Late Pleistocene prey mobility in southwestern France and its implications for reconstructing Neandertal ranging behaviors

As hunter-gatherers, Neandertal mobility and corresponding adaptations were influenced by the mobility of their prey; thus, it is critical to track how the movement patterns of each species varied over time at specific sites. Here, prey paleomobility is reconstructed by measuring radiogenic strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) in herbivore teeth recovered from two archaeological sites (Pech de l'Azé IV and Roc de Marsal) in the Dordogne Valley (Aquitaine Basin) of southwestern France that span marine isotope stages (MIS) 5-3. These ratios are compared to a published isoscape as well as new environmental samples (soil, Helix shells, rodent teeth, water, and wine). Our results show that reindeer (Rangifer) likely moved within the sedimentary basins of France and did not venture into mountainous regions. Instead, reindeer, bison (Bison) and other prey species were available year-round in the Aquitaine and Paris basins. Red deer (Cervus) and horse (Equus) may have ventured into the mountains. These results suggest that Neandertals could find year-round faunal resources in these basins, at least during MIS 4 and 3.