A species’ trophic niche is shaped by several factors, including prey availability and intra- and interspecific interactions. Although anurans are generally considered dietary generalists, detailed studies investigating the trophic niches of individual species remain scarce. In Brazil, published research has addressed these aspects in only 19% of anuran species. Knowledge gaps are particularly pronounced for endemic and threatened species, whose conservation could greatly benefit from a better understanding of their ecology. 

A recent paper published in Acta Herpetologica investigates the trophic niches of Boana atlantica and Boana semilineata, two endemic, sympatric hylid frogs inhabiting Brazil’s Atlantic Forest. Researchers captured 39 individuals of B. atlantica and 25 of B. semilineata at a study pond. After temporarily housing the frogs in the laboratory and recording their measurements, they flushed and analysed their stomach contents, identifying food items to the lowest possible taxonomic level. 

Both species exhibited generalist diets, although B. atlantica had a broader trophic niche than B. semilineata. In both species, plant material and spiders (Araneae) were among the most frequently recorded food items. Plant fragments, often assumed to be accidentally ingested while capturing invertebrate prey, were the most frequent item found in the stomach contents. This unexpected finding raises the possibility of deliberate plant material consumption, potentially associated with intestinal parasite elimination or prey digestion, although further research is needed to test these hypotheses. 

Neither body length, body mass nor mouth width was associated with prey volume. This suggests that dietary composition in both species may be influenced more strongly by prey availability and mobility than by the morphological traits examined.

The study also revealed substantial trophic niche overlap between the two species, consistent with their opportunistic feeding strategies. However, without detailed data on prey availability, it remains unclear to what extent B. atlantica and B. semilineata compete for food resources at the study site.

Click here to read the full paper to discover more about the feeding ecology of these two Atlantic Forest endemics and its implications for understanding their ecological interactions.

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