Long-term behavioural consistency in prey capture but not in web maintenance in a social spider

摘要

Behavioural differences between individuals that are consistent over time or across context are termed behavioural types or personalities. Social spiders are an emerging model for studying animal personality in social systems and our study was motivated by the lack of work examining the persistence of personality in the long-term and under changed conditions. We examined consistency and plasticity in two key behaviours, prey capture and web maintenance, and tested for the presence of a behavioural syndrome between them in the social spider, Stegodyphus sarasinorum. Our experiments over a large part of the adult life span show that not all spiders capture prey, suggesting behavioural consistency with implications for task differentiation. Through prey manipulation experiments, we further probed the role of hunger, proximity to prey, body weight and number of days into the experiment on individual propensity to capture prey. Our results demonstrate that under altered prey availability, responses of individuals are plastic and influenced by hunger. These results suggest that behavioural consistency can be modulated significantly by extrinsic factors. In contrast, we did not find consistent differences between individuals in their participation during web maintenance. Additionally, we did not find a behavioural syndrome. Together, these results suggest a scenario of quasi-specialisation in which there is no strict partitioning of tasks. For the first time, our results demonstrate behavioural consistency over extended periods of time in social spiders and have implications for colony efficiency and survival. We argue that studies spanning ecologically relevant time periods and environmental variation can reveal the full extent of behavioural consistency and flexibility.