Takuma Matsumoto, University of Tsukuba

Understanding the impact of landscape variables on these dynamics of Asian black bear (Ursus thibetanus) is essential to propose effective management programmes to mitigating human-bear conflicts, which have become quite serious in Japan. This can also contribute to maintaining long term evolutionary integrity of the species. In this study, we aimed to identify mountainous landscape factors which affected local genetic structure of the bears, employing landscape genetics approach. This study was conducted in the Ina Valley of central Japan, one of Japan's largest mountainous regions, where human habitats have been developed along the Tenryu River in the valley for long history. We examined about 500 bear individuals which were culled in the study area. We determined sequences of control region of maternal inherited mitochondrial DNA (mtDNA) and genotyped 16 simple sequence repeats loci of biparental inherited nuclear DNA for population genetic analyses. The relationships between pairwise genetic distance among individuals and landscape variables were evaluated using Resistance GA (RGA, Peterman 2018). Both mt and nuclear DNA variations showed that the examined individuals were divided into two major genetic groups separated by the Tenryu River. The RGA analysis identified human development, elevation, broadleaf forests, and coniferous forests as significant landscape factors which restricted the bear dispersal. Notably, this is the first study which identified the forest types as the important landscape variables for the bear dispersal. Moreover, sex-specific RGA analyses showed that the ranking of landscape factors was not consistent between males and females. This study shed a new light on deep understanding of the genetic structure and dispersal of bears in mountainous areas. It also sheds light on landscape factors that restrict bear dispersal, which can be applied to local bear management in the Ina valley.