Learning rules for social foragers: Implications for the producer-scrounger game and ideal free distribution theory

In population games, the optimal behaviour of a forager depends partly on c ourses of action selected by other individuals in the population. How indiv iduals learn to allocate effort in foraging games involving frequency-depen dent payoffs has been little examined. The performance of three different l earning rules was investigated in several types of habitats in each of two population games. Learning rules allow individuals to weigh information abo ut the past and the present and to choose among alternative patterns of beh aviour. In the producer-scrounger game, foragers use producer to locate foo d patches and scrounger to exploit the food discoveries of others. In the i deal free distribution game, foragers that experience feeding interference from companions distribute themselves among heterogeneous food patches. In simulations of each population game, the use of different learning rules in duced large variation in foraging behaviour, thus providing a tool to asses s the relevance of each learning rule in experimental systems. Rare mutants using alternative learning rules often successfully invaded populations of foragers using other rules indicating that some learning rules are not sta ble when pitted against each other. Learning rules often closely approximat ed optimal behaviour in each population game suggesting that stimulus-respo nse learning of contingencies created by foraging companions could be suffi cient to perform at near-optimal level in two population games. (C) 2000 Ac ademic Press.