Investigating the dietary patterns of Yamnaya pastoralists and the dietary impact of the Yamnaya horizon on local populations in modern day Romania and Bulgaria

Abstract

The migration of the Yamnaya from the Pontic-Caspian Steppes into modern-day Bulgaria and Romania in the Early Bronze Age led to sweeping changes in the genetic and linguistic landscape of Europe, however little is known about the diet and subsistence practices in this region and how these were affected by this movement of pastoralist peoples. Dietary reconstruction of the Yamnaya Horizon in the more eastern areas of the expansion point towards a nomadic pastoralist diet relying heavily on domesticated ruminants, specifically cattle. Aside from a few paleodietary reconstructions using the bulk carbon and nitrogen from single individuals, little is known about the dietary practices of the westernmost part of the Yamnaya Horizon or the affects this movement had on the local communities or the Yamnaya individuals themselves. Reconstruction of the subsistence strategies of local Eneolithic and Early Bronze Age societies using archaeobotanical and zooarchaeological methods suggests a reliance on wheat varieties and domesticated fauna, namely ovicaprids, cattle, and pigs.
This thesis aims to investigate diet and possible subsistence changes surrounding the Yamnaya Horizon in Bulgaria and Romania using a multi-proxy approach. A range of 38 sites were selected to chronologically span the Eneolithic through the Early Bronze Age and to the Middle Bronze Age as well as to spatially cover a range of geographical environments namely, coastal, foothills, and steppe environments. This multi-proxy approach includes bulk δ13C and δ15N stable isotope analyses performed on 550 human and 21 faunal skeletal samples from 34 sites and lipid residue analysis on 251 potsherds from four sites. This combined approach provides new insights into the subsistence strategies of local communities in the Eneolithic, Early Bronze Age, and Middle Bronze Age, as well as provides a better understanding of the subsistence strategies of the Yamnaya Horizon in the westernmost part of the migration.
The Yamnaya individuals showed a dependence on domesticated herbivores through bulk δ13C and δ15N analyses of bone collagen, with dietary proportions indicating this to be the majority of the Yamnaya diet. The reliance on domesticated herbivores for subsistence is a hallmark of a pastoralist dietary. The bulk δ13C values of the Yamnaya individuals reflected the ovicaprid and cattle δ13C signatures signifying these species were the predominant species consumed. There are several enriched δ13C signatures in both the faunal and human individuals suggesting a possible C4 influence, however based on the environmental reconstruction it is more likely this is due to increasing aridity in the studied regions.
Bulk δ13C and δ15N analyses of bone collagen from the local populations suggests a terrestrial C3 diet throughout the Eneolithic, Early Bronze Age and Middle Bronze Age in Bulgaria and Romania. There is a greater reliance on plants in the Eneolithic and Middle Bronze Age with a lower dietary proportion of plants in the local Early Bronze Age individuals. Lipid residue analysis of pottery vessels from settlements of local Eneolithic and Early Bronze Age peoples revealed both ruminant and non-ruminant fats reflecting the faunal assemblage of ovicaprid, cattle, and pig. Ruminant dairy fats were identified supporting both dairy and meat processing.
Integration of Bayesian hierarchical modeling demonstrated there were no subsistence or environmental baseline changes between males and females and between age categories in the Yamnaya individuals. This suggests similar access to dietary components and to the landscape. The Yamnaya individuals in comparison to the local communities relied mostly on animal products, specifically ruminant herbivores, while the local populations supplemented their diet with plants and omnivore protein indicating the Yamnaya individuals maintained a diet distinct from the local Eneolithic and Early Bronze Age societies. There is a subsistence shift in the Early Bronze Age away from plant consumption and an increase in wild fauna consumption in the local population, which is likely a response to the influx of people with the Yamnaya expansion. This shift does not continue into the Middle Bronze Age, suggesting changing subsistence practices as a response to the Yamnaya Horizon were reversed after the Horizon had faded.

Date of Award	30 Sept 2025
Original language	English
Awarding Institution	University of Bristol
Supervisor	Lucy J E Cramp (Supervisor), Mélanie Roffet-Salque (Supervisor) & Volker Heyd (Supervisor)