Hoolock gibbon. Photo: Special Arrangement
GUWAHATI The conservation status of India’s only ape was a cause for concern at a global event on gibbons held a week ago in China.
Gibbons, the smallest and fastest of all apes, live in tropical and subtropical forests in the southeastern part of Asia. The hoolock gibbon, unique to India’s northeast, is one of 20 species of gibbons on Earth.
The estimated population of hoolock gibbons is 12,000.
“Like all apes, they are extremely intelligent, with distinct personalities and strong family bonds. Unfortunately, the current conservation status of gibbon species is alarming – all 20 species are at a high risk of extinction. Since 1900, gibbon distribution and populations have declined dramatically, with only small populations in tropical rainforests,” the Global Gibbon Network (GGN), which had its first meeting at Haikou in China’s Hainan province from July 7-9, said.
Dilip Chetry, a senior primatologist who heads the primate research and conservation division at Aaranyak, an Assam-based non-profit conservation organisation, gave an account of the conservation status of the hoolock gibbon in India.
The hoolock gibbon faces threat primarily from the felling of trees for infrastructure projects.
“GGN was founded with a vision to safeguard and conserve a key element of Asia’s unique natural heritage — the singing gibbon and their habitats, by promoting participatory conservation policies, legislations, and actions,” Dr. Chetry said.
Aaranyak, he said, was one of the 15 founding organisations of the GGN from seven countries.
One species, not two
American naturalist R. Harlan was the first to describe the hoolock gibbon, characterised by their vigorous vocal displays, from Assam in 1834.
Over the decades, zoologists thought the northeast housed two species of the ape — the eastern hoolock gibbon (Hoolock leuconedys) found in a specific region of Arunachal Pradesh and the western hoolock gibbon (Hoolock hoolock) distributed elsewhere in the northeast.
A study led by Hyderabad-based Centre for Cellular and Molecular Biology (CCMB) in 2021 proved through genetic analysis that there is only one species of ape in India. It debunked earlier research that the eastern hoolock gibbon was a separate species based on the colour of its coat.
The CCMB study concluded that two populations of the western hoolock gibbon and the assumed eastern hoolock gibbon split 1.48 million years ago. It also estimated that the gibbon divergence from a common ancestor occurred 8.38 million years ago.
However, the Red List maintained by the International Union for Conservation of Nature categorises the western hoolock gibbon as endangered and the eastern hoolock gibbon as vulnerable.