Distribution of Western Hoolock Gibbons and Nutritional Status of Food Plants in Cachar District of Assam, India: Reaching Out to Local Communities for Conservation

Abstract

Western hoolock gibbon (Hoolock hoolock) is listed as an endangered mammal in IUCN Red List. It is also listed in CITES Appendix I and in the Schedule I of the Indian Wildlife (Protection) Act, 1972. In the present work the status and distribution of Western hoolock gibbons in Cachar district of Assam, India was explored by conducting field studies from September 2012 to August 2013 using line transect and call count methods. Group composition, group size and adult sex ratio of nine gibbon groups and one solitary male were recorded. Groups comprised 36 % adult males, 32 % adult females, 10 % sub‑adult males, 11 % juveniles and 11 % infants and the encounter rate was 0.17. Group size ranged from 2 to 5 and mean group size was 2.8 ± 1.1. Nutritional status of food plants consumed by Western hoolock gibbons were analyzed and chemical composition was determined. Proximate analysis revealed that the mean value of crude protein (9.73 ± 0.4), crude fibre (16.1 ± 0.6), ether extract (1.07 ± 0.06), NFE (66.24 ± 0.43) and ash (7.03 ± 0.27) in plant samples. A moderate positive correlation was noted between higher protein content and higher crude fibre content in food plants (r = 0.48), which is likely to influence food selection and feeding pattern. Timber felling, fuel‑wood collection, agriculture and expansion of tea estates were identified as major threats to conservation of Western hoolock gibbons. The present study recommends taking up awareness programmes and formulation of policy interventions involving the local communities to arrive at a participatory biodiversity conservation plan at local levels particularly involving the village councils (gram panchayats).