Signaling by prey animals can draw the attention of a predator and delay escape, both potentially lethal costs. Hypotheses to explain the evolution of this behavior typically involve benefits due to kin selection or reciprocal altruism. We consider an alternative mechanism – the ability of a signal to reduce the value of a prey patch to a predator, relative to other patches in the landscape. Previous theoretical models are restricted to one-prey one-predator systems and while signaling equilibria are identified, whether they are dynamically stable is not known. Previous work also keeps predator behavior to a minimum. We use evolutionary game theory and behavioral adaptive dynamics to identify signaling equilibria in a two-prey one-predator system. We define prey strategy as the probability of signaling upon detecting a predator, and predator strategy as the probability of pursuing a prey upon receiving a signal. We identify joint evolutionarily stable strategies, test for stability, and note conditions under which stable signaling can evolve.
Results/Conclusions
Our analysis reveals several interesting results. As the probability of detecting the predator increases, signaling is more likely to evolve if signal cost is sufficiently high. When signal cost is low, we find a non-signaling equilibrium where the predator always attacks. We find that mixed evolutionarily stable strategies exist for intermediate signal costs. Also, prey are more likely to signal upon detecting a predator when predators are more difficult to detect. On receiving a signal, the predator is more likely to attack as travel time between patches increases. This model offers a novel mechanism for the evolution of signaling behavior in group-living prey. It advances current understanding by allowing predator behavior to be more sophisticated, and truly testing pursuit-deterrence as an alternative mechanism to existing theories.