Dietary composition of Oxyrhopus trigeminus in the Brazilian semiarid: new records, a literature review, and an incidental case of plastic ingestion

The Caatinga, the largest seasonal dry tropical forest in South America, has been experiencing significant environmental disturbances due to deforestation, agricultural expansion, and increasing energy infrastructure installation. These changes can impact local biodiversity, particularly aspects of natural history, such as trophic ecology. This study investigates the diet of Oxyrhopus trigeminus (the Brazilian false coral snake) in the Caatinga biome of northeastern Brazil, combining a literature review and an analysis of stomach and intestinal contents of 48 specimens. Our findings confirm that the species primarily preys on lizards, particularly Tropidurus hispidus and Ameivula ocellifera , which are among the most abundant lizards in the semiarid region of the Caatinga. Additionally, we report for the first time the presence of Micrablepharus maximiliani in the diet of O. trigeminus . The study also documents the ingestion of plastic fragments, highlighting a growing concern regarding pollution in natural environments and its potential effects on trophic interactions. As part of the study, weight and morphometric data were collected from all examined specimens; although not the primary focus, these measurements are included as supplementary information, given their potential value for future comparative and ecological analyses. Given the increasing habitat alterations in the Caatinga, changes in prey availability may potentially affect the dietary patterns of Oxyrhopus trigeminus and other snake species. Despite the limited sample size, our findings highlight the importance of baseline dietary data and underscore the need for long-term monitoring to better understand how environmental changes may influence predator-prey dynamics and the ecological stability of semiarid ecosystems.