Trophic ecology of tropical frogs ( Leptodactylus ) assemblage during a drastic drought in Southern Pantanal

Extreme environmental events such as prolonged droughts can drastically alter trophic dynamics in freshwater ecosystems. Amphibians, due to their permeable skin and dual life cycle, are particularly sensitive to such disturbances. The Pantanal, one of the largest floodplains in the world, has recently experienced unprecedented drought and fire events, yet the ecological consequences for the local amphibian fauna remain poorly understood. Here, we investigate the trophic ecology of a Leptodactylus assemblage during a severe drought in the southern Pantanal, Brazil. We sampled 84 individuals belonging to three Leptodactylus species from a temporary pond over two nights at the end of 2021, examined their stomach contents, and assessed prey availability using pitfall traps. Coleoptera was the most important prey category for L. fuscus and L. podicipinus, whereas L. macrosternum was dominated by Blattaria and Araneae. Electivity analysis revealed active selection for Hemiptera and avoidance of highly abundant taxa such as Collembola and Formicidae, indicating nonrandom foraging under environmental stress. Leptodactylus macrosternum and L. podicipinus also consumed unidentified tadpoles, representing a novel record of anurophagy involving larval forms in these species. Morphometric ordinations showed broad interspecific differentiation with partial overlap among individuals, consistent with shared morphospace among sympatric species. Our findings suggest that extreme drought promotes short-term trophic compression driven by habitat contraction, characterised by convergent prey selection for Hemiptera, reduced prey heterogeneity, maintenance of generalist feeding patterns, and occasional opportunistic predation on tadpoles.