Modelling the many-wrongs principle: the navigational advantages of aggregation in nomadic foragers.

We develop a simple individual-based model to gain an understanding of the drivers of aggregation behaviour in nomadic foragers. The model incorporates two key elements influencing nomadic foragers in variable environments: uncertainty regarding the location of food sources and variability in the spatio-temporal distribution of ephemeral food sources. A genetic algorithm is used to evolve parameters describing an individual's movement and aggregation strategy. We apply the aggregation model to a case study of the Bornean bearded pig (Sus barbatus). Bearded pigs are ideal for considering the foraging advantages of aggregation, because they are highly mobile and exhibit a variety of aggregation strategies, ranging from solitary and sedentary to mass aggregation and wide ranging migration. Our model demonstrates the "many-wrongs principle", and shows that environmental variability, uncertainty in the location of food sources, and local population density drive aggregation behaviour.