Population, Time Activity Budget and Habitat Utilization of Nilgiri Langur (Semnopithecus johnii) in Nilgiri Forest Division, Tamil Nadu, Southern India

The aim of the study was to understand population, time activity budget and habitat utilization of Nilgiri langur (semnopithecus johnii) in Nilgiri Forest Division from June to October 2018. Totally 57 Nilgiri langur troops comprising 535 individuals with an average group size of 9.38±3.65 individuals were recorded from six forest ranges altogether. The sex ratio between an adult male and an adult female of Nilgiri langur was 1:1.09. Similarly, the sex ratio between sub adult male and sub adult female was 1:1. An adult female and young one sex ratio was 1:2.9. Out of 153 hours of observation, it was found the Nilgiri langurs utilized six different habitat types for its various ecological purposes. Among them, the shola forest was effectively utilized by them to fulfill their all ecological requirements including feeding, resting and moving, etc. The Nilgiri langurs fed eighteen plant species of which, five of them were highly preferred food plants. It is very important and management point of view to note that except Syzigium cumini others are exotic plant species namely Acacia mearnsii, Acacia melanoxylon, Pinus wallichiana and Cupperssus macrocorpus. The fruiting phenology of Syzigium cumini occurs in stipulated period of time in the year unlike other exotic plants and its availability also comparatively lesser than other exotic plants. Most of the exotic plant species’ parts are edible to Nilgiri langurs which minimized the movement of the animals to get their nutritional requirements. Therefore, this study suggests eradication of exotic species is highly needed of the hour. Because the effects of secondary components on Nilgiri langurs is not known if the animals are forced to feed such exotic plant parts continuously.