Abstract
I describe the seasonal food habits of the Asiatic black bear, Ursus thibetanus, based on 193 fecal droppings collected in 1993 and 1994 in the Chichibu Mountains of Japan. The percent importance value of each food item was estimated based on the frequency of its occurrence and the volumes of all food items. The bears’ diet changed seasonally and annually. In spring of 1993, the importance value of new leaves was 100%, whereas in 1994 it was only 57%, while the importance value of various nuts was 44%. In contrast, berries (46%) and animal materials (34%), e.g., colonial insects (particularly Hymenopterans), were dominant in the summer of both years, while green vegetation was less important (17%). In the fall of both years, nuts were eaten almost exclusively (74% and 82%). These data suggest that these bears forage for high-quality food in the summer and fall, but not in spring, probably because they find less high-quality food in spring.
