Optimizing prey-capture behaviour to maximize expected net benefit

Biologists have long known that predators vary (modulate) their prey-capture behaviour in response to different prey. We propose an optimization model to predict when and why capture behaviour should vary. The predator's attack 'effort' (reflecting any unidimensional kinematic variable such as acceleration) determines both the probability of capturing the prey and the energetic cost of attack. The optimal capture effort then reflects a balance between the marginal benefit of greater success and the marginal cost of added energy outlay. Using this model, we explore how the optimum responds to variation in prey traits (evasiveness and energy value). The model predicts three different types of response to prey variation: (1) no modulation, (2) increased effort for more elusive prey and (3) decreased effort for more elusive or lower energy prey.