Wolf leaves island

Graphic provided by National Park Service This GPS tracking map shows the path taken by a female wolf that returned to the mainland from Isle Royale via an ice bridge on Jan. 31.

ISLE ROYALE — One of the four wolves brought to Isle Royale National Park last fall to help restore the dwindling wolf population has crossed an ice bridge back to Minnesota, the National Park Service announced Wednesday.

The female wolf was tracked via radio collar to an Isle Royale’s north shore. Its path from there was spotted by Michigan Technological University researcher Rolf Peterson and pilot Don Murray, who were on the island tracking the wolves as part of the long-running wolf-moose survey.

Satellite data then confirmed the wolf had left the island on Jan. 31, heading north on the island then west to an area north of the pigeon River, located on the border between Canada and Minnesota.

“I was excited to see locations after not seeing anything for five days, but that excitement quickly gave way to disappointment as my eyes followed the track that led away from Isle Royale,” Mark Romanski, Isle Royale National Park’s division chief for natural resources, said in an NPS release. “I knew this could happen, but of course you always hope for the best.”

The ice bridge was created by offshoots from the polar vortex that brought abnormally cold temperatures to the Midwest last week. The infrequency of ice bridges with warming winters has been one of the factors causing the decreased population of wolves on the island.

The wolf’s return to the mainland disappointed the research team but didn’t blindside it. There have been numerous instances of wolves returning to its territory.

Early research on translocation showed wolves, especially breeding animals, would try to move home if moved less than 80 miles, said Dave Mech, wolf biological with the U.S. Geological Society and former member of the Isle Royale research team.

However, the wolves were likely to stay in the area if kept for three to four weeks. The wolf was one of four brought to the park in October.

“Since all the new wolves were moved in the fall, it will take time to tease out the behaviors related to translocation,” he said in a National Park Service (NPS) release. “The Isle Royale wolf translocation is new territory in understanding wolf behaviors and will be groundbreaking with new information as it unfolds.”

Park Superintendent Phyllis Green said final funding for the project has not been received for this year because of continuing budget resolutions. She was optimistic about continuing the relocation of up to six wolves from Canada through partnership efforts by the National Parks of Lake Superior Foundation and funding from the NPS.

“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,” Green said in the release. “We’re going to continue the project for the next three years, a window we feel affords us the opportunity for successful restoration.”

The NPS continues to work with the Ontario Ministry of Natural Resources and Forestry to move wolves from Canada this winter.

The recent polar vortex that created the bridge to the mainland also disrupted translocation efforts and forced the team to adjust their plans. MTU researchers will stay on Isle Royale to complete annual survey efforts until March 4.