By Paresh Dave, Los Angeles Times
On an icy island wilderness near the tip of Minnesota, a female gray wolf’s demise has added to the debate about whether authorities should try to save the wolves of Isle Royale National Park.
Once, wolves could regularly move on and off the island along ice bridges to find fresh mates. Now, researchers say, climate change has made ice bridges rare on Lake Superior, and the increasingly isolated wolf population has grown weak through inbreeding. The death of the wolf nicknamed Isabelle, who had apparently crossed an ice bridge in search of a mate, reduced the known population to nine.
The researchers have called on the federal government to interfere with a wilderness area, a drastic break from tradition that they say is forced by climate change. They want the National Park Service to import fertile wolves from robust neighboring populations.
“To preserve a healthy ecosystem with climate change, we at times are going to have to intervene, and that’s a hard thing to wrap our heads around,” said Michael Nelson, an Oregon State University professor who specializes in environmental ethics and philosophy.
That proposal is controversial, and the National Park Service has not decided what to do.
The carcass of 5-year-old Isabelle, one of three potentially fertile Isle Royale wolves, was found Feb. 8 and announced late last month. An initial necropsy failed to determine a cause of death.
At least, researchers say, three of the island’s surviving wolves are less than a year old — a welcome development after a worrisome year without any pups.
Isle Royale is a rare place where predator and prey, wolves and moose, can fend for themselves without interfering predation by humans or bears. The matchup has been closely tracked since 1959. The park gets fewer visitors in a year than Yosemite National Park sees in two days, but thanks in part to scientists, Isle Royale has more repeat visitors than anywhere else.
Moose migrated to Isle Royale around World War I, and wolves after World War II. Two decades ago, the wolf population dipped from 50 to about a dozen. Researchers won approval to install tracking devices on some of the wolves and draw their blood.
Researchers discovered that the wolves had been ravaged by a disease brought to the island by visitors’ pet dogs. But the population rebounded, reaching 30 before falling again about five years ago.
Now, climate change is further stressing the wolves. Once, solid ice bridges to Minnesota happened seven out of 10 winters. Now, it’s more like once a decade, including in 2008 and two weeks this winter.