Herpetofauna of a Cerrado-Caatinga transition area in the municipality of Pedro II, Piauí state, Northeastern Brazil

Abstract

Abstract Anthropogenic disturbances represent a direct threat to populations of amphibians and reptiles. Therefore, herpetofaunal checklists are important to understand the species distribution, to fill sampling gaps, and aiding protection initiatives for these animals. Herein, we present the first herpetofaunal checklist of the municipality of Pedro II, Piauí state, Northeastern Brazil. It is inserted in the Complexo da Serra Grande bioregion within a transitional area between the Caatinga and Cerrado biomes. We searched for amphibians and reptiles using a non-systematic methodology over five years, from January 2019 and April 2023. We found 82 species, 27 amphibians, and 55 reptiles, representing the third region with the highest species richness in Piauí state. Except for the species with deficient data or not evaluated, all amphibians and reptiles are classified as least concern regarding the risk extinction. Most amphibians and reptiles reported in Pedro II are widely distributed in Brazilian biomes, but three snakes are endemic to the Caatinga biome and transitional zones: Boiruna sertaneja, Erythrolamprus viridis, and Epictia borapeliotes. Additionally, it is the only region in Piauí state where the species Kinosternon scorpioides, Epictia borapeliotes, and Micrurus lemniscatus occur. Almost half of the species of amphibians and reptiles known in Piauí state occur in the municipality of Pedro II, which might be associated with different phytophysiognomies within the Caatinga and Cerrado biomes influencing this region. Overall, our work contributes to unveiling the rich herpetofauna of this understudied area from the Complexo da Serra Grande bioregion, raising awareness of the need for effective conservation plans to maintain and preserve this real herpetofaunal “hotspot” in Piauí state.