USDA National Wildlife Research Center Symposia


Date of this Version

August 2007


Published in: Witmer, G. W., W. C. Pitt, and K. A. Fagerstone, editors. 2007. Managing vertebrate invasive species: proceedings of an international symposium. USDA/APHIS Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado, USA. Also available online at


Island ecosystems are highly sensitive to the impacts of introduced species. Non-native invasive snakes, lizards, and amphibians can introduce diseases into native populations and have other deleterious effects through predation, competition, and habitat manipulation. The United States (US) Virgin Islands are situated on the Puerto Rican Shelf in the Caribbean Sea and have a long history of human impacts and species introductions. Two species, the green iguana (Iguana iguana) and the red-legged tortoise (Geochelone carbonaria) were historically introduced and have become naturalized with little apparent impact to the local ecosystem. Recent years, however, have seen the introduction of several highly invasive species that have proved to have severe impacts when introduced elsewhere, specifically the Cuban treefrog (Osteopilus septentrionalis), cane toad (Bufo marinus), and the red-eared slider (Trachemys scripta). The distribution of non-native herpetofauna has been documented on all main islands of the US Virgin Islands and potential routes for introduction and dispersal have been identified. Additional species are still being identified, having arrived via cargo shipments from other Caribbean ports.