In the 1.6 million years that caribou have roamed the northern hemisphere, their populations have risen and fallen with cycles of glaciation and deglaciation. In that time, caribou found a way to survive when many other Ice Age animals such as the woolly mammoth didn't. In more recent millennia, populations have ebbed and flowed on a regional basis for a variety of other reasons, not all of them clearly understood. So when the Bathurst herd began showing signs of decline around the time I was on that canoe trip, no one was overly concerned. A few eyebrows were raised in 2003, however, when only a third of these animals could be accounted for. Still, there was no panic. That didn't set in until 2009 when the herd plummeted to just 32,000.
Caribou are to Inuit, Dene, and other Arctic people what bison were to the North American Indians. When bison were wiped out on the Great Plains, tribal and First Nations cultures collapsed and never fully recovered.
The absence of caribou in a future Arctic would be just as devastating. Four or five caribou can save a family living in a remote village or hamlet between $2,000 and $4,000 annually in food costs. The importance of these animals, however, extends far beyond scales of economy. Visit any community in Alaska, northern Canada, northern Scandinavia, Greenland, or Arctic Russia and you see caribou in the clothes people wear, the stories they write and tell, and the artwork they create. Like the polar bear, the caribou plays a near mythical role in many people's lives. Each time a hunter kills a caribou, an offering is made to God or the Creator.
Overhunting, however, is one reason caribou have declined in some places. Until 2009, the annual aboriginal harvest from the Bathurst herd alone was between 4,000 and 7,000 animals. Many of them were cows, which are key to the sustainability of a herd. According to one study, the number of breeding females in the herd fell from 203,800 in 1986 to just 16,400 in 2009.
Hunting alone does not account for the freefall, though. What concerns many caribou experts now is the precipitous warming in the Arctic that is adding to the stress that caribou already face in a world in which deep snow, predators, pathogens, insects, and overgrazing limit their numbers.
These climate-induced factors include bigger, hotter, and more frequent forest and tundra fires, extreme weather and ice storms, changes in the dates of freeze-up and breakup of large rivers and lakes, which may affect migrations, a new parasitic disease previously unknown in caribou that live in the Great Bear Lake area of the Northwest Territories, and weather conditions favoring insects that torment the animals and prevent them from foraging and gaining the body mass needed to successfully reproduce.