What does the future hold for a thermophilus and widely introduced gecko, Tarentola mauritanica (Squamata: Phyllodactylidae)?

Abstract

The continuous growing and movement of the human population is increasing the frequency in translocating species from their native ranges to novel environments. However, biological invasions offer a rare opportunity to investigate how species are able to colonise and adapt to new conditions. In that sense, Ecological Niche Models (ENMs) can be a powerful tool to predict where invasive species will spread over the next decades, although they depend heavily on climatic niche conservatism between native and exotic ranges. To reduce these uncertainties, ENMs can be refined by accounting for dispersal constraints. The common wall gecko, Tarentola mauritanica is a native and widespread Mediterranean lizard that has been introduced across different tropical and sub-tropical regions. In this study, we aim to predict the potential and future distribution of T. mauritanica geckos using correlative models, its potential colonization regions under a dispersal model, and the niche overlap between native and introduced populations. The correlative models predict that the most suitable geographic areas for this gecko correspond to Mediterranean-type ecosystems, such as California, central Chile, the Cape Region of South Africa, around the Caspian Sea, south-eastern Asia, and south-western and southern Australia. The species distribution models projected to 2061–2080, forecast that the range of T. mauritanica is likely to shift towards northern latitudes but, surprisingly, not to expand. According to the dispersal models, T. mauritanica will be able to colonise a similar geographic range compared to the one obtained with the correlative models for the future. Finally, the niche overlap results demonstrate that T. mauritanica’s realised niche has not been conserved over space, as the naturalised climatic niche of the introduced populations differs significantly from its native one. The latter results suggest that there has been no climatic niche conservatism during the several introductions of T. mauritanica, and that this species seems to be able to cope with novel and more humid environments, typical from the tropics.