Life in transit: habitat use, behavioural profile and feeding ecology by Nilgiri langur (Semnopithecus johnii) in a fragmented evergreen habitat of the Anamalai Tiger Reserve, Western Ghats, India

Primates in fragmented habitats show behavioural flexibility and adaptive changes in response to ecological challenges in the search for food resources within their home range.Nilgiri langurs (NL, Semnopithecus johnii), endemic to the Western Ghats, face anthropogenic pressures, including habitat modifications.To understand its behavioural profile, feeding ecology and habitat use in such habitat conditions, we observed NL in a forest fragment in the Anamalai Tiger Reserve, India.Their daily path length, though shorter in the dry season, did not significantly vary seasonally.The home range in the dry season, though smaller than in the wet season, was more intensively used in the dry season, indicating the patchy distribution of food sources.They fed on resources from 23 plant species, largely from Elaeocarpus munronii, Ficus sp. and Cullenia exarillata, with leaves being their primary diet.Most of the time the langurs spent on resting which is a typical trait of folivorous colobines to digest the leaves with the cellulose wall.In response to disturbances such as firewood extraction and increased tourism, they shifted habitat use from the understorey and middle canopy to intensive use of the upper canopy (>15 m).These findings suggest management interference in these forest fragments and highlight the need for a proper conservation plan.