The gray wolves in Isle Royale National Park just off Minnesota's far northeastern point – long a symbol of the wilderness character of the Lake Superior island chain – are increasingly threatened, scientists said this week, the Associated Press reports.
No pups have been spotted during the past year and scientists are fretting that the animals may have stopped reproducing, according to a summary of a Michigan Technological University study. That's a first since the reproduction of the wolves was first monitored in 1971, the study says.
Only eight island wolves remain, down one from last year. There were 24 just five years ago, the study reports.
Scientists suggest that inbreeding could be to blame for the population decline.
Most wolves live only about five years, so the population could soon disappear, the study notes. The National Park Service is reviewing possible management responses, but it won't be easy, National Parks Traveler says in a report with more about the plight of the wolves.
The wolves and moose on Isle Royale are known worldwide, and they are the focus of the longest-running study of a predator-prey system in the wild, the National Park Service says.
Here's more about the research.