Use of nest boxes, with reference to height selection, by Japanese dormouse at Mt. Yatsugatake, central Japan

Nest boxes (43 pairs) were set on tree trunks at heights of 0.5 m and 1.8 m above the ground in a larch forest at Mt. Yatsugatake, central Japan in May, 2013. The use of the nest box by small mammals and the nest materials brought by them were determined four times in 2013 and 2014. Approximately 27.7% (101 out of 364) of the nest boxes were used. Most of the boxes (93.5%) were used by the Japanese dormouse (Glirulus japonicus), and a few boxes were used by the small Japanese field mouse Apodemus argenteus. The use rate was particularly high (40%–50%) in September, after the rearing season. Boxes at higher height (1.8 m) were used more frequently than boxes at lower height (0.5 m). The dormice used mosses, beard lichens, and barks. For each nest, a particular material was predominant, and others occupied small portions.