Movement response patterns of livestock to rainfall variability in the Richtersveld National Park

Abstract

We studied the seasonal and daily movement patterns of livestock (pastoralists) in the Richtersveld National Park to suggest management strategies that would support a balance between biodiversity conservation and livestock grazing. Livestock movement patterns indicated that forage is the motivation for winter movements and water is the motivation for summer. The movement followed a predictable direction from grazing areas in the wet season towards the Orange River riparian area with permanent water during periods of low rainfall. The latter can be considered as a 'key resource' area to sustain animal numbers through critical periods of low rainfall. Overall, seasonal movement patterns were in transect of approximately 10km in distance. However, these patterns varied amongst the pastoralists which suggest diverse approaches to tracking resources. On average, a pastoralist moved his animals six times a year between stock posts in a network of grazing routes. The grazing area around a stock post was 2.49km comprising an area of ca. 1 950ha. Herds walked much more quickly in the morning (1.25km hr⁻¹) than in the afternoon (0.82km hr⁻¹) and thus covered more grazing ground per unit time. On the basis of the grazing area and travelling rate (particularly in the morning), all the 36 identified conservation-worthy sites in the National Park were threatened by livestock grazing. Effective management strategies may possibly include zoning, closing some stock posts and careful consideration for opening new roads.