WHY DOES TAIL LOSS INCREASE A LIZARD'S LATER VULNERABILITY TO SNAKE PREDATORS?

Abstract

We examined how autotomy–induced shifts in behavior of a diurnal lizard (Lampropholis guichenoti) and two natural snake predators influence the outcome of predatory interactions. During staged encounters in seminatural enclosures, we estimated the consumption order of lizards with recently autotomised tails (“tailless”) and intact tails (“tailed”). Tail loss increased a lizard's chances of being consumed first by a diurnal snake (Demansia psammophis), but not by a nocturnal species (Rhinoplocephalus nigrescens). We presented snakes with an inert tailed lizard vs. tailless lizard, scoring which was consumed first. Neither predator actively selected tailless prey. We quantified variation in the behavior of tailed and tailless lizards that determines the outcome of predator–prey interactions. Tailless lizards were not easier to detect visually or via chemoreception than were tailed lizards. Instead, the higher consumption rate of tailless lizards by the diurnal snake probably reflects reduced locomotor performance, and their tendency to flee sooner from approaching predators (thereby eliciting attack by this snake). In contrast, tail presence or absence did not determine a lizard's chances of detection by the nocturnal snake. Thus, tail loss can induce shifts in behavior of lizards, affecting their later chances of being consumed by some predators, but not by others.