Nardelli, A. & Iversen, D. & Tabarelli de Fatos, K. & Bombieri, G. & Corradi, L. & Bin, S. & Pederzoli, A. & Toscano, Y. & Zotto, M. dal (2021) -
At the edge of meridionalization: the case of alien lizards Podarcis siculus Rafinesdque-Schmaltz, 1810 (Sauria: Lacertidae) around Lake Garda (northern Italy). - Abstracts XII° Congresso Nazionale Societas Herpetologica Italica. Rende (Cosenza), 1-5 ottobre 2018. pp. 110-111.

×Alien species constitute a serious threat to biodiversity, also contributing to reduce the ecological resilience of ecosystems to global climate changes. The Italian wall lizard Podarcis siculus Rafinesque-Schmaltz, 1810 (Sauria: Lacertidae) is the only species in the genus Podarcis that can be considered as a true alien pest, since it has established reproductive populations on three different continents, seeming capable of adapting to a variety of habitats, temperature ranges and food sources, also competing with native lizard species. P. siculus, even though endemic to most of the Italian peninsula, was observed for the first time around Lake Garda (northern Italy) during 2016: in the municipality of Arco (Province of Trento), in the touristic area of Limone sul Garda (Brescia), in three garden centres in Padenghe sul Garda (Brescia), Peschiera and Castelnuovo del Garda and in Valeggio sul Mincio (Verona), inside the historical garden park “Sigurtà”. We have confirmed the presence of P. siculus after decades on Trimelone islet (Verona) as well, and in other localities in the pre alpine hilly area surrounding the southern edges of Lake Garda, which clearly affects their climate conditions. We used phylogenetic analyses to confirm the exotic origin of most of these populations, which derive from specimens imported throughout aged olive trees trading activities. Multiple separated colonization events occurred, since in at least two sites different genetic clades, imported from various localities of central and southern Italy, can be found thriving together. This brought to hybridization that has probably offset the negative consequences of low genetic diversity typically occurring in newly established animal populations. Aged olive trees perfectly host P. siculus acting as a Trojan horse for the colonization of new environments, representing an all-in-one microhabitat, where lizards can find food and basking sites, lay eggs and survive to cold climate conditions during winter. Aged olive trees are frequently sold to private citizens for ornamental purposes and, to this regard, garden centres act as stepping stones for a rapid and unpredictable lizard invasion, which could affect a large portion of northern Italy, firstly south of the 46th parallel. The presence of P. siculus exotic lineages brings forward major considerations on their impact on native P. s. campestris and P. muralis populations occurring in the same area. Extreme adaptations that we observed in the field, the role of olive trees and other allochthonous entities in favouring lizard survival, and the effect of alien P. siculus on habitat meridionalization around Lake Garda are discussed.
Masó, G. & Vicente-Sastre, D. & Fitze, P.S. (2022) -
Neuer Data used in `Masó et al. 2022 Intrinsic climatic predictability affects ornamental coloration of adult males: evidence for compensation among carotenoid- and melanin-based coloration, Functional Ecology.Eintrag - https://digital.csic.es/handle/10261/259670 