Cultural transmission of vocal traditions in cowbirds (Molothrus ater) influences courtship patterns and mate preferences

In this study, the authors tested the cultural transmission of vocal tradit ions in cowbirds (Molothrus ater). Young cowbirds from a South Dakota (SD) population were housed over winter with adults of the SD population or with adults from an Indiana (IN) population. Song differences between the origi nal SD and IN adult models were acquired by South Dakota culture (SDC) and Indiana culture (INC) males, respectively, and were transmitted to a 2nd cu ltural generation of birds. During playback tests of SDC and INC songs, SD females gave more copulatory responses to SDC songs. Finally, males with SD -like songs courted SDC females preferentially in breeding season tests, wh ereas males with IN-like songs courted INC females preferentially. These re sults indicate that the transmission of vocal traditions plays a fundamenta l role in the courtship patterns and mating decisions of cowbirds.