Informing the Grazing Debate With Empirical Data on Black Wildebeest (Connochaetes gnou) Patch Use

Abstract

High-density short-duration grazing (SDG) is widely suggested to increase productivity. Among various SDG practices, the most widespread and popular, “holistic grazing,” claims to mimic the movement patterns of wild African ungulate herds to improve rangeland health and promote biodiversity. However, this claim has rarely been empirically tested. Focusing on Karoo Escarpment Grasslands in the eastern Karoo, South Africa, we compared patch use patterns of black wildebeest (Connochaetes gnou) in a continuously grazed wildlife system with cattle paddock use on farms implementing SDG management in the same landscape. Camera trap data revealed heterogeneous wildebeest patch use over the 26-mo sampling period, with wildebeest consistently using some patches more intensely than others. Mean intensity of patch use by wildebeest varied with a factor of 10, from 0.05 LSU · ha⁻¹ · day⁻¹ to 0.51 LSU · ha⁻¹ · day⁻¹ across patches. The relative difference in mean intensity of paddock use among farms ranged across a similar magnitude from < 0.01 to 0.18 LSU · ha⁻¹ · day⁻¹ for least to most intensely grazed paddocks, respectively. Grazing durations in wildebeest patches ranged from 3-15 d (mean = 8 d), compared to the range of 3-60 d (mean = 18 d) for cattle. Intense grazing periods in wildebeest patches ranged from 0 to 2 d (mean = 1 d) and from 1 to 30 d (mean = 7 d) across cattle farms. The greatest difference was between rest intervals, lasting from 1 to 5 d on average across wildebeest patches, compared to 60–365 d across cattle farms. Our findings suggest that SDG systems prevalent in Karoo Escarpment Grasslands differ from the patch use patterns of black wildebeest in most aspects. These findings add to growing literature on grazing behavior of wild herbivores, and effectively contrasts these patterns with SDG cattle farming practices in the same landscape.