UPSC Prelims 2021 Q23: Hedgehog, Marmot, Pangolin — Explained
Consider the following animals:
1. Hedgehog
2. Marmot
3. Pangolin
To reduce the chance of being captured by predators, which of the above organisms rolls up/roll up and protects/protect its/their vulnerable parts?
- 1 and 2
- 2 only
- 3 only
- 1 and 3
Answer: (d) 1 and 3
Statement-wise explanation
- 1: correct — When a hedgehog is threatened, it rolls into a tight ball. A band of muscle along its sides pulls the spiny skin over the body like a bag, which makes the spines stand up and covers the head, legs and soft belly. Hedgehogs also crouch, hiss and raise their spines, but rolling up is their main defence. It works against most mammal predators, though owls and other birds of prey can still get through.
- 2: incorrect — A marmot is a large burrowing ground squirrel. It has no spines or scales and does not roll up. When it is alarmed, it gives a sharp whistle and runs into its burrow, which often lies under boulders or in crevices and has more than one entrance. Its defence is an alarm call followed by escape into cover, not armour.
- 3: correct — A pangolin is covered in overlapping scales made of keratin, the protein found in hair and nails. When threatened, it curls into a ball with its scales facing outward, which shields its face and its belly, which has no scales. The name comes from a Malay word meaning 'rolling over'. The same reflex makes pangolins easy for poachers to pick up.
How to eliminate
This question needs basic knowledge of animal defences, but each fact is common knowledge. The pangolin is a well-known 'armoured ball', and its curling habit comes up in most stories about pangolin trafficking. That rules out the options that leave statement 3 out. The hedgehog rolling into a spiny ball is just as familiar. If you know the marmot is a burrowing squirrel with soft fur and no armour, it drops out at once. A quick test: an animal can only gain from rolling up if its outer surface has protection, such as spines, scales or bony plates. Soft-furred rodents run away and hide instead. Fact to remember: hedgehog and pangolin roll up; marmot whistles and runs for its burrow.
Know more
Anti-predator defences: armour and rolling up
Prey animals use one of two broad strategies. They escape: they flee, hide in burrows or give alarm calls. Or they resist: they use armour, spines or chemicals. Rolling up (sometimes called volvation) only helps an animal that has a protected outer surface. Curling up hides the soft belly, face and limbs and leaves only spines or scales facing the attacker.
| Animal | Body covering | Main defence |
|---|---|---|
| Hedgehog | Spines (modified hairs) | Rolls into a ball, spines erect |
| Pangolin | Overlapping keratin scales | Curls into a ball; can also give off a foul-smelling fluid from glands |
| Three-banded armadillo | Bony plates | Can close fully into a ball |
| Porcupine | Long quills | Raises and rattles its quills; does not roll up |
| Marmot | Fur only | Whistles an alarm and escapes into its burrow |
Pangolins in conservation
- Eight species exist: four in Asia and four in Africa. India has two, the Indian pangolin (Manis crassicaudata) and the Chinese pangolin (Manis pentadactyla).
- IUCN Red List: the Indian pangolin is Endangered and the Chinese pangolin is Critically Endangered.
- All eight species have been on CITES Appendix I since 2017. That bans international commercial trade in them.
- Pangolins are among the most trafficked mammals in the world. Their scales and meat are the main targets. Armour that works against a leopard does nothing against a poacher.
- They eat ants and termites and dig burrows, so they help control insects and turn over soil.
UPSC often frames questions around such animals as a behaviour fact paired with a status fact, for example 'rolls up' plus 'IUCN category'. Learn both together.