an Excellent Insulation

Reindeer has adapted well to great changes in temperatures. The difference between summer and winter temperatures can easily be 70 degrees Celsius. In Siberia, reindeer have adjusted to -70 degrees Celsius in the winter and +40 degrees Celsius in the summer.

The old winter fur starts to moult in the summer and the new fur starts to grow in August. The winter fur is extremely dense and the heat-insulating air pockets make it light, but well-insulated. Hence, a reindeer in good condition can survive even in -50 degrees Celsius in the winter.

 

The coarse, outer protective hairs are thick from the middle and have heat-insulating air pockets. An adult reindeer can have 1700 hairs in one square centimetre and the fur is 3-4 cm thick. For every outer protective hair there are several under hairs that prevent the movement of air.

A well processed reindeer fur is known as very good insulation. No wonder that reindeer fur is still a popular, warm sleeping pad. It resists the damp and is warm even during the winter.

The Senses of a Reindeer

The most important sense that reindeer has is smell. Reindeer can smell lichen through thick snow. A reindeer does not start digging unless it has a smell of food.

Like other ruminants, reindeer cannot really see colours, but it sees weather something is dark or light. When reindeer escape, they lift their tails and show the white side of it. The other reindeer coming after follow and the herd stays together.

The tail of a reindeer is up when escaping and is a warning sign for other reindeer. Image: Sonja Kyrönniemi.

The eye of a reindeer has adapted to different seasons. Hence the colour of the layer that reflects light (tapetum lucidium) and the sensitivity for light, change during the seasons. In the summer, the colour of the layer is golden and, in the winter deep blue. The change helps reindeer to see in the dark (Nieminen 2014).

 

Reindeer (BBC)

Eight reasons to love reindeer