Global dynamics of functional composition in CITES-traded reptiles

Global wildlife trade is a billion-dollar industry, with millions of individuals traded annually from a diversity of taxa, many of which are directly threatened by trade. Reptiles exhibiting desirable life-history or aesthetic traits, such as large body sizes or colorful morphologies, are traded preferentially. A key issue is understanding geographic and temporal variation between desirable species traits and their trade. Poor understanding of this can generalize patterns of consumer trait preferences and conceal functional consequences of wild harvest in ecosystems. Using records of legal, international trade in Convention on International Trade in Endangered Species (CITES)-listed reptiles between 2000 and 2020, we examine geographic and temporal variation in the functional composition of traded assemblages, both captive- and wild-sourced, identifying key hotspots and routes of functional diversity in trade. We also identify associations between functional traits and species presence in trade. We find that functionally diverse trade assemblages are exported primarily from the tropics, with hotspots in sub-Saharan Africa, and imported across Asia, Europe, and North America. Patterns of functional composition in trade remained broadly stable from 2000 to 2020. Globally, the species most likely to be traded were large, fecund, generalists. Sustained wild harvest of functionally diverse reptilian assemblages in trade hotspots, such as Madagascar and Indonesia, places substantial pressure on large-bodied reptiles that fulfill important ecological functions, including population control and nutrient cycling, while also endangering harvest-vulnerable species with slow life histories. Despite limited species-specific descriptions of reptilian ecological functions, management in harvest hotspots can safeguard ecosystem functioning by prioritizing protection for threatened species that contribute disproportionately to local and regional functional diversity.