Present distribution, population status, and conservation of Western Hoolock Gibbons Hoolock hoolock (Primates: Hylobatidae) in Namdapha National Park, India

Awadhesh Kumar,Pushkal Bagchie,P.P Mary

doi:10.11609/jott.o1955.203-10

Abstract

A survey on the present distribution, population status and conservation of Western Hoolock Gibbon (Hoolock hoolock) was conducted from September 2006 to April 2007 in Namdapha National Park, Arunachal Pradesh, northeastern India. The data were recorded from 12 localities in the Park: Gibbon land, Baghnallah, Deban, 15th Mile, 16th Mile, Hawaghar, 19th Mile, Haldibari, Hornbill camp, Baranallah, Firmbase camp, and Embyong. A total of 50 individuals in 20 groups were recorded during the census by using direct and indirect methods. Out of 20 groups, nine groups were observed through direct visual observation. The remaining 11 groups were estimated by using indirect observation methods such as songs, calls, and branch shaking. The composition of the population was 19 adult males (38%), 19 adult females (38%), and 12 immatures (24%). The group size was estimated as 2.5 individuals per group. Anthropogenic disturbances observed in the gibbon habitat were habitat loss, hunting and poaching, canopy gaps, livelihood issues for local people, and livestock grazing.

Highlights

India has 32 taxa of primates in the wild (Molur et al 2003)
Population distribution The population survey was mostly concentrated in the buffer zone areas of National Park (NNP) except for a few areas of the core zone
Nine populations of H. hoolock were found throughout the entire tropical evergreen forest of NNP and three populations were recorded from subtropical moist-deciduous and bamboo thick forest

Summary

Introduction

India has 32 taxa of primates in the wild (Molur et al 2003). Of these, the Western Hoolock Gibbon Hoolock hoolock and Eastern Hoolock Gibbon Hoolock leuconedys are two species of lesser apes found in India (Das et al 2006). The Hoolock Gibbon was formerly associated with genera Hylobates (Prouty et al 1983a, 1983b) and Bunopithecus (BrandonJones et al 2004; Groves 2005) Today it is classified in the genus Hoolock (Mootnick & Groves 2005) with two species: Western Hoolock Gibbon Hoolock hoolock from northeastern India south of the Brahmaputra River (Mukherjee 1982; Alfred & Sati 1986; Choudhury 1987), Bangladesh (Anderson 1878; Siddiqi 1986; Das et al 2003a) and western Myanmar (Tickell 1864), and Eastern Hoolock Gibbon H. leuconedys from Lohit District of Arunachal Pradesh, India (Das et al 2006), Myanmar and China (Groves 1971; Anderson 1978; Lan 1994). In India and Bangladesh, the Hoolock range is strongly associated with the occurrence of contiguous canopy, broad-leaved, tropical wet evergreen and semievergreen forests

Methods

Results

Conclusion