Isle Royale National Park Wolves

Isle Royale National Park is famous for its wolves, which have been on the island since 1949. A pair crossed an ice bridge to the island that year in search of food during an especially harsh winter. The number of wolves over the years reached as high as 50 before dwindling in recent years.

Isle Royale is a remote island in Lake Superior known for its population of moose and wolves. The populations of the moose and wolves on the island are interconnected in a predator-prey relationship. The moose population is kept in check by the wolf packs, which hunt them. As the wolf population has dwindled in recent years, the amount of moose on the island has grown. In 2018, there were an estimated 1500 moose on the island.

Why did the wolf population fall?


The population of wolves and moose has had its ebbs and flows on the island over the year. Over the past five decades, the average number of wolves has been 25.

The wolf population fell dramatically in the 1980s due to the introduction of the canine parvovirus from a dog that was brought on to Isle Royale. In the 1990s, a new wolf crossed an ice bridge to the island and helped rejuvenate the species.

The number of wolves on Isle Royale declined dramatically in the past decade due to limited genetic diversity and the failure of any wolves to stay on the island after the formation of an ice bridge. During one winter with an ice bridge, no wolves crossed. During another, a wolf crossed to the island from the mainland but did not interact with the pack and left on the ice shortly after reaching Isle Royale.

The Reintroduction of Wolves to Isle Royale


After two years of consideration, the National Park Service has decided to bring 20-30 wolves to Isle Royale National Park over a three year period. The plan is to release them in stages during the fall/winter.

Why are they reintroducing wolves? Since there were only two wolves on the island, it was unlikely that there would be a rebound of the population without the addition of new wolves to the equation. It has been hoped for several years that a wolf would cross an ice bridge during the winter and reinvigoration the population. However, because there have been fewer and smaller ice-overs of Lake Superior in recent years, this has seemed less likely to happen. The result of this analysis was that without human intervention, the population of wolves would reach zero. As a consequence, the population of moose on the island. They have no natural predator on Isle Royale other than the wolves. It was expected that without wolves the number of moose would continue climbing to 2500 and cause destruction to the island vegetation as they sought food. The ecological destruction as a result of the loss of the wolf population was expected to be severe.

Why did they consider not adding wolves? The National Park Service attempts to minimize its interference in the national parks. Its mission is to leave the parks as natural and undisturbed as possible.

How many wolves are currently on Isle Royale?


The father-daughter pair has been on the island for years.

Four wolves from northeast Minnesota and two from Michigan’s Upper Peninsula were supposed to be released onto the island during Fall 2018. The media reported that two of the Minnesota wolves (a male and female) were on the island at the end of September and two female wolfs were added in early October.

Isle Royale Wolf Population 2019: There are 6 wolves on the island according to the latest media reports.

Where is the best place to see wolves on Isle Royale?


Wolf sightings are rare in Isle Royale National Park. The island’s terrain and topography makes it unusual to see the predators. They also tend to frequent the trails at night, when people are not on them. When we were there in August 2017, we did not see a wolf or any tracks.