托福口语 Task 4

Today we're going to talk about a fascinating behavior in the animal kingdom called 'mimicry.' More specifically, I want to focus on a type of mimicry where a harmless species evolves to look like a dangerous one. This is called 'Batesian mimicry.' The main point is that this adaptation helps the harmless species survive because predators learn to avoid the dangerous appearance. Let me give you two examples. First, consider the king snake. It is non-venomous, but it has bright red, yellow, and black bands very similar to the coral snake, which is highly venomous. Predators that have had a bad experience with coral snakes will avoid anything that looks like them, so the king snake gets protection. Second, there is a type of hoverfly that has black and yellow stripes, just like a wasp. Although the hoverfly has no stinger, birds that have been stung by a wasp will not attack it. In both cases, the mimic gains a survival advantage without having to be actually dangerous itself.