Taking the sensory approach: how individual differences in sensory perception can influence mate choice

Many male signallers convey information to female receivers in multimodal courtship displays. While much is known about how males vary in terms of signalling, variation in female detection of these multimodal signals is relatively unexplored. We suggest that there is a critical, albeit underdeveloped, link between multimodal sensory reception and individual variation in mate choice. This review addresses the potential effects of developmental and conditional factors (e.g. nutrient availability, hormone profiles and age) on female multimodal processing, and illustrates that differences in the (1) source of individual variation and (2) the number of sensory processing modes affected by this variation can influence the receiverʹs mate choice patterns. Based on these two factors, we outline novel predictions of preference functions and choosiness in a redundant multimodal signalling context. Moreover, we explore the theoretical implications of individual variation in multimodal signal perception in relation to sensory drive, honest signalling, assortative mating and intrasexual selection. We propose that understanding the role of variation in sensory processing and its relation to mate choice can help us better identify the factors that influence sender and receiver fitness, and subsequently the rate and direction of signal evolution.