A Scientific report of Field Science Course : Effects of vegetation and elevation on distribution of Japanese Macaque ( Macaca fuscata yakui ) in Yakushima Island

We conducted route censuses in Yakushima Island in order to investigate the current island-wide distribution of Japanese macaques (Macaca fuscata yakui). In particular, we focused on two factors, namely vegetation and elevation. During censuses, monkeys were detected by direct observation, feces, or vocalizations. In total, we detected 460 feces, 10 calls, and 42 direct sighting during our route censuses. We analyzed detection frequency in relation to the altitude and vegetation. Our results suggest that monkeys were more likely to be detected in natural forests compared with other vegetation areas including grassland, plantation,or village areas, implying that forests were more suitable habitats for them. Monkeys were less likely to be detected around village areas. This might be because of methods to keep them away by farmers. When it comes to the elevation, higher percentage of signs of monkeys were detected at low to mid altitude (‘0-400’ m and ‘401-800’ m a.s.l) whereas lower percentage of signs of monkeys were detected at high altitude areas (‘>1200’ m a.s.l). The results are simplistically hypothesised to be affected by the habitat quality or possibly due to the uneven sampling effort in different elevational classes during the survey.