托福口语 Task 3

In biology, the concept of “behavioral thermoregulation” refers to the deliberate actions taken by animals to regulate their body temperature by exploiting their environment. Unlike physiological mechanisms (such as sweating or shivering), behavioral thermoregulation involves choices like moving to sun or shade, changing posture, or altering activity times. This strategy is crucial for ectotherms—animals that rely on external heat sources—because it allows them to maintain optimal body temperatures for vital functions like digestion and movement, without expending metabolic energy.

Professor: Let’s take a lizard, say a desert iguana. Early in the morning, the ground is cool, so the lizard basks on a sunlit rock. It flattens its body to absorb more heat. As the day heats up, the rock becomes too hot, so the lizard moves to a shaded area or burrows underground to avoid overheating. Later, in the late afternoon, it may come out again to warm up. Here’s another example: some snakes, like the rattlesnake, will coil in a sunny spot after eating. This raises their body temperature, which speeds up digestion. So, they don’t have internal controls like we do; they simply change their location or posture to manage their heat needs. That’s behavioral thermoregulation in action.