Mesocarnivore community structuring in the presence of Africa’s apex predator

Apex predator reintroductions have proliferated across southern Africa,
yet their ecological effects and proposed umbrella benefits of associated
management lack empirical evaluations. Despite a rich theory on top-down
ecosystem regulation via mesopredator (<20kg) suppression, a
knowledge gap exists relating to the influence of lions (Panthera leo)
over Africa’s diverse mesocarnivore communities. We investigate how
geographical variation in mesocarnivore community richness and occupancy
across South African reserves is associated with the presence of lions.
 An interesting duality emerged: lion reserves held more
mesocarnivore-rich communities, yet mesocarnivore occupancy rates and
evenness-weighted diversity were lower in the presence of lions. Human
population density in the reserve surroundings had a similarly ubiquitous
negative effect on mesocarnivore occupancy. The positive association
between species richness and lion presence corroborated the umbrella
species concept but translated into small differences in community size.
Distributional contractions of mesocarnivore species within lion reserves,
and potentially corresponding numerical reductions, suggest
within-community mesopredator suppression by lions, likely as a result of
lethal encounters and responses to a landscape of fear. Our findings offer
empirical support for theoretical understanding of processes underpinning
carnivore community assembly and are of conservation relevance under
current large-predator orientated management and conservation paradigms.