托福口语 Task 4

Today we're going to talk about a fascinating concept in animal behavior called 'sensory exploitation.' This is when a species evolves a trait or behavior that takes advantage of an existing sensory bias in another species, often for mating or survival. Let me give you two clear examples. First, consider the male túngara frog. Female frogs are naturally attracted to the 'plop' sound that falling fruit makes in water, because it signals a potential food source. Male túngara frogs exploit this by adding a 'chuck' to their call, which mimics that plop sound, making them more attractive to females. However, this also attracts predators like bats, so it's a trade-off. Second, look at the guppy fish. Female guppies have an innate preference for orange colors, likely because in their natural habitat, orange indicates ripe fruit that falls into the water and provides food. Male guppies have evolved bright orange spots on their bodies to exploit this preference, increasing their chances of mating. So, in both cases, the sensory bias existed before the trait evolved, and the trait simply taps into that pre-existing preference.