Ephemeral rivers and the vegetation they support have numerous ecological and economic values to the mammals and people who rely on these systems. Yet, these crucial environments are believed to be threatened by exotic plant invasion. In Africa, invasive trees of the genus Prosopis have detrimental effects on native vegetation, bird and dung beetle communities; however, to date, there is no evidence that Prosopis establishment has affected indigenous wild mammalian distribution and ecology in its introduced range. Using a combination of camera traps and vegetation surveys, we tested the hypothesis that Prosopis invasion has a negative impact on the mammals of the ephemeral Swakop River in Namibia by reducing mammal species richness and species occupancies. Prosopis was found to have no negative impact on species richness; however, evidence for species-specific responses to Prosopis abundance was found. This is the first study to confirm an impact of Prosopis on sub-Saharan African mammals, providing a foundation for future research and the development of appropriate management policy.

Keywords: camera traps, drylands, invasive, Prosopis, riparian, wildlife.