Isle Royale: The Wolves

“It has been said that wilderness without wildlife is mere scenery. Then, it is the moose and wolf that make Isle Royale more than just another pretty place.”

                       -Jeff Rennicke, author of Isle Royale: Moods, Magic and Mystique

Do you remember in 4th grade when you were required to draw a food web? You were likely given a picture depicting a bear, an eagle, fish, squirrels, plants, a deer and perhaps a couple of insects. Your teacher then asked you to draw a line between predator and prey. It was pretty simple—the bear ate the deer and the deer ate the plants. Or the eagle ate the fish, and the fish ate insects.  This is a food web. For humans it is also really quite simple—we eat cows, cows eat corn and corn gets its energy from the sun. Understanding a food web is a very basic way of understanding how we get our energy.

Isle Royale is facing a food web problem.  The primary predator on the island is the gray wolf. In recent times, there have only been three wolves inhabiting the island. For an island that is 40 miles long and has 1,250 moose, “three” is quite a small predator count. The problem becomes an issue of imbalance. Moose numbers grow unencumbered without a primary predator until the population reaches the point when the island can’t sustain the population. After several years, you have a decrease in vegetation and possible moose starvation due to lack of population control and necessary resources.

The issue that the National Park Service is faced with is, “what do we do?” Do they introduce more wolves to the island? Do they let the current wolves die off and let nature run its course? There are dozens of questions that these options bring up:

Do you introduce more wolves to the island?
·      What if the packs don’t get along and kill each other?
·      What if one of the packs decides to swim back, or walk back across the ice?
·      What if they kill too many moose?
·      How many wolves do you introduce?

Do you let nature run its course?
·      What if the moose population skyrockets and they eat more vegetation?
·      What does a skyrocketing moose population do to other herbivores?
·      What if the wolves die off and no new ones come to the island?

There are numerous options with both predictable and unforeseen consequences. The National Park Service is even collecting public comment on the subject until August 29th of this year.

I think back to Jeff Rennicke’s quote, “It is the moose and the wolf that make Isle Royale more than just another pretty place.” When I first read that, I couldn't help but be more engaged in the discussion about whether or not to introduce more wolves. Then I read some more literature from the National Park Service and I think about it a little differently.

Here is the info from the National Park Service that made me think differently.

·      Caribou – last seen in 1927
·      White-tailed deer – last seen in 1936
·      Coyotes – last seen in the 1950s
·      Lynx – last seen in 1981

A little over 100 years ago, there were neither moose nor wolves on the island. The large prey were caribou and deer, while the large predators were coyotes and lynx. The ecosystem and food web was entirely different. Maybe the isle is undergoing a similar change right now, maybe the wolves are moving north and don’t want to be on Isle Royale. Do we force them to stay? Do we incentivize them with a fat and happy food source of moose? What if they are moving away because the weather isn’t favorable?

I don’t know the correct answer. On one hand, I love wolves and moose and want to see them present on Isle Royale. On the other hand, it makes sense to have Darwinian natural selection run its course. What do you think?