Due to a sudden medical issue with the ski-plane pilot, researchers were unable to conduct their annual wolf-moose survey on Isle Royale this winter. This setback adds to a series of challenges faced by scientists attempting to count the animals on the remote island park. Isle Royale, a 134,000-acre (54,200-hectare) island located in far western Lake Superior between Grand Marais, Minnesota, and Thunder Bay, Canada, serves as a national park and a unique opportunity for scientists to study wolves and moose in their natural environment, free from human interference. Since 1958, researchers have been conducting yearly surveys of the island’s wolf and moose populations.
Initially, scientists from Michigan Tech University had planned to return to the island in January for seven weeks of aerial surveys using ski-planes. The winter conditions, with snow and bare branches, make it easier to track the animals from the air. However, due to the absence of a land-based runway on the island, the scientists rely on ski-planes that can land on the ice-covered harbors.
The researchers’ annual report, released recently, does not include updated population estimates. The report mentions that the team faced challenges this winter as their aviation resources became unexpectedly unavailable, leaving insufficient time to find a suitable alternative. Michigan Tech spokesperson Hailey Hart explained in a phone interview that the ski-plane pilot’s last-minute medical issue prevented the flights from taking place, and the team couldn’t secure a replacement pilot in time.
This is not the first time the researchers have encountered disruptions during the survey. In three of the past five years, unexpected circumstances have hindered their efforts. The COVID-19 pandemic led to the cancellation of the survey in 2021, marking the first year without population counts since 1958. In February 2024, warm weather conditions forced an early end to the survey when the ice around the island became unsafe for ski-plane landings, prompting the National Park Service to suspend the researchers’ activities and evacuate them.
Before departing, the scientists managed to collect data indicating that the wolf population had decreased to 30 animals from the previous year’s count of 31, while the moose population had declined by 14% to 840 individuals compared to 2023. The report also highlights findings from observations made by a group of college students during the summer of 2024, including regular wolf sightings, a wolf chasing a moose, and the discovery of wolf remains dating back a decade before the wolves were reintroduced to the island in 2018. Additionally, the students found the remains of 115 moose, with 22 believed to have died in 2024, mostly due to wolf predation.
Despite the challenges faced this year, the scientists are already making plans for another aerial survey next winter.
