Vibratory communication in the jumping spider Phidippus clarus: polyandry, male courtship signals, and mating success

The jumping spider Phidippus clarus uses signals that combine visual and substrate-borne vibrations, which predict the outcome of male-male competition and are important to copulation success. We investigated the function of males' substrate-borne vibrations by examining phenotypic correlates of vibratory signal traits and assessing whether these affect female mating and remating decisions. Virgin females were first paired with males, and females that copulated in first trials were then paired with a second male to determine whether females remate. We measured vibratory signals produced by males during these interactions to determine 1) correlations between substrate-borne signal traits and male phenotypes, 2) whether properties of substrate-borne signals predicted mating success in first and second copulations, and 3) whether females of different mating status have different acceptance thresholds for male characters. Courtship vibration rate was positively correlated with male leg size, and signaling rate significantly predicted mating success in all copulations. Some females were polyandrous; however, copulation with mated females occurred after longer courtship durations, and courtship duration was positively correlated with male size, demonstrating that mated females are less receptive to mates and suggesting that females may be trading up in subsequent matings. Our study shows that males invest significant effort in courtship and that sexual selection via female choice may play a nontrivial role in the mating system. These results are the first to show that honest information about male size is encoded by substrate vibrations, and these signals are important for male mating success in both virgin and mated females.