Intraspecific Variation in Courtship and Copulation Frequency: an Effect of Mismatch in Partner Attractiveness?

AbstractThe aim of this paper is to present a verbal theoretical model that could account for the among pair variability in courtship and copulation behaviour that occurs both during and after pair formation in socially monogamous species. We assume that copulation acts to prevent mate loss, by reducing the availability of an individual to other potential partners. Variation in copulation and courtship frequency then arises as a result of variation in the risk of mate loss. Because of the constraints on free or ideal choice, pairs will form in which it may be possible for one individual to improve upon the quality of its partner. In a mismatched pair it will pay the poorer quality mate to guard the higher quality individual and prevent it from leaving to pair with a better quality mate. The poor quality individual will therefore solicit copulations at a high frequency while it's partner may not always respond. We predict that high levels of courtship and solicitation will relate to a high risk of mate loss and that a lack of response by a partner will relate to the potential opportunities it has to improve on partner quality. Our thesis is that variation in mating behaviour arises as a result of any deviations from assortative mating that may exist in a population.