Interplay of diet and sympatry in the morphological evolution of noctilionoid bats

Abstract

Aim: The remarkable ecomorphological diversity of the bat superfamily Noctilionoidea is the result of a diet-mediated adaptive radiation. Stemming from a putatively insectivorous ancestor, noctilionoid bats diversified to adapt to the widest range of dietary ecologies among mammals. The high concentration of noctilionoid diversity in the Neotropics raises the question as to whether competitive ecological interactions influenced their diversification. However, patterns of morphological diversification along gradients of coexistence in Noctilionoidea are understudied. Here, we assessed the effect of dietary adaptations on patterns of morphological divergence associated with coexistence in noctilionoid bats. Location: The Americas and the Caribbean. Taxon: Bat superfamily Noctilionoidea. Methods: Using a set of five dental morphological traits and a sample of 108 species, we quantified morphological distances between noctilionoid species pairs to reveal patterns of morphological divergence along gradients of range overlap and dietary similarity. We incorporate phylogenetic information to control for the effects of species' relatedness on morphological distances. Results: Overall, we found a significant association between morphological divergence, coexistence and diet. Decomposing the correlation between morphological divergence and sympatry across dietary groups, our results revealed distinctive patterns consistent with both character convergence and divergence. Specifically, we found evidence of character convergence in herbivorous species and character divergence in omnivorous species. Main Conclusions: Our results indicate that the morphological diversification of noctilionoid bats followed parallel evolutionary trajectories of directional (both divergent and stabilising) and nonselective evolution linked to dietary adaptations.