Abstract
<title>Abstract</title> <p> Although snakes of the genus <italic>Oxyrhopus</italic> are generally regarded as opportunistic predators, the relative roles of interspecific dietary differentiation, ontogenetic shifts, and morphological constraints in shaping their feeding ecology remain poorly understood. We analyzed the diet of 429 preserved specimens representing six <italic>Oxyrhopus</italic> species from Bahia, Brazil. Dietary composition was quantified using the Index of Relative Importance (%IRI), trophic overlap was estimated with Pianka's niche overlap index, ontogenetic changes were evaluated using linear models, and morphological constraints were assessed through relationships between snake body size, head width, and prey dimensions. Species showed distinct dietary compositions and generally low trophic overlap, supporting trophic niche differentiation among sympatric congeners. Juveniles fed predominantly on lizards, whereas adults incorporated proportionally more mammals and birds. Prey size increased with snake body size rather than ontogenetic stage itself, and head width was positively associated with prey width, indicating that cranial morphology constrains maximum prey size. Together, these results show that trophic niche differentiation in <italic>Oxyrhopus</italic> arises from the interaction between interspecific dietary divergence, ontogenetic dietary shifts, and morphological constraints. This study provides the first comparative assessment integrating these mechanisms across multiple sympatric <italic>Oxyrhopus</italic> species. </p>