Estimated spatial requirements of the medium- to large-sized mammals, according to broad habitat units, in the Cape Floristic Region, South Africa

Abstract

Conservation planning in the Cape Floristic Region (CFR) of South Africa, a recognised world plant diversity hotspot, required information on the estimated spatial requirements of selected medium- to large-sized mammals within each of 102 Broad Habitat Units (BHUs) delineated according to key biophysical parameters. Spatial requirement estimates were derived for 19 omnivore and carnivore species, following a review and extrapolation of extant information. The estimates for 23 herbivore species were derived from a simple spreadsheet model based on forage availability estimates and the metabolic requirements of the species in question; this analysis incorporated adaptations of the agriculture-based Large Stock Unit (LSU) or Animal Unit approach. The LSU approach has various shortcomings but given the virtual absence of information on forage availability (quantity, quality and seasonality) for indigenous herbivores in the CFR, it provides the only extant measure of the influence of key biophysical factors on this parameter, especially at a regional scale. The outcomes of the exercise, viz. densities (hectares/animal), are presented here; these should be considered as testable hypotheses and a cautious 'management by hypothesis' approach should be adopted in their use. This information can be used to guide both conservation planning activities and practical conservation management decisions.


Keywords: forage production; species assemblages; herbivore densities; conservation planning; conservation management


African Journal of Range & Forage Science 2002, 19(1): 29-44