Chemosensory predator recognition in the lizardPodarcis hispanica: Effects of predation pressure relaxation.

We compared the behavior of two subspecies ofPodarcis hispanica lizards in cages that had been chemically marked by a saurophagous snake, the viperVipera latastei. One of the subspecies (P.h. atrata) has experienced a relaxation from predation pressure by this viper, as snakes were eradicated from the island it inhabits over 100 years ago. Nevertheless, individuals fromP.h. atrata responded to the snake's chemicals similarly to individuals from a population ofP.h. hispanica, currently sympatric withV. latastei. Lizards exhibited more stress-indicating behaviors (foot shakes, tail vibrations, sudden starts), became less mobile, and tongue-flicked more while moving in a snake-inhabited terrarium than when in a clean, unfamiliar terrarium.