Declining wolf populations lead to explosion of moose on Isle Royale, posing possible problems

National Park Service map

The declining wolf population in Isle Royale National Park in Michigan's Upper Peninsula has led to a population explosion of moose, which could hurt the region's vegetation and cause starvation among moose, says a study by scientists at Michigan Technological University. Wolves are the island's top predator.

During their annual study, scientists counted only two wolves and 1,600 moose, Stefanie Sidortsova reports for Michigan Tech News. John Vucetich, a professor of ecology at Michigan Tech and co-author of the study, said a lack of wolves could lead the moose population to double over the next three to four years. He said more moose means more vegetation is eaten, which would deplete food supplies.

Scientists also fear that without predators cutting their numbers, moose are overeating the park's balsam fir trees, John Flesher reports for The Associated Press. Rolf Peterson, a research professor at Michigan Tech, said "balsam fir is the predominant tree of Isle Royale and has long characterized its landscape." He told AP, "It's a race between the slowly growing trees and the rapidly growing moose."

Wolf numbers have plummeted since 2009, from 24 to 2, Sidortsova writes. The decline is largely blamed on inbreeding. The two remaining wolves, which are believed to be father and daughter, have mated before, but are not expected to reproduce again. The National Park Service in 2016 published a proposal that includes reintroducing 20 to 30 wolves in the next three to five years. A final decision is expected in the fall.