Relevance: GS-3 (Environment & Biodiversity Conservation) | Source: The Indian Express

1. The Core News Context

Recently, in Assam’s Hollongapar Gibbon Sanctuary, a Western Hoolock Gibbon was recorded using an artificial rope bridge to cross a railway line.

This is a global first and a major conservation success. However, ecologists warn that these artificial bridges are just a temporary fix and cannot replace natural, uncut forests.

2. Knowing the Hoolock Gibbon (The Basics)

• India’s Only Ape: It is the only ape species found in India. (Apes are different from monkeys because they lack tails and have higher intelligence).
• Tree-Dwelling: They are strictly arboreal (live in trees). They move by swinging from branch to branch using their hands—a technique called Brachiation.
• Protection Status:
  • IUCN Red List: Endangered. (The Eastern Hoolock Gibbon is Vulnerable).
  • Wildlife Protection Act (WPA), 1972: Schedule I (Highest level of legal protection).
• The Habitat: The Hollongapar Sanctuary is a very small, isolated forest surrounded by tea gardens, making the gibbons highly vulnerable.

3. The Core Issue: Linear Infrastructure

When the government builds “linear infrastructure” (like railways, highways, and powerlines) through protected forests, it causes Habitat Fragmentation.

The Impact:

• Isolation: Animal families are broken into smaller, disconnected groups.
• Genetic Weakness: Animals cannot cross over to find new mates, leading to inbreeding and a higher risk of extinction.
• Accidents: Animals are frequently killed by speeding trains or vehicles when trying to cross.

4. Are Canopy Bridges a Perfect Solution?

While artificial bridges (designed by the Wildlife Institute of India) help animals cross safely, they come with hidden administrative and ecological risks:

• The “Greenwashing” Risk: Conservationists worry this will give authorities an excuse to clear-cut more forests, falsely claiming that “rope bridges will save the wildlife.”
• Predator Traps: Bridges are narrow choke points. Predators can easily wait at these spots to hunt crossing animals.
• Animal Bullying: Dominant monkeys often take control of these bridges. They block weaker animals, forcing them to take dangerous routes on the ground.
• Disease Spread: Connecting two isolated animal groups through a single bridge can suddenly spread new diseases among them.

5. UPSC Value Box

• Principle of Avoidance: A core administrative strategy. It mandates that linear projects should be routed around Eco-Sensitive Zones (ESZs) and Protected Areas, rather than cutting through them.
• Eco-Bridges in India: Similar bridges have been built in Tamil Nadu for the endangered Lion-tailed macaques and in Uttarakhand for reptiles.
• Habitat Restoration: The permanent solution is not tying nylon ropes, but actively planting trees to naturally reconnect fragmented forest patches.

With reference to the Western Hoolock Gibbon and wildlife conservation in India, consider the following statements:

1. The Western Hoolock Gibbon is India’s only ape species and primarily moves through the forest canopy using a technique called brachiation.
2. The Western Hoolock Gibbon is currently classified as ‘Least Concern’ on the IUCN Red List due to successful captive breeding programs.
3. Linear infrastructure passing through Protected Areas often leads to habitat fragmentation, which can cause genetic isolation and inbreeding among wildlife populations.

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 1 and 3 only

(c) 3 only

(d) 1, 2 and 3

Correct Answer: (b) 1 and 3 only

Explanation:

• Statement 1 is correct: It is India’s only ape species, strictly tree-dwelling, and uniquely adapted for brachiation (hand-over-hand swinging).
• Statement 2 is incorrect: The Western Hoolock Gibbon is highly threatened by habitat loss and is classified as Endangered on the IUCN Red List, not ‘Least Concern’.
• Statement 3 is correct: Linear infrastructure (like railways) splits forests, isolating animal populations. This prevents genetic exchange, leading to inbreeding and threatening their long-term survival.