Topography-specific seed dispersal by Japanese macaques in a lowland forest on Yakushima Island, Japan

Abstract

1. We investigated patterns of seed dispersal (i.e. dispersal distances and topography of seed-deposition sites) via the cheek pouches of Japanese macaques (Macaca fuscata yakui) during three seasons in a lowland forest on Yakushima Island, Japan. 2. The mean seed-dispersal distances were 16.7, 26.1, 41.8, and 32.4 m from the trunks of mother trees of Myrica rubra, Persea thunbergii, Neolitsea sericea, and Litsea acuminata, respectively. 3. We assessed the possible effect of macaque foraging patterns and the spatial distribution of fruiting trees on topography-specific seed dispersal. The topography of the locations of macaques differed across seasons, likely because the spatial distribution of fruiting trees determined the seasonal foraging patterns of macaques. 4. In early summer, macaques foraged on a ridge and fed on fruits of M. rubra and P. thunbergii, which were primarily distributed and dispersed within this area. In contrast, during the winter, macaques foraged within a valley and fed on fruits of L. acuminata, which were chiefly distributed and dispersed within the valley. 5. Seeds of M. rubra, P. thunbergii, and L. acuminata were directly dispersed to the specific topographic areas in which adult trees were distributed and in which juveniles have a predictably high probability of survival relative to random sites. © 2008 The Authors.