Anuran Assemblage Structure in the Serra Da Capivara National Park, Piauí State, North-Eastern Brazil

Biological communities consist of species that coexist and interact with each other and the environment over the same spatial and temporal scales. How species use the available resources can shape community structure, particularly in mechanisms that favour species coexistence, such as niche partitioning. This study investigated the spatial and trophic dimensions of the ecological niche of anuran species from the assemblage of the Serra da Capivara National Park. We recorded the microhabitat use of 551 individuals and the diet of 239 individuals across 16 species. We used null models to test whether there is spatial and/or trophic niche partitioning in the anuran assemblage, with a subsequent phylogenetic principal component analysis to assess the influence of phylogenetic and ecological factors on the use of available resources. Overall, we found no evidence of spatial or trophic niche partitioning in the investigated assemblage. Despite this lack of partitioning, our results indicate that these niche dimensions are shaped by different factors: Spatial patterns reflect a strong phylogenetic signal (historical constraints), whereas trophic patterns are primarily driven by local ecological factors. By demonstrating that these species maintain phylogenetically structured habitat preferences while remaining opportunistic in their diet, this study provides important insights into the organisation of anuran communities in semiarid environments.