The Japanese squirrel (Sciurus lis) is an endemic squirrel of Japan that inhabits mixed forests and pine forests on Honshu and Shikoku. It is relatively small in body size and mainly eats walnuts and pine seeds, showing less preference for acorns. It does not hibernate and stores food; forgotten seeds that later germinate mean it also functions as a seed disperser. It is diurnal and generally solitary. Breeding begins in spring, and the gestation period is about 39–40 days. Changes in its habitat and impacts from introduced species are causes for concern, but its current conservation status is listed as Least Concern.