托福口语 Task 4

Today, we're going to talk about a fascinating biological phenomenon called 'behavioral thermoregulation.' This refers to the ways animals actively adjust their behavior to control their body temperature, rather than relying solely on physiological mechanisms like sweating or shivering. The main point I want to emphasize is that behavioral thermoregulation is often more energy-efficient than physiological responses, allowing animals to survive in extreme environments. Let me give you two examples. First, consider the desert lizard, the chuckwalla. When the sun is too hot, it climbs onto a rock and positions its body to face the sun, reducing the surface area exposed to direct sunlight. Then, if it gets too warm, it retreats into a narrow crevice between rocks, where the temperature is cooler. This moving between sun and shade helps it maintain an optimal body temperature without using much energy. Second, think about honeybees. In a hive, when the temperature rises, worker bees collect water and spread it thin over the comb, then fan their wings to create evaporative cooling. Conversely, when it's cold, they cluster together and shiver their flight muscles to generate heat. These behaviors allow the entire colony to stay within a safe temperature range, even when the outside temperature fluctuates widely. So, as you can see, behavioral thermoregulation is a key survival strategy.