The study - stated to be the first of its kind for the gibbon in Mehao wildlife sanctuary - recorded around 150 groups of Eastern hoolocks in the sanctuary. This study also identified Mehao sanctuary as a potential conservation site for the species.
"Although more detailed studies are needed, it is evident that forest loss and fragmentation due to expansion of tea gardens, ginger and mustard cultivation, horticulture (orange), jhum cultivation pose a major threat to the gibbon in this area," Dr Chetry said, adding that a detailed study was needed to evaluate the population status of the species between Dibang and Lohit rivers in particular and in India in general.
Dr Chetry also underscored the need for a community-based programme taking the hoolock gibbon as flagship species in the area for conservation of the region's biodiversity.
This study was carried out with support from Critical Ecosystem Partnership Fund (CEPF), Ashoka Trust for Research in Ecology and the Environment (ATREE), and Department of Environment and Forest, Government of Arunachal Pradesh.
The team members were Abhijit Das, Kumud Ghosh, Pradip Barman, Lalit Saikia and Pradip Baruah (all researchers) besides Dr Rekha Chetry (lecturer).
The North-east has India's highest primate diversity, with 11 of the country's 25 primate species inhabiting the tropical and sub-tropical forests of the region. The seven north-eastern States are further unique in that both the Western and Eastern hoolocks are found here.