In late January 2019, during a bitterly cold winter spell, scientists flew to Isle Royale in Lake Superior to try to locate three wolves that had recently been relocated to the island, the first part of a landmark effort to restore the delicate balance between wolves and moose — their chief prey — in the remote national park.
Four wolves from the Grand Portage reservation on the far northeastern tip of Minnesota were trapped and moved to Isle Royale the previous fall. One died shortly thereafter. The other three survived, but scientists had lost track of them. The wolves’ GPS collars hadn’t transmitted any locations for five days.