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Isle Royale martens are back

Nov 24, 2018 08:07AM ● By Editor

Isle Royale is once again the home of the American marten.  Photo:  Boreal Community Media

From - November 24, 2018

When I heard American martens are once again inhabiting Michigan’s famous Isle Royale far offshore in Lake Superior, three iconic movie quotes popped to mind. The first was from the 1986 film Poltergeist, “They’re baaaaack...!”

Martens are a large weasel (about twice the size of a fox squirrel) native to the coniferous forests or mixed conifer/hardwood woodlands across the northern portion of North America. Their affinity for living in pine or spruce forests gives them their other common name, pine marten.

They were once common on Isle Royale, one of only 19 species of mammals documented to live on the 45 mile long island. Think of that number in comparison to the number of mammal species which can be found living on the mainland shores of Lake Superior. It’s not easy colonizing an island that remote, surrounded by miles of deep, cold water.

Historically, the island was visited or occupied by people of the Ojibwa Tribe. Descendants of European settlers mined the island for copper and logged it commercially. Much of the island was deforested by the late 1800s and by the early 1900s martens were eliminated.

The mines played out and soon only commercial fishermen lived on the island (at least part of the year) which allowed the forests time to regenerate. In 1940 Isle Royale became a National Park. Over time, it’s become an increasingly popular destination for visitors wanting a truly remote and wilderness like experience.

It’s also become a wonderland for wildlife researchers to study the few species of four footed wildlife present since the island is essentially a wilderness and has a paucity of outside influences. Books have been written about he interaction between moose and wolves on Isle Royale.

So when the pine marten announcement was made, “They’re baaaaack,” the question became, “How could that be?” My first thought was another movie quote, this one from the Kostner epic, Field of Dreams. “If you build it, they will come.”

It’s actually one of the tenants taught in the wildlife management classes I took in college. Wildlife management, more than anything else, is habitat management. It’s been proven time and again from coastal lowlands to high mountain areas. Create a marsh where there was once only open water or dry land and a variety of wetland species will soon populate the area. Create a grassland where there once was only soybeans or other crops and prairie animals and birds will show up. Build a baseball diamond in an Iowa cornfield and legendary baseball players will start emerging from surrounding corn rows.

Okay, maybe that’s only in the movies, but once the Isle Royale forests regenerated, it’s not surprising for martens to come back to reclaim their niche. The question then becomes, how did they get there?

One thought is they never really went away. Perhaps a tiny number of martens remained on the island after they were thought to be extirpated. That’s unlikely. Uncountable numbers of wildlife scientists, naturalists and park visitors have traversed the island at all seasons of the year. It’s unlikely a small breeding population would go unnoticed for so long by so many.

The easiest way would be via human intervention. The Park Service and/or other government wildlife agencies could team up to live trap martens from the mainland and then relocate the captured animals to the park. That didn’t happen. Plans were considered back in the 1960s but never instituted. It would have been very time consuming, labor intensive and expensive to gather, harbor and transport martens to the island.

It’s possible, but highly unlikely, an individual did the restocking. Don’t even consider the “hows” of someone doing this on the sly. Ask why?

This leaves only one other alternative which brings up the famous quote from the Jurassic Park movie, “Life finds a way.” Somehow, enough martens made the journey from the lakeshore to Isle Royale under their own power. The minimum distance for this is 22 miles of either ice or water and it’s unlikely any marten attempting the journey (for what ever reason) would know the best, shortest route. Consider, too, martens are solitary animals, not living in herds or colonies and so at least two (and more likely, several) would have had to found their way to the island and then found each other during the mating season.

No one will ever know for sure how “life found a way” but they’re baaaaack!

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