Population Status, Distribution and Behavioural Ecology of Hanuman Langur (Semnopithecus entellus Dufresne, 1797) at Devghat, Chitwan, Nepal.

Abstract

A study on “Population Status, Distribution and Behavioural Ecology of Hanuman Langur (Semnopithecus entellus Dufresne, 1797) at Devghat, Chitwan” was made by direct observation, field survey and behavioral sampling methods. Field research was mainly conducted from June 2007 to September 2007 to explore the age-sex composition and distribution pattern of Langur population, food plants of Langur monkey and daily activity pattern of the Langur population in Devghat area of Chitwan.

The total population of the Hanuman Langur in the study area was 43, out of which 26 (60.46%) were adults, 6 (13.95%) were sub-adults, 1 (2.32%) was juvenile and 10 (23.25%) were infants. The male to female sex ratio from the sex identified age groups of adult and sub-adult was 1:1.13. From the four different troops of Hanuman Langur observed in Devghat, the average troop size was computed to be of 10.75 individuals per troop. The distribution of Langur population inside the study area was found regular or random type of distribution.

A total of 87 plant species were recorded from the study area among which Sal (Shorea robusta), Sissoo (Dalbergia sissoo), Jamuno (Syzygium cumini), Kyamuno (Cleistocalyx opperculatus) etc. were dominant species. Among the recorded species, 13 (14.94%) were found to be used by the Langur monkey as food plant. The leaves, fruits, flowers and buds of the plants were used as food. Feeding, grooming, resting, playing, fighting (agonistic) and monitoring were the major behaviour observed in Langur monkeys from Devghat. Resting (inactive) was the major activity of the Langur monkey in summer and rainy seasons followed by feeding, locomotion playing and grooming.

Deforestation, human encroachment, pressure of pilgrimage and competition with domestic livestock (cattle, goats) were major threats to Langur of Devghat. The conservation awareness raising programs and further researches on ecology and behaviour of the Hanuman Langur can be recommended from this study.