Longitudinal dietary resilience of lion (Panthera leo) in a semi-arid fenced reserve of South Africa

Abstract

Understanding the dietary composition of large carnivores and how these relate to the availability of suitable habitat and prey is crucial to population management, especially in fenced reserves. This study aimed to determine the current diet of the lion (Panthera leo) in the Karoo National Park and to establish whether prey preference has changed over the 12 years post-introduction. Global positioning system-collar-based kill-site cluster investigations and scat analyses were used to determine contemporary lion diet, while multinomial logistic regressions were used to investigate longitudinal changes in prey preference by comparing a decade of historical kill and aerial census records. Lion (n = 8) collar fixes identified 358 (12%) ‘potential’ kill-site clusters across 2945 discernible clusters over 15 months (i.e. 2021/2022). The subsequent in-field investigation of 227 (63%) ‘potential’ kill sites yielded 144 (63%) and 103 (45%) independent lion kill and scat samples, respectively. While these two methods offered different sampling advantages, both provided sufficient data to show lion preference for greater kudu (Tragelaphus strepsiceros), common eland (Tragelaphus oryx) and red hartebeest (Alcelaphus buselaphus caama). Other prey species included gemsbok (Oryx gazella), springbuck (Antidorcas marsupialis), common duiker (Sylvicapra grimmia) and mountain zebra (Equus zebra). Historical carcass records (n = 1035, 19499 = 89.6 ± 13.8 Standard Error [SE] per annum), since the reintroduction of lions in 2010, indicate no significant change in dietary composition over time (Χ2 = 1.98, df = 5, p = 0.85), when controlling for lion population size, despite post-introduction acclimation with substantial inter-annual variability in rainfall and prey availability. Conservation implications: Understanding dietary changes in response to systemic disturbances is crucial to ensuring that lions are ethically and sustainably managed for their ecological efficacy in fenced metapopulations. With no significant change in hunting behaviour, management concerns are unlikely to be driven by reduced prey suitability or availability.