Saturday, May 3, 2014



This reality for Gray Wolves in Michigan's Isle Royale illustrates "Trophic Cascade" in action.

The Isle Royale wolf pack is dwindling (because they are geographically isolated  and cannot find mates outside of their pack to breed with ), 

the Moose population is growing, and the island environment is at stake from overgrazing by the Moose. 

So, if there were more Gray Wolves, the Moose population would not grow in excess, the balsam fir trees on the island, (which process CO2 ), would not be in danger of disappearing due to overgrazing by the Moose, and the island ecosystem would be balanced and healthy.

In short, Michigan's Isle Royale needs their wolves to remain protected and genetically aided to ensure that they have a chance to grow their pack numbers, and have a shot at a future. Then the island habitat, and the Moose population that share it, remain ecologically balanced.


Reposted from our friend, CanisLupus101 
May 3. 2014


Photo: John Vucetich/Michigan Technological University

May 2, 2014 
By Dan Roblee , The Daily Mining Gazette        
HOUGHTON - Researchers for the Isle Royale Wolf-Moose Study counted nine wolves at the end of last winter, one more than the year before but not nearly enough to keep the island's moose population - now over 1,000 - in check.

That data was released Wednesday in the study's annual report, which showed the moose population has more than doubled over the past three years. According to one of the study's lead researchers, John Vucetich, if that type of growth continues the moose could permanently change the island's ecosystem. "The wolves are no longer limiting moose, and there's no reason to expect they'll be limiting moose in the foreseeable future," Vucetich said. "If moose are able to grow in unlimited fashion, they'll begin to over-browse the island and cause harm to the forest that's there."

A pair of wolves walk through the snow on Isle Royale National Park last winter. Scientists counted just nine wolves on the island this past winter. In particular, he said, the moose could destroy most of the island's balsam fir trees, none of which have grown to the seed-bearing canopy stage on most of the island.

The problem, according to the report, is that the wolf population, which once peaked at 50 in 1980, over the last three years are at their lowest population since the study began in 1959. They've also become less successful hunters and breeders, due to genetic inbreeding. "Observations we've collected show (the wolves) aren't able to perform their ecosystem function to limit the moose growth," Vucetich said.

Vucetich said the best solution to restoring ecological balance is reinvigorating the wolves' gene pool by introducing "new blood" from the mainland. A stronger wolf population, he said, could keep wolves in check. That solution has been on the table for a few years, but the Park Service has so far resisted any intervention after officially considering the issue last fall. "It's a natural population and we see it as a natural process, not necessarily as a problem," said Isle Royale National Park Administrative Officer Betsy Rossini. "We are concerned about the populations of the wolves and the moose, but at this point we're going to continue to monitor it and see how it plays out."She added, "As long as there is a population out there, we're just going to wait, I think it's a dynamic environment, and a lot of things could have an effect including a changing climate."

Vucetich said putting off a response until forests began to show signs of over-browsing would be a bad idea, as the moose population's growth momentum could make any response too late. "Waiting any longer is an unnecessary risk to the ecosystem health of Isle Royale," he said.

The report showed that three wolf pups were born on the island in the last year, almost certainly from the same litter, and brought the West Pack number up to six wolves. Another three wolves were counted in the Chippewa Harbor Group, which scientists believe is incapable of reproduction.

Despite the successful litter, Vucetich said it was unlikely the wolves would be able to rebuild their own population naturally, due to genetic issues. One lone wolf, not counted in the study's end-of-season total, crossed this winter's ice bridge to Lake Superior's north shore, where it died in Minnesota as the result of a pellet gun wound. Researchers had hoped the land bridge would offer opportunities for new wolves to migrate to the island, but Vucetich said none had been spotted and it was highly unlikely any had remained hidden or crossed in the few days the ice bridge remained after the researches left the island.

Vucetich said moose population growth, on the other hand, would be limited only by the severity of winters, and would likely continue to grow at the same pace as in the last few years. The only thing stopping that growth, he said, would be would be when the moose exhausted their food supply.
Rossini said that despite any differences of opinion between park officials and study researchers on how to move forward, the study has long been a great resource for understanding ecological relationships on the island. "Absolutely, it's been a very valuable study," she said.


Photo credits:
Isle Royale
Captain Kidd Island, Isle Royale National Park | Flickr - Photo Sharing!

Poop Reveals an Immigrant in Isle Royale Wolves' Gene Pool | Michigan Tech News

Balsam Fir trees
Isle Royale National Park (Page 2)
This is a view of the fog shrouded south shore of Isle Royale.

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