Home › PYQs › Environment › All questions › 2026 · India’s only ape
UPSC Prelims 2026 · Environment · Species Watch
With respect to the Western Hoolock Gibbons, which of the following statements is/are correct?
- A Sanctuary in North-east India is home to this ape species listed as Endangered in the IUCN Red List.
- They have specialized brachiation and can easily swing between trees.
- They possess a strong and heavy build like gorillas, yet are remarkably agile tree climbers.
- (a) 1 only
- (b) 1 and 2
- (c) 2 and 3
- (d) 3 only
Show the answer and explanation
Answer: (b) 1 and 2
Endangered + sanctuary in Assam ✓, brachiation ✓. Statement 3 is wrong: they are light, not gorilla-heavy.
Statement by statement
1. ✓ CORRECT — Hollongapar, Assam Hollongapar Gibbon Sanctuary (Jorhat, Assam) is India’s only sanctuary named after a gibbon. IUCN status: Endangered. The eastern hoolock is listed as Vulnerable.
2. ✓ CORRECT — arm-swinging Brachiation means moving by swinging arm over arm under the branches. Gibbons are the best brachiators of all apes and cover several metres in one swing.
3. ✗ WRONG — light and slender Gibbons are the “lesser apes”: about 6–9 kg, with long arms and a light body. A male gorilla can weigh 150 kg or more.
The idea
Apes differ from monkeys in three visible ways: no tail, arms longer than legs, and a more upright body. Gibbons are the small apes. Their very long arms and light body are made for swinging under branches.
Light body → Very long arms → Hook-like hands → Swings hand over hand below the branches → Needs an unbroken forest canopy
Why the others are wrong
(a) Misses brachiation, which is the gibbon’s signature movement.
(c) Statement 3 is wrong, since gibbons are the light “lesser apes”.
(d) Picks the only wrong statement.
The trap
Statement 3 flatters the animal: “strong like a gorilla, yet agile”. Swinging on thin branches needs a LIGHT body. Heavy apes like gorillas spend most of their time on the ground.
Also know
Hoolocks sing loud morning duets to mark territory, and pairs are largely monogamous. The species is in Schedule I of the Wildlife (Protection) Act.
🔒 Hoolock gibbon = India's only ape · Endangered · Hollongapar (Assam) · light body + brachiation.