Patterns of Haemoproteus occurrence in wild populations of Podarcis muralis

The common wall lizard, Podarcis muralis, is widespread in the Italian territory and, for this reason, it was studied extensively in the last decades. However, some aspects of its biology are still unclear and require specific research. This is the case of the parasite-host interaction with ubiquitous blood parasites of terrestrial vertebrates such Apicomplexa. Given the broad distribution of the common wall lizard in the territory and the frequent presence of haemoparasites in wild populations of reptiles, it is worth investigating how the two counterparts interact and the possible factors affecting presence and abundance of such parasites in lizard populations. In this study we have investigated 61 populations of the Italian peninsula from 2008 to 2017, analyzing frequency and intensity of the presence of Haemoproteus spp. in blood samples in relation to lizard size, latitude and checking for any effect of seasonality. The analyses showed that females are generally parasitized more frequently and intensely than males; moreover, in both sexes size has a positive effect on parasite presence as larger individuals are parasitized more frequently and intensely; on the other hand, latitude has a negative effect on as northern populations show lower parasite presence and load in both sexes. Eventually in terms of seasonality, we recorded a slight though significant effect in both sexes on both parasite presence and intensity. In conclusion, our study highlights that many different factors can influence such parasite-host interaction, although seasonality appears to play a marginal role in comparison to life-history traits or geographic factors