托福口语 Task 4

Today, we're going to talk about a fascinating concept in animal behavior called 'sensory exploitation.' This is the idea that in some species, a male's courtship display evolves to exploit a pre-existing sensory bias in the female, even if that bias originally had nothing to do with mating. Essentially, the male's signal triggers a response in the female that she already had for other reasons. Let me give you two classic examples. First, consider the guppy. Female guppies are naturally attracted to the color orange, which happens to be the color of their favorite food—small orange fruits that fall into the water. Males have evolved bright orange spots on their bodies to take advantage of this pre-existing preference. The more orange a male has, the more attractive he is to females, simply because his spots resemble food. Second, think about the tungara frog. Female tungara frogs are drawn to the low-frequency 'whine' sound, which they normally use to locate other frogs in the dark. But males have added a 'chuck' at the end of their call. This 'chuck' actually mimics the sound of a predator, like a bat, which would normally cause females to freeze. Yet, in the mating context, the combination of whine and chuck makes the male more attractive because it exploits the female's heightened attention to low-frequency sounds. So, in both cases, the male's display isn't just about showing off—it's about tapping into what the female already finds salient or appealing.