Assessing the potential impacts of exotic reptile species advertised for sale in the South African pet trade

Assessing the impacts of non-native species is essential for preventing, monitoring and eradicating introduced species. In South Africa, impact assessment has been adopted for species introduced through various pathways, including the legal and illegal wildlife trade. We conducted a comprehensive literature search to collate information on the impacts associated with 76 non-native reptiles sold as pets in South Africa, using the Generic Impact Scoring System (GISS), Environmental Impact Classification for Alien Taxa (EICAT), and Socio-Economic Impact Classification for Alien Taxa (SEICAT). Using GISS, we found that 12 species were associated with environmental impacts (E_GISS), and 10 had socio-economic impacts (SE_GISS). For EICAT and SEICAT, 12 species had environmental and seven had socio-economic impacts, respectively. Despite extensive research efforts, most (82 %) of the evaluated species had no documented impacts, implying that these species are unlikely to have significant impacts. Environmental impact scores differed between GISS and EICAT, indicating that both schemes should be used when assessing environmental impacts. In contrast, while the socio-economic impact scores of GISS and SEICAT were comparable, both schemes provide a comprehensive assessment by capturing different aspects. Popular pet species such as the Iguana iguana, Python bivittatus, and Trachemys scripta elegans, already introduced in the country, scored the highest impacts in all schemes, prompting strict monitoring and policy development regarding their trade. Using multiple impact schemes, we show that despite extensive research efforts, 82 % of reptile species sold as pets in South Africa have no documented impacts. Concerningly, species with documented impacts showed high environmental but minor socio-economic impacts.