Prey Availability Increases Less Quickly Than Nest Size in the Social Spider Stegodyphus Mimosarum

Stegodyphus mimosarum, a social spider, lives in colonies which may contain hundreds of individuals. The interactions between body size, nest size and prey size were investigated. 2. Spiders in larger nests caught larger prey than those in smaller nests. 3. The increase in prey availability did not keep pace with increasing spider numbers as nest size increased. 4. This resulted in spiders from larger nests being smaller than those from smaller nests. 5. The most likely individuals to leave experimental groups were the intermediate-sized ones. 6. Spiders were more active in the presence of plant defensive spines than in their absence. 7. Spiders from smaller nests were more cooperative and less competitive than those from larger nests.