Primate-ungulate sympatry: a review of ecological interactions and research perspectives

The co-occurrence of species within the same area raises fundamental questions about how they can persist while sharing space and resources. One of the central aims of community ecology is to understand the processes that allow species to coexist over time. The sympatry between primates and ungulates has not received much specialized attention, despite long-term acknowledgment that the two groups frequently co-occur. In this contribution, we have reviewed and summarized empirical evidence from a set of published studies to determine the nature of primate and ungulate association in space and time, the ecological contexts within which such associations occur, and the types of interactions that have been reported. We particularly examined the trends in the study taxa, the geographic distribution of research, and the functional categories of interactions. Within the literature, interspecific interactions are frequently reported in Africa, between baboons (Papio sp.) and small to medium-sized ungulates. Foraging facilitation and antipredator benefits are among the most frequently documented interaction types, typically resulting in commensalistic or asymmetrical mutualistic outcomes favouring ungulate species. Nonetheless, mutualism and antagonistic interactions are also reported, which indicates the context-dependent nature of these relationships. The frequency and form of associations appear to further depend on seasonal variation and habitat structure, although these factors were not consistently taken into account in the studies considered in this review. This synthesis helps establish a set of research priorities to promote more systematic and focused studies of primate-ungulate sympatry.