Isle Royale sits like a gem in a cold ring of Lake Superior water some 15 miles off the shore of Grand Portage, Minnesota. Its isolation has been the island’s preservation. Today, as a national park, the 210-square mile island is not much different than when Norwegian fisherman built the first fish camps on its shores in the mid-1800’s.
A balance between life and death, predator and prey, has kept this island in check since the 1940’s. Ice bridges during the cold winter months enabled the first grey wolves to find the island 75 years ago. Those wolves stayed and, for the most part, flourished, living off the abundant moose population.
Over the decades, the predator and prey populations ebbed and flowed in a forest ecosystem that worked. Scientists studied it, but for the most part, they stayed out of it.
Then, the ice bridges stopped forming and the wolves – after their population peaked at 50 – started dying. Canine parvovirus took many; wolves killing other wolves took some. At times, the wolves were dying at an alarming rate, while the moose, with fewer canines to bring them down, grew in relatively unchecked numbers.
Today, upwards of 2,000 moose roam Isle Royale. With only two non-breeding wolves left to hunt them, the National Park service decided humans will step in and alter the course of nature before it’s too late.
The predator-prey balance on Isle Royale has already clearly changed. For Rolf Peterson, who has spent 50 years of his life out here studying that dynamic, and with the moose population trending up rapidly, doing nothing in this national park would be disastrous for its ecosystem.
Peterson was 22 years old, just a graduate student, when he first stepped foot on Isle Royale. There is not a trail, nor a bit of shoreline he does not know, Now, he is known around the world for his wolf and moose research conducted on the island annually.
No one knows more about the connection between a healthy wolf population, a healthy moose population and a healthy island than Peterson does.
“The main issue here is there’s a moose population that’s like a runaway freight train right now,” Peterson said. “And if we let it run away, it will be to the detriment of the entire national park.”
Had the park service chosen a hands-off approach to the island, Peterson and other biologists believe that runaway moose population would devastate the park’s dominate balsam fir forests. It is the favorite food of moose. Over-grazing means the forests would eventually be replaced with a barren spruce and grass environment, but adding more wolves back into the mix means fewer moose and balance on the island once again.
The decision to drop wolves back on the island did not come easy. It means interrupting the relative “do not touch” scientific philosophy of this particular national park.
Among those with concerns is Dr. David Mech, a premier expert on wolf behavior. Mech pioneered the wolf-moose study on Isle Royale 60 years ago.
“To be done right, it’s going to take quite a bit of thought and consideration,” Mech said.
Mech said he would like to see a committee of wolf and moose biologists thoughtfully and carefully plan the re-introduction.
“Is the primary objective going to be to bring the wolf population to the point where it real quickly stops the moose population from increasing?” Mech said. “Or, is it going to be just establish a basic wolf population out there? Or is it going to be an experiment? I’d like to see it be an experiment.”
Ironically, it was Peterson that Mech helped guide into the prey-predator study and onto Isle Royale in the early 1970’s. Now, almost 50 years later, Peterson has no doubts about reintroduction.
“[Isle Royale] has a future, basically, a future as a dynamic wolf-moose forest system, whereas without wolves here, it had no future,” Peterson said. “It would be just a runaway moose population that would basically trash the place as only a huge herbivore can do.”
With the debate now over, wolves, likely from Minnesota, will once again dominate the food chain on Isle Royale.
“Nature’s way” will start all over again on the island—a delicate balance under the watchful eye of humans, with a new precedent of stepping in when the balance tips one way or the other.