Wolf pups have been spotted again on Isle Royale, a hopeful sign in the effort to rebuild the predator species’ population at the U.S. national park, scientists say.
It’s unknown how many gray wolves roam the island chain in northwestern Lake Superior. The coronavirus pandemic forced cancellation of the census that Michigan Technological University experts had conducted each winter for 63 years.
But remote cameras detected four pups on the park’s eastern end in January, the researchers say in a new report.
The sightings and other clues such as previously observed scats and tracks suggest that two litters were born in the area last year and perhaps another on the western side.
Park officials said last fall that at least two pups likely were born in 2019.
The population was 12 to 14 during the last Michigan Tech survey in the winter of 2020. The latest births would indicate it is higher now, but some older wolves might have died.
“It most likely will be winter of next year before we have firm information,” said Sarah Hoy, a research assistant professor and animal ecologist. “Things are definitely looking up.”
Scientists with Michigan Tech, the National Park Service and State University of New York will combine available information with genetic analyses to produce a population estimate based on death rates and numbers of litters.
Wolves are believed to have migrated to Isle Royale from Minnesota or the Canadian province of Ontario around the middle of the 20th century, crossing about 15 miles over the frozen lake surface.
Once established, they began feasting on the park’s abundant moose and helped keep the herd from outgrowing its food supply. But wolf numbers plummeted in the past decade, which scientists blamed primarily on inbreeding.
The National Park Service announced plans in 2018 to restore the population, which had fallen to two. Crews took 19 wolves from Minnesota, Ontario and Michigan’s Upper Peninsula to the island in a series of airlifts. Some have died. At least one wandered back to the mainland. But most appear to be settling in.
“They’re killing moose, starting to function as they should,” Hoy said.
The goal is to have 20 to 30 wolves within three to five years. Officials haven’t decided whether to bring more in.
“As wolves bounce back after nearly disappearing from the park, their presence as a predator on the island will help all wildlife and native plants thrive at Isle Royale,” said Christine Goepfert, Midwest associate director for the National Parks Conservation Association.