TOEFL Speaking Task 3

In biology, the concept of 'behavioral thermoregulation' refers to the strategies animals use to control their body temperature by altering their behavior, rather than through physiological changes. This allows them to maintain an optimal internal temperature for survival and activity, especially in environments with fluctuating temperatures. Animals may move to different locations, change their posture, or adjust their activity patterns to either gain or lose heat. This adaptive behavior is crucial for energy conservation and avoiding thermal stress.

Professor: So, let me give you an example from a desert lizard, the chuckwalla. In the early morning, when it’s still cool, the chuckwalla emerges from its rocky crevice and basks on a sun-warmed rock. It flattens its body to increase surface area, absorbing heat quickly to raise its body temperature. As the day heats up, especially around noon, the desert floor becomes scorching. To avoid overheating, the chuckwalla climbs into a shady spot under a boulder or squeezes into a narrow crevice, where the temperature is much cooler. It also lifts its body off the hot ground, allowing air to circulate underneath, which helps dissipate heat. By moving between sun and shade, and adjusting its posture, the lizard keeps its body temperature within a safe range without having to rely on sweating or shivering.