Context: A study led by Centre for Cellular and Molecular Biology (CCMB), Hyderabad scientists states that there is no separate species of eastern hoolock gibbon in northeast India.

• Fourteen years after reports noting that India has two separate species of the gibbon, a genetic analysis has now proved that there is only one species of ape in India.
• The hoolock gibbon (Hoolock hoolock) is the only gibbon (apes in the family Hylobatidae) found in India.
• Earlier, north-eastern India was said to be home to two species: eastern (Hoolock leuconedys) and western hoolock (Hoolock hoolock) gibbons.

About Gibbon

• Known for their vigorous vocal displays, gibbons are unique small apes, with 20 species, all of them endemic to south and southeast Asia.
• Gibbons play an important role in seed dispersal, which contributes to maintaining the health of the forests they call home, and benefit the communities that also use forest resources.
• Gibbons are pair-living, usually with a monogamous mating system, and the adult male and female of a group sing prolonged duets.
• Hoolock gibbon adults exhibit distinct sexual dimorphism in pelage colouration, the males are black overall and the female becomes varying shades of brown and fawn at maturity.
• Both H. hoolock and H. leuconedys infants are born with a pale brown natal coat similar in colouration to that of adult females.
• Infants of both sexes turn black.

Hoolock Gibbon

• The hoolock gibbons are three primate species of genus Hoolock in the gibbon family, Hylobatidae.
• They are native to eastern Bangladesh, Northeast India, Myanmar and Southwest China.
• Hoolocks are the second-largest of the gibbons, after the siamang.
• The sexes are about the same size, but they differ considerably in coloration: males are black-colored with remarkable white brows, while females have a grey-brown fur, which is darker at the chest and neck.
• White rings around their eyes and mouths give their faces a mask-like appearance.

Distribution

• Northeast India­– south of Brahmaputra as well on the North Bank areas and east of the Dibang Rivers.
• Its range extends into seven states: Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura.

Breeding and life cycle

• Young hoolocks are born after a seven-month gestation, with milky white or buff-colored hair.
• Their life expectancy in the wild is about 25 years.