Evolutionary origins of displays used in aggressive mimicry by Portia , a web‐invading araneophagic jumping spider (Araneae: Salticidae)

Portia is a genus of jumping spiders which invade alien webs and use aggressive mimicry to prey on the resident spiders. Portia’s aggressive mimicry repertoire includes numerous different vibratory displays. Portia’s aggressive mimicry displays are compared to its grooming and disturbance behaviours, and hypotheses are discussed concerning the evolution of specific aggressive mimicry displays from specific grooming and disturbance behaviours. The contexts in which Portia and a variety of other salticids and spiders from other families groom and perform disturbance behaviours are investigated. Special attention is given to the conflict theory of ritualisation which has been useful in studies of other animals. This theory is not found to be very useful, however, for understanding the evolution of Portia’s aggressive mimicry displays.