Artificial ponds or irrigated systems scattered throughout farmlands can offer important habitats for anurans and can be interesting sites for research on species resources use in a changing landscape. This study describes the diet and resource partitioning among anurans inhabiting irrigated rice fields in the Pantanal region. Twenty categories of prey were found in the stomachs of Leptodactylus chaquensis, L. elenae, L. podicipinus and Rhinella bergi, the most frequent being Coleoptera, Hymenoptera, larvae of Hexapoda, Hemiptera, Diptera and Orthoptera. The great differences found in the diet of these species in rice fields compared to other locations, according to available records in the literature, was the increased importance of Hemipitera and Orthoptera and the decrease in importance of Hymenoptera in the diet of leptodactylids. These differences might be attributed to changes in the availability of resources in response to habitat modification. Although diet composition was very similar among species, niche overlap was larger than expected by chance, suggesting that the competition for food resources is not, or has not been, a significant force in determining the structure of this frog community. Two non-exclusive hypotheses could be considered as a justification for this result: 1) the high niche overlap could result from resource availability, which is sufficient to satisfy all species without any strong competition; 2) or the high values of niche overlap could be a selective force driving species to compete, but there has not been enough time to express a significant divergence in the species diet because the study area is characterised as a dynamic habitat influenced by frequent and cyclical changes.Keywords: niche overlap, agroecosystems, Leptodactylidae, Bufonidae, diet.
Dieta e partição de recursos entre anuros em campos de rizicultura no Pantanal, Brasil ResumoLagoas artificiais e sistemas irrigados em áreas de produção agrícola podem oferecer habitats importantes a anuros e ser significativos para investigações sobre o uso de recursos pelas espécies em ambientes modificados. Este estudo descreve a dieta e partição de recursos tróficos entre anuros de campos de rizicultura na região do Pantanal. Nos estômagos de Leptodactylus chaquensis, L. elenae, L. podicipinus e Rhinella bergi foram encontradas 20 categorias de presas, sendo Coleoptera, Hymenoptera, larvas de Hexápoda, Hemiptera, Diptera e Orthoptera as mais frequentes. Maiores diferenças encontradas na dieta dessas espécies em campos de arroz comparadas a de outros locais, de acordo com dados da literatura, foram o aumento da importância de Hemipitera e Orthoptera e a diminuição na importância de Hymenopteras na dieta dos leptodactilídeos. Essas diferenças talvez sejam reflexos de mudanças na disponibilidade de recursos de presas, em resposta às modificações ambientais. Apesar de as espécies apresentarem dietas bastante similares, a sobreposição de nicho foi maior que a esperada ao acaso, sugerindo que a competição por recursos aliment...