Size- and Sex-Dependent Variation in Diet of Rhinella arenarum (Anura: Bufonidae) in a Wetland of San Juan, Argentina

Abstract

We studied body-size and sex-dependent variation in the diet of Rhinella arenarum in a wetland of San Juan, Argentina. We hypothesized that prey size would be positively correlated with toad size and that the guts of larger toads would contain fewer prey items. Toads from this population eat primarily ants and, secondarily, beetles, indicating a feeding strategy that is intermediate between specialist and generalist. This feeding strategy may be influenced by prey availability. Contrary to our expectation, prey size was not related to toad body size, and the relationship between the prey number and toad body size was positive. Our findings, coupled with similar diet studies of toads, suggest geographically widespread phylogenetic conservatism in the diet of bufonids.