Social information quality and environmental volatility shape collective foraging behaviour

Abstract

Abstract Collective foraging is widespread across the animal kingdom, allowing animals to more effectively discover resources. However, collective foragers need to balance a key trade-off between private exploration and using social information. Social information can come in very distinct forms, ranging from simple positional cues to complex pay-off information. However, how the types of available social cues and environmental volatility shape collective foraging behaviour is not well understood. We address this using a spatially explicit model in which agents track a mobile resource via multi-agent reinforcement learning (MARL). Agents choose between random exploration, private tracking and social attraction. We systematically varied resource volatility and the type of available social cues to analyse their effect on individual and collective behaviour. Our results show that the quality of social information dictates the emerging collective behaviour. Low-quality social cues (e.g. positions and actions) result in a fragile strategy that is effective in stable environments but fails as volatility increases. Conversely, high-quality social information (e.g. pay-offs) enables behavioural diversity: agents selectively copy others and flexibly change between individual tracking or exploration depending on the environmental volatility. Our findings identify the interplay between information quality and ecological context as an important mechanism governing the emergence of distinct forms of collective behaviour from individual decision rules.