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Four Canadian wolves airdropped into Isle Royale National Park, Michigan to hunt moose and reproduce

March 2019 - A crack team of Canadian wolves were airdropped in Michigan last week to carry out two important missions—hunting moose and making babies.

The four wolves were captured by specialists at the Ontario Ministry of Natural Resources and Forestry (OMNRF) and transferred to Isle Royale National Park, a wildlife preserve on an archipelago in Lake Superior.

The relocation is part of an ongoing joint project with the US National Park Service to restore a healthy population of the iconic predators to the island chain after years of decline. If all goes to plan, the wolves will also cull the booming moose population, which is damaging the island’s ecology due to the herd’s overconsumption of plantlife. 

The Canadian quartet joins an existing group of four wolves in the park. Two of those wolves are the last surviving descendents of the island’s original pack, while the other pair were captured in Minnesota and introduced to the park in 2018. The new total population of eight wolves is equally split between males and females.

The Isle Royale wolf population has experienced dramatic booms and busts since scientists first started studying it in 1958.

Since the study began 60 years ago, fluctuations in populations of wolves and moose on the island were studied because of how direct the predator-prey relationship is between the two species. Wolves were the island moose’s only natural predator and moose were the wolves’ main prey. So when one species’ numbers grew because of good food availability, limited disease or good weather; the other proportionally declined; and vice versa. Wolves helped stabilize moose herd numbers by preying on the old, young and sick, while strong moose numbers ensured that the wolves had enough to eat during the long, brutal winters. Both helped keep the ecosystem of the island in balance.

But by 2011, the wolf population had taken a sharp nosedive and by just five years later, only two wolves remained because of inbreeding on the islands after the wolves living there became largely stranded from the mainland

Historically, the wolves had come to the island via an ice bridge between the island and the Canadian mainland. For decades, they would continue to use similar ice bridges, which would usually form for about 50 days a year during the winter, to move to and from the mainland. New wolves would come, old wolves would leave; regular, seasonal migrations were common.

However, over the last 20 years, warming temperatures made these ice bridges less and less common, and when they did form, they were not consistent. This limited the wolves ability to leave the island and prevented new mainland wolves from joining the pack. With no new wolves, the genetic diversity of the pack declined through inbreeding, the wolves stopped thriving, and their numbers dwindled. 

The newcomers were captured by OMNRF teams that fired net guns from aircraft. The animals were sedated and examined by veterinarians before and after their helicopter trip to ensure they were healthy enough for release. They were also deliberately selected to be over two or three years old, when wolves become sexually mature enough to breed, but not too old, so that they have a shot of surviving multiple breeding seasons. All of them are collared so that researchers can track their movements.

The elite Canadian crew includes a female and male from a pack based on the mainland near Wawa, Ontario, and two males from Michipicoten Island Provincial Park. The female was released on Isle Royale last Tuesday, while her pack mate was set loose a day later. The Michipicoten males were introduced separately to the island on Thursday and Friday.

One of the wolves in its transport crate. (Photo Credit: A. McLaren / OMNRF)

The wolves are probably a bit weirded out by the week’s turn of events, according to John Vucetich, an ecologist at Michigan Technological University and leader of the Wolves and Moose of Isle Royale project.

“They live in families, so imagine what happens to a dog when they’re plunked into a foreign place,” Vucetich told The Guardian. “They are being introduced to each other. It’s tense and nervous, and it’s tough to find food in a new place. It’s stressful.”

That said, the wolves are apparently adjusting to their new homes and pack mates without major issues. Mark Romanski, who is the project manager for the park’s wolf reintroduction as well as Division Chief of Natural Resources for Isle Royale National Park said he was “blown away by the resilience of these wolves,” in a statement.

“Within hours after undergoing capture and handling and arriving on Isle Royale, [the wolves] immediately got on the trail of their pack mates,” Romanski said. “These large males, all around 90 pounds, will almost certainly know what to do when they encounter a moose.”

Moose are the main food source for the Isle Royale wolves, and their unique predator-prey relationship has fascinated scientists for decades. As the wolf population dwindled, the moose population exploded from 975 individuals in 2013 to about 1,500 in 2018. This ecological disruption may sound like a good deal for moose at first, but a similar population boom during the 1990s led to thousands of moose dying of starvation in the winter.

Isle Royale National Park officials and their collaborators hope to avoid similar calamities by introducing 20 to 30 wolves to the park over the coming years.  As Phyllis Green, superintendent of Isle Royale National Park, said in a statement, “To see these wolves disappear into the forests of Isle Royale and to have an opportunity to start a new generation of wolves on the island fulfilled a major objective in the first year of reestablishing the population.”

>> More on the Isle Royale situation

Photo: A white wolf is  airlifted and released at Isle Royale National Park. (Photo Credit: OMNRF, National Park Service, and National Parks of Lake Superior Foundation)

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