Troop size, home range area and seasonal range use of the Japanese macaque in the Northern Japan Alps

Home range area and habitat use of the wild Japanese macaque (Macaca fuscata) were investigated between elevations of 600 m and 3000 m in the Northern Japan Alps, in areas where there is great variation in vegetation type. A total of 22 troops were located either visually or by radiotracking from December 1996 to February 2000. The average troop size was 48.4 individuals, the average ranging area (65% probability distribution calculated using the adaptive kernel method) was 3.7 km2 and the average elevation of each troop varied from 740 m to 1458 m. Two troop types were distinguished according to their habitat use: (i) ‘rural’ type groups frequently utilized cultivated land (n = 12); and (ii) ‘natural’ type groups never utilized cultivated land (n = 10). Natural groups inhabited higher elevation areas and showed a greater dependency on deciduous broad‐leaved forests during all seasons. In contrast, rural groups utilized the larch plantation more in spring, and the red pine forest in summer. Rural groups were observed on cultivated lands more often from summer to winter than in spring. The size of the rural groups was twice as large as that of the natural groups. Troop size and home range area showed significant correlation within each group type. The per capita home range area of rural groups was smaller than that of natural groups. These results suggest that per capita home range area is negatively correlated with habitat quality.