Mate copying in <i>Drosophila simulans</i>

To find a suitable mate, many animals across taxa use social information. Mate copying is a form of social learning in which individuals use information regarding potential mates by observing and copying the mate choices of other individuals. While mate copying in <i>Drosophila melanogaster</i> has been extensively documented in the laboratory and its potential for cultural evolution has been demonstrated, little is known about mate copying in other <i>Drosophila</i> species. Here, we report the first evidence that <i>Drosophila simulans</i> females also copy the mate choice of their conspecifics. We used the well-established protocol developed for <i>D. melanogaster</i>: a naive, unmated female first observes a conspecific's mate choice between one artificially coloured green and one artificially coloured pink male and is afterwards allowed to choose between two males of the same phenotypes herself. Just as with <i>D. melanogaster</i>, <i>D. simulans</i> females were more likely to choose the same type of male as in the demonstration. This finding underscores the capacity of <i>D. simulans</i> females to engage in rapid social observational learning, a process that may play a significant role in the evolution of reproductive isolation.