Introduction pathways and socio-economic variables drive the distribution of alien amphibians and reptiles in a megadiverse country

Abstract

Aims: We identify alien reptiles and amphibians, invaders or not, in Brazil and evaluate the following: (a) which alien species are found in the country; (b) where they originate from; (c) how they are distributed; (d) why and how they were introduced; and (e) which factors affect the record incidences and local richness of these species. Location: Brazil. Methods: We conduct a comprehensive survey of different data sources to collect records of alien amphibians and reptiles. We then use a causal model approach to evaluate the influence of space, climate, anthropogenic predictors, and introduction pathways on alien richness and number of records. Results: We find a total of 2,292 records of 136 species of alien reptiles and amphibians. Although species from many regions of the world can be found, most are snakes, lizards and anurans originating in the Americas. Although records of alien amphibians and reptiles are found throughout Brazil, they are concentrated in more economically developed areas. Socio‐economic measures have both a direct and indirect causal relationship over the distribution of alien species and affect all introduction pathways, which are key factors explaining the alien species’ distribution. Pet trade was directly related to alien diversity, while all the three introduction pathways contributed to explain the number of records. Main Conclusions: We reveal a high diversity of alien amphibians and reptiles widespread in an already megadiverse country. The finding that alien richness occurs in highly populated and wealthy areas and that it is linked to the pet trade helps to direct efforts towards the surveillance and prevention of the spread of alien species in Brazil. A higher record incidence is associated with species introduced accidentally or for human consumption, mainly represented by a few already invasive widespread species, impairing management measures.