Wolf-Moose study team reaches remote Michigan island during deep freeze

ISLE ROYALE, MI – For more than six decades, researchers from Michigan Technological University have flown into Michigan’s remote Isle Royale in Lake Superior to document the wolf packs and the moose that live there.

They spend weeks each winter monitoring wolf and moose activity from aerial surveys and collecting data on foot. This cold-weather work pairs with an established summer research program.

This year’s Winter Study could be extra challenging for the team. In the last week, they landed on the island archipelago during the bitter deep freeze at a time when wind chills on Isle Royale were registering 50 below zero.

“Winter Study has begun,” the team posted on social media, along with some frigid-looking photos. “The small team arrived Thursday in a brief window of good weather. They landed on Washington Harbor where the ice is about 18 inches thick.

The photos shared show the team’s small plane parked on the harbor’s ice. Another showed one of the Winter Study’s lead researchers, Rolf Peterson, using an axe to chop a hole in the harbor for water.

“The conditions on Isle Royale, like much of the Midwest, are bitterly cold and windy making it challenging to get everything open and underway.”

The Isle Royale wolf and moose study is now entering its 68th year. It is the world’s longest-running predator-prey study and takes place on this remote island archipelago, about 60 miles from the Upper Peninsula’s mainland.

This year’s Winter Study is vitally important because the team’s cold-weather research window has either been canceled or cut short for the last two years. In early 2025, the Winter Study had to be called off because the team’s plane was unexpectedly unavailable and there was not enough time to find an alternative. In 2024, unseasonably warm weather cut the Winter Study short.

That means the last good wolf/moose estimates for Isle Royale are from 2024, which showed the island had become home to at least four territorial wolf packs. One mega pack on the east side of the island had nearly half the island’s estimated 30 wolves.

Researchers in 2024 noted that the wolf population had “stabilized” in the years since 2018, when the National Park Service began its plan to bring in new wolves to help balance the fast-rising moose population. At that time, the island’s native wolf population had dwindled to just 2 inbred wolves.

As for the moose count, researchers in 2024 estimated there were 840 on Isle Royale – a nearly 60% drop compared to 2019, when the moose population hit a high of more than 2,000 and the big animals’ overbrowsing on island trees was a big concern.

New wolf/moose estimates based on the ongoing Winter Study are expected to be released this spring, once the scientists have had time to pore through the data and images captured during this trip.

The study also typically offers detailed information about the island’s other wildlife, including its large beaver population and its foxes.

Any new wolf pup and wolf pack information will also be interesting to see. Isle Royale is open to hikers and day-trippers from spring through fall. While it’s is one of the least-visited national parks, rangers there have stepped up their public information campaign about some bold wolf antics in the last couple of years. Wolves coming into the island’s campsite areas and taking hikers’ personal packs and other food items has been an issue.

Rangers have responded with a campaign of wolf-deterrence and have enacted new food-storage rules for campers. In August, they shot and killed a nuisance wolf.

“In August, Isle Royale NP took lethal measures to control one of the problem wolves due to the escalating number of concerning incidents reported by park visitors,” park staff said in a news release at the time.

“After extensive monitoring and attempts at deterrence, and in consultation with state, federal and tribal agencies, the difficult decision to lethally remove this wolf was made. Park personnel will continue to track wolf/human interactions and remove additional wolves only if necessary.”