Explain hibernation and its adaptive significance for mammals.

• A. A short daily drop in metabolic rate.
• B. A prolonged period of torpor with reduced metabolism and temperature to conserve energy during cold or food-scarce periods.
• C. A seasonal molt.
• D. A continuous high metabolic rate.

Answer: (B)

Hibernation is a prolonged period of torpor in which a mammal greatly lowers its metabolism and body temperature to save energy during times when food is scarce, typically in winter. By entering this state, the animal slows heart and breathing, stays in a sheltered den, and relies on stored fat to power the body with minimal energy input. This energy-saving strategy is adaptive because it lets the mammal survive extended periods of cold and food scarcity without constant foraging, reducing energy needs when resources are limited. It differs from a short daily drop in metabolic rate, which is torpor that lasts only briefly; it’s not a seasonal molt, and it’s not a state of ongoing high metabolic rate.