TOEFL Speaking Task 3

In biology, the term “behavioral thermoregulation” refers to the actions an animal takes to control its body temperature by moving to different environments or changing its posture. Unlike physiological mechanisms, such as sweating or shivering, behavioral thermoregulation involves conscious or instinctive choices. These behaviors help animals maintain an optimal internal temperature for survival, allowing them to avoid overheating or excessive heat loss. For example, many reptiles bask in the sun to warm up and then retreat to shade to cool down, demonstrating a simple form of this adaptive strategy.

Professor: So, let me give you a clear example from a study on desert lizards. These lizards live in an environment where temperatures can swing dramatically—very hot during the day and quite cool at night. To manage this, they engage in behavioral thermoregulation. In the morning, when the ground is still cool, the lizards lie flat on sun-warmed rocks, spreading their bodies to maximize heat absorption. As the day heats up and the rocks become scorching, they shift their behavior—they lift their bodies off the ground, using only their toes to touch the surface, which minimizes contact and reduces heat gain. If it gets even hotter, they retreat into shaded burrows or under bushes until the temperature drops. This way, they keep their body temperature within a safe range without relying on internal cooling mechanisms.