EPICURE: Spatial and Knowledge Limitations in Group Foraging

Abstract

We propose an agent-based model of group foraging, EPICURE, for patchily distributed resources. Each agent makes probabilistic movement decisions in a gridworld through a linear combination of cur rent perceptual information and a reinforcement history. EPICURE captures the empirical results from several foraging conditions in previous works, and it leads to a reevaluation of findings from those papers. In particular, human foragers show contingent usage of information, initially using social infor mation to discover resource pools before private sampling information has been established. We describe a series of simulations that test the sources of resource undermatching often found in group foraging experiments. After testing the effects of foragers' starting locations, travel costs, the number of foragers, and the size of uniform food distributions, we discuss a novel hypothesis for undermatch ing. Spatial constraints lead to inadequate individual and group information sampling and cause group undermatching. The foraging group size, food rate, spatial distribution of food, and resulting forager reinforcement histories interact to produce undermatching, and occasionally overmatching, to resources.