Food exploitation: searching for the optimal joining policy

Commonly invoked foraging advantages of group membership include increased mean food intake rates and/or reduced variance in foraging success. These f oraging advantages rely on the occurrence of 'joining': feeding from food d iscovered or captured by others. Joining occurs in most social species but the assumptions underlying: its analysis have been clarified only recently, giving rise to two classes of model: information-sharing and producer-scro unger models. Recent experimental evidence suggests that Joining in ground- feeding birds might be best analysed as a producer-scrounger game, with som e intriguing consequences for the spatial distribution of foragers and patc h exploitation.