TOEFL Speaking Task 3

In biology, the concept of 'behavioral thermoregulation' refers to the active strategies animals use to control their body temperature by altering their behavior, rather than through physiological changes. This allows animals to maintain an optimal internal temperature for survival and activity. Examples include moving to shaded areas, basking in sunlight, or changing posture to maximize or minimize heat absorption. Behavioral thermoregulation is especially important for ectothermic animals, which rely on external heat sources to regulate their body temperature.

Professor: Let me give you an example from a desert lizard species. During the early morning, when the ground is cool, the lizard emerges from its burrow and lies flat on a sun-warmed rock, spreading its body to absorb maximum heat. As the day progresses and the rock becomes too hot, the lizard lifts its body off the ground, using its legs to raise its torso and allow cool air to circulate beneath it. By midday, when temperatures soar, the lizard retreats into the shade of a crevice or burrow to avoid overheating. Later in the afternoon, it may return to the sunlit rock again, but this time it positions itself perpendicular to the sun's rays to warm up more slowly. Throughout the day, the lizard changes its location and posture in response to temperature cues, demonstrating behavioral thermoregulation.