Four gray wolves (Canis lupus) have been airdropped into Michigan for a very important assignment. The quartet, originally from Canada, has been helicoptered into Isle Royale national park to check the 2,300-square-kilometer island's moose population, which has exploded in the absence of the canine predator.
But the animals are there on a second mission. Wildlife specialists at the Ontario Ministry of Natural Resources and Forestry (OMNRF) hope their introduction will revive the island's wolf population ? a conservation technique known as rewilding. The foursome (one female, three males) will be joining a pair introduced in September, and the OMNRF hopes to introduce a further 14 to 24 sometime over the next three to four years.
In the past, the Isle Royale national park was connected to the mainland via an ice bridge for 50 days of the year or more, allowing wolves to come and go more or less as they pleased. Now, thanks in large part to climate change, that ice bridge has become less dependable, effectively leaving any individuals on the island stranded. The result: the park's wolf population has dwindled. From a high of 50 in 1980, numbers dropped to a low of just two in 2016.
This has had an effect on the island's moose, whose population has boomed as wolf numbers have plummeted. It might not sound like a bad thing ? at least as far as moose are concerned ? but it can put a strain on resources. As large animals, moose can outcompete other herbivores for food. Previous population explosions have resulted in thousands of deaths due to starvation. OMNRF hopes this new project will change that.
However, actually finding the right wolves for the job is a trickier beast than it first appears. "You don’t get to choose the wolf you trap," explained John Vucetich, an ecologist from Michigan Technological University who leads Wolves and Moose of Isle Royale project, the Guardian reports. "It could be old, young, or injured when captured."

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