Wolf and moose populations are stabilizing on Michigan's sole national park, according to new data from the world's longest-running predator-prey study.
Warm winter conditions cut the annual wolf and moose survey on Isle Royale five weeks short, but researchers were still able to collect population data.
According to the report, there are now 30 wolves and roughly 840 moose. Wolves are holding steady, and moose numbers are inching closer to a more sustainable level after peaking at around 2,000 in 2019.
John Vucetich is a researcher with Michigan Technological University, which coordinates the annual study. He said malnutrition had been the leading cause of death among moose, competing over limited resources, but that's now changing.
"Now the decline is a little bit more of the responsibility of wolves," Vucetich said. "Wolf predation is (becoming) the much stronger force. It won't be too long, I think, before the moose population bottoms out to its lowest point and then stabilizes."
The survey also revealed that wolves re-introduced on the island in 2019 have organized themselves into four packs and established their territory. There is at least one lone wolf and at least three litters of cubs on the island.
Vucetich said wolves have complicated group dynamics, but the survey indicates the island population has finally settled in socially.
"They've figured out their neighbors," Vucetich said. "They get the landscape figured out pretty quick, but it (takes time to sort out) who's in charge of this corner of the island and who's going to duke it out over this part."
Vucetich said there aren't any target goals for what the moose and wolf population should be on the island, but he hopes the forest can recover from past moose overpopulation.
"The best thing we can do is gauge things as how they have been in the past," Vucetich said. "...Both populations are within ranges we'd expect them to be, and we kind of understand what's going on scientifically, so that's of some value."
For the survey's complete findings, check out Michigan Tech's 2023-2024 wolf report.
