Female fiddler crabs, Austruca lactea (Decapoda: Ocypodidae), adjust their rate of mate sampling based on remaining days until oviposition under a size-dependent temperature constraint

Rate of mate sampling is one of the critical components associated with sampling costs in female mate choice. In ectotherms, environmental temperature generally constrains locomotion performance. In addition, females will adjust the mate sampling rate depending on their breeding schedule because of the risk of remaining unfertilized eggs or a loss of benefits related to mating, if they lose the opportunity to copulate. This study investigated how these effects influence the rate of female mate sampling in the temperate fiddler crab (Austruca lactea) in the field. The number of sampled males per searching duration formed a convex curve against environmental temperature. The optimal environmental temperature increased with the female body size. These results suggest that mate sampling rate is under a size-dependent temperature constraint, and sampling costs are lower for larger females than smaller individuals under high-temperature conditions. Furthermore, when there were fewer remaining days, the mate sampling rate increased. Females would hasten the sampling rate to ensure a suitable burrow for breeding. Mate sampling rate in female A. lactea is therefore associated with environmental temperature, female body size and remaining days until oviposition.

A sensory ecological perspective on mate sampling strategies: simulation models and an empirical test

Long-range communication signals play a central role in mate search and mate choice across a wide range of taxa. Among the different aspects of mate choice, the strategy an individual employ to search for potential mates (mate sampling) has been less explored despite its significance. Although analytical models of mate sampling have demonstrated significant differences in individual fitness returns for different sampling strategies, these models have rarely incorporated relevant information on the ecology of signalers and sensory physiology of receivers, both of which can profoundly influence which sampling strategy is optimal. In this study, we used simulation models to compare the costs and benefits of different female mate sampling strategies in an acoustically communicating field cricket (Plebeiogryllus guttiventris) by incorporating information on relative spacing of callers in natural choruses, their signal intensity and the effect of signal intensity on female phonotaxis behaviour. Mating with the louder caller that the female first approaches emerged as the optimal strategy, thus reflecting the importance of physiological mechanisms of sound signal localization (passive attraction) over active sampling. When tested empirically in the field, female behaviour was consistent with passive attraction.

From Preferences to Choices

This chapter focuses on mate sampling and on how choosers decide among sampled mates. The thinking in this regard has largely focused on the fitness consequences for courters and choosers. For courters, how does mate sampling affect choosiness and therefore variance in courter fitness, and how do courters exploit sampling and decision mechanisms? For choosers, how does fitness depend on different putative sampling schemes and decision algorithms? Much of this literature flows back to an influential paper that explored the fitness consequences of several hypothetical sampling schemes. The chapter describes what we know about the heuristic rules that animals use to evaluate finite pools of courters, and about the cognitive constraints underlying mate assessment and comparisons among mates.