Incidence patterns of ectodermic lesions in wild populations of Common Wall Lizard (Podarcis muralis)

Abstract

Skin lesions frequently present in adult lizards may be due to a variety of causes, both physical and infectious, including excessively high humidity and environmental temperature, malnutrition, concurrent disease etc. On the other hand, skin lesions in lizards could be simple evidence of various behavioural patterns and biotic interactions. However, studies on frequencies of dermal lesions and their anatomical and environmental correlates in lacertid lizards are rare. Here, we use Podarcis muralis to analyse the relations between occurrence of ectodermal lesions and three possible indicators of environmental stress (body condition index - BCI, infestation by ticks and tail condition) by evaluating differences among local populations at uni- and multivariate level. Our results showed that BCI, together with body size and sexual size dimorphism, varied between populations but had no direct influence on the presence of lesions. Males had higher frequencies of lesions and ticks but lower frequencies of broken tails than females. All three parameters varied between sites likely due to differences in predation/parasite exposures and agonistic interactions with conspecifics between sexes and populations. Results of multivariate analyses suggested that the occurrence of lesions is decoupled from the other morphological stress indicators. Detected associations indicated that relations between presence of lesions and other analysed variables are rather complex. Directions for further research on ectodermal lesions in lacertid lizards are provided.