Zoogeography of Terrestrial Mammals on Kunashiri Island : Are There Arboreal Small Mammals on this Small Boreal Island?

[ABSTRACT] On Kunashiri Island which is adjacent to the Shiretoko Peninsula of Hokkaido Island, we searched for three arboreal small mammal species common on Hokkaido Island: Siberian flying squirrel (Pteromys volans), small Japanese field mouse (Apodemus argenteus), and Eurasian red squirrel (Sciurus vulgaris). To find Siberian flying squirrel and small Japanese field mouse, we set 30 wooden nest boxes in a natural boreal mixed forest in the southern part of Kunashiri Island for two years (July 2013 - August 2015). We did not find either species. In July 2012, we interviewed 30 inhabitants of Kunashiri Island about Eurasian red squirrel. No inhabitants saw Eurasian red squirrels. Therefore, it was suggested that there are no arboreal small mammals on Kunashiri Island, as reported previously. Loss of these three species could be due to severe forest reduction and environmental change during Pleistocene glaciation.