The Most Attractive Is Not Always the Preferred: Lessons From Necrophagous Dung Beetle Assemblages in a Region of the Central Amazon

Resource attractiveness and preference is determinant to assess how biodiversity is structured in different ecosystems. Necrophagy is the alternative or complementary dietary habit of dung beetles, but a few studies have focused on evaluating how different carrion types attract different species. The goal of this study was to assess the effect of carrion type on attractiveness and preference of dung beetle taxonomic diversity in a region of Central Amazon. Pitfall traps baited with bovine spleen, chicken liver, and fish (freshwater sardine) were installed. Bait attractiveness was estimated through a sampling design that kept exclusively one food type in the field, while bait preference comprised a sampling design with more than one food type offered simultaneously in a concentrated area. We collected 3151 individuals from 24 dung beetle species. Bovine spleen was the most attractive bait in both food preference and food attractiveness experiments, being the only carrion type in which species demonstrated preference. Each carrion type attracted distinct dung beetle assemblages. This study demonstrates that Amazonian dung beetles prefer specific carrion types, which serves as a basis for future studies related to dung beetle diet.