Leading the flock:Tracing herding strategies and resource exploitation in the Valais Alps from Prehistory to the Middle Ages through isotopic analysis

This study presents a comprehensive investigation of herd mobility strategies and resource exploitation in the Valais region, based on archaeological assemblages spanning from the Early Neolithic to the Early Middle Ages and encompassing sites from the Upper to the Lower Valais. Through stable isotope analyses (δ¹⁸O and δ¹³C) of sequential enamel samples from caprine molars, this research aims to explore pastoral exploitation of altitudinal zones, the use of associated ecological resources, and the role of seasonal vertical mobility in shaping subsistence strategies across millennia. The dataset includes individuals recovered from high-altitude contexts, such as the Giétroz Devant chasm, which is likely linked to seasonal alpine pasturing. The observed isotopic patterns provide the first empirical validation of a model for vertical transhumance in the Western Alps. Similar signatures identified at La Planta suggest that this mobility practice was already in place during the 6th millennium BCE and continued throughout later periods. Results reveal a recurrent pattern of vertical mobility, combined with a flexible use of diverse environments, including forested areas—particularly in winter or transitional seasons. The variability in husbandry practices reflects both the adaptability and resilience of Alpine pastoral systems over time. This study not only offers a new framework for interpreting past mobility in mountainous regions but also establishes a reference dataset for future isotopic and geospatial investigations of complex pastoral networks in the Alps.