Hoolock Gibbon -UPSC NOTES(Prelims & Mains)

Hoolock Gibbons are a type of ape that is smaller than a gorilla. After Siamang, they are the second largest gibbons. It was previously stated that India (North East India) is home to two species of hoolock gibbons: the Eastern and Western Hoolock Gibbons.


  • The only apes in India are the Western Hoolock gibbons (Hoolock Hoolock). Mishmi Hills gibbons (Hoolock leuconedys), the other species, are not found here.
  • There was previously some uncertainty because the populations of these little apes found in the northeast have varied morphological characteristics.
  • Mitogenome (genetic information contained in mitochondria) research by the CCMB team confirmed the findings, estimating that the split between two species occurred 1.49 million years ago.
  • The new findings will aid in the development of conservation programs by allowing the two groups to interbreed and maintain their genetic variety.
  • According to a recent study conducted by the Centre for Cellular and Molecular Biology, India is home to only the western Hoolock Gibbon.
  • In zoos, the Western and Eastern Hoolock Gibbons were separated and not allowed to breed. They can now be housed together in the same cage and bred.

The study’s main findings

The Hoolock gibbons separated from their common ancestor 8.38 million years ago. 1.49 million years ago, the western and eastern Hoolock Gibbons split.

Illusions from the Past

  • The Hoolock Gibbons were first described in 1834 by R Harlan, an American naturalist. Until 2005, the eastern and western Hoolock Gibbons were thought to be separate species. Eastern Hoolock Gibbons were first documented in a distribution in 2006.
  • Western Hoolock Gibbons can be found in northeast India, along the Brahmaputra River’s east and south banks, as well as in Myanmar and Bangladesh. Between the Lohit and Dibang rivers in Arunachal Pradesh, Eastern Hoolock Gibbons can be found.
  • Gibbons, according to the International Union for Conservation of Nature (IUCN).
  • The occurrence of Eastern Hoolock Gibbons in India is unknown, according to IUCN (International Union for Conservation of Nature).

Additional Info

India’s lone ape is the little Hoolock Gibbon.

  • Eastern Bangladesh, Northeast India, and Southwest China are among the primate’s native habitats.
  • There are two different types of Hoolock Gibbons:
  • The western hoolock gibbon is found in all of the northeastern states, but only between the Brahmaputra and Dibang rivers. Outside of India, it can be found in Bangladesh’s east and Myanmar’s north-west.
  • The International Union for Conservation of Nature (IUCN) Red List has it classified as Endangered.
  • The eastern hoolock gibbon can be found in Arunachal Pradesh and Assam in India, as well as in southern China and north-eastern Myanmar.
  • According to the IUCN Redlist, it is classified as Vulnerable.
  • Both species are protected by India’s Indian (Wildlife) Protection Act 1972, which lists them on Schedule 1.
  • The different species of Hoolock Gibbons have been classified by the IUCN into the following groups:
  • Endangered Species: Western Hoolock Gibbon
  • Vulnerable: Eastern Hoolock Gibbon
  • Gibbons of Skywalker: Endangered
  • Gibbons of Hoolock
  • Hoolock Gibbons come in three varieties. Western Hoolock Gibbon, Skywalker Hoolock Gibbon, and Eastern Hoolock Gibbon are the three species of Hoolock Gibbon.
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