Multi-isotope analysis of mammalian fauna from the Middle Pleistocene (MIS6) Lazaret Cave: palaeoecological, palaeoenvironmental and archaeological implications

• Tooth enamel carbon and oxygen isotope data are used to reconstruct dietary niche. • Light woodland and grassland environments surrounded Lazaret Cave throughout MIS 6. • Red deer and ibex δ 13 C and 87 Sr/ 86 Sr reveal differences in niche and landscape use. • Red deer oxygen isotope data are used to estimate palaeotemperatures. • MIS 6 temperatures were cooler than today, but elevated relative to other proxies. Caves and rock shelters, rich in archaeological and palaeoecological evidence, offer exceptional archives for reconstructing past climate and environments, as well as human and animal ecologies of the Pleistocene. In this study, we explore possible changes in dietary and movement ecology of mammalian fauna from the Middle Pleistocene (MIS 6) Lazaret Cave, France, to infer broader palaeoenvironmental conditions of a classic southern glacial refugia. Tooth enamel from various MIS 6 mammalian fauna, including wolves and ungulates, was sampled for carbon ( δ 13 C), oxygen ( δ 18 O) and strontium ( 87 Sr/ 86 Sr) isotopic analysis. δ 13 C and δ 18 O data demonstrate consistent differences in isotopic niche space between the carnivore and herbivores, and amongst the different ungulate species, largely consistent with the results of previous dental microwear studies. Strontium isotope data from red deer and ibex demonstrate use of diverse landscapes nearby the site. Their habitat ranges largely overlap, except during Complex CII sup. where a spatial partitioning can be observed. δ 18 O data from red deer was used to reconstruct mean annual temperature (MAT) and results indicate colder climatic values than today, but relatively elevated ranges of estimated temperature compared to other paleoclimate proxies. Together, these findings provide new insights into Middle Pleistocene faunal palaeoecology, local environmental conditions, and hominin activity at Lazaret Cave, within the context of its role as a southern refugium during a glacial period.