Hoolock gibbon (Bunopithecus hooklock), the only ape found in India is confined in its distribution in Northeast India; one of the two biodiversity hotspots in India.  Lowland tropical rain forests in northeast India, the habitat of hoolock gibbon, are the most species-rich of the terrestrial ecosystems.  But, following large scale habitat fragmentation over the past few years, mainly due to agricultural expansion, illegal encroachment, shifting cultivation, establishment of tea and coffee estates, illegal logging, and diversion of forest land for developmental projects, the lowland tropical forests are present in form fragments of varying size, shape and succession stages.  Estimates suggest that throughout its range, a 67% reduction in hoolock gibbon habitat has occurred within ten years between 1987 and 1997.  Although, it is categorized as endangered by IUCN and listed in Schedule I of the Indian Wildlife (Protection) Act, 1972, yet, it is one of the least studied primate species among Indian primates for its biology, ecology and conservation.  In this WII-USFWS collaborative project it was mandated to documenting the population status of gibbons across its distribution range in Tripura, Meghalaya, Mizoram and Gibbon Wildlife Sanctuary in Assam, with special emphasis on making an assessment of the fragmented habitats. It was also attempted to document potential habitats based on the features that fit well as ideal gibbon habitats.  The sampling methodology using the songs of the gibbons and actual sightings on the randomly selected line transects (all existing paths, forest roads etc. inside the forest and non-forest areas were used as transect for the purpose of conducting this survey) was adopted to undertake forest fragment surveys, gibbon populations survey, vegetation samplings and assessing biotic pressures. Information on gibbon presence and absence was also noted following personal communications with the local people, forest staff and other sources.

A total of 14 protected areas in all the three states were covered during this study besides many reserve forests, protected forests, private forests and community forests. A total of 72 groups were located in Mizoram, of which, 35 were found inside the protected areas and reserved forests and remaining 37 in private, village and community forest areas.  In Meghalaya, out of a total of 83 gibbon groups, only 29 were found inside the protected areas and reserved forests, while remaining 54 were either in the private forests or abandoned village forests. Only in case of Tripura, out of a total of 42 gibbon groups, more groups (25) were located inside the protected areas and reserved forests than outside the government controlled forests (17 groups).  Habitat fragmentation is considered a major conservation risk.  Main challenge facing managers and conservationists relates with the management of fragmented gibbon populations across its distribution range.  The study also revealed that there are still many gaps in the information base concerning this species that would be required to develop a holistic conservation plan involving entire distribution range and different stakeholders. It is recommended to develop location specific action plans for the conservation of this highly endangered schedule I species.
 

Conservation of Hoolock Gibbon(Bunopithecus hoolock) in northeast India.