The clock is ticking for a decision on Isle Royale's wolves

Nov 19, 2013

Wolves are doing fine in many parts of the Upper Midwest, so much so that people are hunting them now.

But a protected population of wolves on Isle Royale National Park in Lake Superior has plummeted.

There are just eight adult wolves on the island. There's been a glimmer of hope with the discovery of new pups this past July, but pup survival has been a serious issue for the last several years.

Here's a chart showing "pup recruitment" on Isle Royale. It shows the number of pups that survive to see the winter.

Pup recruitment on Isle Royale (percentage of pups that survive to see their first winter). The black line shows the five-year decline in recruitment.
Credit Michigan Tech

So even though there were pups in July, they won't know if they survived until the Wolf-Moose Project's "Winter Study."

This has the researchers who have led the longest predator prey study in the world concerned. Michigan Tech's Rolf Petersen and John Vucetich would like to see a few new wolves introduced on the island before the current population dies out.

Normally, news wolves get to the island across an ice bridge when Lake Superior freezes between Isle Royale and the northern shore. But the warming climate has cut the number of bridges that form. In the 1960s, an ice bridge would form on average in two out of three winters. In the 2000s, that dropped to just one in ten winters.

In the 1960s, an ice bridge would form on average in two out of three winters. In the 2000s, that dropped to just one in ten winters.

It's up to the Superintendent of Isle Royale National Park to decide what to do next.

There are three decisions facing Phyllis Green, the Park's Superintendent.

  1. She could decide to let nature take its course, and do nothing.
  2. She could decide to bring new wolves onto the island before the current population is gone.
  3. Or she could decide to let the current wolves die out, and then bring new wolves in.

Green is traveling around the region gathering input from people. She says she’s heard a full range of opinions so far.

“I am hearing from the wilderness people that say, ‘You can’t take back tinkering … It’s unfortunate what’s going on, but you leave it alone.’ I am also hearing those who say, ‘It is the longest predator-prey study in the world. Why would you do anything that would alter it?’”

At the recent public meeting in Chelsea, Michigan, Green said she hasn’t set a deadline for her decision yet, but she says she plans to make it before "nature takes one of the options off the table" - meaning before the current population dies out.

Whether or not that will happen is unclear. The recent trend is not a good sign, but Green said the wolves on the island have surprised them before.

Listen below for her explanation on her timeline for a decision:

What do you think the Park Service should do? The managers of Isle Royale want to hear your opinions.

You can email your comments and ideas here:ISRO_Wildlife@nps.gov

The next public meetings will be held tonight in St. Paul, MN, and tomorrow night in Duluth.