Genetic and demographic recovery of an isolated population of brown bear Ursus arctos L., 1758

摘要: The brown bear Ursus arctos L., 1758 population of the Cantabrian Mountains (northwestern Spain) became isolated from other populations in Europe about 500 years ago and has declined due to hunting habitat degradation. At beginning 20th century, split into eastern western subpopulations, genetic exchange between them ceased. In early 1990s, total size was estimated be < 100 bears. Subsequently, reduction human-caused mortality brought an increase numbers, mainly subpopulation, likely promoting male-mediated migration gene flow nucleus eastern. To evaluate possible recovery small genetically depauperate 2013 2014 we genotyped hair faeces samples (116 subpopulation 36 western) for 18 microsatellite markers. Data annual count females with cubs year (COY) during past twenty-six used analyze demographic changes. number COY fell a minimum seven three subpopulations biennium 1993-1994 reached respective maximum 54 10 individuals 2013-2014. We also observed increased dispersal flow, subpopulation. Of 26 unique genotypes detected 14 (54%) presented admixture composition, (27%) were determined migrants Hence, two separated clearly structured identified currently show some degree admixture. This research shows partial change composition process bears that been several centuries.