Precopulatory mate guarding in crustaceans: Male competitive strategy and intersexual conflict

Precopulatory mate guarding in crustaceans is a common male mating strategy when female receptivity for copulation is short. The decision to start guarding is not made by only males, however; it is commonly found that females resist the guarding attempts of males. Furthermore, experimental data show that males aim for longer guarding durations than females allow. Shorter guarding durations may be favored by females because of a number of potential costs of guarding. Precopulatory guarding therefore presents a model case of intersexual conflict where the fitness maximizing strategies of males and females differ. When the interests of the sexes are in conflict, the actual guarding duration may be a compromise between mat and female optima, resulting from the adjustment of contest behavior to the fitness gains of winning and to the fighting abilities of the parties. Intersexual conflicts are also likely to generate sexual selection on male and female traits related to the outcome of the contests.