การฟัง TOEFL

🎧 บทถอดเสียง

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 example of animal communication: the waggle dance of honeybees. When a forager bee finds a good source of nectar, she returns to the hive and performs a series of movements on the honeycomb. These movements, which we call the waggle dance, convey information about the direction and distance of the food source. The bee waggles her abdomen while moving in a straight line, then loops back. The angle of the waggle run relative to vertical indicates the direction of the food relative to the sun. The duration of the waggle run signals the distance. For example, a longer waggle run means the food is farther away. Interestingly, this dance is not just a simple signal; it's a symbolic language. The bees can also adjust their dance based on the quality of the nectar. If the nectar is particularly rich, they may repeat the dance more often to recruit more foragers. This discovery, first made by Karl von Frisch, earned him a Nobel Prize in 1973. Now, what's remarkable is that bees can learn variations of this dance from other bees, suggesting a form of cultural transmission. Any questions?