Warming climate threatens caribou in Nunavik, Labrador, Baffin
Study links species’ survival with stable climate
Global warming could wipe out caribou populations in Nunavik, Labrador and Canadian provinces in 60 years, according to a recent ground-breaking international study on the effects of climate on caribou species.
Caribou herds that range on lands stretching from Labrador and Nunavik in the east, south to Ontario and Alberta in the west, have the least chance of surviving climate changes predicted by a “business-as-usual” scenario from the Intergovernmental Panel on Climate Change, the study said.
Published Dec. 15 in the journal Nature Climate Change, the study, headed by researchers at Université Laval in Quebec, found that northern circumpolar regions with the most stable climates in the past 21,000 years also have animals with the greatest “genetic diversity.”
Caribou throughout north circumpolar regions fall into two distinct groups that share common genes, the study says. The northeast and south Canadian group is one.
The other, known in the study as the “Euro-Beringia” group, covers the rest of the circumpolar regions — including Canada’s three territories, Alaska, Siberia and northern Europe.
The two groups became distinct after they were separated by glaciers in the last ice age, the study says.
Populations in the second group are more adaptable to change because they have more genetic diversity, according to researchers. Herds in south and eastern Canada, on the other hand, will be at risk because they are less diverse and will face more drastic changes in their habitat due to climate change.
“Genetic diversity is the key factor in a population’s ability to adapt to future environmental change,” Kris Hundertmark, the study’s co-author and wildlife biologist at the University of Alaska Fairbanks, said in an e-mail.
Canada’s northwestern caribou, ranging from Nunavut’s Kivalliq region to Yukon, stand a better chance of surviving global warming, the study found.
Researchers predict these caribou and their related populations stretching west to Siberia and Northern Europe (where the animals are called reindeer) will lose about 60 per cent of their habitat in the next 60 to 70 years.
The study predicts that caribou in Canada’s south and east, including Nunavik and Labrador, will lose 89 per cent of their habitat by 2080.
“Most of the herds that belong to this lineage are already considered as endangered or threatened,” the study says.
Caribou in northwestern Canada and Alaska “will lose some habitat as well but not to that extreme,” Hundertmark said. “Those areas are forecasted to hold much of the genetic diversity of North American caribou in the future.”
Caribou conservation efforts in Canada “should focus on this particular region, where climate will be stable, where we expect a higher level of genetic diversity,” said Glenn Yannic, Université Laval wildlife biologist and lead author of the study.
This will ensure that caribou populations in Canada can “cope with new environmental conditions” brought on by global warming, Yannic said.
The outlook is not as favourable for caribou that range on Arctic islands, where herds will become more isolated, Yannic said.
Even though the study finds that climate will be ideal for caribou throughout Nunavut, much of the territory is made up of islands.
“We cannot say caribou will be able to colonize those islands, and move from island to island to ensure interbreeding [and survival] of populations,” he said.
Entitled “Genetic diversity in caribou linked to past and future climate change,” the study does not consider factors other than temperature, snow and rainfall, Yannic said.
Recent studies on the Arctic predict a “greening” of the circumpolar region. The U.S. National Oceanic and Atmospheric Administration’s Arctic Report Card for 2013 noted that plant growth throughout the region is expanding, but could not predict its effects on caribou.
Such expansion is not necessarily better for caribou, said Steeve Côté, wildlife biologist with Université Laval and senior author of the Nature Climate Change study.
“The animals won’t have access to better conditions, but actually worse conditions,” Côté said.
Peak periods of plant growth will be “out of sync” with the caribou birthing season, he said, and plant growth will not be suited for the animals.
“Warming climate also has positive impacts on insects,” he added. “And caribou are sensitive to insect harassment.”