Spatial patterns and rarity of the white‐phased ‘Spirit bear’ allele reveal gaps in habitat protection

Abstract

Abstract1. Preserving genetic and phenotypic diversity can help safeguard not only biodiversity but also cultural and economic values.2. Here, we present data that emerged from Indigenous‐led research at the intersection of evolution and ecology to support conservation planning of a culturally salient, economically valuable, and rare phenotypic variant. We addressed three conservation objectives for the white‐phased ‘Spirit bear’ polymorphism, a rare and endemic white‐coated phenotype of black bear (Ursus americanus) in Kitasoo/Xai'xais and Gitga'at Territories and beyond in coastal British Columbia, Canada. First, we used non‐invasively collected hair samples (n = 385 bears over ∼18,000 km2) to assess the spatial variation in the frequency of the allele that controls the white‐coloured morph (mc1r). Second, we compared our observed allele frequencies at mc1r with those expected under Hardy–Weinberg equilibrium. Finally, we examined how well current protected areas in the region aligned with spatial hotspots of Spirit bear alleles.3. We found that landscape‐level allele frequency was lower than previously reported. For example our systematic sampling estimated a frequency of 0.25 (95% CI [0.13, 0.41]) on Gribbell Island compared with the previously reported estimate of 0.56. Also, in contrast with previous reports, we failed to detect a statistically significant departure from Hardy–Weinberg equilibrium at mc1r, which calls into question the previously posited role of homozygote gene flow, heterozygote disadvantage, and positive assortative mating in the maintenance of this polymorphism. Finally, we found a discrepancy between the placement of protected areas and the 90th percentile hotspots (upper 10% of all estimated values) of Spirit bear alleles, with ∼50% of hotspots falling outside of protected areas.4. These results provide new insight into hypotheses related to the maintenance of this rare polymorphism, and directly relevant information to support evidence‐based opportunities for Indigenous Nations of the area to attend to gaps in conservation planning.