HOUGHTON — Barring unforeseen circumstances, last week’s transfer of four wolves from Canada to Isle Royale National Park will be the last of the winter, said park superintendent Phyllis Green on Wednesday. 

“They’re really complicated, and we really only had a narrow window,” she said. “If we had more window and an opportunity, we wouldn’t mind meeting our objectives, but that’s kind of a slim possibility at this point in time.”

The Ontario Ministry of Natural Resources and Forestry (OMNRF), with the aid of the National Park Service, captured a male and female from the mainland near Wawa, Ontario, and two from Michipicoten Island Provincial Park.

An earlier attempt at bringing wolves over from Michipicoten was scuttled because of bad weather, Green said. They took advantage of a four-day window of good weather last week. 

“For this operation, Ontario made the determination that if they couldn’t get out to the island because of fog or weather condition, they would look to move wolves from the mainland,” Green said. “It was a very good strategy, and it worked successfully for us.”

Provided by A. McLaren/Ontario Ministry of Natural Resources and Forestry The first wolf of four brought from Canada arrives on Isle Royale National Park from land near Wawa, Ontario Tuesday. The 65-pound female was brought to the island in a partnership between the National Park Service and Ontario Ministry of Natural Resources and Forestry.

The mainland wolves, a 65-pound female and 92-pound male, arrived on Tuesday and Thursday. Both have black coats, a rare mutation that may date back to domestic dogs of eastern Asia that bred with North American wolves after crossing the Bering Strait.

The black coat also could be associated with a stronger immune response, according to the NPS.

The two Michipicoten wolves are both around 90 pounds. The last, transported on Friday, was the alpha male of its pack, which had nearly exterminated the island’s caribou population. 

Green was on hand to witness the release of the first Michipicoten male around 9:30 p.m. on Isle Royale’s Washington Harbor. 

“He bolted out of the crate looking like a silver ghost raising a cloud of powder with each leap,” she said. 

The mainland wolves are estimated at around 2 years old, Isle Royale Natural Resources Division Chief Mark Romanski said in an email. The Michipicoten alpha male is estimated at 5, while the other is between 4 and 6.

In both cases, the wolves released earlier quickly latched onto the trail of their packmates, Green said. Loose meat was set out for the wolves to provide them energy for their initial exploration of the island. 

Last year the NPS approved plans to bring 20 to 30 wolves to the island over a three- to five-year period. The population had dwindled to two closely related wolves who could not produce a viable offspring. With no check on their numbers, the moose population boomed to over 1,600, putting the island at risk of vegetation loss. 

The transfers bring the wolf population on the island to eight — four males and four females. In addition to the two longtime natives, two wolves remain of the four that were brought from the Grand Portage Reservation in Minnesota.

Of those four, one died of pneumonia last year, while another crossed back to the mainland after an ice bridge formed over Lake Superior in February. Another female died before she could be released onto the island due to a reaction to anesthesia.

Green said the NPS reviewed its protocols after the early fatality, and now holds the wolves longer before release.

Before being brought to the island, wolves undergo a process similar to the annual physicals for a pet dog, Green said. They’ve checked for heart worm and a number of diseases that don’t exist on the island. Other checks include body temperature and the condition of their teeth. 

The most difficult part of bringing wolves to the island is the logistical hurdles of accessing the island, and placing them in spots that will minimize conflict, Green said. That has gone well. 

“We can definitely feel like this was an extremely successful year,” Green said. “We were a little short of our targets and it would be nice to continue, but opportunities are very limited.”