Last Lake Superior caribou herd may be down to 30
Ontario wildlife officials are finalizing plans to save the last remaining Lake Superior-region caribou herd, which continues to dwindle as wolves take their toll on Michipicoten Island.
Experts say as few as 30 caribou may remain on the Lake Superior island where more than 450 caribou roamed as recently as 2014, before wolves crossed over the ice from Pukaskwa National Park on the mainland.
The Ontario Ministry of Natural Resources and Forestry has a plan to trap and then helicopter several caribou from Michipicoten Island to the nearby Slate Islands. Brent Patterson, research scientist and caribou expert for the ministry, said Wednesday that the goal is to start moving caribou within two weeks if snow and ice conditions are suitable.
Ontario Natural Resources Minister Kathryn McGarry announced on Dec. 7 that the province would work with the tribal wildlife officials of the Michipicoten First Nation to move the animals "soon."
But caribou supporters, critical of provincial officials for moving too slowly on the transfer, said far fewer than 30 caribou may now remain on Michipicoten Island based on recent surveys and estimated predation rates. On average about one caribou is being killed by wolves every three days.
Patterson said an aerial survey was conducted of Michipicoten Island on Dec. 20 and, along with trail camera photos, he estimates 30 or more caribou remained there, enough to transport several to the Slate Island to restart a viable population there.
"Based on recent observations ... a sufficient number of caribou remain on the island to support a mid-January translocation to the Slate Islands," Patterson told the News Tribune.
Christian Schroeder, a caribou advocate who owns a camp on Michipicoten Island, said the ministry waiting until mid-January to rescue the island's caribou "is cutting it dangerously, inexcusably close. Based on their own (radio) collar data, half of the caribou population has been killed since about December 1."
"This group of animals represents the finest chance we've ever had to restore the Lake Superior caribou population around the entirety of the coast. We need vision and leadership now to seize this opportunity, not more careless wandering and reactivity," Schroeder said.
Ironically the Michipicoten caribou were originally moved off the Slate Islands years ago to help spread the population out. Michipicoten had more than 650 caribou just 20 years ago.
Now, the Slate Islands have only a few if any caribou left because of wolf predation there. So few caribou remain that the last wolves have now starved or left, making the Slates once again safe for airlifted caribou.
It's a confusing, expensive and complicated chess game as climate change and a trend toward unpredictable ice bridges between Ontario's North Shore and the islands confounds wildlife experts. Scientists say that, for centuries before European settlement of the region, caribou thrived both on the islands and the mainland surrounding Lake Superior. Ice bridges occurred regularly between the mainland and the islands, allowing caribou and wolves to move freely back and forth, avoiding and seeking each other.
Now, caribou have been trapped on the islands, with wolves moving out across ice bridges that form only occasionally. By the time caribou sense there are too many wolves, it's too late for them to leave the islands, and there are no caribou remaining on the mainland to resupply the islands. (The wolves on the Slate Islands apparently became trapped there, too, after recent warm winters, with dead wolves found emaciated because so few caribou remained.)
Caribou were common across the Lake Superior region through the 1800s but had mostly disappeared from Michigan and Minnesota by the mid-1900s. They have been declining in parts of Ontario as well, pushed north out of the Lake Superior region by development, logging and the expansion of whitetail deer and wolves. Efforts to restock a Minnesota caribou herd were abandoned years ago because too many non-native whitetail deer have infiltrated the state's far northern forest. Deer carry a parasitic brainworm that, while harmless to deer, is fatal to caribou.