The relationship of ungulate δ¹³C and environment in the temperate biome of southern Africa, and its palaeoclimatic application

The relationship between ungulate stable carbon isotope values and environmental variables (temperature, relative humidity, precipitation) remains poorly understood. In this paper, we evaluate this relationship for, predominantly, C3 ecosystems in the winter rainfall areas of southern Africa. In our dataset (290 individuals representing 23 species), δ13C values of ungulate enamel are significantly correlated with mean annual precipitation (MAP), moisture index (MI) and summer aridity index (SAI), variables that also influence the distribution of C3/C4 grasses. Our study confirms previous findings that faunal δ13C values in C3 ecosystems are most strongly correlated with variables related to precipitation. δ13Cenamel values for ungulate browsers are more strongly correlated with a larger number of environmental variables than values for grazers and mixed feeders and vary according to vegetation type. We apply regressions derived from the modern dataset to estimate palaeoclimatic shifts based on δ13Cenamel values of browsing fauna at the Pleistocene sites of Hoedjiespunt and Elandsfontein in South Africa.