Isle Royale Wolf Population Hits 37, Highest in Nearly 50 Years

The gray wolf population on Isle Royale, a 132,000-acre national park in Michigan near Thunder Bay, Canada, has surged to 37 individuals, the highest in nearly 50 years, according to the annual survey conducted from January 22 to March 3. The moose population has declined to an estimated 524 animals. The Isle Royale Wolf-Moose Project, now in its 68th year, is the world's longest continuous predator-prey study. Researchers observed wolves from planes, followed tracks, and inspected kill sites. The wolf population is split into three packs: West Pack, East Pack, and Northeast Pack, all expected to welcome pups this spring. For the first time since the study began, no moose calves were observed this winter. In 2018 and 2019, the National Park Service translocated 19 wolves from Minnesota, Canada, and Michigan's Upper Peninsula to improve genetic diversity. Since then, numerous litters of wolf pups have been observed. Moose heavily browsed balsam fir saplings from 2018 to 2021, and the trees have not rebounded, showing record-low growth rates. Wolves killed an estimated 24 percent of the moose population over the last year. Ecologist Rolf Peterson noted that wolf and moose populations are approaching historical edges. Sarah Hoy, co-leader of the project, expects the wolf population to decline as food becomes scarce. The ecosystem appears to be reaching a tipping point, with trends expected to stabilize soon.