Abstract
The feeding selectivity of Japanese macaques (Macaca fuscata) on plant foods was investigated at three levels; 1) species 2) vegetation types 3) plant patches, on Koshima Islet located in a warm-temperate region, southern Japan. The selectivity was evaluated using the Jacobs' index on the basis of feeding behavior and availability of plant resources at four seasons. At the species level, the selectivity calculated with feeding behavior through the year was highest for Myrica rubura. However, the most selected species at each season varied: Ficus erecta in February, Myrica rubura in June, Euscaphis japonica in September and Neolitsea sericea in November. Infrequent species, including deciduous pioneer trees, comprised those with high selectivity at a specific season. Vegetation types and plant patches were also selected differently at each season. Japanese macaques were taking calories at where not only one particular species but also multiple species were abundant. These results suggested that plant food diversity contributed to energy support for Japanese macaques in evergreen forest area through the year.
