The Western Hoolock Gibbon is an endangered, tailless ape native to Northeast India. Known for loud, melodic duet calls, they live in tropical rainforest canopies. Males are completely black, while females change color to a distinct honey-buff coat.
Assam's Hollongapar Gibbon Sanctuary recorded the world's first instance of a Western hoolock gibbon using an artificial canopy bridge to safely cross a railway line.
The Hoolock Gibbon is India’s only ape species.
Taxonomists classify the genus into three distinct species:
Habitat and Geographical Distribution
The species inhabits the tropical and semi-evergreen forests of Northeast India, spanning Assam, Arunachal Pradesh, Meghalaya, Manipur, Mizoram, Nagaland, and Tripura.
They restrict their Indian geographic range specifically to areas south of the Brahmaputra River and east of the Dibang River.
Beyond India, they occupy forest habitats in Bangladesh, Myanmar, and Southwest China.
The Hollongapar Gibbon Sanctuary in Assam’s Jorhat district serves as a prominent and dedicated stronghold for the species.
Physical Characteristics and Ecological Behavior
Strictly arboreal (tree-dwelling) primates spend their entire lives in the forest canopy and show extreme reluctance to descend to the ground.
Navigate the treetops using brachiation, a specialized suspensory movement where they swing hand-over-hand from branch to branch.
Clear sexual dimorphism in coloration: males possess black fur with prominent white brows, whereas females display grey-brown fur.
Lead a diurnal lifestyle and form monogamous family groups (usually 4-6 members), maintaining genetic diversity by choosing mates strictly outside their own family lines.
Diet: Fruits, insects, and leaves.
Conservation Status
IUCN Red List: The Western Hoolock Gibbon ranks as Endangered, while the Eastern Hoolock Gibbon ranks as Vulnerable.
Wildlife Protection Act, 1972: The Indian government grants them the highest level of legal protection by listing them under Schedule I.
Source: INDIANEXPRESS
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PRACTICE QUESTION Q. The Hollongapar Gibbon Sanctuary, recently in the news for the successful installation of an artificial canopy bridge to mitigate railway track fragmentation, is located in which state? (a) Arunachal Pradesh (b) Assam (c) Meghalaya (d) Mizoram Answer: (b) Explanation: The Hollongapar Gibbon Sanctuary is located in the Jorhat district of Assam. It made global headlines when a male Western Hoolock Gibbon was documented using a newly installed artificial canopy bridge to safely cross the Lumding-Dibrugarh railway line that fragments its forest habitat. |
The Hoolock Gibbon is India's only ape species. It is strictly arboreal and navigates tree canopies using a swinging motion called brachiation.
They inhabit the tropical and semi-evergreen forests of Northeast India, specifically south of the Brahmaputra River and east of the Dibang River.
It is listed as Endangered on the IUCN Red List and holds the highest legal protection under Schedule I of the Wildlife Protection Act, 1972.
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