Food habits of sika deer in a depopulated mountain village: a case study in Hayakawa, Yamanashi Prefecture

Abstract

The food habits of sika deer (Cervus nippon) in Hayakawa, Yamanashi Prefecture, central Japan, a depopulated area, were studied through faecal analysis. Faecal analysis showed that the diets of deer in this area were relatively poor, with plant-supporting organs like fibre and culms comprising a large part of the diet, while live leaves accounted for only a small proportion of the faecal composition. In spring, fibre and culms comprised as much as 45.0% and 17.7% of the faecal composition, respectively. These proportions were not significantly different in summer, when fibre (54.6%) and culms (14.2%) remained predominant, although the proportion of dicot leaves increased to 13.5%. In autumn, the proportion of live leaves increased to 36.0%, probably because deer fed on newly fallen leaves on the forest floor. The diets were poorest in winter, when fibre accounted for 82.7% of faecal composition and the proportion of live leaves was extremely small (2.5%). Comparison with three other areas showed that deer in Hayakawa had the poorest diet. We discuss the importance of food analysis for deer management with reference to depopulated areas.