美国科学60秒 SSS 2013-03-06（在线收听）

 　　Unless you are a convention, speaking middle English is not going to impress a potential romantic partner in 2013. Similarly, male sparrows have to make sure their vocalization is up to date. Researchers analyze three decades of recordings of male sparrows. And birds change their tune over the ears did better with the ladies. The researcher's in the journal animal behavior. While introductory notes of the sparrow's songs did better with the ladies, the middle and end part changed over time. In the 1980’s, songs concluded with longer, high-pitched trills. More recent songs contain serials of clicks in the middle and short low-pitched trill at the end. Researchers found that the male sparrows that adopted the newer songs have higher rates of sexual reproduction. Because you don't want to be seen as behind the times.  Indeed, Ch~~ might have had his pick of the ladies in the 14th century. But few today can make heads or tails of his tales.