Isle Royale wolves on the rise while moose continue to decline
Wolves on the remote island of Isle Royale appear to be thriving, but they’re making deep dents in the moose population that they rely on as a leading food source, according to a report released Monday.
Isle Royale is a 134,000-acre national park on Lake Superior, located about 22 miles from Grand Portage.
Researchers have conducted annual surveys of wolf and moose populations on the island since 1958.
This year, a team of researchers led by scientists from Michigan Tech University conducted a survey from Jan. 22 through March 3. Their findings led them to estimate the island’s wolf population at 37 animals. Data gathered from researchers in 2024 showed the population was 30.
The 2026 estimates are the highest since the late 1970s and represent a marked improvement since the population dwindled to just two wolves a decade ago. Researchers believe inbreeding led to depressed survival rates in pups.
The island’s moose population, though, is declining dramatically. This year’s survey put the population at 524 moose, down 75% from a high of 2,000 in 2019. Wolves likely killed almost a quarter of the moose population over the last year, scientists estimated. For the first time in almost 70 years, researchers observed no moose calves during the winter survey.
In a March interview with WTIP, Dr. Rolf Peterson, one of the researchers involved in the annual surveys, said the data is “no real surprise.”
Peterson said that wolf numbers have been growing while moose populations have been declining for “several years.”
Scientists plan to conduct summer research on the island with an eye toward how the burgeoning wolf packs can maintain balance with the rest of the ecosystem.
WTIP’s Kalli Hawkins spoke with Dr. Rolf Peterson in March about the 2026 wolf and moose survey at Isle Royale National Park. Peterson talks about observations from the annual winter surveys, ongoing research, predator-prey dynamics, and more. The audio is below.
The Associated Press contributed to this report.
Kalli Hawkins April 29, 2026
