Population, Behavioural Ecology and Conservation of Hoolock Gibbon in Northeast India
Pp. 242-266 (25)
Awadhesh Kumar, Ashalata Devi, Atul Kumar Gupta and Kuladip Sarma
The Hoolock Gibbon is the only ape found in India and its distribution in
Southeast Asia, spans India, Myanmar, Bangladesh and southern China, between 20° N
and 28° N, and 99° E to 98° E. Gibbons typically consist of an adult pair with 0-4
immature offspring with average group size ranging from 2.7 to 4. They are exclusively
arboreal and spend 15–25% of their time moving for foraging, feeding, sun basking and
resting. They occupy a home range of about 14 to 55 hectares covering a day range of
about 600-1200 m (300-1600 m). They are frugivorous in nature and their diet consist
of 51-65% fruits followed by 5-23% leaves, 13% buds, 12% flowers, 0.1% animal prey.
They are highly social animal and their reproductive strategies are less documented.
The duration of the menstrual cycle is 27.83 days ranging from 20 to 33 days for six
cycles and of which the gestation period is about 210 days (but may vary from 195– 210
days). Usually a single birth occurs during winter (November-February). The
population of gibbons in the wild has declined by more than 90% over the past three
decades due to various anthropogenic threats, possibly because of burgeoning human
population. Although some socio-cultural values are associated with these attractive and
agile forest gymnasts, hoolock gibbons are seriously threatened due to anthropogenic
activities like agricultural cultivation, tea plantation, hunting and poaching etc.
Therefore there is an urgent need to launch ‘Project Primate’ akin to ‘Project Tiger’ and
‘Project Elephant’ for future survival of the species.
Western hoolock gibbon, Eastern hoolock gibbon, population status,
distribution, habitat, behavioural ecology, feeding behaviour, food plant, dietary diversity, activity pattern, home range, reproductive behaviour, social
behaviours, sun basking, vocalization, grooming, anthropogenic threat,
conservation, protected area, importance of gibbon.
Department of Forestry, North Eastern Regional Institute of Science & Technology (Deemed University), Nirjuli-791109 (Itanagar), Arunachal Pradesh, India.