Antipredator responses of two anurans towards native and exotic predators

Abstract

AbstractWhen faced with the risk of predation, tadpoles of many amphibian species are known to modify their phenotype. In this work we studied the effect of an exotic species, the red swamp crayfish (Procambarus clarkii), on the phenotype of two species of amphibians with different reproduction habitats: the Iberian painted frog, Discoglossus galganoi, that normally reproduces in temporary water bodies and the common toad, Bufo bufo, that reproduces in permanent water bodies. The responses were compared with the ones shown in the presence of a native predator, dragonfly (Aeshnidae) larvae. Behaviour, growth and morphology of tadpoles were monitored in a factorial experiment with five treatments. Our results showed that only the permanent habitat species altered its behaviour and life-history traits in the presence of P. clarkii; however, this was mediated by chemical cues from consumed conspecifics. Antipredator responses of B. bufo towards the exotic crayfish were similar to the ones towards the native predator, while D. galganoi responded to the dragonfly larvae but not to P. clarkii. This may be the result of infrequent colonization events of temporary habitats by the crayfish. Therefore, the consequences of the introduction of P. clarkii might be more serious for D. galganoi and other species living in temporary habitats. Species breeding in permanent habitats, more prone to having generalized antipredator responses, may be relatively protected against this exotic crayfish although the effectiveness of these responses still needs to be tested.