Genetic variation and relatedness in grizzly bears in the Prudhoe Bay region and adjacent areas in northern Alaska

Abstract

Abstract The Prudhoe Bay region of northern Alaska has large oil fields and hunting on adjacent lands, and there are concerns about potential effects on grizzly bears (Ursus arctos) in this region. Because effects on grizzly bear populations may include loss of genetic variation, we assessed the genetic variation and family relationships among grizzly bears in this region as part of a long-term research and monitoring project. We determined genotypes at 14 microsatellite DNA loci for 78 bears from the Prudhoe Bay region from samples collected 1990–2002. The genetic data identified one or both potential parents of 33 offspring. Potential parent–offspring and siblings had pair-wise relatedness indices of approximately 0.5, as expected. The entire sample of related and unrelated bears in the Prudhoe Bay region had a mean pair-wise relatedness index of approximately zero. Approximately 5.3% of the bears had relatedness indices within the range of first-order relatives (parent–offspring or siblings). Genetic d...