An epic experiment on Lake Superior's islands, starring wolves, moose and caribou

Over the course of a few months this winter, the wolf population on Isle Royale National Park ballooned from 2 to 15 in an extraordinary project to artificially shift the balance of a wilderness.

Captured on the mainland and a neighboring island in Lake Superior, the wolves were anesthetized, vaccinated, collared with GPS devices, and transported across the icy waters by boat and helicopter to their new home. In all, it took the combined effort of a university; a cadre of scientists; state, federal, Canadian and tribal governments; and a couple of nonprofit organizations to accomplish the feat between ferocious winter storms.

The wolves' purpose is primal: to prey on the moose that overpopulate Isle Royale. But meanwhile, their new home has become a stage for all the world to watch. The high-tech GPS collars strung around their necks will track their daily lives, generating a treasure trove of data for the next generation of wildlife researchers in the longest predator-prey study ever conducted.

And this year, for the first time, the research includes 20 collared moose as secondary characters who could help explain why Minnesota's moose are dying at such a troubling rate.

"To have two systems that are geographically close to each with similar climate and habitat is rare," said University of Minnesota scientist Tiffany Wolf, who is working on the study with wildlife officials from the Grand Portage Band of Chippewa.

But perhaps more importantly, the overt interference of humans in the balance of life on Isle Royale recognizes a painful truth — that what was once a natural ebb and flow of species on Lake Superior islands is a relic of the past.

"We are starting to realize that because of what we've done in the past, if we don't intervene we will jeopardize what we take to be ecosystem health," said Michael Nelson, a professor of environmental ethics at Oregon State University who analyzed public comments on the National Park Service's wolf reintroduction plan.

What's striking, he added, is that the costly undertaking is not being done for the benefit of humanity; it's about preserving a healthy ecosystem on a wilderness island that gets just 28,000 visitors a year.

"It's moving how much people care about that," Nelson said.

There are those who think humans are overplaying their hand. Marvin Roberson, conservation director for the Michigan chapter of the Sierra Club, questioned whether the massive effort was necessary. After all, wolves and moose are relatively recent residents of Isle Royale; for most of its history it was home to lynx and woodland caribou. And, Roberson said, the island managed to withstand at least one moose population explosion in the past before wolves arrived on an ice bridge in the 1950s.

"They are treating it like a terrarium," he said of the island and the research experiments.

If so, that's also true of other major islands in Lake Superior, each of which has its own story of the rise and fall of historic species — and of recent human interference.

Six of the new wolves on Isle Royale came from Michipicoten, an island in the northeast corner of the lake, near mainland Ontario. It's been a refuge for endangered woodland caribou that were transplanted there in the early 1980s by the Ontario government. By 2015 their number had grown to some 450.

But then four wolves crossed to the island on ice bridges and proceeded to eat their way through the herd. The Ontario government rescued a dozen or so caribou by helicoptering them to the Slate Islands on the western end of the Lake. On that predator-free refuge the number of caribou regularly rise and crash over time with the food supply.

On Michipicoten, by contrast, there were about 20 starving wolves by this winter — and no caribou.

Throughout history, the species found throughout the northern boreal forest — woodland caribou, moose, wolves and even lynx — have naturally blinked on and off on Lake Superior's islands. They rose and fell according to nature's rules — food supply, ice bridges, population and predators.

That, in fact, is the standard pattern of all isolated biological systems, a science known as Island Biogeography. The same dynamic helped create the unique species on the Galápagos Islands that led Charles Darwin to his theory of evolution.

But that was before climate change raised questions about the future of ice bridges on Lake Superior, and before logging, mining and overhunting killed off most the native caribou, lynx and wolves throughout Minnesota and Ontario.

And it was before many in the public fell in love with the idea of a National Park in Lake Superior ruled by wolves and moose, and a growing number of scientists became eager to share that story with the world.

For instance, this summer some 55 citizen volunteers will pay for the privilege of carrying heavy backpacks for seven days over rough terrain across Isle Royale to collect moose bones for scientists. For the first time in the decades since Michigan Technological University researcher Rolf Peterson has been studying wolves and moose on the island, there's even a waiting list.

"That's an indication that people want wolves on the island," Peterson said.

Regardless of what nature might have planned.

Josephine Marcotty is a Twin Cities science writer and former Star Tribune environment reporter. She can be reached at josephinemarcotty@gmail.com.