Restoring apex predators can reduce mesopredator abundances

Abstract

The role that apex predators play in ecosystem functioning, disease regulation and biodiversity maintenance is increasingly debated. However, the positive impacts of their presence in terrestrial ecosystems, particularly in human-dominated landscapes, remain controversial. Limited experimental insights regarding the consequences of apex predator recoveries may be behind such controversy and may also impact on the social acceptability towards the recovery of these species. Using a quasi-experimental design and state-of-the-art density estimates, we show that mesopredator abundances were reduced after the restoration of an apex predator, with evidence of resonating positive impacts on lower trophic levels. Iberian lynx Lynx pardinus reintroduction was followed by the reduction of the abundance of mesocarnivores (red foxes Vulpes vulpes and Egyptian mongooses Herpestes ichneumon by ca. 80%) and the recovery of small game of high socio-economic value (European rabbits Oryctolagus cuniculus and red-legged partridges Alectoris rufa). The observed mesopredator reduction resulted in an estimated 55.6% less rabbit consumption for the entire carnivore guild. Our findings have important implications for the social acceptability of Iberian lynx reintroductions, which crucially depend on the perception of private land owners and managers. Under certain circumstances, restoring apex predators may provide a sustainable and ethically acceptable way to reduce mesopredator abundances.