Profitability, rate maximization, and reward delay: a test of the simultaneous-encounter model of prey choice with Parus atricapillus

Black-capped chickadees always preferred higher-profitability prey, regardless of encounter rate. Chickadees seem to have been choosing prey so as to maximize profitability. Contrary to what has previously been assumed, foragers often choose prey to maximise profitability rather than long-term intake rate, the traditional currency of optimality models of foraging. This might have been obscured by the empirical emphasis on testing the sequential-encounter diet model. The sequential-encounter case does not present foragers with a clearly dichotomous choice between maximization of short-term and long-term intake rates, whereas the simultaneous-encounter case does. A model of prey choice based on maximizing profitability that incorporates discounted future rewards can explain a variety of empirical results. -from Authors