托福口语 Task 4

Today we're going to talk about a fascinating concept in biology called 'behavioral thermoregulation.' This is when animals actively change their behavior to control their body temperature, rather than relying solely on physiological mechanisms like sweating or shivering. Let me give you two clear examples. First, consider the desert iguana, a lizard that lives in the scorching American Southwest. In the morning, when the ground is cool, it basks in the sun to warm up. But by midday, the sand can reach 50 degrees Celsius, so it climbs onto rocks or bushes to get above the hot surface, where it's cooler. This way, it avoids overheating while staying active. Second, think of honeybees in a hive. In winter, when it's cold outside, worker bees cluster together and shiver their flight muscles to generate heat, keeping the center of the cluster at about 35 degrees Celsius. But in summer, if the hive gets too hot, some bees fan their wings at the entrance to bring in cooler air, and others collect water to spread over the comb, which evaporates and cools the hive. So in both cases, animals use specific actions to maintain a safe body temperature, a key to survival.