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?

(a) 1 and 2

(b) 2 only

(c) 3 only

(d)1 and 3

10. Ans: d

Explanation:

Reason for rolling up by organisms:

• For some animals, the first and only way to defend themselves is to hide. Rolling into a ball-like shape presents the harder and sometimes more dangerous part of their body to their predator to protect their vulnerable part.
• Hedgehogs while coming back down on surfaces curl inward and drop down, the fall is cushioned by their exterior.
• Certain animals are unable to migrate as the season change. This puts them at risk of harsh elements during the colder and drier months. To preserve themselves, they curl into a ball shape to wait the weather out.

The armadillo, pangolin, hedgehog, chiton,  Armadillo Girdled Lizard, Golden Wheel Spider, and Isopods are common animals that roll into a ball. However, that list extends longer to include some unlikely creatures like spiders and aquatic animals.

Hedgehogs

• In hedgehog, the ear pinna is large, zygomatic arc is present and robust, occiput is flat or concave. The bullae are incomplete, tympanic bones form an annulus, the first and second molars are quadrate and low cusped. The testes are ventral but non-scrotal. The dorsum of the hedgehog is covered with stout spines, the venture is furred, and the tail is very reduced. 
• Indian long-eared hedgehog is an endemic species in the region distributed in the arid zones of northwest India (east to Agra, north to Jammu, south as far as Pune) and Pakistan (west to Indus).
• Indian Hedgehog and Madras Hedgehog are species endemic to South Asian and distributed in the arid zone of Pakistan and northwest India from the Indus river to the east in Agra, and south to Kathiwar peninsula and even recorded from the south Indian states of Tamil Nadu and Kerala.

Marmots

• Marmots  are relatively large ground squirrels.Two species of marmots (comprising 15 species worldwide) occur in South Asia, in the alpine and cold desert regions of higher Himalaya and Trans-Himalaya in India, Nepal and Pakistan. 
• They are burrowing squirrels that live in holes in the ground. They are stout with a squat build, a short to moderate-sized bushy tail, and small ears. Unlike of the solitary territorial tree squirrels, they live in large colonies and are social animals. They live in burrows that have several entrances, excavated in well drained soil. 
• They  have a long hibernation period, sleeping upto nine months in a year, though may emerge briefly during spells of mild weather. They typically emerge in spring.
• Their food includes roots, leaves, grasses, herbs, forbs and sedges. Their anti-predatory behavious is well-documented, they utter a whistling scream to warn other individuals of the colony, and run into their shelter.

Pangolins

• The pangolins are scaly anteaters survive as a single family and are distributed in the Old World Tropic.
• Pangolins aree myrmecophagus, specialised for feeding on ants and termites. The long claws and powerful limb muscles allow them to dig into termite mounds and also to construct burrows. The teeth are absent and tongue is extremely long .
• When attacked pangolins roll into a ball and make their scales erect. Yet another method of defence employed is the erection of well-directed jets of an ill-smelling liquid from the naal region.
• Most species are terrestrial and nocturnal, while retaining the ability to climb trees. It may use tree cavities as well as burrows to nest. Normally quadrupedal, pangolins when running assume a bipedal gait with the tail acting as a counterbalance. 
• They are considered as habitat engineers as they dig soil to live and feed helping soil aeration and mineral fixation. The abandoned burrows act as shelter for many fossorial animals. 

Hence, option d is correct.

Read: Previous Year UPSC Environment Questions (PYQs) With Explanation 2021