Isle Royale 2022 Wolf Moose Report

Over the past year, fieldwork resumed at pre-pandemic levels. In February 2022, the wolf population was likely comprised of 28 wolves. This is an increase from the next most recent estimate of 12-14 wolves, made 24 months earlier in March 2020 (Fig. 1). The wolf population appears to be primarily organized as two main social groups—an eastern pack consisting of at least 13 wolves and a western pack most likely consisting of 13 wolves—and two wolves that may not be part of either pack. There is evidence that pups were born to both packs in April 2021. For context, there is also evidence that one litter of pups was born in 2019 and two litters were born in 2020. Wolves appear to be an important cause of mortality for moose once again. In particular, this past year, the proportion of the moose population killed by wolves (i.e., the predation rate) was 8.7 percent. That rate is almost twice as high as the predation rate observed in 2020 (4.5 percent) and it is the highest predation rate observed since 2011. Overall, the new population of wolves on Isle Royale appear to be well-established and functioning healthily. Over the past year, the U.S. National Park Service (NPS) continued its efforts to outfit a small proportion of the wolf population with GPS radio collars to help monitor the recovering population.