Mediterranean precipitation isoscape preserved in bone collagen δ²H

The prehistory of the Mediterranean region has long been a subject of considerable interest, particularly the links between human groups and regions of origin. We utilize the spatial variation in the δ²H and δ¹⁸O values of precipitation (isoscapes) to develop proxies for geographic locations of fauna and humans. Bone collagen hydrogen isotope ratios (δ²H) in cattle (and to a lesser extent, ovicaprids) across the Mediterranean reflect the isotopic differences observed in rainfall (but δ¹⁸O values do not). We conclude that δ²H in herbivore bone collagen can be used as a geolocation tracer and for palaeoenvironmental studies such as tracing past isotopic variations in the global hydrological cycle. In contrast, human bone δ²H values are relatively tightly grouped and highly distinct from precipitation δ²H values, likely due to human-specific food practices and environmental modifications. Given the inter-species variability in δ²H, care should be taken in the species selected for study.