About the Hoolock Gibbon
The Hoolock gibbon is India's only ape and the largest of India's primates, found only in the forests of northeast India east of the Brahmaputra River. India holds roughly 12,000 western Hoolock gibbons, making it the most important country for this endangered species. Unlike monkeys, gibbons do not have tails and move through the forest by brachiation — swinging hand-over-hand from branch to branch with astonishing speed and grace, covering up to 15 metres in a single swing.
Hoolock gibbons are famously monogamous, living in small family groups of a mated pair and their offspring, and their spectacular dawn duets — a coordinated series of whoops, whistles, and hoots that echo across the forest for kilometres — are among the most extraordinary sounds in the Indian jungle. Males are black while females are golden-buff, making the pair immediately distinguishable. Hollongapar Gibbon Sanctuary in Assam is the easiest and most reliable place to observe gibbons in India, where seven primate species share just 20 square kilometres of forest.
- Arrive at Hollongapar by 5:30 am to hear the dawn duets begin — the pair starts calling before first light and the sound carries across the entire sanctuary.
- Gibbons move rapidly through the canopy and do not stay in one place for long. Having a skilled local tracker who knows individual group territories dramatically improves sighting quality.
- Namdapha, Pakke, Nameri, and Dehing Patkai also have healthy gibbon populations in wilder settings.