托福口语 Task 4

Today we're going to discuss a fascinating concept in animal behavior: 'informational parasitism.' This occurs when one animal copies the behavior of another to gain information, but without providing any benefit to the original animal. Let me give you two examples from the wild. First, consider the sage grouse. When a female sage grouse chooses a mate, she observes other females. If she sees a female selecting a particular male, she often copies that choice, even if she hasn't evaluated the male herself. The first female gains nothing from being copied—she's just going about her own business. The copying female, however, benefits by using the first female's assessment to pick a high-quality mate without spending time and energy on evaluation. Second, think about ravens. When a raven finds a large carcass, it may call out to attract others. But sometimes, a raven will remain silent and follow another raven to a food source. The silent raven avoids the risk of revealing the food to predators or competitors, while the calling raven's behavior is exploited. The silent raven gets a meal, but the calling raven gains no advantage—it might even lose food. So, informational parasitism is a clever, though selfish, strategy.