Maternal behaviour in response to predation threats in a vulnerable lizard from Patagonia, Argentina

Abstract

Climatic and ecological conditions can determine the existence and degree of parental care. In species that live in cold-temperate environments and exhibit high reproductive effort it is expected that parental care would have greater selective value. In this study, we aimed to detect maternal behavioural responses to predation threats in the lizard Phymaturus spectabilis from cold-climate environments of Patagonia, Argentina. Seventeen females with their offspring each were exposed to four treatments in the laboratory: first a treatment with no stimulus, and then in a random order a carnivorous sympatric lizard, a conspecific male and a simulated flight of a museum mount of a raptor. We analysed the occurrence of 11 specific behaviours. Two clearly different parental responses occurred. In the presence of the raptor, mothers stayed near the offspring and remained motionless longer than in the other treatments. Their freezing response is consistent with their cryptic coloration and this species may rely on this strategy to avoid raptor predation. In contrast, in the presence of the predator lizard, mothers presented higher frequencies of flights, tail waves and head bobs. Head bobs are commonly interpreted as dissuasive signals to the predator to discourage attack. The behaviours observed in P. spectabilis together with similar behaviours observed in congeneric species would suggest the existence of a common pattern of parental care related to the high reproductive investment in Phymaturus.