Interference affects food-finding rate in schooling sticklebacks

Experiments on sticklebacks seeking for food patches show that foraging in schools enhances food-finding rate of individuals. A stochastic information-sharing model characterizes food-seeking behaviour in which food-finding by one in a school of fish results in food-sharing by many. The model predicts the food-finding rate of a randomly selected individual in a school of n fish to be that of a solitary forager weighted by the inverse of the school size, 1/n. In sticklebacks this seems not to be the case, however. Though the food-finding rate of individuals in the school reduces with n , the improvement is much slower than predicted by the basic model. We argue that a variant of the information-sharing model accounting for interference among individuals affecting their food-seeking behaviour fits the data better.