托福口语 Task 4

Today we're going to talk about a fascinating behavioral adaptation in animals called 'safety in numbers.' This is a strategy where prey animals reduce their individual risk of being attacked by grouping together. The main point is that by staying in a crowd, each animal decreases its chance of being the one that gets caught by a predator. Let me give you two examples to illustrate this. First, consider the sardine. When a school of sardines is attacked by a predator like a tuna, the sardines instinctively form a tight, swirling ball. This confuses the predator because it sees a moving mass rather than a single target. The tuna may strike repeatedly but often misses, and the individual sardines within the ball are much less likely to be singled out. Second, think about wildebeests during their migration. When lions attack a herd, the wildebeests don't scatter randomly. Instead, they bunch together and run in a synchronized way. A lion typically targets the slowest or weakest individual, but in a tightly packed herd, it's harder for the lion to isolate one. Often, the lion gives up after several attempts because the effort is too high, and the herd moves on with only a few losses. So, as you can see, grouping behavior significantly increases an individual's chances of survival.