The influence of lion predation on the population dynamics of common large ungulates in the Kruger National Park

Abstract

The impact of lion ( Panthera leo ) predation on buffalo ( Syncerus caffer ) and medium-sized ungulates over periods of changing environmental conditions in an area of the Kruger National Park was investigated. Lions were found to prey proportionally most heavily on the resident buffalo and wildebeest ( Connochaetes taurinus ) populations, and less so on the semi-migratory zebra ( Equus burchelli ) population, and have the least impact on the high-density impala ( Aepyceros melampus ) population. The selection was largely in accordance with the abundance of the larger species, but not for impala, which were relatively under-represented in the diet. Zebra and wildebeest were preyed upon more frequently during periods of high rainfall, and less so during drier times, leading to relative population stability. In contrast to wildebeest and zebra, the buffalo population varied in accordance with ecological conditions, with strong evidence for an interaction between drought conditions and lion predation. Male lions preyed more heavily on buffalo than did females, the latter preying mostly on impala, wildebeest, and zebra. However, lionesses did prey on buffalo more frequently during drier periods than during wet periods. Calving and survival rates determined for buffalo were used to parameterize a simulation model, which incorporated ecological conditions and culling pressure on a yearly basis, to predict buffalo population trends. The resultant model closely tracked real population trends, whichmay be of use in future projections.