Large African herbivore diversity is essential in transformed landscapes for conserving dung beetle diversity.
Abstract
Mammals are globally in decline, with habitat loss a primary driver. There are also human-wildlife conflicts, such as elephants destroying crops, which results in the ranges of many large mammal species being fenced off. Yet, how this activity affects functional associations of insects with large mammals has received little attention. Previous work suggests a generalised association with large mammals, as well as a strong response to landscape transformation. Here we assess how well dung beetle diversity tracks large African mammal herbivore diversity across a forestry plantation land use gradient by assessing how dung beetle taxonomic, phylogenetic and functional richness compares to large mammal diversity. We also determine how land use intensity affects dung beetle-to-mammal interaction networks. Dung beetles responded more intensively to an array of large mammals than to differences in land use intensity. Beetles also showed a strong preference for specific mammalian dung, with elephant dung being the most important factor for maintaining local dung beetle diversity. Large mammal abundance, functional diversity, dung beetle phylogenetic richness and number of realised mammal-to-dung beetle interactions were highest in the protected area. Land use intensity categories had distinct mammal and dung beetle assemblages. Transformed areas also have conservation value but provided that there is functional connectivity between remnant vegetation within the modified landscapes. Synthesis and applications. The loss of any native large mammal, especially African elephants, from transformed landscapes is likely to lead to a decline in biodiversity. This suggests that protected areas are essential for the conservation of native biodiversity and its interactions, while well-designed and managed transformed areas can have additional conservation value. African conservation managers and landowners should be encouraged to maintain a diversity of large mammals on their properties to maintain functional diversity and ultimately ecological resilience.