FEEDING AND RANGING IN THE MENTAWAI ISLAND LANGUR (PRESBYTIS-POTENZIANI)

Presbytis potenziani is found only on the Mentawai Islands, Indonesia, and its ecology and feeding and ranging behavior have been little stu died. I studied 10 groups of Presbytis potenziani in the primary fores ts of North Pagai Island, Mentawai, Indonesia. P. potenziani used prim arily the upper strata of the forests for feeding, movement, and resti ng. Groups remained cohesive during their daily activities, ranged bet ween 100 to > 1000 m daily, and occupied home ranges of less than or e qual to 40 ha. Neither sex predominantly initiated group movement. Loc omotion was primarily quadrupedal, with frequent leaping. P. potenzian i showed two feeding peaks, one in early morning and one during midaft ernoon. P. potenziani fed mainly on climbers and frees of the Dipteroc arpaceae. They ate primarily leaves, but also fed on fruits and other plant parts.