The Herpetological Journal

Authors: Roberta R. Pinto, Samuel C. Ribeiro, Átilas R. Sousa & Robson W. Ávila

Abstract: Epictia borapeliotes is a fossorial blind snake endemic to north-eastern Brazil. Despite its ecological role as a specialised predator of social insects, its occupancy patterns and the environmental drivers within the Caatinga and Atlantic Forest biomes remain poorly understood due to its cryptic lifestyle. This study reassessed the species' geographic distribution, expanded the knowledge of its morphological variation, and identified areas of environmental suitability through Ecological Niche Modeling (ENM). Based on a dataset of 135 individuals and 42 filtered occurrence points, seven modeling algorithms were correlated with 11 bioclimatic and topographic variables. Results indicate a broad distribution across the Brazilian Northeast, encompassing approximately 100,000 – 140,000 km² across Caatinga, Atlantic Forest and urban zones, suggesting high habitat plasticity. ENM showed high predictive performance (TSS = 0.87; ROC = 0.89) and identified peak habitat suitability in the eastern Borborema Plateau and eastern Rio Grande do Norte. Habitat suitability was primarily driven by annual temperature range (Bio7), isothermality (Bio3), precipitation seasonality (Bio15) and terrain slope, with optimal conditions occurring on moderate slopes (mean ~8°) that provide stable thermal gradients and favourable conditions for prey availability. Models incorporating ENVIREM predictors expanded the estimated suitable area by approximately 43%, highlighting the importance of energy-water balance variables – such as potential evapotranspiration and climatic moisture index – in shaping the species’ ecological niche. Despite occurring across a range of rainfall regimes, Epictia borapeliotes appears to depend on thermally stable environments to maintain its biological functions. These findings provide a spatial framework for targeted surveys and reveal a substantial mismatch between suitable habitat and protected areas, offering key insights for conservation planning of fossorial fauna in seasonal tropical ecosystems.

Keywords: Scolecophidia, epictini, geographic distribution, ecological variation, snakes