Trophic ecology of small to large hylids from an Amazonia-Cerrado transitional zone in Brazil

Abstract

The diet of an organism is related to its intrinsic characteristics, such as morphology, physiology, and behavior, and those of the prey it consumes. For species occurring in sympatry, the knowledge of the mechanisms that favor the co-occurrence of morphologically and ecologically similar species may be important to understand the resource partition in the assemblage. In this study, we analyze the diet of small to large hylids (i.e., Scinax fuscomarginatus, Dendropsophus anataliasiasi, Boana caiapo, and B. raniceps) in an Amazonia-Cerrado transitional zone, verifying if the diet of species with different body sizes is similar and if species diet is explained by the availability of prey in the environment. We found that the dietary patterns of the studied hylids were not driven by prey availability in the environment, with species feeding preys in an opportunistic way. In addition, the diet composition was similar among species, however, the volume of consumed prey varied according to the body size, with large species feeding more prey volume than the small ones. This pattern is predicted by the optimal foraging theory, in which larger predators tend to maximize their energy intake by consuming large prey. Altogether, the segregation depending on the body size can play a key role in trophic resource partitioning, with small species feeding small prey and larger species consuming small to large prey, but preferring the larger ones when there is an option, avoiding interspecific competition.