We conducted a quantitative dietary analysis of the Japanese dormouse (Glirulus japonicus) using fecal samples collected in the subalpine zone of the Yatsugatake Mountains, central Japan. Dormouse diets were dominated by insects (69.2%) in summer and both fruit (43.0%) and insects (33.4%) in autumn. Leaves accounted for a small proportion of the diet in all seasons. Dormice may be reliant on insects because fruits are scant in summer, and on fruits to accumulate body fat in autumn before hibernation.
Keywords: Gliridae; arboreal mammal; frugivorous; insectivorous; nest box.