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 selecting environments that provide optimal thermal conditions. This behavior is crucial for ectothermic animals, such as reptiles and insects, which rely on external heat sources to maintain metabolic functions. By actively seeking out warm or cool microhabitats, these animals can enhance digestion, locomotion, and reproduction while avoiding overheating or hypothermia. Behavioral thermoregulation is a key adaptation that allows ectotherms to thrive in fluctuating climates.

Professor: So, let me give you a clear example from a study on desert lizards. These lizards, like the desert iguana, are ectotherms, so they can't generate their own body heat. In the early morning, when the desert ground is still cool, the lizards bask on sun-warmed rocks. This raises their body temperature, allowing them to become active and hunt for insects. But as the sun climbs higher and the sand temperature reaches over 50 degrees Celsius, the rocks become too hot. So, the lizards then move to shaded areas under bushes or burrow into the sand, where it's cooler. They only emerge again in the late afternoon when the surface cools down. This way, they keep their body temperature within a safe range—around 37 degrees—so they can digest food and avoid lethal heat stress.