Early social experience significantly affects sexual behaviour in male guppies

Studying the mechanisms by which immature males learn courtship behaviour is essential to our understanding of the evolution of different mating strategies, yet generally this has been neglected. Here I demonstrate an effect of early social experience on the sexual behaviour of male guppies, Poecilia reticulata. I tested whether the social rearing environment (visual access to females only, males only or both males and females) affects malesʹ sexual performance, including the time and frequency of courtship displays and forced copulation attempt frequency. I conducted trials in which focal male guppies were allowed to interact with a female. Males that experienced early social interactions with mature males performed significantly longer courtship displays than males that grew up without observing other males. This result suggests that young males learn to court efficiently by observing other males courting. Males raised with females performed more forced copulation attempts, possibly because males might need to physically interact with females in order to learn to strategically alternate courtship displays and forced copulation attempts. Early social interactions may play a stronger role in the structure of the mating system in guppies than previously recognized, and might contribute to the differences in sexual behaviour observed between different populations of guppies.