Historically, ice bridges would have formed almost every winter, giving both wolves and caribou freedom to move around, said Gordon Eason, a retired biologist who worked with the ministry for three decades. But because of global warming, he said, those bridges now form only occasionally, trapping the caribou on islands, together with their predators.
“It’s like being confined in a prison cell with someone who’s trying to murder you,” Dr. Eason said.
Caribou-transplant operations are not unheard-of on Lake Superior. In the early 1980s, after a lighthouse keeper noticed the tracks of a lone bull who had crossed an ice bridge to Michipicoten Island, Dr. Eason and his colleagues hauled seven females (and an extra male) to the island to join him, in the hopes of creating a new community.
It worked — at least for a few decades.
Dr. Rodgers and a colleague, Brent Patterson, a government research scientist and adjunct professor at Trent University in Ontario, said they were optimistic about the fate of Michipicoten Island’s remaining caribou. But other scientists feared they would be killed by wolves in the next few weeks. Serge Couturier, a biologist who has been studying caribou for 34 years, said it was “likely” that wolves would “take the last few caribou before the end of the snow period.”
Dr. Eason, who led the original caribou relocation to Michipicoten Island, is among those calling for the ministry to do more to save Lake Superior’s caribou. “We have to become that agent of immigration instead of just natural immigration occurring,” he said.
“I guess that’s one of the costs of managing threatened species or endangered species,” he added. “You have to intervene in part of the cycle that isn’t functioning anymore.”
The relocation comes after months of complaints from people who live nearby on Lake Superior, who have long voiced concerns about the island’s caribou and at one point even considered culling the wolves themselves.
“We wanted to keep the caribou on Michipicoten — it’s an incredible habitat, and they’ve thrived there,” said Leo Lepiano, the lands and resources coordinator for the Michipicoten First Nation, an organization representing the native community. Now, some people are calling for the ministry to move the remaining Michipicoten caribou to other islands as “backup” populations.
“As it stands now, the survival of the Lake Superior caribou will be entirely dependent on the animals on the Slate Islands,” Mr. Lepiano, Dr. Eason and others wrote in a letter sent to the ministry on Monday. Mr. Lepiano said he was concerned another ice bridge could form from the mainland to the Slate Islands.
“It’s possible that wolves could make it over to the Slate Islands, and it would only take them a couple of weeks to eat through the caribou,” he said. “It’s kind of foolish to put all your eggs in one basket.”