Research of provisionized wild Japanese monkeys in Yakushima Island-comparison between 1993 and 1995

Abstract

In the previous research in 1993, three of the authors found that some troops of wild Japanese macaques were provisionized by tourists, around the road in the western forest of Yakushima Island, south of Kyushu, Japan. Again in 1995, we conducted a research with the same methods in the same area. Here we reported the results of 1995 and compared them with those of 1993.We surveyed the area along the road of 19.2km, passing through the forest. We set eight stations along the road as survey units, with a mean length of 2.4km. Each station was surveyed for two days. Each of us walked slowly in the station and searched troops of monkeys. When the observer found the monkeys on or near the road, he or she began observation session for maximum of 30 minutes. At the end of observation session, the observer began to search another troop.During the observation session, we recorded the activities of monkeys and conducted“orange tests”. In the “orange tests”, we showed an orange to a monkey and recorded its response. If the monkey accessed to the orange, it was determined as provisionized.Percentages of provisionized monkeys were significantly different among the stations. However, no significant difference was found between the results of 1993 and 1995. Numbers of traffic passing through the road per day was 138.5, which was larger by 40 than in 1993. Among the traffic in 1995, at least 60% was due to tourists.The numbers of provisionized monkeys did not increased distinctively during the two years. However, numbers of tourists visiting the area apparently increased and the percentages of provisionized monkeys increased in some of the stations. Therefore, we should continue to monitor the provisionized monkeys and to make efforts to stop tourists from feeding monkeys.