Size Variation in the Rock Hyrax (Procavia capensis) and Late Quaternary Climatic Change in South Africa

Abstract

The average adult size of the rock hyrax varies greatly across South Africa. Regression analysis suggests that mean hyrax size is more closely linked to precipitation than to temperature, probably because precipitation has a much greater impact on preferred hyrax food plants. The relationship between mean size and precipitation is curvilinear, such that size increases up to about 700 mm/annum and declines thereafter. This parallels a tendency for less palatable grasses to replace more palatable ones where rainfall exceeds 700 mm/annum. In conjunction with other indicators of past climate, hyrax size variation can be used to reconstruct precipitation history near deeply stratified South African late Quaternary sites, including Elands Bay Cave, Die Kelders Cave 1, and Nelson Bay Cave.