Beverly caribou decline not as drastic as once feared: new study
“I think habitat deterioration and disturbance is a factor"
The Beverly caribou herd lost half its population between 1994 and 2011, a Nunavut government study has found, but the decline is not as bad as officials once feared.
The herd’s population stood at 276,000 animals, an all-time record, in 1994.
But the June 2011 survey, released last week, showed there are only an estimated 124,000 caribou left within the Beverly herd and an estimated 83,300 caribou within the Ahiak herd.
The study also confirmed the Beverly herd has shifted its calving grounds about 200 to 300 kilometres north of breeding grounds documented in previous surveys.
That explains why surveyors only found 93 caribou cows in the herd’s former calving grounds in 2007 — the calving grounds had moved.
So amid fears about drastic declines in northern barren ground caribou populations, the report’s clarification of changes in the population of the two herds is taken as positive news by government and conservation officials.
The Nunavut department of environment described the population count as “the most accurate estimate for the Beverly herd to date.”
“Caribou are and essential component of Nunavut’s terrestrial ecosystem,” said James Arreak, Nunavut’s environment minister, in a news release.
“They represent an indispensable source of sustenance, clothing, and economic opportunities through guided hunts, tourism, and commercial hunts,” he said. “And the importance of the animal “to Nunavummiut and our cultural heritage cannot be overstated.”
The study looked at caribou abundance on the Beverly calving grounds in the vicinity of Beverly Lake and the Queen Maud Gulf, as well as the calving range of the Ahiak subpopulation in the vicinity of the Adelaide peninsula, east to Pelly Bay.
Government-commissioned biologists and 38 community representatives, including 34 Nunavut beneficiaries, two Saskatchewan representatives and two Government of the Northwest Territories’ representatives participated in the field program.
They used cutting-edge digital tools and fly-over visual surveillance of the herd’s calving and foraging grounds for their population estimates – 124,000 Beverly caribou for the summer of 2011.
Reasons for this shift in the calving area are unknown, but it may be related to numerous human and natural factors: range-wide human disturbances, such as road construction and increased hunter access to caribou; harassment by biting insects; food limitations; predation, and forest fires.
Similar shifts have been documented for other barren-ground caribou herds.
Whether the herd is at the low or high end of its population cycle is hard to tell, said Ross Thompson, executive director of the Beverly and Qamanirjuaq Caribou Management Board.
But he said the calving grounds’ northward shift appears to be in areas where levels of hunting are lower.
“It’s in a new area, where there’s concern about non-traditional communities harvesting the herd,” said Thompson.
The herd’s range extended further south in the past, to areas that included aboriginal communities in Saskatchewan and Northern Manitoba.
Communities in these areas may be facing shortages due to the shift, “no question about it,” he said.
Declines in population, which are still the prevailing trend, can’t just be pinned on hunting or any other single factor, said Thompson.
The priority in conservation must be to protect calving grounds.
“If you get a low calving rate for whatever reason – parasites, predation, disturbance, poor weather – that really affects [growth] because it’s such a low percentage that feeds back into the population,” he said.
“Personally I think habitat deterioration and disturbance is a factor.”
Pin-pointing any single one “would be dangerous,” he added, because several effects are at play at any given time.
Thompson praised the study as an important step for caribou management over the next 10 years, which coincides with the renewal of his management board’s mandate to protect the herd for the benefit of aboriginal treaty rights.
The Government of Nunavut plans to monitor any changes from the June 2011 results.
A 2011 study by John Nagy, wildlife biologist and researcher from the University of Alberta, also concluded the Beverly herd had moved further north in Nunavut to calve near the western Queen Maud Gulf coast rather than at its “traditional” calving ground. That also confirmed the traditional knowledge of elders who maintained the herd simply relocated.
The financial value of caribou as a staple to Nunavummiut has been “conservatively” estimated to be well over 22 million dollars per year territory wide, the GN said.
You can read the full caribou study here.