First Swiss alpine agropastoral societies: Contribution of isotope analysis to the study of their diet and mobility

The aim of this study is to add new data to the knowledge of the first alpine agro-pastoral societies by studying their dietary practices and mobility. Using the principles of isotopic biogeochemistry, the stable isotope ratios of carbon (δ13 C), nitrogen (δ15 N) and sulphur (δ34 S) on bone collagen and strontium isotopes (87Sr/86Sr) on dental enamel were measured to discuss the diet and residence history of 49 individuals from the Middle Neolithic necropolises of Collombey-Muraz − Barmaz I and II (Valais, Switzerland). Individuals from both burial assemblages have collagen isotope values indicating a diet based on terrestrial resources with a very high consumption of animal proteins. However, the individuals from Barmaz II have consumed a nitrogen-15 enriched resource. The strontium results show that only a few individuals buried in Barmaz I show non-local values, whereas all individuals buried in Barmaz II have values similar to the environment in which they were buried. Whether in terms of diet, access to resources or mobility, no differences were observed between male and female individuals, neither in their isotopic values nor in the variability of these values. Taken all together, the results suggest the existence of a possible reserved area in the burial zone, even if coming from ’elsewhere’ did not seem to have any influence on access to food resources. However, if being male or female did not seem to play an important social role in this population, it seems that it is the location of their burial that gives more information about their status. Finally, these new data, combined with previous knowledge, raise the question of whether the individuals buried at Barmaz II belonged to a group that was socially distinct from the rest of the Barmaz population.