Urbanization affects refuge use and habituation to predators in a polymorphic lizard

Abstract

Prey–predator interactions are plastic behaviours shown by both players, which constantly modify their decisions depending on physiological conditions and ecological context. We investigated whether the behavioural response to repeated simulated predatory attacks varied between adult males of the common wall lizard, Podarcis muralis, inhabiting environments characterized by different degrees of human presence. Our aim was to detect possible effects of urbanization on antipredator responses, in terms of activity, time spent hidden in refuges and habituation. Moreover, since this lizard species exhibits intrapopulation colour polymorphism, we looked for the occurrence of possible correlations between antipredator strategy and individual ventral coloration. We found that urban lizards spent less time in their refuge after predatory attacks and decreased successive hiding times faster than rural lizards, suggesting different wariness towards a potential predator. Irrespective of population, yellow lizards gradually spent less time in the refuge before appearing and emerging outside than the other two morphs. Conversely, red lizards showed progressively longer appearance and emergence times after successive tests, suggesting a growing sensitization to the potential threat of a predatory attack. In conclusion, our study showed the occurrence of different levels of behavioural plasticity in common wall lizard's antipredator response: the population level, depending on ecological context, here different degrees of exposure to human disturbance, and the individual level, which suggests the occurrence of morph-specific antipredator strategies. Thus, using a lizard species as a model, we shed light on two key points of evolutionary ecology concerning both the antipredator response and the factors driving the maintenance of intraspecific polymorphism.