TRAVERSE CITY, Mich. — Federal officials said Wednesday they will take a closer look at whether to bring more gray wolves to Isle Royale National Park, where the iconic predator is on the verge of dying out after suffering a population free-fall in recent years.
The National Park Service began a wide-ranging study in 2015 of strategies for managing the Lake Superior island chain's wolves, moose and vegetation for at least the next two decades. But with only two wolves believed to remain as of February, the agency said it would narrow its focus to whether to bolster their numbers — and if so, how.
"At this time, natural recovery of the population is unlikely," the park service said in a statement. "The potential absence of wolves raises concerns about possible effects to Isle Royale's current ecosystem, including effects to both the moose population and Isle Royale's forest/vegetation communities."
Taking the closer look does not necessarily mean the park service is leaning toward moving more wolves to the island, Superintendent Phyllis Green said. But internal discussions and public comments have led staffers to drop consideration of alternatives for keeping moose numbers in check through methods such as hunting, as opposed to maintaining the reliance on wolves as predators.
"The central question is in the next 20 years, while things are changing on the island, will wolves play a role in managing moose or not," Green said.
Wolves have been a beloved feature of Isle Royale, a rugged, isolated wilderness roughly 15 miles from the Canadian shoreline. Sightings are unusual, but visitors thrill to the occasional nighttime howls that announce the wolves' presence.
Scientists believe they first migrated to the island park across winter ice bridges in the late 1940s. Their numbers grew as they feasted on moose, which themselves had arrived around the turn of the 20th century. Since then, the two species have benefited each other, as moose provided the wolves an ample food supply, while wolves kept moose numbers from rising so high that they would gobble up too much of the island's trees and bushes.
Biologists with Michigan Technological University have studied their relationship since the 1950s in what is described as the world's longest continuous study of a predator-prey relationship in a closed ecosystem.
Wolf numbers have averaged in the low 20s, divided into several packs, but have declined steeply in recent years — probably because of inbreeding and disease, scientists say.
The park service hosted public meetings last summer and received thousands of comments, with some favoring bringing more wolves to the island and others opposing it. Because the study is being revised, the agency said an additional 30-day public comment period will be granted.