Reptile species of the western region of Paraná State, southern Brazil

Abstract The state of Paraná exhibits one of the most significant data gaps on reptile biodiversity among Brazilian states. One of the most pronounced data gaps is in the western region of Paraná State, where only a single inventory has been published to date, conducted in a forest area managed by Itaipu Binacional. The western region of Paraná State encompasses 50 municipalities and four protected areas, including the largest remaining fragment of the Semideciduous Seasonal Forest within the Atlantic Forest. In this context, this study aimed to: compile a list of reptile species for western Paraná State based on secondary data and records from scientific collections; gather information on the conservation status of each species; map the spatial distribution of species richness; and compare the reptile fauna of western Paraná State with that of other regions within the Atlantic Forest. We recorded 62 reptile species in western Paraná State, including three species of Testudines, one of Crocodylia, and 58 of Squamata —comprising 47 snakes, seven lizards, and three amphisbaenians. Approximately 95% of these reptile species are classified as Least Concern on state, national, and international Red Lists. The species composition of the reptile fauna in western Paraná State showed the highest similarity to adjacent regions bordering the Paraná State, such as Misiones Province in Argentina and Alto Paraná Department in Paraguay. We found that over one-third of the municipalities in western Paraná State had no reptile records, while another third had fewer than five species documented. Furthermore, none of the protected areas in the region has systematically surveyed their reptile fauna, suggesting that reptile biodiversity in the western region of Paraná State may be underestimated. Therefore, additional biodiversity inventories—particularly within protected areas—are essential to accurately assess reptile biodiversity and guide effective conservation and management strategies in this region.