The Lost Wolves of Isle Royale National Park

09 Aug The Lost Wolves of Isle Royale National Park

gray wolf in Michigan’s Isle Royale National Park

Gray wolves have lived in Michigan’s Isle Royale National Park for almost 70 years. Should we intervene to save them, or let them “wink out”?

On a wild, remote island in Lake Superior, gray wolves have lived and thrived for almost 70 years. In the island’s forests — which make up the majority of Michigan’s Isle Royale National Park — a wolf population that grew to almost 50 individuals once contributed to a biodiverse, healthy ecosystem.

Today, however, it is believed that only two wolves remain. The survivors belong to the Chippewa Harbor pack. They are siblings who share a mother and, in addition, the female wolf is the daughter of the male.

An era that began with the wolves’ arrival on Isle Royale in the late 1940s, and that continued through the formation of three packs with memberships typically in the range of 18 to 27 animals, is coming to a close.

Some blame climate change for the loss. Others say it is just the natural order of things for species to come and go in a particular area. But whatever the cause, the question for the future health of the island and the national park is: Should we intervene to keep wolves on Isle Royale?

Climate change culminates a long-standing study

Isle Royale National Park, Michigan

Surrounded by Lake Superior, Isle Royale National Park is rugged, isolated and far from the sights and sounds of civilization. ©Joe Ross, flickr

In 1949, three gray wolves from Canada walked 15 miles across the ice of Lake Superior to Isle Royale, a 45-mile-long, up-to-nine-miles-wide island located off Minnesota’s North Shore. The island’s appeal for the wolves probably had a lot to do with a resident population of moose, descended from forebears that, it is thought, swam to the island around 1900.

In 1958, what would become the longest continuous study of a predator-prey system in the world — called the Wolves and Moose of Isle Royale Project — began on the island. By 1980, it was estimated that the wolf population there had grown to 50 individuals. By 2009, however, scientists could verify only 24 wolves living on the island. That number dwindled to nine in February 2014 — a figure that at the time was the second lowest total for the island ever recorded. Now, in 2017, we believe there are only two wolves left.

Most scientists believe that climate change — and the resulting lack of gene diversity available to the wolves — is the culprit. In the past, during most winters, the Lake Superior waters between mainland Ontario, Canada, and Isle Royale would freeze over, allowing new wolves to find the island. But beginning in the 1970s, rising temperatures caused ice bridges to form only about once a decade, which means that the chance of new wolves making it to the island to supplement the gene pool steadily decreased. What’s resulted is the most extreme case of inbreeding ever documented in a wolf population.

moose in Isle Royale National Park

Without wolves, moose numbers on Isle Royale could double within four years. ©Ray Dumas, flickr

Intervene to interrupt a wiping out of wolves?

Losing its wolves also means that Isle Royale National Park will most likely lose its forests and current ecosystem. Moose love to browse balsam fir. Unchecked by predators, they quickly decimate all the balsam fir trees around them — damaging the forest’s ability to regenerate. That causes change that cascades down through the food chain. According to a report issued by the School of Forest Resources and Environmental Science at Michigan Technological University on March 31, 2017, the balsam fir forest had been recovering to its healthiest state in a century or more until the wolves went into their current decline.

Once, in an average year on Isle Royale, wolves killed about 10 percent of the moose; but as wolf numbers have declined, the moose population has skyrocketed: from 1,300 in the winter of 2015–2016 to 1,600 in the winter of 2016–2017. Because of high moose reproduction rates, mild winters, an abundance of food and now virtually no pressure from wolves, the moose numbers could double to record high levels within three or four years. Eventually, though, the moose will run out of food, they’ll starve, and their population will crash.

As for beavers, a secondary food source for the island’s wolves, the study found that the “population has continued to increase, a pattern initiated when the wolf population collapsed in 2010–2012. There were almost 300 active beaver sites in 2016, a threefold increase in the past half decade.” While the precise results of a beaver surge on the island are not yet known, we are certain that beavers reshape landscapes; especially in isolated systems such as Isle Royale. It is also probable that in the end, they will starve, too.

wolves attack moose

Wolves keep the moose population in a healthy balance, protecting the island’s forests and ecosystem. ©Rolf Peterson

The National Park Service has proposed transplanting up to 30 wolves on Isle Royale, a precedent-setting idea that acknowledges that extraordinary steps need to be taken if a healthy balance of predator and prey in this Lake Superior wilderness is to be restored. By fall 2017, the service hopes to reach a final decision on what to do about introducing the wolves to the landscape. It’s possible that a new wolf population could be in place by the end of 2018.

Sense for standing back

The recommendation is a remarkable switch for the National Park Service, which has traditionally adhered to a hands-off policy in managing wilderness. Some conservationists have been critical, since the strategy would violate the intent of the 1964 Wilderness Act, under which almost the entire island of Isle Royale is protected. The rationale for those who are against bringing new wolves in is that the natural order on Earth is for species to continually “wink in” and “wink out.” Human manipulation of species’ numbers in a landscape, they say, can be a slippery slope. In 1900, caribou and lynx were the largest animals on Isle Royale. Both eventually disappeared, along with smaller species, such as coyotes and spruce grouse. Wolves and moose are relative newcomers here, along with tricolored bats and tree frogs. Unlike in Yellowstone National Park, wolves aren’t native to Isle Royale. Therefore, performing a genetic rescue by introducing wolves would break new ground.

Those who don’t wish to see the Isle Royale wolves wink out counter that the Wilderness Act was anchored in the idea that letting nature take care of itself was the surest way to preserve a natural system, a concept that may now be outdated. Today, there is a growing realization that sometimes climate change and other factors are so overwhelming that nature is not enough. And, the isolation of Isle Royale makes it, in some ways, even more fragile than many other parks and wilderness areas.

Chippewa Harbor at sunrise

Places where wolves are free to roam are rare on the planet. Perhaps Isle Royale should remain one of them. ©Ray Dumas, flickr

Research by Michael Nelson of Oregon State University shows overwhelming public support for having wolves on Isle Royale, even if that involves intervention. According to his analysis, 86 percent of public comments solicited by the National Park Service agree that wolves should be present in that national park. Half of those commentators cited maintaining ecosystem health as a key reason.

The loss of wolves in Isle Royale National Park saddens those who have visited the island, those who wish to, and those who never will, but are concerned nonetheless.

I think that’s because places where wolves roam free are mighty rare on this planet.

Do you think that because of human-caused climate change, we need to step in and bring new wolves to Isle Royale? Can nature be expected to repair itself today, with unnatural, anthropogenic climate change?

Here’s to your adventures, in whatever corner of the world you find them,


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Candice Gaukel Andrews
A multiple award-winning and five-time book author and writer specializing in environmental issues and nature-exploration topics, Candice Gaukel Andrews has traveled around the world—from the Arctic Circle to Antarctica and from Greenland’s coasts to Patagonia’s steppes—searching for and telling the stories that express the essence of a place. To read her articles and see samples of her nature photography, visit her website at and like her Nature Traveler Facebook page at
Candice Gaukel Andrews

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  • Chris West
    Posted at 10:56h, 09 August Reply

    There’s no reason to introduce new wolves to Isle Royale. To do so would only invite further inbreeding unless a constant introduction program is sustained.

    Wolves were only ever occasional visitors to the island and that is how it should remain.

  • Wally Elton
    Posted at 15:34h, 22 August Reply

    Having visited Isle Royale multiple times, I definitely understand the appeal of knowing wolves are there. Nevertheless, I have opposed any manipulation of wolf populations because nearly all of the island is designated Wilderness, where natural processes are supposed to operate freely. Too many people are prepared to sacrifice the principles of the Wilderness Act on behalf of a species that is thriving in the region as a whole. Nationwide, Wilderness is at greater risk than the gray wolf is.

  • Jim Backus
    Posted at 15:35h, 22 August Reply

    We don’t know if wolves where native at Isle Royale at any other time and died off for the same reason we’re losing the wolf today. Because of climate change new wolves can’t get to the island so let’s help them, we did at Yellowstone. Wolves balance the eco system. We know what the island will look like with too many moose that will die from starvation. How much of the wolf population died because of humans bringing dogs to the island. Isle Royal without howling won’t be the same.

  • Mark Boyce
    Posted at 15:43h, 22 August Reply

    Break new ground and violate the fundamental reason that we have national parks, i.e., to allow natural ecological processes to run their course. Wolves got there on their own so I’d argue that they are native. And we fully understand that predator-prey dynamics can lead to metapopulation structures. Why would NPS consider interfering?

  • Thomas Nesler
    Posted at 15:44h, 22 August Reply

    Once the NPS grants the exception here to intervene despite the direction and the founding mandate of national parks, then intervention in any national park is possible. We will always choose management over natural processes, especially when they are contrary to what we like.

  • Tom McNamee
    Posted at 15:45h, 22 August Reply

    Isle Royale has sustained human intervention at every level of its ecosystem ever since its founding. To argue for “natural processes” to sustain themselves now is magical thinking. It’s an island–it’s too small. Read up on the theory of island biogeography. What’s far more important is perhaps the most important predator-prey population study in the world. IF those last two wolves die, that’s the end of the study. If new wolves were to walk across the ice and accomplish a genetic rescue, that, according to advocates of “naturalness,” would be fine and dandy, and the study would continue. But ANTHROPOGENIC warming will probably prevent ice from forming in the foreseeable future. Let’s be realistic.

  • Thomas Nesler
    Posted at 15:45h, 22 August Reply

    True, but there is a difference between direct intervention, like importing more wolves as part of a management plan, and indirect intervention, like the introduction of canine parvovirus through domestic dogs. Also, I think we are differentiating between intervention and management actions here. A hands-off approach attempts to allow natural processes and biotic interactions to play out. I agree with you that we are talking about the confines of an island something like this was bound to happen anyway.

  • Deborah Antlitz
    Posted at 15:46h, 22 August Reply

    I love wolves but when they established a native population it was to an island with no wolves. Presumably it had not been wolf free for millions of years, something kept happening. Let the meta population dynamic work and study what happens to the prey and vegetation when they disappear.

  • Gaddy Bergmann
    Posted at 15:47h, 22 August Reply

    Well, of course wolves are native there. Wolves are among the widest ranging animals known, and their historic range covers the vast majority of the Holarctic biogeographic realm, including Michigan. Just because one particular island has fluctuating levels of moose and wolves doesn’t mean they don’t belong there. If you’re going to manage Isle Royale, you need both predator and prey, especially since the North American wolf population has plummeted from over a million in the 1800s to only a few thousand today. Alternatively, you could say that because the wolf population there is too small or meta-stable, then it’s not worth rescuing. That’s logical, too. But all this hand-wringing over the presence of wolves is ridiculous. Wolves are a native carnivore in Michigan and other northern (and southern) states. Just because they wandered into a particular part of Michigan on their own during historical times doesn’t make them any less native.

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