By Tanda Gmiter
ISLE ROAYLE, MI – More than a year into the National Park Service’s relocation effort to create strong wolf packs on Michigan’s remote Isle Royale, researchers have found the new predators are having no problem taking down members of the island’s teeming moose population.
Researchers who spent this summer tracking wolf kill sites found the remains of 60 prey animals. Most of these were moose, but evidence showed the wolves were also feasting on snowshoe hares and beavers.
Isle Royale’s current wolf population stands at 17, nine males and eight females. This is a huge change from just the original island-born pair that until fall 2018 had been the only wolves on the island for years – as the moose population soared past 2,000.
In addition to the original pair, who cannot have viable pups, the new wolves include 12 relocated from Minnesota and Canada last fall and winter, and three that were caught and relocated from Michigan’s Upper Peninsula this past fall.
Park staff and researchers from the State University of New York spent several months this summer and fall using data from the new wolves’ GPS tracking collars to check out possible kill sites.
More than half of the prey remains were that of moose, park staff said. Of those, about 63 percent were calves. Researchers said this shows the new wolves are adapting well to Isle Royale’s environment, and have not had a problem adjusting to larger prey.
Last winter, another set of researchers estimated 10 moose kills by wolves, and another 2 moose that died likely due to accidents or possibly malnutrition.
“Combining recent advances in technology with our knowledge of predator-prey relations will provide new insights, not only in the year-round foraging ecology of wolves on Isle Royale, but their overall role in this island ecosystem,” said Jerry Belant, a SUNY professor and collaborative partner on wolf research.
The New York research team is the newest group to collect data from the island that sits more than 60 miles northwest of the Upper Peninsula’s mainland. For more than 60 years, researchers from Michigan Technological University have been conducting the world’s longest predator/prey study on the island. They’ve watched as the wolf population decades ago grew strong, split into distinct packs, then crashed from disease, inbreeding and accidental deaths.
Layering the research teams allows more and different kinds of information to be collected.
Rolf Peterson, an MTU research professor who guided citizen science teams of “Moosewatch” volunteers in the field, said “our team members found it fascinating to explore clusters of wolf locations from last winter and spring, trying to locate bones from moose that had been killed or scavenged by wolves.”
More than just tracking wolf and moose populations, national park staff want to understand the island’s broader ecosystem changes now that more predators are being added. The multi-year plan is to add up to 30 new wolves to help bring a better balance to the wilderness island, where the moose have started to overbrowse sections of the forest.
“Restoring wolves is really about restoring integrity and resiliency to the ecosystem; making the ecosystem whole. Capturing the effects on the ecosystem as a result of our management actions is paramount to measuring the success of the program,” said Mark Romanski, Division Chief for Natural Resources at Isle Royale and project coordinator for the wolf translocation efforts.