托福口语 Task 3

In biology, the concept of 'behavioral thermoregulation' refers to the actions animals take to regulate their body temperature by moving to environments that help them maintain an optimal internal temperature. Unlike physiological mechanisms such as sweating or shivering, behavioral thermoregulation involves conscious or instinctive choices about where to be in their habitat. This can include seeking shade, basking in sunlight, or changing posture to expose more or less body surface to heat sources. Such behaviors are crucial for survival, especially for ectothermic animals that rely on external heat to regulate their temperature.

Professor: Let me give you an example from a desert lizard species, the desert iguana. In the early morning, when the sand is still cool after the night, the iguana emerges from its burrow and flattens its body against the warm rocks. Its dark skin absorbs heat quickly, and it faces the sun directly to warm up faster. By mid-morning, as the sun gets intense and the ground temperature rises, the iguana starts to feel too hot. So it climbs onto a low branch of a creosote bush, which is about half a meter above the ground. There, the air is cooler, and it can also angle its body to minimize sun exposure. When the afternoon sun is at its peak, the iguana retreats into the shade under a rock or into its burrow to avoid overheating. So you see, the iguana actively chooses different microhabitats at different times of the day to keep its body temperature within a comfortable range.