Use of native animal dung by an introduced species of dung beetle (Onthophagus nuchicornis)

Non-indigenous dung beetle (Coleoptera: Scarabaeoidea) species in North America are important contributors to ecosystem functions, particularly in pasture-based livestock systems. Despite the significant body of research surrounding non-indigenous (and often invasive) dung beetles in agricultural contexts, there has been minimal study concerning the impact of the competition that these species may have on indigenous dung beetle populations in natural environments. Here we examine the potential impact of introduced dung beetle Onthophagus nuchicornis on indigenous dung beetle populations via resource competition. Using a controlled laboratory experiment, we quantified how readily beetles could use dung from bobcat (Lynx rufus), red fox (Vulpes vulpes), moose (Alces alces), raccoon (Procyon lotor), and domestic sheep (Ovis aries). To determine the suitability of each dung type for reproduction, we measured offspring fitness, abundance, and development time.