An ecological study of Hanuman langurs,Presbytis entellus

A troop of 23 Hanuman langurs was studied for a year in the dry deciduous forest at Dharwar, South India. The size of the territory and the home range of the troop was reduced due to a new-group formation during the period of this study, but the area size per each member of the troop did not change much. No distinct seasonal use of different parts of the range was observed. There was a tendency toward increased activities, especially feeding, toward the evening. However, feeding was frequently observed during the daytime. The langurs ate leaves, stalks, shoots, buds, flowers, and the fruit of many plant species, and they well utilized the common and abundant species in the area as food. The langurs spent 20% to 40% of the daytime on the ground. And they moved longer distances on the ground than they did in trees. When feeding on the ground, they changed food plants more frequently, moving more often and longer distances, than when feeding in trees. The home range of the langur troop overlapped with that of a troop of bonnet monkeys, but the relations between the two species were rather peaceful.The field work on which this report is based was financed by a Rockefeller Foundation grant, RF 60229, for the study on the behavior of Indian monkeys.