Read our COVID-19 research and news.

Extreme inbreeding likely spells doom for Isle Royale wolves
Rolf Peterson

In reversal, U.S. Park Service aims to move new wolves to Isle Royale

As wildlife ecologists prepare for next month’s 59th annual winter study of wolves and moose on Isle Royale in Michigan, the U.S. National Park Service (NPS) today announced a surprising change in its usual hands-off management of the island wilderness on Lake Superior: proposed plans to introduce 20 to 30 new wolves over the next 3 years.

“This is what I had hoped for,” says wildlife ecologist Rolf Peterson of Michigan Technological University in Houghton. Scientists, including Peterson, who has studied the wolf-moose interaction since 1971, earlier advocated for a genetic rescue of the island wolf population as wolf numbers in recent years dwindled to all-time lows. Only two highly inbred wolves remained on the island this past year, which coincided with the park’s decision to study the possibility of bringing new wolves to the park. There was no sign that the pair reproduced this year, although they were spotted on camera in July.

The plan to introduce new wolves was one of four alternatives considered for Isle Royale as part of an environmental impact statement. Instead of remaining with the “no action” alternative, the park’s preference now is “immediate introduction of enough wolves to the park to sustain a population.”

“This catches me by surprise,” says social scientist and environmental ethicist Michael Paul Nelson of Oregon State University in Corvallis, who has studied public comments sent to NPS on the question of Isle Royale wolves. But he sees the announcement as a “really important step. We are facing a future where human intervention is going to be required to secure ecosystem health. … We can’t just do nothing.”  

Wolves have been successfully moved and reintroduced to other areas, most notably in Yellowstone National Park and in Sweden. But the Isle Royale wolf introduction would follow nearly 6 decades of study of the predator-prey interaction on an island, and could illuminate how that interaction unfolds in a changing climate. Isle Royale Park Superintendent Phyllis Green emphasizes that the planning is not about a single species. “The focus really needs to be on ecosystems,” she says.

Although the park’s preferred alternative is for “immediate introduction,” Green says it likely won’t happen until the winter of 2018–19. The technical details won’t be made final until after the 90-day required public comment period.