Convenience polyandry or convenience polygyny? Costly sex under female control in a promiscuous primate

Abstract

Classic sex roles depict females as choosy, but polyandry is widespread. Empirical attempts to understand the evolution of polyandry have often focused on its adaptive value to females, whereas 'convenience polyandry' might simply decrease the costs of sexual harassment. We tested whether constraint-free female strategies favour promiscuity over mating selectivity through an original experimental design. We investigated variation in mating behaviour in response to a reversible alteration of sexual dimorphism in body mass in the grey mouse lemur, a small primate where female brief sexual receptivity allows quantifying polyandry. We manipulated body condition in captive females, predicting that convenience polyandry would increase when females are weaker than males, thus less likely to resist their solicitations. Our results rather support the alternative hypothesis of 'adaptive polyandry': females in better condition are more polyandrous. Furthermore, we reveal that multiple mating incurs significant energetic costs, which are strikingly symmetrical between the sexes. Our study shows that mouse lemur females exert tight control over mating and actively seek multiple mates. The benefits of remating are nevertheless not offset by its costs in low-condition females, suggesting that polyandry is a flexible strategy yielding moderate fitness benefits in this small mammal.

Fertility control to mitigate human–wildlife conflicts: a review

“…The bias toward female contraception is due to (1) studies focussed on human fertility (Barfield et al 2006), (2) the recognition that polygyny and polyandry are common among many mammal species (e.g. Garrott and Siniff 1992;Kennis et al 2008;Huchard et al 2012) and, thus, extremely high levels of male sterility would be required to have any effect at the population level and (3) models demonstrating that effective control at the population level could be achieved only by rendering infertile a high proportion of females (e.g. Caughley et al 1992;Hobbs et al 2000;Merrill et al 2006).…”

Senescence or selective disappearance? Age trajectories of body mass in wild and captive populations of a small-bodied primate

“…In the highly promiscuous mating system of M. murinus [41][42][43], female reproductive skew is negligible [44] and female lifetime fitness increases with lifespan. Longevity is slightly male-biased in our captive study population [19,45] but strongly female-biased in the wild [30].…”

Sexual Conflict in Nonhuman Primates

“…Thus, its effectiveness in deterring coercion may be greatest when combined with postcopulatory mechanisms to manipulate sperm, for which there is some evidence (Schwensow et al, 2008). Huchard et al (2012) reject this interpretation of female mouse lemur sexual behavior, however. In captive experiments in which they manipulated female body condition, they tested the prediction of the convenience polyandry hypothesis that females in relatively poorer physical condition will show greater polyandrous mating.…”