Researchers analyzed three (decades) of recordings of male Savanna sparrows. And birds that changed their tune over the years did better with the ladies. The research is in the journal Animal Behaviour. [Heather Williams et al., Three decades of cultural (evolution) in Savannah sparrow songs]

While introductory notes of the sparrow’s song stayed the same, the middle and end parts changed over time. In the 1980’s, songs (concluded) with longer, high-pitched trills. More recent songs contain a series of clicks in the middle and a shorter, low-pitched trill at the end.

Researchers found that the male sparrows that adopted the newer songs had higher rates of sexual reproduction. Because you don’t want to be seen as (behind) the times. Indeed, Chaucer might have had his pick of the ladies in the 14th century. But few today can make heads or tails of his tales.