Question

Consider the following statement: Assertion (A): In winter Siberian birds migrate to India in search of feeding and breeding grounds. Reason (R): The day length is very less in India at that time (than in Siberia).

• A. Both (A) and (R) are correct, (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct, (R) is not the correct explanation of (A)
• C. (A) is correct, but (R) is not correct
• D. (A) is not correct, but (R) is correct

Hint:

Bird migration occurs mainly due to seasonal changes in climate, food availability and breeding requirements rather than merely differences in day length.

Answer 1

The Correct Option is C

Concept: Migration is a seasonal movement of animals from one geographical region to another in response to environmental changes such as temperature, food availability, breeding requirements and photoperiod. Birds are among the best known migratory animals. Many birds migrate from colder regions to warmer regions during winter to escape harsh climatic conditions and to obtain sufficient food resources.

Step 1: Analyze the Assertion. Siberian birds migrate to India during winter because India provides comparatively warmer climatic conditions, abundant food resources and suitable habitats. Many migratory birds such as Siberian cranes visit India seasonally. Therefore the Assertion is correct.

Step 2: Analyze the Reason. The reason states that day length is very less in India than in Siberia during winter. This statement is incorrect. During winter, Siberia experiences extremely short days and severe climatic conditions, whereas India generally has comparatively longer day length and milder environmental conditions. Therefore the Reason is false.

Step 3: Final conclusion. The Assertion is true, but the Reason is false. \[ \boxed{\text{Assertion is correct, but Reason is not correct}} \] Hence option (C) is correct.