托福口语 Task 3

In biology, the concept of 'behavioral thermoregulation' refers to the deliberate actions an animal takes to regulate its body temperature by moving to or creating environments that help it maintain an optimal internal temperature. This behavior is crucial for survival, as many species cannot generate heat internally and must rely on external sources. By adjusting their position, posture, or activity level, animals can warm up or cool down efficiently, thereby conserving energy and avoiding thermal stress. Behavioral thermoregulation is distinct from physiological mechanisms like sweating or shivering, as it involves the animal’s active choice and environmental interaction.

Professor: Let me give you a clear example from the desert. Consider the desert iguana, a lizard that lives in the scorching heat of the American Southwest. In the early morning, when the ground is cool, the iguana emerges from its burrow and lies flat on a sun-warmed rock. It spreads its body to maximize surface area, absorbing heat to raise its body temperature quickly. But as the sun climbs higher and the sand becomes scorching, the iguana faces danger of overheating. So it climbs onto a low shrub or a cactus, lifting its body off the hot ground to catch a breeze, and it may even stand on just two legs to reduce contact with the hot surface. Later, when the afternoon heat becomes unbearable, the iguana retreats into its burrow to escape the extreme temperature. Each of these movements—basking, perching, and hiding—is a conscious choice the animal makes to keep its body temperature within a safe range.