Habitat suitability and connectivity modelling predict a latitudinal-driven expansion in the Mediterranean basin for a historically introduced reptile

Abstract

Species introductions outside their native ranges, often driven by trade and other anthropogenic activities, present significant ecological challenges. Reptiles, frequently traded as pets for their attractiveness, are particularly susceptible to such introductions, leading to shifts in distribution patterns and potential ecological impacts. The common chameleon (Chamaeleo chamaeleon), which has been historically introduced in several European countries, is such an example, yet no overall assessments are available to date for this species. In this study, we used ecological niche models to assess habitat suitability for the common chameleon in the Mediterranean basin for current and future scenarios. Concurrently, circuit theory techniques were employed to evaluate habitat connectivity in two historically introduced areas. We identified areas of high habitat suitability and dispersal corridors in introduced regions. Our results reveal a latitudinal gradient in habitat suitability changes, with the species facing both expansion and decline in different parts of its range, depending on the ecozone considered. Severe declines are noted in southeastern Spain, Tunisia, and Israel, while habitat suitability increases westwards in Portugal, Morocco, and Southern Italy. These insights contribute to a better understanding of the common chameleon’s ecological dynamics, providing a foundation for targeted management and conservation efforts. Our study highlights the importance of integrating ecological niche modelling and circuit theory techniques to predict habitat suitability and identify critical dispersal corridors for effective conservation strategies. Considering the ongoing challenges posed by human-mediated dispersals for the common chameleon, our research establishes a foundation for future studies to enhance our understanding of this elusive species.