LISTEN TO THE AUDIO VERSION
One of the wolves net-trapped in Canada in winter 2019 and Photo courtesy of Michelle Verant and the National Park Service.
By Tanda Gmiter
ISLE ROYALE, MI – A wolf that was net-trapped in Canada in late February and relocated to Michigan’s Isle Royale was found dead recently in the middle of a large swamp area in the island’s Siskiwit Bay, the National Park Service said.
The death of this black male wolf from Ontario is the second on-island death of a wolf involved in the long-term relocation effort being overseen by the NPS. Its goal is to boost the number of predators on the remote wilderness island that is now teeming with moose. They hope to introduce up to 30 new wolves onto Isle Royale in the next few years.
Since last fall, 14 wolves have been caught in Minnesota and different parts of Canada and been brought to Isle Royale for release. With this latest death, the number of new wolves has dropped to a dozen. They joined the two remaining island-born wolves, who researchers have said are not able to have any viable offspring.
The recent wolf death was disappointing to park service staff, who said they were not able to recover its body in time to get a conclusive cause of death.
There are at least a couple black-coated wolves among those that have been released on the island since last September. The wolf known as W006M was one of them. His GPS tracking collar began transmitting a mortality signal in late March, and it would be later in April before park staff could reach the island to investigate.
The small national park is an island archipelago in Lake Superior that sits about 60 miles from the Upper Peninsula mainland. It typically opens for the season in late April.
“NPS personnel, unable to access the island, had to wait until the park reopened for the 2019 season to investigate. The wolf was located in the middle of Siskiwit swamp, a large wetland complex at the southwest end of the island,” park staff said this week.
“NPS personnel and cooperating investigators from State University of New York-College of Environmental Science and Forestry (SUNY-ESF) using coordinates provided by the GPS collar traveled five miles into the swamp to recover the carcass and determine the cause of death. The GPS collar quit transmitting two weeks prior.
“Investigators found no apparent signs of injury or struggle, however, the carcass was in a very deteriorated state due to melting snow and wet conditions, making an accurate cause of death determination impossible.”
Male wolf found dead on Isle Royale
Necropsies detail deaths of 2 wolves in Isle Royale relocation project
One female wolf died after being caught in Minnesota, and a male wolf was found dead on the island a short time after being released.
Statistically speaking, project organizers knew losses were likely with a multi-year relocation effort. The other male wolf found dead on the island was discovered in October after his GPS tracker transmitted a mortality signal. He had been on Isle Royale for several week after being caught and relocated from Minnesota. A necropy showed he died of pneumonia.
Another Minnesota wolf, a female, died after she was caught but before she could be transported to the island. In that case, scientists think her death was due to anesthesia-related stress. After this death, project staff made changes to the way they handled the wolves after they were caught.
Another loss was not a death, but a departure. A female wolf relocated from Minnesota left the island in late January, walking back toward Canada on an ice bridge created by last winter’s Polar Vortex.
In this Feb. 28, 2019 file photo provided by the Ontario Ministry of Natural Resources and Forestry, the U.S. National Park Service and the National Parks of Lake Superior Foundation, a white wolf is released onto Isle Royale National Park in Michigan. AP
The annual survival rate for wild wolves in Michigan’s U.P. is about 75 percent, park staff said.
“After translocation of 11 wolves this winter it was a disappointment to learn of this mortality and even more frustrating that the carcass could not be accessed in a timely way for a detailed necropsy,” said Mark Romanski, division chief of natural resources for Isle Royale. “A few weeks prior, this male was traveling with one of the females translocated from Minnesota in October 2018. It would have been nice to see them stay together.”
As for the 12 new wolves still settling in on the island, overlapping signals from their GPS tracking collars show some are starting to hang out together.
The first female wolf relocated from Minnesota last September has been traveling since early April with two males wolves relocated from Michipicoten Island in Canada.
“While GPS data indicate these three wolves have been together on numerous occasions, it’s too early to tell whether we have a makings of a wolf pack,” said Romanski, “but it is reassuring that we have wolves spending time together and feeding.”