TOEFL Listening

🎧 Listening Transcript

Listen to part of a lecture in a biology class. The professor is discussing animal communication. Professor: Today we’re going to talk about a fascinating aspect of animal behavior: communication. While many animals use visual signals, such as colorful displays or body postures, others rely heavily on chemical signals, particularly pheromones. Pheromones are chemical substances released by an animal that affect the behavior or physiology of others of the same species. For example, ants use pheromones to mark trails to food sources, and some moths release sex pheromones to attract mates from long distances. However, chemical communication is not limited to insects. Many mammals, including dogs and cats, use scent marking to establish territory or signal reproductive status. Interestingly, chemical signals can be more effective than visual ones in certain environments, like dense forests or dark waters, where visibility is low. But there are drawbacks: chemical signals are often slower to disperse and can be less precise than visual or acoustic signals. So, the choice of communication method depends on the species' ecological niche and the environment it inhabits.