Rock hyrax middens are important palaeoenvironmental archives in southern Africa. Carbon and nitrogen isotope measurements on middens (hyraceum) are key components of climate reconstructions, but their interpretations require refinement. Although d 15 N in hyraceum often correlates with independent proxies for palaeo-aridity, the impacts of dietary and physiological controls on hyraceum d 15 N remain to be resolved. We analyse d 13 C and d 15 N in plant foliage, hyrax faecal pellets and hyraceum from 21 sites across southern Africa. Faeces are generally depleted in 13 C (d 13 C typically