Ecosystem impacts of folivory and frugivory by Japanese macaques in two temperate forests in Yakushima

Japanese macaques (Macaca fuscata) on Yakushima Island have a negligible impact on leaf production but significantly influence fruit consumption. While their folivory accounted for only about 0.04% of total leaf production—far less than insect folivory—they consumed 6-40% of the fruit production for three major fleshy-fruited species, rivaling bird consumption (32-75%). This suggests that macaque frugivory could play a substantial role in shaping forest dynamics. Researchers estimated consumption through direct observation of macaque groups over a year and calculated leaf and fruit production by accounting for litter fall and other consumers.

Hanya, G., Fuse, M., Aiba, S.-I., Takafumi, H., Tsujino, R., Agetsuma, N., & Chapman, C. A. (2013). Ecosystem impacts of folivory and frugivory by Japanese macaques in two temperate forests in Yakushima. American Journal of Primatology, 76(6), 596–607. Portico. https://doi.org/10.1002/ajp.22253