Identifying biodiversity hotspots of terrestrial and freshwater vertebrates in Buenos Aires province, Argentina: a guide to conservation planning

Biodiversity loss is a major environmental challenge, and limited resources require conservation actions to be strategically prioritized. Buenos Aires Province, Argentina, is one of the most transformed, with over 60% of its territory altered by agriculture and urbanization and only 5% formally protected. This study identifies priority areas for the conservation of terrestrial and freshwater vertebrates in the province. We compiled extent of occurrence maps for all native vertebrate species using IUCN assessments, national red lists, field surveys, and biodiversity databases. Distributions were mapped across the 135 districts that serve as administrative units. To estimate conservation importance, species were weighted by threat status and endemism, and potential ranges were delineated under the precautionary principle. The province hosts 708 vertebrate species: birds (55%), freshwater fish (22%), mammals (11%), reptiles (8%), and amphibians (4%). Ten are strict endemics, and many are threatened. We identified 18 districts with high species richness and 15 with the highest conservation priority, concentrated in the Paraná Delta, the Atlantic coast, and the Ventania and Tandilia highlands. Our results provide an updated, province-wide assessment to support decision makers in developing conservation strategies. Strengthening connectivity, safeguarding freshwater ecosystems, and fostering science–policy–community strategies will be crucial.