"We’re incredibly disappointed" – warm weather halts Isle Royale wolf and moose count for first time in 65 years

A wolf snarling in the snow
The research project is the longest-running study on predator/prey populations in the world (Image credit: Terry W. Eggers)

Unseasonably warm weather in the Great Lakes region this summer has halted the annual survey of wolf and moose populations on Isle Royale for the first time in over six decades.

As we've previously reported, wolves have made an unlikely resident on the remote island since the 1950s, crossing ice bridges between the island on Lake Superior from the mainland some 15 miles away and feeding on the local moose population.

The co-existence of the two species on terrain that is barely touched by humans spawned the Isle Royale Wolf-Moose Project in 1958, which is today the longest-running study of predator-prey populations in the world. Each winter, when the National Park is closed to visitors, a small team of researchers including Sarah Hoy spends between four and five weeks on the island observing the wolf and moose populations, which have important implications for the health of the island's ecosystem. 

This year, however, temperatures in the region have stubbornly remained above freezing since late January, which is about 20 degrees above average, and have got as high as 47°F according to the National Weather Service. The warm conditions have made the ice in the harbor too unstable for the scientist's sea planes to land safely.

"Everybody had to leave," Hoy tells Detroit Public Television, explaining that helicopters aren't an option because they're too expensive and too noisy for the wildlife.

"So the island’s now only occupied by wolves and moose and a bunch of critters. We’re incredibly disappointed that we’re not able to continue our work.”

Hoy says the team hopes to be able to return to the island before winter is over, if conditions permit, or in the spring by boat.

Black wolf at Yellowstone National Park

The most famous example of a wolf reintroduction project is that of Yellowstone National Park which began returning wolves to the area in 1995 (Image credit: Getty Images)

Wolf reintroduction program

Though wolves have inhabited the island for decades, they came close to extinction several years ago. Consequently, in the fall of 2018, 20 wolves were translocated from Minnesota, northern Michigan and other areas of the Lake Superior region to the island. Within just five years, their population was up to 30.

“They’re doing everything you expect wolves to do. They've got territories, they’re producing pups, they're killing moose, they're defending their territories,” reports Hoy.

Last year's report revealed that the wolf population was up by three from the year before, while the moose population had shrunk by 379, a change that is observed to have a good impact on the health of the moose population, as wolves tend to prey on ailing moose, as well as that of the forest.

Because an average adult moose can weigh over 800 lbs, they can chow down on as much as 40 lbs of vegetation every day in an attempt to increase their body weight to help them survive the long winter. When there are a lot of moose on the island, that level of grazing can really start to take its toll on the forest. 

The most famous example of a wolf reintroduction project is that of Yellowstone National Park which began returning wolves to the area in 1995. A new study suggests that that program has not had the same effects on vegetation as the one on Isle Royale. More recently, the howl of wolves returned to Colorado with the release of 10 wolves into the wild. 

For scientists and ecologists, the move towards restoring wolf populations is exciting, but for hikers and dog walkers, the prospect is often met with fear and resistance. Experts advise that you are highly unlikely to ever encounter a wolf in the wild, however, as these elusive creatures prefer to give humans a wide berth. Read more in our article on what to do if you meet a wolf on the trail.

Julia Clarke

Julia Clarke is a staff writer for Advnture.com and the author of the book Restorative Yoga for Beginners. She loves to explore mountains on foot, bike, skis and belay and then recover on the the yoga mat. Julia graduated with a degree in journalism in 2004 and spent eight years working as a radio presenter in Kansas City, Vermont, Boston and New York City before discovering the joys of the Rocky Mountains. She then detoured west to Colorado and enjoyed 11 years teaching yoga in Vail before returning to her hometown of Glasgow, Scotland in 2020 to focus on family and writing.