Environment & Climate Change

Lessons from Isle Royale's Wolves and Moose

To find the northernmost point in Michigan, you have to take a boat or seaplane to Isle Royale.The island is the largest in Lake Superior and it's also home to Michigan's only National Park.The remoteness of the island, and the fact that the island is largely untouched by humans has made for a perfect place to watch nature take its course.Michigan Radio's Rebecca Williams and Mark Brush traveled to Isle Royale to meet the researchers who have been watching how wolves and moose interact for 54 years. The research project is the longest continuous study of any predator-prey system in the world.What researchers have learned on this natural island laboratory has informed ecological science around the world.

Wolves barely hanging on, moose "on vacation" on Isle Royale

Michigan Public | By Rebecca Williams

Published May 1, 2014 at 5:35 PM EDT

In 1992, biologists counted 20 wolves in Michigan. The population has gone up since then and in 2010, 557 wolves were confirmed in the U.P.

It’s the 56^th year of the study of Isle Royale’s wolves and moose. Researchers at Michigan Tech have just finished this year’s Winter Study.

Rolf Peterson is a research professor at Michigan Tech and he just spent his 44th winter on the island. I called him up to find out how the animals are doing. This year, the team counted nine wolves, up from eight last year.

“I guess I’d say they’re bumping along at the bottom, the bottom of where they’ve been for the last 56 years. So for the last three years, there have been either eight or nine animals total, and that’s as low as we’ve seen them.”

The moose, on the other hand, are having a field day.

"They're on vacation now, with wolves so low. Wolves are sort of taken off the table so the moose population is increasing right along with the wolf decline."

“They’re on vacation now, with wolves so low. Wolves are sort of taken off the table so the moose population is increasing right along with the wolf decline. The number of moose has roughly doubled in the last three years.”

He says there are a little over a thousand moose on Isle Royale.

With climate change, there are fewer ice bridges forming from the mainland. This year, an ice bridge did form, but instead of new wolves coming to the island, as some people were hoping, one wolf left, and she was shot when she got to Minnesota.

“It took one prime breeding female off the table. She’s gone. She thought she was doing the right thing. She’d been trying to find an appropriate mate for at least two years and things weren’t working out very well for her. So on the first chance she had to leave Isle Royale, she took off,” says Peterson.

A few weeks ago, the National Park Service announced it would not bring new wolves to the island for now. Peterson says he was disappointed to hear the decision.

“We had recommended serious consideration be given to genetic rescue, which would amount to just putting a couple wolves from the mainland on the island and give the wolves options for out-breeding.”

He says there's no way to predict how long the island's wolves will hang on without intervention: he says they could collapse very quickly, or they might hang on for several years.