Estimating the repeatability of memories of captured prey formed by Frontinella communis spiders (Araneae: Linyphiidae)

How animals deal with the challenges posed by their ecological and social surroundings often hinges on the acquisition and storage of information about those surroundings. That is, an animal's fitness may be influenced by variation in the mental representations it has formed of its environment. Studying such variation is challenging because it involves documenting inherently subjective phenomena. However, observations of behaviour may provide objective descriptions of mental representations. We used the behaviour of Frontinella communis spiders after removal of prey from their webs as an assay of the contents of their memories of the prey. Spiders searched for lost prey, exerting greater effort in searching for larger prey, and distinguishing between the object of the search and old prey remnants. We thus infer that spider memories included information about prey features such as size or quality. We found significant repeatability in the spiders' searching behaviour, suggesting repeatability in memory content. As an indication of consistent between-individual differences in searching and memory, these repeatability estimates suggest that selection may act to shape mental representations and their relationship with foraging behaviour.