Trophic ecology of juvenile amphibians: relative level of myrmecophagy in two anuran species

ABSTRACTResearch on trophic niche dimensions is essential to understanding the role of species in ecosystems. In the case of amphibian conservation, it is particularly important to study juveniles, given the vulnerability of this life stage. Here, the diets consumed by juvenile Rhinella arenarum and Odontophrynus sp. were evaluated, with special attention paid to the incidence of ants. Diet composition was quantified by analyzing the amphibians’ stomach contents. The representation of different taxonomic prey groups was determined, and the relationships between the amphibians’ morphological traits and the characteristics of their prey were explored. Diet composition and diversity differed between juveniles of the two species. Juvenile R. arenarum occupied an intermediate position along the specialist-generalist spectrum. Their most commonly consumed prey were ants (mainly Solenopsis and Linepithema) followed by mites. Juvenile Odontophrynus sp. had a more generalist diet. Their most commonly consumed prey were Isopoda followed by Coleoptera and miscellaneous larvae. Snout-vent length (SVL) was greater for juvenile Odontophrynus sp. than for juvenile R. arenarum, but the latter consumed more prey. The results suggest that juveniles of R. arenarum tend to specialize more on ants than do juveniles of Odontophrynus sp.KEYWORDS: Anurajuvenile amphibiansFormicidaetrophic ecologyRhinellaOdontophrynus AcknowledgmentsWe thank Francisco Sola and Martín Bolazzi for identifying some ant genera and species. We are grateful to the team at the Laboratory of Systematics and Natural History of Vertebrates -Herpetology (Faculty of Sciences, UdelaR, Uruguay) for their contributions over the entire course of our work. We thank Jessica Pearce, the professional science editor, for the English editing service. We appreciate the valuable feedback provided by the editors and three anonymous reviewers.Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementThe data obtained in this study are provided in the Supplementary Materials (Appendices 1–2).Additional informationFundingThis research was made possible by financial support from the Spanish Ministry of Economy and Competitiveness [BES-2013-064713, EEBB-I-17-12165], and PEDECIBA Biología. Partial support was provided by Uruguay’s National Agency for Research and Innovation (ANII) and the regional government of Andalucía (Department of Education, Research, and Innovation, PROYEXCEL_00688 within PAIDI 2020).