The effects of morphology, phylogeny and prey availability on trophic resource partitioning in an anuran community

Several factors influence the partitioning of trophic resources in ecological communities, such as morphology, evolutionary history, and resource availability. Although the effects of morphology, phylogeny, and resource availability on trophic ecology have long been explored by theoretical studies, little has been done to empirically test these relationships. Here, we tested whether phylogenetic and morphological distances correlate with trophic niche overlap using a path analysis of multiple partial regression of distance matrices. Also, we tested whether niche breadth is influenced by body size using Phylogenetic Generalized Least Squares analysis. Trophic niche overlap was better explained by morphology per se than by the phylogenetic distance. We also found that predator's body size influences niche breadth calculated considering prey traits and availability, but not when we do not include these availability data. Additionally, trophic niche breadth was usually smaller when we considered prey traits and availability, differently from niche overlap, whose values increased when we did not consider these data. Our findings show that the interpretation of trophic niche in communities changes if we consider availability data, affecting inferences about coexistence and trophic specialization. Our study contributes to understanding trophic specialization and emphasizes the importance of incorporating prey availability and their traits into diet analysis. (c) 2020 Gesellschaft fur okologie. Published by Elsevier GmbH. All rights reserved.

Automated summary

Morphology and phylogenetic distance are more influential on trophic niche overlap, while body size affects niche breadth. Trophic niche breadth is usually smaller when considering prey traits and availability, whereas values of niche overlap increase when these data are not considered.