Isle Royale narrows wolf study

ISLE ROYALE NATIONAL PARK -- With just two wolves left alive on Isle Royale and little or no hope for the population to rebound naturally, National Park Service officials Wednesday said they are narrowing the focus of a study on whether to trans...

A grey wolf howls on top of a snowy hill. (Wikimedia Commons)
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ISLE ROYALE NATIONAL PARK - With just two wolves left alive on Isle Royale and little or no hope for the population to rebound naturally, National Park Service officials Wednesday said they are narrowing the focus of a study on whether to transport new wolves to the island.

Isle Royale National Park officials in 2014 started the environmental review process on what, if anything, to do about the big Lake Superior island's wolf population that has been dwindling for years.

But the study was expected to take years and was looking at broader environmental, climate and social issues, as well as the philosophical and legal definitions of wilderness and how far humans should intervene in the island's ecosystem, including moose and wolves.

That broader, go-slow process drew the wrath of some scientists who have promoted an immediate "genetic rescue" of the island's wolves by introducing several wolves from other areas. Even members of Congress have weighed in, urging the Park Service to act faster and introduce new wolves.

Now, "following public comments and internal deliberations," the Park Service has decided to "narrow the scope of the EIS (Environmental Impact Statement) to focus on the question of whether to bring wolves to Isle Royale in the near term."


Wolf numbers have bounced up and down over the years on the island but have been dropping fast over the past five years. There were 24 wolves as recently as 2009. But that number dropped to eight in 2013 and just three in 2015.

This winter's annual survey, conducted in February, confirmed only two wolves, said Liz Valencia, the park's chief of interpretation and cultural resources, in an email Wednesday.

"At this time, natural recovery of the population is unlikely," Valencia noted.

"The potential absence of wolves raises concerns about possible effects to Isle Royale's current ecosystem, including effects to both the moose population and Isle Royale's forest/vegetation communities."

Phyllis Green, the park's superintendent, said in an interview Wednesday that her staff will have a preferred alternative on what to do about wolves by this fall, with a final decision by autumn 2017. Had the environmental review continued with a broader scope, Green said it likely would not have been finished by 2017.

The Park Service will hold another 30-day public comment period on the revised parameters of the study, but all comments made during the first round will remain part of the official record.

Green said no decision has been made on new wolves.

"The no-action alternative is still very viable," Green said, noting public comments have been divided between immediate stocking of new wolves to doing nothing and letting nature take its course.


"The change is that we are going to get to a decision, hopefully, faster, not that we've made a decision," Green said.

This year's survey of moose and wolves on the island, headed by Michigan Technological University scientists Rolf Peterson and John Vucetich, was the 58th annual and is the longest-running predator-prey study in the world.

Researchers have said they believe genetic health problems from inbreeding are the primary cause of the wolf decline, noting food is not an issue thanks to ample moose on the island.

Peterson said in an interview Wednesday that he saw little new in the revised Park Service study. He said he and Vucetich would withhold comment until they release their formal 2016 moose/wolf report in April. Last year, Vucetich said that, without intervention, the island's wolf population is "doomed."

At issue is how much humans should be "tinkering" with a natural system, especially an isolated island system that for millennia has evolved differently than the mainland just 20 miles away. It's not certain, for example, why Isle Royale moose are thriving while nearby Minnesota moose are rapidly declining.

Park officials note that there were no wolves on the island when it became a national park in 1940.

Some have suggested a genetic wolf rescue similar to the Florida panther situation, in which Texas cougars were released in parts of Florida to bolster genetic diversity among the state's inbred cats. The effort seems to have worked, with the number of deformed cats now diminishing, even as the overall population slowly grows.

Peterson and Vucetich have been among the most ardent supporters of a genetic rescue for the island's wolves, saying a failure to act soon threatens the population and the fragile predator-prey balance on the island.


Green said there is scientific debate on whether it would be better to allow the last two island wolves to die before restocking, to rid the island of the genetic defaults, or to restock immediately to keep some of the original bloodlines intact.

"Genetic rescue has always been troublesome because of that. You just keep passing on the problems," she said. "The opinions on this (wolf issue) are all over the board."

The 2015 winter study found 1,250 moose on Isle Royale, about 18 miles off Minnesota's North Shore at the Canadian border. (This year's results have not yet been tabulated.) Moose numbers, like those of the island's wolves, have varied greatly, hitting a high of 2,422 in 1995 while bottoming out at 385 in 2007. It's believed that moose first swam to the island in the early 1900s and thrived for decades with no predators, with their numbers crashing after population highs due to a lack of food after years of heavy browsing.

Wolves are relatively new to the 45-mile-long, 143,000-acre island complex, having crossed Lake Superior ice to get there in 1949. Before the current downturn, wolf numbers ranged from a previous low of 11 in 1993 to a high of 50 in 1980.

One climate problem affecting the gene pool issue is the lack of ice in most recent years connecting the island to the mainland, allowing fewer chances for new wolves to cross and add their bloodline to the island packs.

John Myers reports on the outdoors, natural resources and the environment for the Duluth News Tribune. You can reach him at
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