Abstract

We hypothesized that, through persistent predatory attacks, lizards should increase progressively the magnitude of their escape response. We simulated in the field a continuous attack by a persistent predator on Acanthodactylus erythrurus lizards and examined the characteristics of successive escape responses, microhabitats used for fleeing, and the refuges used. Lizards responded to the persistent attacks by increasing the distances they fled and the degree of cover in microhabitats into which they escaped. Lizards also changed their escape strategy from the first to the successive attacks. Initially, most individuals did not hide but stopped after running and remained vigilant, whereas almost all individuals hid subsequently. In addition, after successive predatory attacks, lizards used more structurally complex refuges (i.e., larger and with more obstructive cover). These refuges were probably safer although they may lower the lizard's capacity to observe the predator's subsequent behavior. These data suggest that lizards interpret persistent predatory attacks as an increase in predation risk and that lizards adjusted the magnitude of their escape and antipredatory responses to predation risk level.