Michigan Department of Natural Resources wildlife technician Brad Johnson, right, and Nick Fowler, graduate research assistant with the State University of New York’s College of Environmental Science and Forestry take measurements of a gray wolf captured Sept. 6, 2019 in Michigan’s Upper Peninsula. Looking on are National Park Service veterinarian Michelle Verant and Michigan DNR veterinary specialist Dan O’Brien.

Isle Royale — One year into its effort to reestablish the wolf population on Isle Royale, the National Park Service and its partners have a problem: The new wolves keep dying and nobody knows why.

Since the park service began its relocation efforts in September 2018, 19 wolves have been transplanted from Minnesota, Ontario, Canada and Michigan’s Upper Peninsula. Three of the wolves have died, the most recent on Sept. 15. Another wolf left the island for mainland Ontario on an ice bridge in January.

via Park service looks to solve mystery deaths of Isle Royale wolves