Reindeer (Rangifer tarandus tarandus)

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

Reindeer has adjusted to the arctic climate very well

Both female and male reindeer grow solid bone antlers that drop once a year and grow again. In the deer family, the only female that have antlers are reindeer. 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.

Image. Tarja Konstig.

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

Calves start growing their antlers during their first summer reaching 20 cm by autumn. They 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 go smaller. Reindeer living in the mountainous area have lighter-coloured and broader antlers, whereas reindeer in the forest areas have darker and narrower antler, 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 East, reindeer are lighter and bigger than in West.”

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

Reindeer in Numbers

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

Moving in the Snow

Reindeer has adjusted well to cold, snowy climate

Reindeer is a long-legged, four toed herbivore who has adapted well to the harsh Arctic climate. The nails of the toes are long, broad and shape of a half circle. In a soft snow, reindeer supports itself with whole hoove and an additional toe in each makes it even easier to move. Because of these, the surface pressure that reindeer cause is only 85-100 grams, where as the corresponding number for a wolf is 90-110 grams and for an elk even 1200 grams per cm2. 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 goes below freezing, the temperature of a reindeer feet is only a few degrees on plus. 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.

Image. Helena Rännäli.

Reindeer Fur – an Excellent Insulation

Reindeer has adjusted 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 comes off 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 degree Celsius in the winter.

 

The coarse outer guard hairs are thick from the middle and inside them there are heat-insulating air pockets. A grown reindeer can have 1700 hairs in square centimetre and the fur is 3-4 cm thick. For every outer guard hair there are several under hairs that prohibit the movement of air.

A well processed reindeer fur is known as a very good insulation. No wonder, that reindeer fur is still a popular, warm sleeping pad. It resists well damp and keeps 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. Reindeer does not start digging unless it has a smell of food.

Like other ruminants, reindeer cannot really see colours, but it does see 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 these and the herd stays together.

image. Sonja Kyrönniemi.

The eye of a reindeer has adjusted to different seasons. Hence the colour of the layer that reflects light (tapetum lucidium) and the sensitivity for light change along 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).