Ice bridge to Isle Royale impacts wolf population

Ice bridge to Isle Royale impacts wolf population

When cold temperatures freeze up part of Lake Superior, they create ice bridges that impact the environment at Isle Royale National Park.

Even in the frigid temperatures, the folks at Isle Royale National Park are hard at work, researching the island that sits 56 miles off the coast of the Keweenaw Peninsula.

A crew is on the island right now, and Natural Resources Chief Paul Brown said they are doing a lot of work out there.

“Isle Royale has lots of research relative to wildlife management and the island ecosystem so there’s research that goes on about snakes, fish, and all kinds of mammals; wolves and moose being the most prominent and the most highly recognized and well known,” he said.

Michigan Tech biologist Rolf Peterson reported earlier this week one of the few remaining grey wolves was found dead after it escaped to the mainland.

Brown said ice bridges sometimes lead to problems like this, but they are vital to the population as well.

“Ice bridges are the main means of immigration and emigration, so coming to or from the island, for the wolf population.  And so the presence of an ice bridge allows animals to come to the island and it also allows animals to leave the island.”

The wolf population on Isle Royale has been taking a hit in the last five years.

Only eight remained in 2013, the smallest count since scientists began observing the island’s wolves in the 1950’s.  There were 24 wolves on the island in 2008 but Brown said it’s natural fluctuation.

“The population of wolves and, for that matter, all wildlife on the island fluctuates overtime.  It’s an island ecosystem and so things are fairly dynamic,” he said.

For more information on the wolf research that is done on the island, you can visit the Isle Royale National Park Visitor Center in Houghton or visit their website at