TOEFL Speaking 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 different environments or changing its posture. Unlike physiological mechanisms such as sweating or shivering, behavioral thermoregulation involves conscious choices that help the animal maintain an optimal internal temperature for survival and activity. This behavior is especially evident in ectothermic animals, which rely on external heat sources to regulate their body heat.

Professor: So, consider the desert iguana, a lizard that lives in the hot, arid regions of the southwestern United States. When the morning sun rises, the ground is cool. The iguana emerges from its burrow and basks on sun-exposed rocks, orienting its body perpendicular to the sun's rays to maximize heat absorption. As the day progresses and the sand becomes scorching, the iguana's body temperature would rise dangerously. So, it moves to shaded areas under rocks or bushes, and it may even lift its body off the hot ground by standing on its toes to allow cooler air to circulate beneath. In the hottest part of the day, it retreats into a burrow to avoid overheating. By moving between sunny and shaded spots and adjusting its posture, the iguana keeps its body temperature within a safe range, allowing it to forage for food and avoid predators.