Modelling information acquisition and its impact on social structure

Numerous social structures exist in the animal kingdom, all of which fill a niche in which the organisms find themselves. The various levels of aggregation and hierarchy within the majority of these social structures can be explained by selective pressures such as predation avoidance, resource exploitation and mating opportunity. The necessity and affordance of acquiring social and ecological information has been proposed as another possible factor in the evolution of certain colonial structures, such as those of ravens and ospreys. We explore the conditions under which the use of socially acquired information benefits individuals within a colony using an agent-based model. The agents are simple finite-state automata following a forage-and-return behaviour in which they can also breed and die. The model allows agents to socially acquire information by determining whether foragers have been successful. The agents can then decide whether to follow other agents or forage on their own. Increased competition at foraging sites is the cost for following but environments in which resources are patchily distributed and/or ephemeral in time provide a challenge to individual foragers. The preference for the use socially over personally acquired information, in the model, is a heritable trait and allowed to vary across generations. We demonstrate that more sociality in groups evolves in challenging environments. Although the model is an abstract representation of colonial species, it can provide a platform for understanding the behaviour of real animals.