Context: The conservation status of India’s only ape (hoolock gibbon) was a cause for concern at a global event on gibbons held a week ago in China.
More about the news:
- Gibbons, the smallest and fastest of all apes, live in tropical and subtropical forests in the south eastern part of Asia.
- The hoolock gibbon, unique to India’s northeast, is one of 20 species of gibbons on Earth.
- 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.
The Western Hoolock Gibbon
Description
- It is an ape found in the tropical forest canopy in India, Bangladesh and Myanmar.
- Tailless like other apes, they are nonetheless set apart by their long arms and dense hair.
- The loud and musical calls of Western Hoolock Gibbons can be heard from far away in the forest. Males and females often sing in unison, a series of duet calls that helps the pair to mark their territory.
- Behaviour
- These gibbons are arboreal and only come to the ground in exceptional circumstances.
- They are omnivorous, consuming over 100 species of plants and some invertebrates and birds’ eggs, with a diet that can greatly vary based on location.
- Western Hoolock Gibbons form small, monogamous family groups and usually give birth to a single offspring. Babies typically spend their first months of life tightly clung around the mother’s waist, followed by gradual weaning over two years. The young gibbon will then stay with his parents until sexual maturity.
- Threats and Conservation
- They are one of Asia’s most endangered primates(ER), with populations expected by the IUCN to at least halve over three generations (2001-2015, 2016-2030 and 2031-2045).
- Threats such as hunting for food and medicine and habitat loss have put this species at risk, and habitat protection is critical for their survival.
The Eastern Hoolock Gibbon
- It is one of two species of Hoolock Gibbon.
- This species is found particularly east of the Chindwin River in Myanmar and in southwest Yunnan (China).
- Indian records of the species likely to actually represent the Western Hoolock.
Difference between Eastern and Western Hoolock
- Both Hoolock Gibbon species are separated by the Chindwin River in western Myanmar, which flows into the Irrawaddy
- The two species differ in their fur coloration and DNA sequences, and may have diverged about 1.42 million years ago.
- The Red List maintained by the International Union for Conservation of Nature categorises the eastern hoolock gibbon as vulnerable.
