Patch-scale selection patterns of grazing herbivores in the central basalt plains of Kruger National Park

Abstract

Large herbivores form an essential component in the ecosystem, because of the impact that they have on their surrounding habitat. In this study, we aimed to evaluate some of the mechanisms behind how herbivores select forage at a patch scale. Thirty-six experimental plots were established and fitted with camera traps in Kruger National Park to test forage selectivity by grazers. Plots were manipulated by clearing with a brush cutter and the application of fertiliser. We used generalised linear models to detect trends in probability of occurrence by seven grazing herbivore species using camera trap data. Our results showed that season was a major determinant of species distribution, especially those that are not obligate grazers or feed exclusively in the 0.5 km to 2 km zone from water. We found that most selective feeding occurred in the late wet season when water would be more evenly distributed across the landscape and forage resources close to water would have had the chance to recover from depletion, as a result of dry season use. This has implications for the distribution of artificial water points across the landscape, because areas of reserve forage must be maintained to alleviate grazing pressure close to water.

Keywords: african buffalo, african elephant, Blue wildebeest, extrinsic drivers, forage selection, herbivore distribution, intrinsic traits, Plains zebra, water availability, White rhinoceros