Population Genomics of North Carolina’s Black Bears (Ursus americanus) Reveals Substructure and Identifies Informative SNPs for Population Assignment and Individualization

Background/Objectives: Anthropogenic pressures increasingly fragment populations, reduce connectivity in large mammals, and threaten genetic diversity. Genetic diversity is essential for a population’s ability to respond to environmental change and the long-term persistence of any species. The American black bear (Ursus americanus) is an important ecological regulator of many ecosystems. North Carolina (NC) is home to a large number of black bears that contribute to ecosystem function. In this study, we examined how rapidly changing environmental and anthropogenic effects influence the structure and genetic health of black bears in North Carolina. Methods: Whole genome sequencing data were generated from 82 black bears selected from populations representing two of the three state recognized management units, the Mountain Bear Management Unit (MBMU, n = 49) and the Coastal Bear Management Unit (CBMU, n = 27). Of the 82 black bears, 76 were retained after quality and relatedness filtering. These whole genome sequence data were used to identify almost 900,000 single nucleotide polymorphisms (SNPs) for population genetic analyses. Results: The data identified three genetic clusters, one within the CBMU and two within the MBMU, indicating regional substructure across the sampled populations. Compared with the MBMU, the CBMU exhibited significantly lower genetic diversity and higher inbreeding (p < 2.2 × 10−16), suggesting reduced connectivity and increased genetic vulnerability in the coastal population. Finally, a candidate panel of 4990 SNPs was developed that can be used for the population and individual assignment of black bears. Conclusions: These findings provide a valuable genome-wide resource for black bear conservation in North Carolina and support management strategies aimed at maintaining connectivity, preserving genetic diversity, and promoting long-term population resilience.