Press Release Sep 14, 2020

New Wolves Helping to Restore Balance at Isle Royale National Park, Moose Numbers Down

For the first time in nearly a decade, Isle Royale's skyrocketing moose population has declined.

Background: Today, two studies document good news since new wolves were introduced at Isle Royale National Park – wolf pups were born at the park and the moose population declined for the first time in nearly a decade.

The National Park Service and the State University of New York-College of Environmental Sciences and Forestry (SUNY-ESF) released a summary of the wolf recovery efforts (PDF) to date, which estimates 14 wolves are now on the island and confirms wolf pups were born in 2019 and 2020.

In addition, researchers from Michigan Technological University (MTU) announced that for the first time in nearly a decade, the park’s moose population has declined. As reported in MTU’s annual Isle Royale Winter Study, until this year, the moose population had been steadily increasing at a rate of roughly 19 percent per year while the wolf population plummeted to just two. MTU’s 62 years of research on the park’s wolf and moose populations is the longest running predator-prey study in the world.

Without wolves as predators, the moose population was outgrowing its food source, threatening native balsam fir and the health of the broader park landscape. To address these concerns, the National Park Service began introducing new wolves to the park in 2018, which researchers note contributed to the decrease in the moose population.

Each new wolf released at the park is tagged and collared, enabling the Park Service to monitor movement and behavior. Research shows the park’s wolves are hunting together, staking out their territories and breeding, ultimately supporting a self-sustaining population at the park.

To learn more, please visit or follow along for updates on social with #wolfwatch.

Statement by Christine Goepfert, Midwest Associate Director for the National Parks Conservation Association

“Today’s exciting news confirms what scientists predicted – the new wolves are feeding on Isle Royale’s abundant moose. Although several of the introduced wolves did not survive, the current population is having a substantial impact by reducing moose numbers for the first time in almost a decade. And with wolves starting to group together and breed, we are moving closer to achieving a sustainable population, while protecting the unique ecosystem at the park. What researchers are learning here is helping to inform wildlife management practices around the world.

“Seeing this progress in such a short time is worth celebrating – the Park Service plan is working. This is another incredible example of the importance of science in decision-making at our national parks.

“From the return of wolves to Yellowstone to seeing these positive results at Isle Royale, science continues to show us that such recovery efforts not only strengthen park wildlife but the health of the larger ecosystem. We look forward to the continued benefits that wolves bring to Isle Royale and hope to see more wolves born at the park.”


About the National Parks Conservation Association: Since 1919, the nonpartisan National Parks Conservation Association (NPCA) has been the leading voice in safeguarding our national parks. NPCA and its nearly 1.4 million members and supporters work together to protect and preserve our nation’s most iconic and inspirational places for future generations. For more information, visit

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