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 studied. I studied 10 groups ofPresbytis potenziani in the primary forests of North Pagai Island, Mentawai, Indonesia.P. potenziani used primarily the upper strata of the forests for feeding, movement, and resting. Groups remained cohesive during their daily activities, ranged between 100 to > 1000 m daily, and occupied home ranges of ≤ 40 ha. Neither sex predominantly initiated group movement. Locomotion was primarily quadrupedal, with frequent leaping. P. potenziani showed two feeding peaks, one in early morning and one during midafternoon. P. potenziani fed mainly on climbers and trees of the Dipterocarpaceae. They ate primarily leaves, but also fed on fruits and other plant parts.