Study Area
Isle Royale National Park is a 540-km2 archipelago in Lake Superior, 22 km from mainland Ontario, Canada. Over 99% of the park is designated wilderness and supports mixed boreal forests characteristic of the transition between temperate and boreal zones (Sanders and Grochowski, 2013). Mammals on Isle Royale include moose, wolves, red foxes (Vulpes vulpes ), beavers, river otter (Lontra canadensis ), snowshoe hare, red squirrels (Tamiasciurus hudsonicus ), muskrats (Ondatra zibethicus ), deer mice (Peromyscus maniculatus), and several species of bats (Johnsson et al ., 1982). Mean daily high temperatures in summer (June–August) are 21°C and mean daily high temperatures in winter (December–February) are 3°C. Isle Royale receives an average of 734 mm in annual precipitation.
Isle Royale National Park personnel and partner organizations released 19 wolves into IRNP in 2018 and 2019 to supplement the population. Eight of these wolves represented a family group from Michipicoten Island, Ontario and the remaining wolves were unassociated and unrelated individuals (Hervey et al. , 2021). Before restoration, only two highly inbreed wolves remained on the island (Hervey et al. , 2021). All translocated wolves received Vectronics or Telonics radio-collars with on-board Global Positioning System (GPS) scheduled to take a location every 5 hours (NPS, unpublished data).