ABSTRACT Ecological niche modelling (ENM) is a valuable tool in climate studies, supporting investigations into species distributions and historical refugia. This approach is especially relevant for lizards in the genus Brasiliscincus whose poorly defined distributional limits underscore the need for ENM‐based studies to better understand their biogeographic patterns. After an extensive record review, we applied ENM to analyse the distribution patterns of Brasiliscincus spp. and assess whether bioclimatic factors predict niche similarity and equivalence between B. agilis and B. heathi . Using Ensemble of Small Models, we mapped habitat suitability for current and historical periods. Additionally, we tested niche equivalence and similarity and assessed niche overlap to quantify shared ecological space between both species. Occurrence records and the potential distribution indicate that B. heathi is distributed across open areas of the Caatinga and Cerrado, whereas B. agilis occurs in the coastal regions of the Atlantic Forest, from Bahia to Rio de Janeiro, including its first record in the state of Minas Gerais. Brasiliscincus caissara , in turn, appears to be restricted to the Restinga ecosystem in the state of São Paulo. No evidence of sympatry was found among these species. Despite their close geographic occurrence, the potential distributions overlapped only minimally and showed low climatic niche overlap, indicating that they occupy distinct niches that are neither equivalent nor more similar than expected by chance. The distribution boundaries between species appear to be shaped by both current and historical climatic suitability, as well as geographical barriers. The boundary between B. agilis and B. heathi coincides with the mouth of the Paraguaçu River and Todos os Santos Bay and B. agilis is separated from B. caissara by only 80 km, with the Serra da Bocaina and Ilha Grande Bay acting as a natural barrier. Our results are supported by models with good performance, consistent with the actual occurrences of B. agilis and B. heathi , in agreement with their evolutionary history, stable climatic areas and Pleistocene refugia.
Neves et al. (Tue,) studied this question.