Genetic evidence to inform management of rare genetic variants and gene flow: Balancing the conservation of the rare “Spirit bear” allele and population genetic diversity across a complex landscape

Abstract

Abstract Incorporating genetic considerations into wildlife management can require balancing the conservation of rare genetic variants with the maintenance of gene flow. One system illustrating such trade‐offs is coastal British Columbia, Canada, where black bears (Ursus americanus) can carry a genetic variant responsible for white‐coated “Spirit bears.” We examined population genetic structure, diversity, and gene flow using 22 microsatellite loci for 357 individuals collected over a 23,500 km2 area from a long‐term noninvasive bear monitoring collaboration among the Gitga'at, Kitasoo/Xai'xais, Nuxalk, Haíɫzaqv, and Wuikinuxv First Nations and partnering scientists. We found broad‐ (two groups) and fine‐scale (eight groups) population structures. At the finer scale, three islands formed unique genetic groups and four genetic groups showed heterozygote deficiency, including two populations containing Spirit bear alleles. We additionally created effective estimation of migration surfaces and found that breaks among genetic groups and areas of lower than average migration aligned with wide waterways (>2 km). Given the apparent isolation of island groups, heterozygote deficiencies, and the distribution of the rare Spirit bear allele, we provide recommendations to prevent the loss of Spirit bear allele carriers and individuals contributing genetic diversity to isolated, genetically depauperate groups. More broadly, we highlight the value of locally led, fine‐scale genetic monitoring for wildlife management.

Keywords

• black bear population genetic structure
• conservation genetics
• landscape genetics