Wolf treks home across frozen lake

A grey wolf that was moved from Minnesota to Isle Royale National Park last fall has wandered back to the mainland, trekking more than 25km across the frozen surface of Lake Superior to reach her home turf, officials said yesterday.

The female was among four wolves relocated from the Grand Portage Band of Lake Superior Chippewa reservation in September and October – the first steps in an effort to restore the species at the park, where a predator is needed to prevent moose overpopulation.

The National Park Service hopes to move 20-30 wolves to Isle Royale over several years.

The project has hit some early snags. One wolf captured for movement to the park died in captivity. Another perished a month after it arrived. Plans to transfer a new group from Michipicoten Island in Canada have been delayed, first by the partial U.S. government shutdown and then by rough weather.

Still, park superintendent Phyllis Green said such setbacks weren’t unexpected and wouldn’t thwart the operation.

‘‘When we made the decision to restore the predator-prey relationship, we knew we would have to respectfully work with whatever curves nature threw at us, whether it’s adverse weather or wolves working out where they choose to fit on the landscape,’’ she said.

‘‘We’re going to continue the project for the next three years, a window we feel affords us the opportunity for successful restoration.’’

Scientists believe wolves originally crossed ice bridges in the late 1940s to reach Isle Royale, where they formed packs and feasted on moose. But they became inbred and their numbers dropped sharply in the past decade. Only two remained when the relocation began. They’re believed to be alive, putting the current population at four.

The transplanted wolves were fitted with radio collars enabling researchers to track their movements. A team from Michigan Technological University arrived last weekend to begin their annual winter study of the wolves and moose. –AP