Age-related plasticity in male mate choice decisions by Schizocosa retrorsa wolf spiders

Abstract

Investigations of the mechanisms underlying the process of sexual selection historically have focused on female mate choice and male competition. More recently, however, male mate choice has been demonstrated to be an important mechanism in a variety of taxonomic groups, yet our understanding of the role of male age in male mate choice decisions has lagged behind. Here we examined the age-related mate choice decisions of young and old male wolf spiders (Schizocosa retrorsa). We observed male courtship behaviour during encounters with female dragline silk deposited by either virgin female spiders or less receptive and potentially more sexually cannibalistic mated females. Young male spiders were choosy in their deployment of courtship efforts, courting and engaging in grooming chemoexploration more in response to silk deposited by virgin females than to silk deposited by mated females and spending less time on silk of mated females. However, these preferences for virgin female silk were absent in trials with males in the old age class. Our results suggest that male age and variation in the costs of courtship and reproductive behaviour interact to generate age-related changes in male mate choice behaviour.