Snake functional traits are more influenced by microhabitat than by environmental gradients in the Upper Paraguay River Basin

Understanding the mechanisms that shape species distributions and community structure is essential for biodiversity conservation. In this study, we investigate the functional diversity of snake species in the Upper Paraguay River Basin (UPRB), addressing four key questions: (1) Do environmental characteristics of the UPRB influence snake species distribution? (2) Do snake functional traits explain species’ occurrence in specific communities? (3) How do environmental characteristics influence aspects of functional diversity? and (4) How are snake traits related to microhabitat use? We analyzed occurrence and trait data for 145 snake species using multivariate approaches to assess the contributions of environmental variables and functional traits. Our results demonstrate that environmental variables significantly shape species distributions across the UPRB. In contrast, functional traits alone did not predict community composition at broader spatial scales (habitat). However, functional diversity indices responded to environmental gradients, indicating that certain aspects of trait composition vary with local habitat conditions. Additionally, traits were strongly associated with microhabitat preferences, revealing fine-scale trait–environment relationships. These findings highlight the complexity of community assembly in Neotropical snake assemblages and the value of integrating environmental gradients, functional diversity metrics, and trait-microhabitat linkages into conservation strategies.