Thunder Bay

U.S. National Park Service will soon transport wolves to Isle Royale

After much debate and deliberation, the U.S. National Park Service has decided to transport wolves to Michigan's Isle Royale, in hopes that the intervention will save the dwindling population, and restore the balance between wolves and moose on the island.
Isle Royale has long been of interest to researchers because of the opportunity to study interactions between moose and wolves in an isolated environment. (David Mech/Researcher)

After much debate and deliberation, the U.S. National Park Service has decided to trap and transport wolves to Michigan's Isle Royale, in hopes that the intervention will save the dwindling wolf population and restore the island's balance between wolves and moose.

"The decision was made in order to ... provide some resiliency to the ecosystem at Isle Royale by reinstating the predator-prey relationship that's been there for most of the existence of the park," said Phyllis Green, superintendent of Isle Royale National Park. 

A number of factors have caused the wolf population to drop to dramatically low numbers in recent years, said Green.

Wolf population decimated, highly inbred

And whereas in the past, ice bridges that formed between the island and the Canadian mainland would allow the occasional new wolf to travel over, adding genetic variation to the population, a warmer climate has made those bridges much less common. 

Today, only two wolves remain on the island, she said; an inbred pair unlikely to produce surviving offspring. 

A healthy wolf population is needed to keep the moose population in check and to temper boom-bust cycles that would also affect other aspects of the ecosystem, Green said. 

Several years ago, just three wolves were reported to remain on Michigan's Isle Royale. That number has now dwindled to two. (Rolf Peterson)

In particular, she said, a skyrocketing moose population could impact some notable aquatic plants.

"We have one of the largest collections of freshwater sponges in the midwest. We have large populations of native mussels which have become rare in other places, and we have, basically, some plant communities that are important to maintain for our fisheries."

Some of that aquatic vegetation is also attractive to moose, she added, "and so they're in there wading around, roiling things up and eating quite a few of our plants, so basically what we're doing is restoring a dynamic that will kind of moderate how the vegetation changes over time." 

Transporting wolves 'logistical challenge'

Now that the decision has been made to intervene, officials must tackle the "logistical challenge," of moving wolves from the mainland to the island.

It will be no easy matter, said Green, and could take some time.

"Wolves are pretty smart," she said. "They are very hard to capture." 

"Once we capture a wolf on the mainland, we need to process it through a veterinarian, make sure it's healthy, and then move it directly to the island which will be ... either using boats or planes, and it really depends on the weather windows," said Green.

While having a healthy wolf population won't entirely stop the moose population from booming and busting, it will make the cycles less extreme, said Phyllis Green, the superintendent of Isle Royale National Park. (Rolf Peterson)

No decision has been made about where the wolves will come from, although several nearby states have offered to help, Green said, as has Canada's Michipicoten Island, which has had a problem with too many of the predators in recent years. 

The wolves will be brought in gradually, Green said, starting with a small group of perhaps six to 10 animals. The earliest opportunity to move them will be this fall.