Another update on the potential blink out of the Isle Royale, Michigan Wolf population which stands at 8 individuals, down form a high of 50 in 1980..............In past decades, freezing temperatures on Lake Superior would create a frozen bridge between the island and the Minnesota and Ontario mainland roughly eight out of every 10 years............... It allowed wolves to cross the frozen water and maintain and bolster their population on the isolated island.................Warmer weather now leads the ice bridge to form about once every 15 years, contributing to the wolves' decline..................Despite 2 of the 8 Wolves being female, the pattern of decline hit a new low this past winter................ "This last year was the first in more than four decades of monitoring that we haven't been able to detect any evidence of reproduction," said John Vucetich, a population biologist at Michigan Technological University, whose research focuses on the Isle Royale wolf population......................The drastic fall in wolf numbers matches an earlier decline in the island's population of moose — a main source of food for the wolves...............Esteemed Wolf Biologist David Mech favors a "watchful waiting" approach to see if the reproduction will at some point kick back in for the remaining wolves,,,,,,,,,,,,,,Vucetich and fellow Royale Wolf leader Rolf Peterson favor infusing the existing 8 wolves with another 2 to 4 wolves based on human caused global warming disrupting the historical arrival of new wolves via the ice bridge in winter.............The National Park Service will decide in October what action to take, if any

Michigan's Isle Royale

 wolves disappearing

Even as the state debates allowing wolf hunting, pack on island national park are in danger

• Jim Lynch
• The Detroit News
• 
  

Isle Royale's gray wolf population has fallen from a high of 50 in 1980 to 8 this year. The pattern of decline hit a new low this past winter. )

Gray wolves are in danger of disappearing from Michigan's Isle Royale National Park, while these predators in the rest of the Upper Peninsula have experienced a major resurgence.

Michigan's wolf population has made a major comeback, growing from three wolves in 1989 to more than 650 today. By contrast, wolves on the Lake Superior island declined from a high of 50 in 1980 to eight recorded this year.

In past decades, freezing temperatures on Lake Superior would create a frozen bridge between the island and the Minnesota and Ontario mainland roughly eight out of every 10 years. It allowed wolves to cross the frozen water and maintain and bolster their population on the isolated island.Warmer weather now leads the ice bridge to form about once every 15 years, leading to the wolves' decline.

Seeking a solution

The situation would be worse if not for the Old Gray Man, as researchers and park officials call him — a wolf that wandered across the ice from the mainland to Isle Royale in 1997. After years of inbreeding among the island population, this single wolf's infusion of new genes helped bolster the numbers for a short time and showed researchers how weak the island wolves had become.

The pattern of decline hit a new low this past winter. "This last year was the first in more than four decades of monitoring that we haven't been able to detect any evidence of reproduction," said John Vucetich, a population biologist at Michigan Technological University, whose research focuses on the Isle Royale wolf population.

The National Park Service, which oversees Isle Royale, is continuing to gather evidence before deciding how to deal with the island's remaining wolves. It faces three options:

■Do nothing.

■Wait and see if they go extinct on the island, and then reintroduce the animals.

■Introduce two to four new wolves in an attempt to stimulate population growth.

David Mech, a wildlife biologist with the U.S. Geological Survey who is considered an expert on wolves, favors an approach he calls "watchful waiting." It would allow the animals to disappear from Isle Royale if that's how things play out.

The drastic fall in wolf numbers matches an earlier decline in the island's population of moose — a main source of food for the wolves. In addition, the number of wolves dipped to 12 on several occasions before rising to healthy levels again.

"For 25 years, we've been concerned about these wolves, and each time I've counseled that it's better to wait and see what happens," Mech said. "I still think that's the right approach."

But Vucetich wants to introduce new wolves. Unlike prior declines in Isle Royale's wolf population, he said, this one is being intensified by human influence, namely climate change. The loss of regular ice bridges to the island has intensified inbreeding. Despite a large number of moose available for food, the annual percentage killed by wolves has dropped from a typical 10 percent to 2 percent last year. It does not bode well for the future.

"It could pretty easily be another four years before the wolves go extinct," Vucetich said.

A Park Service decision could come in October."Right now we're in fact-finding mode," said Phyllis Green, Isle Royale park superintendent. "We're very concerned about the population numbers, but we also want to make sure we make the right decision for the future."