Where to live in Lisbon: urban habitat used by the introduced Italian wall lizard (Podarcis siculus)

Abstract

Exotic animal invasions constitute a major threat to biodiversity worldwide. Our assessment determined the core range occupied by the Italian wall lizard (Podarcis siculus) in the urban area of Parque das Nações (Lisbon, Portugal), where it was accidentally introduced two decades ago. Des-pite the apparent current scenario of non-expansion, the alien species interferes with the local distribution pattern of the native P. virescens, with both lizard species shown to use the available microhabitats differently. The native P. virescens population displays an overall heterogeneous distribution in the urban matrix. On the other hand, the occupancy of the exotic species clusters within the original area of introduction (garden in front of the Lisbon Oceanarium), as well as in adjacent gardens. There, P. siculus replaced the native P. virescens as the only lizard species present. Appa-rently, there is no known reason there that prevents the alien lizard from colonizing more available geographic area and expanding.