Effects of prey–spider odour on intraspecific interactions of araneophagic jumping spiders

An important prediction from game theory is that the value of a resource will influence the level to which an animal is willing to escalate during conflict with conspecific rivals. Here we use this prediction as the rationale for experiments aimed at determining whether escalation decisions made by predators are influenced by the presence of preferred prey. The predators we use are adult individuals of Portia fimbriata, a jumping-spider (Salticidae) species from Queensland (Australia). P. fimbriata is known to prefer other salticid species as prey and can detect the odour of Jacksonoides queenslandicus, this being an especially common salticid species in the Queensland habitat. Here we show that, for P. fimbriata females, the odour of J. queenslandicus primes escalation of vision-based conflict. However, for P. fimbriata males, no comparable effect was found. These findings suggest intrasexual competition for prey is more important to females than to males.