Rodents and other micromammals from the Pleistocene strata in Excavation 1 at Wonderwerk Cave, South Africa: A work in progress

Abstract

This preliminary report concerns the micromammalian remains recovered from the Pleistocene strata in Excavation 1 at Wonderwerk Cave by Peter B. Beaumont during the 1980s and early 1990s. Because of the large size of the samples (170 656 specimens representing a minimum of 71 304 individuals), identification has so far only been taken to the generic level. Remains belonging to 34, and possibly 36, genera in five Orders have been identified, and there could be as many as 48 species represented. The uneven horizontal distribution of material throughout the excavation indicates probable roost or nest sites of Barn owls (Tyto alba), which is the most likely predator responsible for their accumulation. There is also considerable vertical variation in the amount of material in the different levels, which indicates that the predators were not consistently present in the area throughout the period represented by the deposits. In the majority of the samples, Gerbillinae (Gerbilliscus, gerbils) are best represented when supra-generic groupings are used. This suggests that conditions were reasonably arid during the periods represented by the samples but not necessarily throughout the entire period spanned by the deposits. When original groupings (genus and above) are considered, Otomyinae (Otomys spp., vlei rats) predominate in nearly half the samples. Secondarily important prey taxa are shrews (Soricidae), rats and mice (Murinae) and elephant shrews (Macroscelididae). This implies some variation in environmental conditions over time but more detailed interpretations must await further analysis. In particular it is imperative to identify the species of Gerbilliscus and Otomys before progress can be made. A range of techniques is now available to assist with interpreting the samples to their full potential once this has been done.