New Isle Royale predator-prey study underway

Moose Michigan

Photo credit: Dreamstime

There are too many moose on Isle Royale, an isolated island located 55 miles away from Michigan’s Upper Peninsula in Lake Superior. Once home to a healthy wolf pack that helped keep the moose population in check, dwindling wolf packs have caused an ecosystem imbalance allowing for moose to flourish—and decimate—the vegetation. If an adult moose eats up to 60 lbs of plants per day, imagine what could happen to Isle Royale’s ecology—and the moose population in general—if this goes unchecked.

Last winter’s survey tallied 2,060 moose on the island and data from Michigan Technological University (MTU) discovered that “the moose population has been booming at 19% a year” because their natural predators (wolves) were so scarce over the past eight years. Recently, the state imported several wolves from Minnesota with the intent on re-balancing the predator-prey relationship. Yet, according to Science, the 13 new radio-collared wolves are “largely avoiding the territory of the remaining two wolves of the original population.” 20 female moose have also been collared for the study.

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So far, the findings from the predator-prey study have revealed “stuff we’ve never seen before,” said MTU wildlife ecologist Rolf Peterson. Researchers have learned where moose go to feed on new spring growth and where wolves tend to “cluster,” which are “presumed to be moose kills, which will help researchers collect moose bones” and, according to Peterson, “will totally redirect our attention.”

Meanwhile, researchers say the two remaining wolves that were linked genetically are still hanging on. While no longer breeding, the inbred pair are busy marking their territory and have discovered the ice bridge, making their way across it and back. Unfortunately, it’s assumed that the newly relocated wolves will also eventually be inbred as “[i]nbreeding is basically inevitable due to the island’s small size,” said geneticist Jacqueline Robinson. However, according to Science, the National Park Service hopes to prevent this by bringing more wolves to the island “to further diversify the population.”


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