托福口语 Task 4

Today we're going to talk about a fascinating concept in animal behavior called 'sensory exploitation.' This occurs when a species evolves a trait or behavior that takes advantage of a pre-existing sensory bias in another species, often to the benefit of the first species. Let me give you two examples. First, consider the water mite, a tiny aquatic creature. Female water mites are naturally attracted to vibrations that mimic their prey, such as small crustaceans. Male water mites have evolved to produce similar vibrations – not to hunt, but to lure females for mating. The females approach, expecting a meal, but instead encounter a male. So the male exploits the female's pre-existing sensory system. Second, think about the túngara frog. Female frogs are drawn to a specific low-frequency 'whine' call from males. Some predatory bats have learned to use that same call to locate the frogs. However, male frogs have evolved a more complex call – adding a 'chuck' – which still attracts females but makes it harder for bats to pinpoint them. So the sensory bias in females is exploited by both the frogs (for mating) and the bats (for hunting), but the males adapt to reduce the risk.