Application of δ13C, δ15N and δ34S for the reconstruction of diet and migration at Boğazköy, Central Anatolia

The patterns of human diet and migration of the population of Boğazköy in north-central Anatolia were investigated through the application of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) stable isotope analysis of bone collagen. The materials used for this research include human and faunal bone samples dating from the Bronze Age to the Roman period. This is the first isotopic study conducted at Boğazköy and for these time periods in north-central Anatolia. The aim of the research was both to reconstruct the dietary habits and mobility patterns of this community as well as investigating the usefulness of δ34S analysis as a dietary tool in this region of Anatolia. Examining the diet and economy at Boğazköy through an isotopic perspective provides a clearer understanding of the life of the inhabitants of the city and sheds light of the political and sociological changes observed during this period in Anatolia. Analysis across different periods revealed that the Bronze Age stands out with the most enriched δ15N (9.9±0.8‰) and δ34S (12.6±3.0‰) values, suggesting a higher consumption of protein in relation to later periods and/or foreign origin for these individuals. With the exception of the Bronze Age, dietary behaviours were very similar across all phases of occupation and do not differ significantly from those observed at other Anatolian sites. The δ13C (‒18.6±0.4‰) and δ15N (9.0±0.9‰) average values for the Iron Age, Hellenistic and Roman periods suggested a diet predominantly based on C3 terrestrial sources. Variations between individuals, implying the consumption of different levels of animal protein, were not directly connected to sex or age. The δ13C results for several of the domestic animals suggest inclusion of C4 plants in their diets. Slight elevated δ13C values for humans indicates the consumption of these animals or the variability of C3 plant values, which may relate to the aridity of this region. The δ15N results suggest the consumption of low quantities of meat, dairy products and/or the contribution of pulses. The application of δ34S has also provided insight into Boğazköy’s economy by suggesting the use of transhumance as a herding strategy during the Iron Age. The presence of foreigners during the Hittite period is also implied by the δ34S results from the human samples. These indicate a coastal provenance where sea-spray effect was visible; however, the lack of a δ34S baseline data for large regions of Anatolia hinders further interpretation of the results