Molecular evidence for historic long-distance translocations of brown bears in the Balkan region

We tested the hypothesis that brown bears were translocated from the Romanian Carpathians to Bulgaria via air transportation during the communist regime in the 1970s and 1980s. Microsatellite analysis was performed on 199 bear samples from Bulgaria and Romania. Assignment and admixture tests revealed the existence of seven genotypes (=2.8 %) in Bulgaria that were assigned with high probabilities to the Romanian population, supporting the translocation and successful establishment of Carpathian bears in Bulgaria. While we cannot rule out the possibility that active long-distance dispersal contributed to the observed pattern, the spatial distribution and sex ratio of the detected Romanian genotypes strongly favor the translocation hypothesis.