Caribou or Reindeer

Rangifer tarandus

Description

Caribou have a lightweight coat of hollow hairs which are efficient for insulation, this helps to protect them from the cold temperatures and also making the body more buoyant while swimming. This coat can be a variety of colors based on subspecies, region, sex and season; ranging from dark brown to nearly white. The rump is generally a lighter color and white fur is found on the belly, neck and above the hooves. Caribou have broad, concave hooves to support their bodyweight while traveling on snow and soft tundra and also to aid in swimming. Different subspecies of caribou range in size based on their geographical placement; caribou found in southern latitudes tend to be larger than those of northern latitudes, generally caribou can grow to 120 cm at shoulder height and 150- 230cm in length. Size is also dependant on sex; the males of some subspecies are twice as large as females. Both male and female caribou have antlers; bulls have large, complex antlers that are shed after rut (breeding season) while cows have smaller, simpler antlers that are shed in the spring.

Habitat

This species is distributed circumpolar among actic tundra and subarctic/boreal forest habitats. The woodland subspecies, Rangifter tarandus caribou, is found as far north as 460 degrees north latitude while the Peary subspecies, R. t. pearyi, and Svalbard subspecies, R. t. platyrhynchus, can be found as north as 80 degrees north latitude.

Feeding Behavior and Diet

Caribou are grazing herbivores feeding on a variable diet in the summer. Their summer diet includes leaves of willow and birch trees, mushrooms, cotton grass, and sedges along with other vegetation. During winter months their diet consists mostly of lichens. Males do not feed during rut (breeding season) and rely on fat reserves during that time.

Reproduction

Breeding season, called rut, occurs in October through early November. Males compete for access to groups of 5-15 females by participating in sparring battles. These battles can cause injury and exhaustion. 228 days after mating, females give birth to a single calf. Calves are able to graze one month after birth but they continue to nurse from the mother until the first week of July. Female caribou reach sexual maturity at 16-28 months and can produce calves every year.

Months and Times of Activity

This species migrates great distances during the spring and fall, caribou can travel more than 5,000 kilometers in a year. In the spring caribou migrate from their winter range to the calving grounds. These animals are gregarious, tending to be social, can be found in herds of tens of thousands individuals during the summer. In the fall caribou migrate to forested wintering grounds.

Special Features, Stories, Relationships

• Caribou produce a clicking noise when they walk, caused by tendons rubbing across the bones of the feet.
• A newborn caribou calf can outrun a human one day after birth and can run 80 km/hr as an adult.
• Caribou are the only species of deer which both males and females have antlers.
• To read legends featuring this animal go to:  http://www.native-languages.org/legends-caribou.htm
• Children’s book featuring this animal: CARIBOU GIRL by Claire Rudolf Murphy

References