Cues of uncommon food habits within dung beetles: Notes from a seasonally dry tropical forest in South America

Abstract

The assessment of species’ diet and trophic plasticity serve as key elements to understand their adaptations to harsh ecosystems, such as deserts and dry forests. Among dung beetles, coprophagy is the main feeding habit, which may be substituted or complemented by other unusual diets, such as granivory and necrophagy. This study presents new records of dung beetle uncommon diets in Caatinga, the largest Seasonally Dry Tropical Forest in America. We include novel descriptions of the genera Dichotomius Hope, 1838 and Canthidium Erichson, 1847 in using and removing seeds in Caatinga. We also present the first report of dung beetles from Caatinga attracted to dead millipedes, specifically for Coprophanaeus pertyi (Olsufieff, 1924). Also, we found goat hairballs along with the roller beetle Deltochilum verruciferum Felsche, 1911 inside a pitfall trap, suggesting that this species may use animal fur to feed or breed. Finally, we included an updated list on unusual food records of dung beetle species in Caatinga dry forest. Our findings indicate that dung beetles in Caatinga display diverse feeding habits in response to extreme environmental conditions and/or limited resources. We expand the still-scarce knowledge regarding dung beetle feeding ecology outside their interaction with dung or the soft tissues of carrion. Despite our findings, new evidence is essential to reinforce our understanding on trophic plasticity of dung beetles in Caatinga. A better comprehension of resource plasticity by dung beetles will also be a significant input for biodiversity conservation due to the changes in food availability in anthropogenic landscapes.