Pastoralist Foodways Recorded in Organic Residues from Pottery Vessels of Modern Communities in Samburu, Kenya

Organic residue analyses of archaeological ceramics can provide important insights into ancient foodways. To date, however, there has been little critical reflection on how lipid residues might (or might not) reflect dietary practices or subsistence strategies more generally. A combination of ethnoarchaeological research and chemical and isotopic analyses of lipid residues from pottery made and used by modern Samburu pastoralists in northern Kenya was undertaken to supplement the interpretive framework used in archaeological investigations. A total of 63 potsherds were collected from various contexts, including settlement sites and rockshelters, and analysed using gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The results showed that the free fatty acids, palmitic (C16:0) and stearic (C18:0), dominated the lipid profiles, with extremely broad ranges of δ13C values. The majority of the Δ13C values from Samburu pots suggest that vessels were intensively used to process ruminant carcass products, yet the Samburu economy is not, in fact, meat-based at all. Despite an overall reliance on dairy products, milk is rarely processed in ceramic vessels, largely due to cultural prohibitions. Surprisingly, a number of vessels from one site, Naiborkeju Hill, were used to process dairy products. Compound-specific radiocarbon dating of lipids from these sherds suggests that this pottery originated from an earlier period, demonstrating a possible shift in ceramic use by pastoralist communities in this region over time. The overall conclusion is that lipid residues may not necessarily reflect, in a simple way, the day-to-day consumption or the perceived relative importance of different foodstuffs. In the Samburu case, lipid residues reflect the functional and ideological suitability of ceramics for processing only certain types of food (meat/fat/bones), despite an overall reliance on milk. These conclusions are important when considering the origins and development of African pastoralism, for example, as interpreted from the archaeological record.