Diet of post-metamorphic Rhinella icterica (Spix, 1824) (Anura: Bufonidae) from the Araucaria plateau of Rio Grande do Sul, Brazil

The toad Rhinella icterica (Spix, 1824) is distributed in the Atlantic Rainforest of Brazil, but can be found also in Paraguay and Argentina. Few studies have reported on the diet of adults of this species and none on the diet of post-metamorphics. In this study we analyzed stomach contents of post-metamorphic R. icterica in order to assess the composition of ingested preys and the relation between body size of the toads with the volume retrieved from the stomachs. We collected 45 post-metamorphic individuals at the Centro de Pesquisa e Conservacao da Natureza – Pro-Mata (CPCN – PRO-MATA), Rio Grande do Sul, Brazil. Stomach contents were recovered through stomach flushing after measuring and weighting the toads. The retrieved prey clump was also weighted and the 1293 prey items were classified into 13 categories of the lowest possible taxonomic level. Formicidae were the most well represented prey group, accounting for 81% of the preys, followed by mites belonging to the suborder Oribatida (8,8%) and order Mesostigmata (3,5%), while Ixodidae and Gastropoda showed values below 0,07%. On one hand we retrieved larger prey volumes from toads with a larger snout-vent length, but on the other hand larger prey volumes did not result in a larger prey richness. A larger prey volume was represented by a larger number of prey. While adults feed mainly on Coleoptera and Hymenoptera the diet of juveniles is composed of mites and Hymenoptera.