Mate choice copying in monogamous species: should females use public information to choose extrapair mates?

Abstract

Empirical evidence that females can copy each other's mating preferences comes predominantly from research on lekking species, but recent laboratory studies revealed that public information can also play a role in the evolution of mate preferences in monogamous species with biparental care. Although the question of why monogamous females copy each other's mating preferences is still debated, it has been suggested that public information could be used by females to assess and choose extrapair mates. Since there is only indirect empirical support for this hypothesis, I developed a game-theoretic model to explore the possible roles that mate choice copying may play in mediating extrapair behaviours in monogamous species. Like previous game-theoretic models on mate choice copying, the model predicts that only females that have a high probability of obtaining a better partner should copy the mating decisions of others. On the other hand, unlike previous games that applied to lekking species, the present model predicts that mate choice copying can be advantageous even when there is no variation among females in their discrimination ability and they all can assess the quality of potential partners without error. Moreover, as mate choice copying essentially benefits high-quality males, males of lower quality would be interested in developing defensive tactics to discourage females from seeking extrapair copulations, thereby contributing to intraspecific and interspecific variations in the rate of extrapair paternity.