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Four U.P. wolves taken to Michigan’s Isle Royale, one found dead days later

Sep 22, 2019 07:35AM ● By Editor
One of the wolves caught in Michigan's U.P. is released on Isle Royale. Photo courtesy of the NPS / Phyllis Green.

By Tanda Gmiter of - September 22, 2019

A multi-year project designed to bring new wolves to Michigan’s remote Isle Royale wilderness has ended its fall segment, with three new arrivals from the Upper Peninsula roaming the island.

This brings the island’s wolf population to 17, nine males and eight females. 

In addition to the three new U.P. wolves, this number includes the original island-born pair that is not able to have viable pups, and the 12 wolves relocated from Minnesota and Canada last fall and winter.

The new wolves arriving this fall were flown in by a seaplane. Isle Royale, which is also a national park, sits in Lake Superior, about 60 miles northwest of the U.P. mainland. 

The relocation is part of a three-to-five year plan by the National Park Service to bring up to 30 new wolves onto the island, where more than 2,000 moose are chewing their way through its forests. Years ago, there were up to 50 wolves in different packs on Isle Royale. But a combination of inbreeding, accidents and disease caused their numbers to dwindle to just two. 

Michigan wolf headed to Isle Royale

This month’s relocation effort is the first time the NPS has taken wolves from Michigan’s mainland. It came with another loss, though. 

A wolf moved to the island on Sept. 13 was found dead, the National Park Service said. Its tracking collar began sending out a mortality signal shortly after it was released on the island. Within a couple days, researchers found the wolf’s body, which is being sent to the USGS National Wildlife Health Center in Madison, Wis., for a necropsy to see if a cause of death can be determined.

While each wolf captured for transfer to the island is vet-checked and has to meet certain physical standards, sometimes there is no way to know how their bodies will handle it, park staff said.

“Capture, anesthesia, and translocation are stressful events for wolves and the impact of that stress on each individual wolf is unknown,” Isle Royale Park Superintendent Phyllis Green said. 

“There is a field examination, however underlying health conditions of wolves prior to their capture are difficult to determine. The analysis of the samples collected during the examination and the necropsy may reveal more information about the cause of death, which will inform future transfers.”

This is the fourth wolf to die during this effort to bring predator packs back to Isle Royale.

female wolf from Minnesota died in captivity before she could be brought to the island last fall. In that case, the wolf was sedated for the trip to a holding facility where it was to be examined by veterinary staff who were assisting with the project. Once she arrived at the facility, NPS officials said the wolf’s condition deteriorated and she died, despite the best efforts of the medical team.

“Necropsy results revealed no direct cause of death, but scientists think it was likely due to anesthesia-related stress," NPS staff said.

Because of this belief, the wolf transfer team immediately reviewed its protocols for how the wolves were being handled, park staff said after the wolf’s death last fall. They made adjustments in the length of time captured wolves were kept in the field before they were transported, and re-evaluated how they were sedating the wolves.

The other deaths were two male wolves found dead at different times after they were released on the island. In one of those cases, its GPS tracking collar was found still attached to its body in a swamp. No cause of death could be determined for that one.

In the other wolf’s case, the post-mortem exam revealed the male wolf died of pneumonia, “... though how the wolf developed this condition is unknown,” park staff said.

The goal of creating strong, healthy wolf packs on this remote island means the NPS is trying to establish a good genetic stew, demonstrated by how they are trapping wolves from various points around the Great Lakes and bringing them together on Isle Royale. The hope is that with these new arrivals, the genetic problems that doomed the island’s past wolves won’t be replayed.

Isle Royales island-born wolves

“Adding genetics from Michigan wolves was a key piece of the puzzle to provide the best opportunity for genetic diversity that supports the sustainability of the introduced population," Green said. “Our focus now will be on broad population goals and the opportunity these Michigan wolves represent. We will continue to learn what we can and track how the wolves integrate into the island landscape.”

As fall continues and the island shuts down for the winter, the park service and its research partners will continue to monitor the new wolves to see how they are forming packs, killing moose and possibly pairing up to bring the island its first wolf pups in years.

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