The world's longest running predator-prey study has been halted this year due to prolonged, above-freezing temperatures in Michigan's Upper Peninsula.
Michigan Technological University's moose and wolf study on Isle Royale has been running for 65 years; researchers say this year marks the first time that the winter fieldwork has not been conducted — with the exception of 2021, when fieldwork was canceled due to COVID-19.
"We're really disappointed. It's a lot of work and expense to get people out to the island and, you know, you prepare months ahead to make sure you're all ready to go. So it's very disappointing that because of this warm weather we're not able to continue that research," said Sarah Hoy, research professor and co-leader of the study.
The warm temperatures are melting parts of the ice pack in the Upper Peninsula, which the research team needs in order for their surveying planes to take off and land. After the National Park Service ordered surveying to stop, helicopters arrived to transport the team back to the mainland. The team said they cannot use helicopters to conduct aerial surveys for moose and wolves because they are too loud.
The purpose of the study is to better understand the ecology of predators and their prey and to help conserve the species and their ecosystems, Hoy said.
"Their lives and deaths are linked in a drama that is timeless and historic," says the study's website.
Isle Royale is an isolated wilderness bordered by the cold waters of Lake Superior, which has led to the formation of unique ecosystems. Hoy said climate change poses challenges to those ecosystems:
"There used to be ice bridges that connected the island to the mainland. But obviously as the temperatures have warmed, the frequency and the duration at which those ice bridges form has declined. That led to high levels of inbreeding in the wolf population and they became kind of so inbred that they couldn't reproduce successfully and raise pups any more," Hoy said. She explained that the melting ice bridges — and resulting inbreeding — were the reason the National Park Service brought in and released wolves on the island from 2018-19.
The team said on their Facebook page that if February is consistently colder and enough of the ice pack reforms, they may be able to return to the island to conduct the season's fieldwork.
