Behavioural profiles: individual consistency in male mating behaviour under varying sex ratios

Abstract

Variation in sex ratio can affect mating behaviour, with more intense competition predicted at biased sex ratios. In species with alternative mating behaviours, sex ratio variation can induce switches between behaviour types and this, together with the consistency with which behaviours are expressed, may also affect the intensity of sexual selection. All these factors can be combined to elucidate individual mating behaviour profiles. The establishment of individual behavioural profiles for male mating behaviour in one species, the guppy, Poecilia reticulata, is the focus of this study; specifically, we ask whether individual male mating behaviour profiles show that males have consistent reproductive behaviour across contexts where the advantages of using alternative mating tactics differ. The frequency of both sneak mating and display behaviours varied between sex ratios. Male display and sneak frequency were highly repeatable and males maintained consistent rankings of behaviour under equal, male- and female-biased sex ratios. We conclude, therefore, that male guppies have individual mating behaviour profiles. The use of behavioural profiles fills a gap in the existing literature by allowing behaviours that are functionally related but not correlated, such as alternative mating behaviours, to be treated as an integrated unit.