Whose Poos do Northeastern Ohio Dung Beetles (Coleoptera: Scarabaeoidea) Choose?

Dung beetles (Coleoptera: Scarabaeoidea) are primarily scavengers of decomposing material but are especially reliant on animal feces. While dung beetles have been identified as promising ecological indicators, there has been little work to investigate the associations of dung beetles with native fauna. To learn more about the diet breadth and preference of northeastern Ohio dung beetles, we assessed their attraction to 10 baits, including mushroom and Ohio native animal dung, at two forested localities during the summers of 2021 and 2022. We collected 15 species of scarab beetles in baited pitfall traps, including 12 species from the family Scarabaeidae (eight Aphodiinae and four Scarabaeinae), two species of Trogidae, and one species of Geotrupidae. Overall, we found that white-tailed deer dung (Odocoileus virginianus (Zimmermann, 1780); Artiodactyla: Cervidae) attracted the greatest richness of dung beetles, while North American river otter (Lontra canadensis (Schreber, 1777); Carnivora: Mustelidae) dung attracted the greatest abundance, albeit dominated by a few species. Most dung beetle species exhibited moderate to broad diet breadths, reflecting generalist tendencies; however, the aphodiine Oscarinus rusicola (Melsheimer, 1845) was found to be a deer dung specialist. Onthophagus orpheus (Panzer, 1794) (Scarabaeinae) exhibited a relatively narrow diet breadth and a strong association with gray fox (Urocyon cinereoargenteus (Schreber, 1775); Carnivora: Canidae) dung. Given that gray fox populations are in regional decline, this may reflect a shift in resource use toward more abundant sources like deer dung. Here, we carried out the important first steps in assessing dung beetle and native fauna associations by investigating dung beetle attraction and preference to a wide variety of naturally occurring bait types, providing a basis for understanding the role of dung beetles in non-agricultural ecosystems.