The response of lions (Panthera leo) to changes in prey abundance on an enclosed reserve in South Africa

Abstract

Large mammalian carnivores place significant pressure on their prey populations and this is exacerbated within the fenced reserves of Africa. However, foraging theory predicts that diet switching by predators may mitigate this pressure. In this study, we use data collected between 2003 and 2007 from an enclosed system in the Eastern Cape Province of South Africa to examine the response of lions Panthera leo to changes in the abundance of two important prey species — kudu Tragelaphus strepsiceros and warthog Phacochoerus africanus. As the relative abundance of war- thogs increased, the number of kudu kills decreased signif- icantly, whereas warthog kills became significantly more frequent. A similar pattern was observed for lion prey pref- erence and the switch from kudu to warthog was also reflected in a significant decrease in the mean prey mass. Our results suggest that a diet shift occurs in lions and that the change in diet is primarily in response to an increase in warthog numbers. Prey switching may promote the persis- tence of predator-prey systems, which is particularly impor- tant for fenced systems where natural immigration of prey is not possible. However, continued collection and analysis of long-term observational data from the multipredator, multi- prey systems of Africa is required to facilitate a full under- standing of predator-prey dynamics.