Question 3 from UPSC CSE 2023 - Environme nt

Question

Consider the following fauna:
1. Lion-tailed Macaque
2. Malabar Civet
3. Sambar Deer
How many of the above are generally nocturnal or most active after sunset?

IASCODEX · Accepted Answer

Correct Option: B. Only two

Strategy: The strategy involves evaluating each species based on its known activity patterns to identify those that are strictly nocturnal or predominantly crepuscular/nocturnal. This approach allows for:
-   Excluding the lion-tailed macaque due to its diurnal activity.
-   Confirming the Malabar civet as nocturnal based on its typical predatory behavior.
-   Including the Sambar deer due to its crepuscular and nocturnal tendencies.

Key Info: ## Species Information

### Lion-tailed Macaque (Macaca silenus)
-   **Description**: An Old World monkey endemic to the Western Ghats of South India.
-   **Activity**: Strictly diurnal--active during daylight--and largely confined to dense canopy strata of tropical forests.

### Malabar Civet (Viverra civettina)
-   **Description**: A critically endangered small carnivore, once found in the Western Ghats.
-   **Activity**: Strongly nocturnal; elusive, with confirmed observations primarily at night.

### Sambar Deer (Rusa unicolor)
-   **Description**: The largest Indian deer, widespread in forested regions.
-   **Activity**: Primarily crepuscular (active at twilight) and nocturnal behavior, foraging and moving mostly from dusk till dawn.

Across mammals, nocturnality is often an adaptation for predator avoidance, thermoregulation, and niche partitioning. In South Asian rainforests and woodlands, several small carnivores like civets and large herbivores like sambar adapt their behavior to avoid humans and predators through nocturnal or crepuscular lifestyles.

IASCODEX · Answer

Option A: Only one

IASCODEX · Answer

Option C: All three

IASCODEX · Answer

Option D: None of the above statements is correct

Consider the following fauna: Lion-tailed Macaque Malabar Civet Sambar Deer How many of the above are generally nocturnal or most active after sunset?

Consider the following fauna:

Lion-tailed Macaque

Malabar Civet

Sambar Deer
How many of the above are generally nocturnal or most active after sunset?