Diet and morphometry of two poison frog species (Anura, Dendrobatidae) from the plateaus surrounding the Pantanal of Mato Grosso do Sul state, Brazil

Abstract

ABSTRACT The plateaus surrounding the Pantanal in Mato Grosso do Sul are highly threatened by land-use conversion and are home to Ameerega berohoka and Ameerega picta, two species of poison frogs renowned for their aposematic coloration and toxic skin. The species have diurnal and terrestrial habitats and are often observed among dead tree branches, leaf litter or under rocks. Herein, we investigated the diet and sexual dimorphism of body size in A. berohoka and A. picta, aiming to increase our understanding of the natural history of both species. We collected A. berohoka specimens from the Bonito municipality and A. picta from the Rio Negro Municipality and obtained 1,600 prey items organized into 12 categories. We found that formicid insects had the highest index of relative importance and were the most frequent prey category for both species. Despite prey items such as Acari and Isoptera being present in the diet of these species, the niche breadth of these species was low. We found no evidence of sexual dimorphism in body size or body shape for A. berohoka and A. picta. Based on our findings, we conclude that both species are ant specialists, as proposed for other Ameerega species.