Population genetics of American black bears in Georgia, USA

Abstract

There are 3 American black bear (Ursus americanus) populations in the state of Georgia, USA. We used multi-locus microsatellite genotypes derived from bear hair and tissue samples collected across these populations to assess levels of genetic diversity within and between populations. We used population assignment clustering to evaluate whether there has been recent immigration into the smallest of the 3 populations, the Central Georgia Bear Population. Compared with other bear populations in the United States, the North Georgia and South Georgia Bear Populations have relatively high rates of genetic diversity (Ho = 0.72 ± 0.02, A = 6.68 ± 0.32, and Ho = 0.72 ± 0.02, A = 6.82 ± 0.35, respectively). In contrast, the Central Georgia Bear Population has relatively low rates (Ho = 0.46 ± 0.03, and A = 3.96 ± 0.20). Fixation indices for pairings between Georgia bear populations indicated that the North Georgia Bear Population was more similar to the South Georgia Bear Population than either was to the Central Georgia Bear Population. Our findings suggest that the Central Georgia Bear population has experienced long-term genetic isolation and genetic drift. Of a sample of 365 bears from Central Georgia, we only detected 1 immigrant and no evidence of gene flow into the population. We recommend development and implementation of plans to encourage gene flow toward the Central Georgia Bear Population.