Wild Japanese macaques (Macaca fuscasta yakui) around the Seiburindo Road in the western area of Yakushima Island have been occasionally provisioned by tourists. We censused the provisioned monkeys along the Seiburindo Road (19.2km) in this area.
“Orange tests” were conducted for 236 individuals in 86 observation sessions to discriminate provisioned monkeys. Adult male monkeys were more provisioned than adult females or immatures.
The median time for which they stayed around the road was 26 minutes in 30 minutes observation sessions. They mainly spent time on resting and foraging around the road.
The areas where provisioned monkeys were observed had significantly larger artificial slopes than those where non-provisioned monkeys were observed. In addition, the number of groups that we found along the road were positively correlated with the height of the slopes. The amount of time for which we observed monkeys along the road also showed significantly positive correlation with the lengths of the slopes.
These results suggested that, in the area where the artificial slopes were larger, monkeys tended to stay there for longer time and passengers could find monkeys more easily because of high visibility. Therefore, monkeys ranging larger artificial slopes might be more likely to contact with passengers and tend to be provisioned.