Wolves at Isle Royale: An Island Dilemma

Isle Royale National Park is a remote island in Lake Superior that is 99% federally-designated wilderness.  It is also home to the longest predator-prey study in the world focused on the interplay between the island’s wolf and moose populations, the island’s most famous residents.


Right now there are only three wolves left on the island, which means the character of Isle Royale is in jeopardy. This is the lowest population in over 50 years.  The question now is what should be done about the dwindling wolf population. 

If wolves become extinct on the island, the moose population will continue to increase without a predator.  Eventually moose will eat most of the island’s native vegetation, endangering their food source as well as the food source of other species, threatening the health of the entire island ecosystem.

The reason for this decline in the population is that the route that brought wolves to the island – naturally occurring ice bridges that form in winter from the mainland – do not form as often because of the warming climate.  When ice bridges do form, it is hard to predict whether wolves will use the bridge to arrive and stay on the island or to leave; both scenarios occurred the last two winters. Coupled with a period of disease and other factors, the wolves on the island are now inbred, which negatively impacts the health of the pack and their ability to breed. 

Next Steps

The National Park Service (NPS) is responsible for protecting and managing the wildlife of the park, and so ultimately it must determine the response to the dwindling wolf population. 

NPS is developing an Environmental Impact Statement (EIS) for a plan to manage moose, wolves, and vegetation at the park.  You may review all of the management options here.

NPS accepted comments through August 29, 2015 on several management options under consideration. One option NPS is considering -  Alternative Concept B -  includes introducing new wolves to the island.  After many years of consulting scientific experts and extensive research to determine what we view is the right response, NPCA supports this option, but we urge the park service to do this as needed, rather than one time only. 

NPCA supports Alternative B because bringing news wolves to the island will help balance the delicate ecosystem, preserve the native plant life, and keep the moose population in check.  Alternative B is also much less intrusive in this wilderness park than culling moose, removing moose from the island, or having to replant native vegetation once the moose consume it. 

NPS indicates it will release a DRAFT Plan/EIS in Winter 2016/2017 for public comment and then a FINAL Plan will be released by Fall 2017.  NPCA has urged NPS to expedite this decision-making process because park resources are currently at risk.

More Info

NPS released the report Using Climate Change Scenarios to Explore Management at Isle Royale National Park to better inform their decision about wildlife management at the park.

To better inform the public about the issue and potential responses, NPCA co-sponsored a public forum in Minneapolis in June 2013, where panelists discussed the various alternatives. You may view this forum in full here.

In October 2013, during the International Wolf Symposium in Duluth, Minnesota, filmmaker George Desort interviewed several attendees about Isle Royale’s wolves. Desort asked each interviewee questions in order to solicit their opinion/perspective on the wolf population issue and the available management alternatives.  You may view the interviewees’ responses to Desort’s questions here.

This issue was also featured in NPCA’s National Parks Magazine, Winter 2014 Issue, in an article titled "The Last Wolf?" and in a recent Park Advocate blog post titled "Lone Wolves on Michigan’s Isle Royale: An Island Dilemma".


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