Official Question UPSC 2026
With respect to the Western Hoolock Gibbons, which of the following statements is/are correct? 1. A Sanctuary in North-east India is home to this ape species listed as Endangered in the International Union for Conservation of Nature (IUCN) Red List. 2. They have specialized brachiation and can easily swing between trees. 3. They possess a strong and heavy build like gorillas, yet are remarkably agile tree climbers. Select the answer using the code given below:
Solution & Analysis
Answer: B
Let us analyze the biology and conservation status of India's only ape species:
•Statement 1 is Correct: Native to the dense forests of North-east India, they are protected in reserves like the Hollongapar Gibbon Sanctuary in Assam. Due to severe habitat fragmentation, the Western Hoolock Gibbon is officially classified as Endangered on the IUCN Red List.
•Statement 2 is Correct: They are highly specialized canopy-dwellers. Their primary mode of locomotion is brachiation—using their disproportionately long arms to swing suspended beneath tree branches, allowing them to traverse the forest at high speeds.
•Statement 3 is Incorrect: Taxonomically, gibbons are classified as "lesser apes" (family Hylobatidae), fundamentally distinct from "great apes" like gorillas. They do not possess a strong, heavy build. To facilitate brachiation on fragile upper-canopy branches, they are extremely slender and lightweight, typically weighing only between 6 to 9 kilograms.
Conclusion: Statements 1 and 2 provide accurate ecological and biological data.