Caribou

Alaska’s Big Five: 

Caribou are the only members of the deer family where both sexes grow antlers.  The bulls’ antlers are massive, but the cows’ are shorter and slight.  The hooves of caribou are large, concave and they spread out wide to support the animals on snow and tundra.  The hooves also act as paddles when swimming.

There are 32 herds of caribou in Alaska, with each herd occupying a distinct calving ground.  Calves are born in late May in Alaska’s Interior, and in early June in northern and southwestern Alaska.  The vast majority of calves are born as singles, but twins do happen, although rarely.  They weigh, on average, 13 pounds at birth, and grow quickly.  By 10-15 days after birth, the weight of a calf doubles.  A calf is running alongside its mother within hours of birth.

Bull caribou will reach a weight of 350-400 pounds as an adult, although they can get as large as 700 pounds.  An adult cow caribou averages 175-225 pounds.  An average male lives to 7-8 years, while the females can live to 10 years.

Caribou can migrate huge distances between their summer and winter range.  The larger herds may migrate 400 miles between their two ranges, where a small herd may barely migrate at all.

The caribou population in Alaska is currently estimated at 750,000.  Their population can be cyclic, and can fluctuate widely in a rather short period of time.  The declines and increases in numbers can be extremely difficult to predict.  Predation, climate, weather, disease, population density and hunting can all have an effect on the caribou population.