Resource Selection by African Buffalo (Syncerus caffer) in the Caprivi Strip, Namibia
The African buffalo (Syncerus caffer) is a species of high importance in Namibia’s Caprivi Strip (figure 1). Buffalo provide rural communities with meat for subsistence and use in traditional feasts, as well as income from photographic and hunting safaris (Naidoo et al. 2011. J App Ecol 48: 310-316). The people living in the Caprivi rely directly on the benefits that natural systems provide them and wildlife are an important component of these benefits. Paradoxically, though, buffalo can also be a source of human-wildlife conflict, raiding crops and causing injury to humans (Mulonga et al. 2003. Ministry of Environment and Tourism Namibia). As a species of both high value and conflict, an understanding of habitat preference and resource use by buffalo can inform land use planning in order to conserve this species while minimizing conflict with human populations.
Ungulate movement and space use patterns have been widely studied in temperate regions but have been studied much less in tropical regions (Rivrud et al. 2010 J Anim Ecol 79: 1280-1295). Although some parallels can be drawn between ungulate space use in temperate vs. tropical regions, ungulates living in tropical regions are much more likely to be restricted by water availability than temperate populations (Bucini and Hanan 2007 Glob Ecol Biogeogr 16: 593-605). This is especially true during the dry season.
The Caprivi strip is a densely populated region of Namibia containing a network of human infrastructure and it is now the centre of the Kavango-Zambezi (KAZA) transfrontier conservation area (an effort involving the governments of five countries which, when complete, will be the largest in the world). Despite the effort being put into the planning of KAZA, relatively little is known about drivers and potential barriers to movement for species of prime conservation importance, such as buffalo. Buffalo space use is a key component of conservation efforts for this species, has impacts on rural communities, and affects broader ecosystem function (large herbivores frequently alter primary productivity, nutrient cycling, the availability of quality forage, disease transmission and the distribution of other herbivore species—Bar-David et al. 2009. Ecology 85: 2429-2435). Accordingly, an understanding of the resource use of such species, and its causes, is of great relevance to conservation planning and reserve design (Fryxell et al. 2004. Ecology 85: 2429-2435).
The Caprivi Strip is quite narrow (figure 1). With a fence along the southern border with Botswana, and a road bisecting the Caprivi laterally, among other anthropogenic features, human infrastructure has the potential to limit buffalo movement, fragmenting habitats and restricting migration. Resource selection functions can determine whether buffalo show avoidance patterns of human features. The results of such a study can inform future land use management in order to preserve critical migratory routes, ensuring the success of KAZA and a sustained flow of benefits to the people of the Caprivi.
GIS are a powerful tool for visualizing and analyzing data that is spatially heterogeneous. For GPS collar data from migratory ungulate species, GIS can aggregate many important variables related to ungulate movement that vary spatially and temporally. For this analysis, I used a combination of ArcMap, Geospatial Modelling Environment (GME) and R Statistical Package, to perform a resource selection function (RSF) on 32 buffalo in the Caprivi Strip, Namibia. The RSF was performed on a set of environmental variables and human features in order to determine the statistical significance of different aspects of resource use.
