A first genetic assessment of the newly introduced Isle Royale gray wolves (Canis lupus)

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College of Forest Resources and Environmental Science


The gray wolf (Canis lupus) population of Isle Royale National Park suffered an extreme population decline where by 2017 only two wolves that were both half-siblings and a father-daughter pair remained with low probability of producing viable young. This precipitous decline was in part due to the negative fitness consequences associated with inbreeding. To restore the Isle Royale ecosystem 19 gray wolves were translocated in 2018 and 2019. The founders were translocated from Grand Portage, MN (n = 4), western Upper Peninsula, MI (n = 4), Jostle Lake, ON (n = 3), and Michipicoten Island, ON (n = 8), and genotyped using 18 microsatellite loci. Allelic richness and heterozygosity of translocated Isle Royale founders was similar to reference populations. Population structure assigned the Isle Royale founders to gray wolves with little evidence of admixture from eastern wolves (Canis lycaon cf). In addition, we confirmed wolves translocated from Michipicoten Island were a single family-group. Through simulation and empirical analysis of the new Isle Royale founders we projected a loss in genetic variation over the next 50 years and an increase in inbreeding. However, varying levels of immigration may allow the retention of some genetic variation. Our findings indicate Isle Royale founders are genetically diverse and representative of the Great Lakes region, but the numerical dominance of a single family group may have negative implications for retaining genetic diversity and success of establishment for specific wolves, reinforcing the importance of continued monitoring of genetic fitness.

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Conservation Genetics