Amphibian trophic ecology in increasingly human-altered wetlands

Abstract

Habitat destruction and alteration are among the major causes of worldwide amphibian declines. Resource limitation in altered environments can potentially affect trophic ecology of amphibians and contribute to decline. In this work, we analyzed changes in resource availability and use, and the population abundance of eight amphibian species from six wetlands that differ in type and degree of human disturbance. Food resource availability varied among sites and the occurrence of some arthropods was correlated with type of disturbance regime. Diet evenness, richness, and niche breadth were similar among sites or months. Nevertheless, diet composition showed significant variation among samples for all species. Diet composition changes among populations were correlated with resource availability in four species (Lysapsus limellum, Dendropsophus nanus, Hypsiboas pulchellus and H. punctatus), but not in the remaining species (D. sanborni, H. raniceps, Scinax nasicus and S. squalirostris). These results suggest that species that are able to adjust their diets according to prey availability may have an adaptive advantage in changing environments associated with anthropogenic disturbances. Given the increasing rate of alteration of wetlands by urbanization, agriculture, and livestock grazing, understanding trophic processes in these habitats is important for preserving the great biodiversity living in these habitats.