The Caribou and the Wolf Each year, wolves kill an estimated 21,000 - 90,000 Bathurst caribou, as many as 5 times the number of caribou that are shot by hunters. Nevertheless, wildlife biologists consider the wolf to be an integral part of the caribou ecosystem, with wolves performing a “culling” function that removes aged, injured and otherwise weak caribou from the herd. The hunter-prey relationship between the 2 mammals is finely-tuned and perfectly timed; while wolf packs follow the caribou herds as they migrate to their summer range, they stop short of accompanying them all the way to their arctic tundra calving grounds. The shelter-seeking wolves are not at home in the barren lands of the very far north; furthermore, they are busy giving birth to and rearing their own young. For a few short weeks, the calving caribou are free of the threat of their most dangerous predator.

When it comes to long-distance mammal migration, it’s hard to top the astonishing range of the Bathurst barren-ground caribou. Each spring, the caribou migrate hundreds of kilometres from boreal forest to arctic tundra, following frozen lakes and rivers and snow-free uplands along a steady, unerring path that takes them to the shores of the Arctic Ocean.

With pregnant cows in the lead, and bulls and juveniles bringing up the rear, the caribou navigate their way through vast expanses of treeless territory, somehow ending up near the same calving grounds they left behind the previous summer. Bathurst caribou satellite tracking programs, carried out since the mid-1990’s, have revealed that the range of the herd is much larger than previously thought, with wintering areas varying widely to the north, east and even south of Great Slave Lake. Summer ranges are more predictable, with calving grounds consistently located in an area west of the Arctic Ocean’s Bathurst Inlet. (While the caribou rarely return to precisely the same location, they do head back to same general area.)

Of the estimated 1.24 million barren-ground caribou in the North West Territories, about 350,000 are part of the Bathurst Herd. Since barren-ground caribou herds are named after the location of their calving grounds, other herds in the North West Territories include the Bluenose, Beverly and Qamanirjuaq. The Bathurst Herd ranges from as far south as northern Saskatchewan, as far west as the eastern reaches of Great Bear Lake, as far east as the Clinton-Colden Lake area and as far north as the frozen waters of Bathurst Inlet. The satellite collaring program, which tracks up to 20 caribou at a time, has shown that the Bathurst caribou sometimes winter southeast of Great Slave Lake in a range that was formerly known as the exclusive territory of the Beverly Herd.

The variability of the Bathurst caribou’s migration route to wintering grounds has implications for First Nations hunters such as the Chipewyan Dene from Lutsel K’e, on the east arm of Great Slave Lake. The Lutsel K’e residents continue to take part in the annual harvest of Bathurst caribou; in years past, the occasional failure of the caribou to follow traditional migration routes resulted in starvation for indigenous people, who depended on the hunt for their main food supply.

Calving ground surveys carried out every 6 years show that the Bathurst barren ground caribou herd is in good condition, with a high rate of calf survival. A Management Plan for the Bathurst Herd, established by the North West Territories in 1992, aims to maintain the herd size at 300,000 – 600,000 caribou, allowing an annual harvest of about 16,000 animals.

Caribou Commentary

• Caribou are the only species of the deer family in which both males and females have antlers. Males, however, have much larger antlers than females.

• Caribou have large, concave hooves that are well-adapted to travel through snow and muskeg. They function as scoops when the caribou paws through snow to uncover lichens and other food plants.

• The unique ability of the caribou to use lichens as their primary food source allows them to survive in harsh northern conditions.

• Barren-ground caribou are smaller (90 – 145 kilograms) and lighter in colour than woodland caribou. The Alaskan form of the barren-ground caribou, Rangifer tarandus granti, lives west of the Mackenize River; the Canadian Rangifer tarandus groenlandicus lives to the east.