We study the natural history of wild animals using ecological and ethological methods. In particular, we study the distribution, diet, and behaviour of freshwater turtles and sea turtles, to understand their lifestyle and to study how human activities affect their lives. Additionally, we are conducting researches to elucidate the mechanisms of reproductive isolation in turtles, where interspecific hybridization is common. We are also interested in the distribution and population structure of aquatic species such as the giant salamander and the finless porpoise.