Species diet and the effect of different spatial bait distribution on assemblage of dung beetles in Amazonian white-sand forest

The recognition and use of food resources in animal species may vary according to availability. Trophic niche and resource availability are among the most important drivers involved in the coexistence of species, which may require specific resources or exploit a large variety of resources. Dung beetle species feed from a wide range of food resources, including feces, carrion, and rotten fruit. The aim of this study was to assess the attractiveness and preference of different food types (dung, carrion, and banana) for dung beetles from a region of Amazonian white-sand vegetation (Campinarana). Closely spaced sets of pitfall traps (5 m of distance between traps) baited with different food types were installed to test food preference, and widely-spaced traps (150 m of distance) baited with different food types to test food-type attractivity. Overall, we captured 76 dung beetles of nine species, where Deltochilum septemstriatum Paulian (1938), was classified as a specialist of carrion, Sylvicanthon proseni (Martínez, 1949) and Canthidium gr. lentum were considered specialists of human feces, no species was considered generalist. In terms of assemblage parameters, although food type did not affect species richness or individual abundance in both trap-spacing approaches, the species composition of beetles collected in carrion-baited traps was distinct from that in feces-baited traps. Seven out of nine species were attracted towards one of the resource types, regardless of the trap spacing design. Therefore, we conclude that diet of dung beetles that dwells in Campinaranas are relatively strict, with species being attracted mostly to carrion or feces, regardless of the availability of other food types.