大井川上流域におけるツキノワグマの食性

抄録

The food habits of the Japanese black bear, Selenarctos thibetanus, were studied by scat content analysis in the headwaters of the Ohwi River in Shizuoka Prefecture, central Japan. Fifty scats were collected from May to December from 1981 to 1984 in the low mountainous zone (about 1, 000_??_1, 600m in altitude). The contents were classified into six categories: namely, seeds and fruits, leaves, branches and wood fragments, other vegetable matter, insects, and the other items. The black bear was omnivorous mainly depending on vegetable foods; it amounted to 98.5% of the total dry weight of the contents. Seeds and fruits were detected in summer through fall, and buna (Fagus crenata) and mizunara (Quercus mongolica) were staples of the diet in the period before hibernation. Most of leaves were detected in spring and summer. Branches and wood fragments were detected in all seasons. Other vegetable matters were small both in amount and frequency. All animal matter consisted of adult insects were of some importance in the diet during summer and fall. The nests of Hymenoptera sp. were detected in summer.