The correct option is (c).
Explanation
Bird migration refers to the regular, seasonal movement of bird populations from one geographic region to another. This behavior is an adaptation to survive harsh environmental conditions and ensure reproductive success.
Statement-wise Analysis
- Statement 1 is Correct: Migratory birds fly to far-away areas primarily due to climatic changes. Seasonal variations in weather act as natural cues (such as changes in day length and temperature) that trigger the instinct to migrate.
- Statement 2 is Incorrect: Birds do not migrate to hibernate underground. Hibernation is a state of dormancy used by certain mammals, reptiles, and amphibians to conserve energy during winter. Migratory birds, conversely, expend significant energy to travel to warmer regions specifically to avoid the conditions that would necessitate hibernation.
- Statement 3 is Correct: Migration is driven by the need to escape natural habitats that become very cold, inhospitable, or lack sufficient food resources during winter. Birds move to warmer areas to find food and suitable grounds for laying eggs.
Key Takeaway
Migration is a behavioral adaptation in birds to escape extreme climatic conditions and food scarcity, whereas hibernation is a physiological state of dormancy typically found in other animal groups like mammals and reptiles.