How do dung types affect dung beetle diversity and individuals’ body size?

Abstract Food diversity is one of the main drivers of diversity maintenance of ecological communities. Dung beetles (Coleoptera: Scarabaeinae) are primarily coprophagous, feeding and nesting on different types of dung. Previous efforts aimed to disentangle how different dung types drive assemblage diversity and individuals’ distribution at population scale. The goal of our study was to assess the effect of dung types from three common mammal species (cow, horse, and human) on dung beetle assemblage structure (species presence and its abundances), diversity, abundance, and intraspecific individual body size. Independent sets of pitfall traps baited with cow, horse, and human excrement were set up in Sierra de Guadalupe, Mexico. A total of 153 dung beetles from five species were collected. Traps baited with human feces recorded a higher diversity and abundance of dung beetles compared to traps baited with cow and horse manure. Furthermore, the assemblage structure was distinct only between cow and horse dung. No significant differences were detected in individual body size across feces types. However, since body size analysis was restricted to a single species, this result should be interpreted as a lack of evidence rather than evidence of absence. Our results broaden our understanding of how dung beetles perceive different feces types. Based on the nutritional challenging scenario of anthropogenic landscapes, our results highlight the ecological relevance of human feces as an occasional resource for dung beetles in disturbed environments. This finding reinforces the importance of maintaining diverse mammal communities to ensure the availability of a variety of dung types that sustain dung beetle diversity.