Summary

Both genders of spiders compete for a variety of resources. They typically use non-contact display, followed by increasingly escalated contact phases comprising touching and sparring and then escalated grappling and biting. Studies of spiders have been central to the understanding of assessment strategies and, for the most part, the data support self-assessment rather than mutual-assessment models. There is good evidence for effects of resource value and ownership on the conduct and outcome of these contests. Fights may have short-term consequences with respect to fatigue, but can have longer-term effects such as loss of appendages or death. Specific experience of winning or losing contests may also influence future encounters. Spiders have also been used in studies of the underlying genetic basis for variation in contest behaviour. Spiders have been the inspiration for motivational models of aggression and we propose a new two-dimensional model that uses cost and resource value as the major factors influencing motivational state and hence choice and duration of activities.

Introduction

Spiders present eminently tractable systems for the study of animal contests, both in field and laboratory settings, and have been the subjects in several seminal studies of aggression. While some taxonomic groups build webs and use them to capture prey and others do not, aggressive behaviour spans the taxonomic and foraging strategy distinction. It occurs in sedentary web-builders (e.g. orb-web spiders, money spiders, comb-footed spiders), sedentary ambushing species (e.g. crab spiders) and more cursorial hunting spiders (e.g. wolf and jumping spiders).