Biotic and abiotic drivers of dung beetle assemblage structure in Kenyan Afromontane forest: trees and elephants matter

Abstract Anthropogenic actions are likely to harm dung beetle populations directly through habitat loss and indirectly through the cascading effects of large mammal depletions. Despite the reliance of dung beetles on mammal dung, there are only a handful of studies that have directly assessed the impact of habitat degradation and associated mammalian loss on dung beetle populations in Africa. We evaluated whether patterns in dung beetle species abundance, richness, and body size can be associated with mammalian herbivore abundance and species richness, habitat structure, and the distance between sample sites. Additionally, we ascertained how the presence of elephants ( Loxodonta africana ) may affect a dung beetle assemblage by determining which species could be used as bioindicators of elephant presence. We found herbivore and overall mammal abundance explained 17% of dung beetle assemblage structure, 2% of dung beetle abundance, 10% of dung beetle species richness and, 15% of the variation in dung beetle body size. Habitat structure explained 27% of dung beetle assemblage structure, 11% of dung beetle abundance, and 14% of the variation in dung beetle body size. Spatial distance between trapping locations explained 13% of the dung beetle assemblage structure, 4% of species richness, 3% of abundance, and but had no effect on dung beetle body size. We also identified four dung beetle species that may be used in future management plans as bioindicators of elephant density Afromontane Forest in East Africa. This information may become especially important for future monitoring as it is predicted that the areas in which elephants occur in Afromontane Forest are set to decline due to deforestation, and the expansion and intensification of agriculture.