Researchers hope Great Lakes ice will allow new animals to reach the island
Written by Louise Knott Ahern
The brutal cold we’ve experienced this winter might have an upside.
Researchers who study the declining population of wolves on Isle Royale National Park in Lake Superior are watching the ice on the lake to see if a bridge will develop between the island and the shore of Ontario.
If so — and it’s looking good — they hope it will entice new wolves to walk across the ice to the island and perhaps mate with the current Isle Royale population.
That would literally inject new blood into the threatened, inbred pack, which has declined from a high of 50 wolves in 1980 to just eight adults today.
Satellite images taken by the National Oceanic and Atmospheric Administration this week show a sheet of ice stretching from the mainland to the island, said George Leskevich, manager of NOAA’s Great Lakes Environmental Research Laboratory in Ann Arbor.
That’s not surprising, since all the Great Lakes are frozen at a rate not seen in several years thanks to a steady pace of below-freezing temperatures since Christmas. More than 71 percent of the lakes’ surface now is covered in ice, Leskevich said.
It’s potentially good news for a wolf population that has become the center of a debate within the National Park Service about when and how to intervene in wildlife issues.
The wolves of Isle Royale are the subject of the world’s longest-running study of predator and prey relationships called the Wolf-Moose Study out of Michigan Technological University.
The lead researchers on the study — Rolf Peterson and John Vucetich — have called on the National Park Service to take the unprecedented step of bringing new wolves to the island to add fresh, stronger bloodlines to the current pack.
The park service held public hearings last fall in Michigan and Minnesota but has not yet made a decision.
The park service’s current policy is to intervene in wildlife or ecosystems only when they are threatened by direct human activity.
Peterson and Vucetich argue human activity is to blame — just not directly.
They say the wolves’ decline largely can be traced to decades of declining ice coverage on the Great Lakes because of climate change.
An ice bridge used to develop between the island and the mainland every other year on average. Today, it happens only a couple of times per decade as lake temperatures have slowly risen.
The Great Lakes have seen a 70 percent reduction in ice coverage since the late 1970s.
But the early winter weather and cold temperatures we’ve seen so far this winter have made this year an exception.
“Winter weather is starting off nice and intense,” Peterson said in an email.
He is currently on the island with Vucetich and pilot Don Glaser for the annual Winter Study portion of their research.
For more than a month, they endure the island’s harsh winter because it’s easier to count wolves and moose against the white, snowy background.
Communications are hard from the island, Peterson said, but they keep in touch through a blog whenever their generator allows them to access their laptops.
Their most recent update reported a positive sight during a fly-over in search of one of the radio-collared wolves.
“As Rolf and Don narrowed the source of the (radio) signal, they saw a wolf and then two, and then five,” Vuectich wrote.
“And then a sixth. Six wolves — mostly bedded, a couple milling around — all amongst the trees at the edge of the shoreline.”