This is a middle-sized animal. The weight of the male species in autumn season is 100-220 kilos. The weight of horns is 11-12 kilos. The newborn fawns weigh 6-7 kilos. Both male and female reindeers have horns but sometimes there are hornless she-deers. There are no sex differences in coloration. The change of coat lasts from the end of the winter till the end of the summer. By the winter end the reindeers get very light, almost white color. Hooves are big and flat, fit for the walk on snow and bogs.

Reindeers feed mostly on herbs, grassland litter, low shrubs, mushrooms and moss.
The animal is very common in Siberia. There is estimation that only in Taimyr there are approximately one million reindeers. So-called Taimyr population of the Siberian tundra subspecies inhabits tundra, forest-tundra and northern open forest regions. The bigger Siberian forest deer subspecies inhabits taiga and mountains in the south of the region.

It is generally thought that the forest subspecies populates the forest areas and the zone of bald mountains where it lives in upper parts of ranges. There are about seven thousands forest reindeers in the region.
The forest reindeer feeds on moss, young shoots of willow and birch. The biology of the forest reindeer is very similar to that of the wild reindeer. The forest reindeer is very rarely found in southern taiga; it populates only taiga’s northern outskirts.

Tundra reindeers migrate a lot. Places for fawning are situated in northern tundra. The fawning is in the second half of June. The reindeers concentrate in large herds in July (up to fifty-sixty thousand animals in each herd). Following fall of temperature the herds break apart. During August and September the reindeers spread widely across the tundra where they spend the winter. Taiga and mountain reindeers do not migrate much and move maximum 100-150 kilometers between summer and winter pastures.

The breeding period starts at the end of September and lasts during October. By the start of the breeding the change of coat is finished, the horns are ossified and cleared from velvet, the fatness of males is close to maximum and the neck of animals gets much thicker. There are frequent fights between the male species at this time. The female species reach reproductive age on the second year of life while the males need three years.

The gestation period is about 230 days. The she-deer give birth to one fawn (in very rare cases two fawns). The forest subspecies of the reindeer is in the Red List of Russia.