Gibbon

Gibbon

Context: The Northeast Frontier Railway (NFR) has earmarked funds to construct canopy bridges for hoolock gibbons to move across the Mariani-Dibrugarh railway track.

• The railway track set to be doubled and electrified is bifurcating the Hollangapar Gibbon Sanctuary.
• The fragmentation has disturbed the gibbon’s arboreal nature, putting it at risk when crossing the track.
• Designed by the Wildlife Institute of India (WII), the canopy rope bridges will be installed so that lianas and creepers can be guided m along them, making them look as natural as possible. Earlier, the NFR built an artificial canopy bridge, while the State Forest Department erected a natural one. The gibbons used the natural canopy but ignored the artificial bridge.

Hoolock Gibbon

• The Hoolock gibbons (or the white-browed gibbons) are one of 20 species of apes on Earth.
• They are the only ape species found in India.
• Hoolock gibbons are the second largest of the gibbons, after the Siamang.
• Gibbons are a family of apes and are called Lesser apes. They are the smallest and fastest of all apes.

Appearance:

• Both male and female gibbons are similar in size but differ significantly in coloration. Males are black with striking white brows, while females have grey-brown fur, darker at the chest and neck.
• White rings around the eyes and the mouth give their face a mask-like appearance.

Behaviour:

• They are diurnal and arboreal. With slender, long arms, they swing from tree to tree in a mode of locomotion known as Brachiation. They can brachiate at speeds up to 55km/hr and can cover 6m in just one swing. They spend much of their time on the upper canopy of tall trees, mostly the hollong.
• They live together in monogamous pairs, which stake out a territory.
• They are known for their vocalization, through which they locate family members and ward off other gibbons from their territory.
• Their diet consists mainly of fruits, insects and leaves.

Reproduction:

• Females give birth to one offspring every 2-3 years. Young hoolocks are born after a 7-month gestation with milky white fur. They become fully mature after 8 to 9 years.

Life expectancy:

• About 25 years in the wild.