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With just three remaining, wolves of Isle Royale approach their vanishing point

The National Park Service’s options have dwindled, too, from three general options to just two: a full-scale reintroduction program or “letting nature take its course.”

Taken from the survey aircraft in February 2015, this photograph shows the last three wolves believed to inhabit Isle Royale — two adults and, straggling behind, a deformed and unhealthy-looking pup.
Photo by Rolf Peterson, Michigan Technological University

It’s that time of year when we await fresh images of wolves in the vast whiteness of Isle Royale, photographed as part of the annual aerial survey that documents their population health.

Or, this year, their virtual demise.

The three you see above are quite likely the last survivors in a decline that has brought the island’s wolves just about to the vanishing point.

Because the two larger animals have not been identified by scat-sample DNA, it isn’t known whether they are from the same pack or even of the same sex, nor whether they produced the smaller wolf – probably a 9-month-old pup – that trails behind them.

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But even from an aircraft, researchers write, the straggler’s deformity and other problems are plain:

Its tail was only about half or two-thirds the length of a normal tail, and the end of the tail was marked with two dark bands. …

Even as a pup, this wolf appeared smaller than average. In images taken on February 15th, this wolf was also characterized by a thin waist line (the other two wolves appeared to have full bellies).

This wolf also consistently displayed an unusual posture: a slightly arched back and guard hairs on its back that tended to stand upright. This is not a wolf that we would expect to live for too much longer.  

Nobody can say with scientific certainty that these three represent the end of the line for the wolves of Isle Royale after decades of inbreeding, deepening genetic depression and, in just the last six years, an 88 percent plunge in numbers from a fairly normal 24.

But neither can anyone map a plausible route back to survival, absent major intervention from a reluctant National Park Service. There is only hope that the survivors can produce new pups and that fresh wolves will cross the ice to freshen the gene pool.

Unfortunately, the ice bridges that used to be more common have formed only three times in the last 17 years.

One of these appeared in the winter of 2014 and carried a lone wolf, an injured female nicknamed Isabelle, away from Isle Royale to her death on the Minnesota shore.

Another occurred this past February and brought two wolves over from the mainland. They stayed for less than a week and almost surely returned to Minnesota without even seeing the native trio.

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(Their movements were tracked precisely thanks to a radio collar that had been fitted to one wolf for a study by the Grand Portage Band of Lake Superior Chippewa.)

Meanwhile, the loss of five other wolves besides Isabelle since last winter remains unexplained. Even with protection from hunters and a plentiful supply of moose, whose numbers are exploding in the practical absence of their only predator, Isle Royale is a harsh place for a wolf.

From three options to two

The park service’s options appear to have have dwindled, too, from three general approaches to just two: a full-scale reintroduction program or “letting nature take its course.”

A third alternative preferred by the researchers  – “genetic rescue” via insertion of a few new mainland wolves, to mimic natural immigration – is probably no longer feasible, in the view of John Vucetich and Rolf Peterson, the current director and retired former director of Michigan Tech’s fabled, 57-year study of wolf/moose interactions in the isolation of Isle Royale.

While adding fresh DNA is the main goal of such a rescue effort, Vucetich explained to me last year, it’s also important to retain a healthy complement of genetically encoded knowledge built up by wolves that have inhabited the island since the late 1940s. Knowledge, for example, about the dangers of taking down a moose.

“Genetic rescue is almost certainly too late now,” he told the journal Nature. “These are the last dying gasps,” he said to the Associated Press.

Last April the superintendent of Isle Royale National Park, Phyllis Green, announced that the park service had decided not to intervene in the wolves’ fate before completing a planning process expected to take at least three years:

The plight of these nine wolves is a compelling story, but we are charged with a larger stewardship picture that considers all factors, including prey species, habitat, and climate change, which could, in a few generations, alter the food base that supports wildlife as we know it on Isle Royale. …

The park will develop a management plan addressing the many complex factors that affect persistence of Isle Royale wolves and their role in the island ecosystem, including relationships with moose (their preferred prey), the condition of island vegetation and the effects of ongoing climate change.

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However, she left room for emergency reconsideration of that plan:

If the island population of wolves declines to all males or all females and if the moose population grows to over-browse island vegetation, bringing wolves to the island remains an option.

To Vucetich and Peterson, overbrowsing is already inevitable.

Their winter survey estimates the island’s moose population, too; having experienced virtually no wolf predation for four years now, it stands at around 1,250 and continues to balloon by something north of 20 percent per year. That’s the highest rate in the survey’s 57-year history and means the moose will likely double by the end of the decade.

No reconsideration, yet

But for now, Green and the park service are still sticking with the wait-and-see program that Peterson, in uncharacteristically hot phrasing, derided to Nature as “dithering – we have science coming out our ears and it wasn’t enough to carry the day against an entrenched bureaucracy with a culture of non-intervention.”

In more than one interview with me over the years, Green has made clear that intervening on behalf of the wolves would be  a major boundary crossing and precedent-setter for the park service.

With the sole exception of a wolf reintroduction in Yellowstone – to reverse eradication by hunters and ranchers – no effort of the scope proposed for Isle Royale has yet been undertaken in a national park, nor given more than preliminary consideration.

And according to a report from the Forum News Service, Green thinks there’s still reason to believe the island’s three wolves may include a breeding pair, and that new wolves may still come over from the mainland.

She is said to have explained “that science is just one of several factors that will influence her decision about whether to intervene, along with NPS policies, relevant laws and the needs and the desires of park visitors.

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“Some people love hearing a wolf how in the wilderness; others say ‘if you put the wolf out there, I’m not as thrilled about hearing it.’ “

I have to say, that last bit disappoints me, because if ever there was a resource-management issue on which the tourists don’t deserve a vote, this is it.

The wilderness case

Equally off base, I think, are the efforts by some wilderness advocates to simplify this problem into a purportedly philosophical choice between human intervention on the one hand and “letting nature take its course” on the other.

We need to remember that while wolves have been present on Isle Royale for only 65 years or so, the moose are relative newcomers too, having gotten there sometime around the turn of the last century by unknown means, which could have involved human help.

Also, that even as the first wolves were arriving on their own, others were being brought over – from the Detroit Zoo, of all places – by people concerned about out-of-control moose populations and their devastation of the island’s balsam fir forests.

There is an argument to be made, one I understand and respect, that deliberately introducing new wolves to Isle Royale may well run counter to the Wilderness Act, whose provisions now apply to most of this national park.

Some who make this case also draw a distinction – which I confess I have more trouble grasping – between restoring wolves to Yellowstone as a remedy for human overreaching, and restoring them to Isle Royale, where the entire history of wolves carries human fingerprints.

Infection with canine parvovirus from park visitors who brought their damned dogs ashore is just one example. The dwindling frequency of ice bridges in an era of warming climate is another.

And let’s remember, too, that no less an advocate of the Wilderness Act than Aldo Leopold – a Yale-trained forester and pioneering ecologist – was arguing for importing wolves to Isle Royale as a check on the moose and savior of the fir forest even as the first arrivals, some of them in cages, made the whole matter moot.

* * *

Shortly after wolves were reintroduced to Yellowstone, I spent one of the finest afternoons of my life at a spotting scope in the park’s Lamar Valley, watching adult wolves teach their pups how to dismantle an elk.

I’ve yet to see or hear a wolf in several visits to Isle Royale, but that’s OK; I keep going back anyway and I don’t need a vote on management questions.

I do have a vote on our household’s vacation venues, however, and the idea of hiking an Isle Royale increasingly overrun by huge moose – much more threatening to the inattentive human than a wolf – and denuded of a fir forest that only recently began recovering to natural levels, well, that might have some influence.

There’s a certain appealing simplicity, not to mention economy, in “letting nature take its course” as the wolves fade away. Maybe there’s even a certain relief in disentangling from an ecosystem that we’ve been messing with for longer than we sometimes care to remember.

But if what we’re really after is a return to genuine natural balance on Isle Royale, a belated shift to hands-off management is really no solution at all – though it’s awfully pretty to think so.