Wolf-moose relationship studied on Isle Royale

Photo courtesy R. Peterson & J. Vucetich

Last week, researchers from Isle Royale released their annual Wolf–Moose study and the news is grim for the wolf population. 

ABC 10 Keweenaw Bureau reporter Sam Ali spoke with two of the top researchers to get the details on one of the longest research project studies in the world.

In its 56th year, Isle Royale’s wolf-moose study looks at the relationship between two of the more prominent species on the island. Researchers from Michigan Tech say over the past three years, they’ve tallied the lowest number of wolves ever.

“And all we know that’s happened is wolves left the island because they’re interested in breeding and having pups and reproducing in their own pack. And the wolves that are there now don’t find the kinds of breeding opportunities they want,” Michigan Tech professor Dr. Rolf Peterson said.

Peterson added that one of the bigger problems also is wolf predation, which is the proportion of the moose population killed by wolves. As a matter of fact, Peterson said it’s at its lowest level ever recorded.

“So wolves, in particular wolf predation, is pretty much gone already, even though there’s wolves there. So with wolf predation not having much of an effect on moose, the moose themselves are increasing pretty rapidly,” he said.

John Vucetich, the director of the study, said the harsh weather conditions also had an effect on the dwindling wolf population.

“So on Isle Royale where there are moose, it’s important that not only that there will be wolves but that the wolves be in healthy enough condition that they are keeping the moose under control,” he said.

Inbreeding has also been a problem. Ice bridges bringing in new wolves has helped, but they have become less common than in the past. So why not just bring over some wolves from the U.P. onto the island?

“If a person were comfortable with the idea that protecting Isle Royale’s ecosystem health really is the most important objective to have in mind, if that’s the goal, it would be relatively straightforward to promote that goal and to make sure that goal came about by just bringing a couple wolves to Isle Royale,” said Vucetich.

The idea does seem to make sense in the short term. However, Isle Royale officials say as long as there is a breeding population of wolves on the island, no intervention will take place.