When a wolf from an island near Ontario was brought to Isle Royale two years ago, she was likely pregnant and hungry.
Despite potential malnutrition, the stress of moving and establishing herself in a new home, she dug a den and gave birth to at least two pups last year, according to camera-trap photos from the island.
“Pretty remarkable story on her part,” says Mark Romanski, a biologist at Isle Royale National Park.
The youngsters are thought to roam Isle Royale today. And this year, more pups have joined them. Two other mothers likely had their own offspring on the island this spring, says Romanski, according to GPS collar data, camera-trap photos, and samples of pup-sized scat collected on the island.
The litters are a boon to the park’s efforts to restore the island’s wolf population and control its copious moose herd. Since 2018, the park introduced nearly 20 wolves to Isle Royale’s population of just two island-born wolves at the time. (One has since perished.)
While several of these introduced individuals died or walked off the island over ice bridges that form in the winter, others have flourished.
“We’re starting to see early successes,” says Christine Goepfert of the National Parks Conservation Association, which has long pushed for wolf reintroduction on Isle Royale. “The park service plan is working, and this is all great news.”
The island's wolves have split into four social groups jostling for territory, according to research released this week from Michigan Technological University. Two of the groups are well established, and have the makings of a pack, says John Vucetich, a professor at Michigan Tech who has monitored the wolves of Isle Royale for some 20 years.
This year also marks the first time in a decade the number of moose on the island has declined, according to the report. While the dip may not be entirely due to predation from wolves, it’s a positive sign. And the new offspring will only help keep the moose population in check.
“The wolves are well fed,” conclude the study authors.