Female mate choice copying affects sexual selection in wild populations of the ocellated wrasse

Explaining the factors that determine the distribution of mating success among males is essential to our understanding of sexual selection. Classic theory has focused on how competition among males and female choice for traits of the male or his territory drive sexual selection. Recent theory has also shown that female mate choice copying can alter the strength and direction of selection on male traits. Yet, we know very little about the prevalence and importance of nonindependent female choice in wild populations. In a species with male territoriality and paternal care (the ocellated wrasse, Symphodus ocellatus), I first show that females express nonindependent mate choice, responding both to the recent mating success of the male and to the presence of other spawning females rather than to variation in male courtship or defence of the nest. Females were significantly more likely to spawn with the same male when another spawning female was present than when they were alone at the nest, providing some of the first direct evidence of female mate choice copying under natural conditions in the wild. I further show that a short-term experimental increase in a territorial male's mating success attracts more females in the future and increases male paternal care. These observed patterns of female choice and male care are consistent with female choice for the direct benefits of male care where the best indicator trait of male parental effort is the mating behaviour of other females rather than male courtship behaviour or physical traits.