Feeding ecology of capped langur (Trachypithecus pileatus) in Sri Surya Pahar, a disturbed habitat in Goalpara District, Assam, India

Abstract

A group of capped langurs, Trachypithecus pileatus comprising eight individuals was observed for feeding behavior in Sri Surya Pahar, an archaeological site of religious importance and degraded habitat, located about 12 km southeast of Goalpara town in Assam. The feeding ecology of the species was studied by recording the time spent feeding on different food plants and food categories during different seasons of the year. Scan sampling method was followed from dawn to dusk to record data on various aspects of feeding. Capped langurs spent 37.87% of their total active time in feeding during winter season, 34.12% in pre-monsoon, 26.60% in retreating monsoon, and 26.08% in monsoon season. Altogether 41 species of plants belonging to 24 families were utilized for feeding throughout the year. Capped langurs spent maximum time feeding on leaves. The time spent on feeding new leaves was highest during pre-monsoon season (63.70%) and lowest in winter (7.82%). While the time spent on feeding mature leaves was highest in winter (67.48%) and lowest in pre-monsoon season (2.31%). The time spent feeding flowers (20.78%) was maximum in winter and that on unripe fruits (20.79%) and petioles (9.24%) was maximum in pre-monsoon season. Flower buds, leaf buds, latex and insects were placed in ‘others’ category and were consumed in low quantity. From this study, a significant change was observed in the diet composition of Capped langurs during different seasons. Habitat degradation due to encroachment is the major threat to this endangered species in Sri Surya Pahar and its neighbouring areas. The study focused on the feeding ecology of capped langur in a degraded habitat. Therefore, the information generated from this study could be useful for evaluation and improving the quality of the habitat and formulating conservation and management action plan for capped langur.