TRAVERSE CITY, Mich. — 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 said Monday.
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.
Remote cameras detected four pups on the park’s eastern end in January, the researchers said in a new report. The sightings, and additional 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 winter 2020. The latest births would indicate it is higher now, but some older wolves may 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, adding that the presence of young wolves is reason for optimism. “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.
An initial data summary should be finished this month, said Mark Romanski, a biologist and natural resources program manager at Isle Royale.
“Because of constraints placed on field activities during the pandemic, we are especially pleased to have multiple lines of evidence to enumerate the population,” he said.
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.