Activity Budget and Diet of Phayre’s Langur (Trachypithecus phayrei) in Satchari National Park, Bangladesh

There are few studies of the Critically Endangered Phayre’s langur (Trachypithecus phayrei) in Bangladesh. An understanding of their diet and activity budget is important for the elaboration of conservation management plans. In this study, we obtained data on the activity budget and dietary composition of different age-sex classes in a group of seven Phayre’s langur in the Satchari National Park, Bangladesh. We studied them for four months, from December 2017 to March 2018, recording their behavior by instantaneous scan sampling. They spent most of their time foraging and feeding (40.7% of the total scans), followed by traveling (31.8%), resting (18.3%), grooming (7.8%) and playing (1.4%). The sub-adult male spent the most time foraging and feeding (44.6% of their total scans) and the adult female the least (36.8%). For traveling (locomotion), the juvenile was the most active (37.4%) and the adult male the least (27.7%). The adult female rested more than other group members (24.2%), the juvenile the least (14.9%). The sub-adult female groomed most (18.6%), the sub-adult male the least (5.96%). Leaves were the principal food item (50% of feeding records), followed by fruits (18.6%), flowers (16.2%), buds (8.8%) and bamboo shoots (6.4%). Foraging and feeding was predominant in their activity budget, followed by traveling, in all months except March when the reverse was true due to food scarcity. The composition of their diet varied monthly according to the availability of food items in their habitat. Twenty-two species of plants were identified included in the diurnal activities, including six in the family Moraceae, four in the Fabaceae and three in the Malvaceae. Their diet included items from 17 plant species.