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

Sarah Barakat, Kennedy Williams, Malte Willmes, Emmanuel Desclaux, Kate Britton

► To cite this version:

Sarah Barakat, Kennedy Williams, Malte Willmes, Emmanuel Desclaux, Kate Britton. Multi-isotope analysis of mammalian fauna from the Middle Pleistocene (MIS6) Lazaret Cave: palaeoecological, palaeoenvironmental and archaeological implications. Journal of Archaeological Science: Reports, 2025, 68, pp.105456. 10.1016/j.jasrep.2025.105456. hal-05329625

HAL Id: hal-05329625

https://hal.science/hal-05329625v1

Submitted on 24 Oct 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_2.png" /></figure>

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

Sarah Barakat<sup>a,*</sup> <sup>10B</sup>, Kennedy Williams<sup>a</sup>, Malte Willmes<sup>b</sup>, Emmanuel Desclaux<sup>c,d</sup>, Kate Britton<sup>a,*</sup>

## ARTICLE INFO

### Keywords:

Niche reconstruction

Landscape use

Carbon isotopes

Oxygen isotopes

Strontium isotopes

Saalian glaciation

## ABSTRACT

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 (δ¹³C), oxygen (δ¹⁸O) and strontium (⁸⁷Sr/⁸⁶Sr) isotopic analysis. δ¹³C and δ¹⁸O 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. δ¹⁸O 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.

## 1. Introduction

### 1.1. Overview

Pleistocene stratified archaeological deposits in caves can be rich sources of mammalian faunal remains. In Europe and elsewhere, this is often a function of hominin subsistence behaviours, hunting practices and site use, which, along with the actions of denning carnivores, led to the initial accumulation of these remains. Coupled with the favourable conditions of karstic landscapes for bone preservation, this means that caves and rock shelters are extraordinary sources of potential

information about the past. Faunal remains are often the focus of zooarchaeological studies in aims of reconstructing past animal resources to provide more insight into past human subsistence and behaviours but are also key resources for information about past ecological and palaeoenvironmental conditions that can provide valuable additional contextual evidence for those behaviours (Britton et al., 2011; Pederzani et al., 2021). Faunal communities have been shown to be strongly influenced by the environmental and climatic shifts that characterised the Pleistocene, as reflected in both biodiversity, biomass, and their animal behaviours (Discamps et al., 2011; Steele, 2015).

Stable isotope analyses are an increasingly common means of

<footnote><sup>a</sup> Department of Archaeology, University of Aberdeen, St. Mary's Building, Elphinstone Road, Aberdeen AB24 3UF, United Kingdom</footnote>

<footnote><sup>b</sup> Norwegian Institute for Nature Research, PO Box 5685, 7485 Torgarden, Trondheim, Norway</footnote>

<footnote><sup>c</sup> Laboratoire de Préhistoire du Lazaret, Département des Alpes-Maritimes, 33 bis Blvd. Franck Pilatte, 06300 Nice, France</footnote>

<footnote><sup>d</sup> CEPAM – UMR 7264 CNRS – UCA, 24 Avenue des Diables Bleus, 06300 Nice, France</footnote>

<footnote>☆ This article is part of a special issue entitled: 'Neanderthal landscapes in southern Europe' published in Journal of Archaeological Science: Reports.</footnote>

<footnote>* Corresponding authors at: Department of Archaeology, University of Aberdeen, St. Mary's Building, Elphinstone Road, Aberdeen AB24 3UF, United Kingdom.</footnote>

<footnote>E-mail addresses: Sarah.barakat@abdn.ac.uk (S. Barakat), kennedywilliams2019@gmail.com (K. Williams), malte.willmes@nina.no (M. Willmes), emmanuel.desclaux@univ-cotedazur.fr (E. Desclaux), k.britton@abdn.ac.uk (K. Britton).</footnote>
reconstructing faunal palaeoecologies, and these approaches have been employed at numerous Late Pleistocene sites in Europe. These studies, conducted on both single sites and/or groups of sites, have provided evidence for migratory and dietary ecology of both extinct and (ancestral) extant animals (Bocherens, 2015; Flower et al., 2021). These approaches have also been used to reconstruct past climatic conditions and, through these, to better understand the environmental conditions surrounding hominin site use (Ecker et al., 2013; García García et al., 2009; Pederzani et al., 2021). However, few studies have used the application of stable isotope analyses on faunal remains dating to the penultimate glacial period (Marine Isotope Stage 6; ca. 185–135 thousand years ago (ka)), or earlier, in Europe due to sample preservation, scarcity of finds, and the demands of destructive sampling (Ecker et al., 2013; García García et al., 2009; Pálsdóttir et al., 2019).

With deposits spanning the late Middle Pleistocene (MIS 6), and numerous mammalian faunal remains, the site of Lazaret Cave (Nice, France) represents an opportunity to apply isotope zooarchaeological approaches to investigate the palaeoecology of the various species found. This study aims to create a better understanding of the local MIS

6 ‘refugium’ environment around Lazaret Cave during periods of Neanderthal occupations. To reconstruct past living landscapes, this study uses carbon and oxygen isotopes to analyse the dietary ecology (via isotopic niche space and represented in the δ-space) of ungulates (red deer, ibex, aurochs) and grey wolves. The mean annual temperature (MAT) of different periods of Neanderthal occupation is reconstructed using δ¹⁸O from red deer. Using strontium isotope analysis, we reconstruct relative landscape use of red deer and ibex throughout the site’s main archaeological complexes. Finally, we compare the data to those of previous site-based studies, as well as to the wider evidence for the behavioural palaeoecology of these species in the Middle Pleistocene and for the palaeoenvironmental conditions of MIS 6 in the region.

## 1.2. Lazaret Cave (Grotte du Lazaret)

Lazaret Cave (Grotte du Lazaret) is a Middle Pleistocene south-facing cave site located near modern day Nice in the south of France (Fig. 1). This site is located on Jurassic limestone cliffs at the bottom of the western slopes of Mount Boron and is approximately 26 m above

<figure><img src="image_3.png" /><figcaption>**Fig. 1.** Description of stratigraphy at Lazaret Cave, focused on subcomplexes II and III. ESR dates come from Michel et al. (2009), while MIS periodisation is after de Lumley (2018). It can be noted that if we refer solely to the ESR dates, there is a possible overlap between MIS 6 and 5 at the summit levels of subcomplex CIII and the base of complex E. Nevertheless, the palaeontological data support an MIS 6 age for the CIII summit levels, and we have therefore retained the chronology proposed by de Lumley (2018). Map made with landscape data from European Environment Agency (EEA). Lazaret is denoted with a star while other MIS 6 palaeoclimate sites mentioned in the text are denoted by circles.</figcaption></figure>
modern sea level near the Mediterranean shore (Valensi, 2000; Valensi et al., 2013). From the top of the stratigraphic sequence to the base, 5 complexes have been recognised: Complex E made of a stalagmite floor; Complex D which consists of a breccia overhang in the body of the cave; Complex C, which is 6 m deep and holds all archaeological layers, and Complex B and A below which are older marine beach layers. The age of Complex A remains unknown, however, marine complex B is rich in coral and marine molluscs and dates back to ca. 230 ka, corresponding to MIS 7 (Bahain, 1993; Michel and Yokoyama, 2000). Fig. 1 summarises the stratigraphy of Lazaret cave, focusing on the layers for Subcomplexes CII and CIII which provided most of the archaeological finds (Hanquet et al., 2010; Jrad et al., 2014; Michel et al., 2009; Valensi, 2000; Valensi et al., 2013, Valensi et al., 2007).

Complex C has been the source of archaeological investigation for 70 years and excavations from this complex have revealed a rich archaeological record of lithics, faunal material, and unique finds such as 28 Neanderthal remains. Due to the large amount of archaeological material within Complex C, which dates to the Saalian Glaciation between 190 to 130 ka, it has been subdivided into three smaller subcomplexes (respectively, from the top to the bottom: CIII, CII, and CI, Table 1). While the lowest subcomplex, CI, is largely unknown, Subcomplexes CII (which is subdivided into CII inferior and CII superior) and CIII have currently revealed 29 archaeological layers (named UA for archaeostratigraphic units). Lazaret cave has been defined as a long-term habitation site, although the alternating presence of hominin remains and carnivore bones, found alongside gnawed bones, suggests Neanderthals successively occupied the cave site throughout Complex C using

<caption>**Table 1**</caption>

Table describing the stratigraphy of Lazaret Cave including Pleistocene period, MIS period, subunits (GUA), archaeological level (UA), and complex stratigraphy.

<table><thead><tr><th>Period</th><th></th><th>MIS</th><th>GUA</th><th>UA</th><th>Stratigraphy</th></tr></thead><tbody><tr><td rowspan="10">Pleistocene</td><td rowspan="2">Upper Pleistocene</td><td>MIS 5 to MIS 4</td><td>no human levels</td><td>no human levels</td><td>Complex E Stalagmitic flowstone</td></tr><tr><td>MIS 6 (?)</td><td>no human levels</td><td>no human levels</td><td>Complex D (breccia)</td></tr><tr><td rowspan="7">End of Middle Pleistocene (?)</td><td>MIS 6.2</td><td>GUA A</td><td>UA 1 to UA 4</td><td rowspan="7">Sub complex C III</td></tr><tr><td>MIS 6.3</td><td>GUA B</td><td>UA 5 to UA 7</td></tr><tr><td>MIS 6.4</td><td>GUA C</td><td>UA 8 to UA 9</td></tr><tr><td>MIS 6.5</td><td>GUA D</td><td>UA 10 to UA 12</td></tr><tr><td>MIS 6.6</td><td>GUA E</td><td>UA 13 to UA 18</td></tr><tr><td>MIS 7</td><td>NO GUA</td><td>UA 19 to UA 25 (C II sup.)</td></tr><tr><td>MIS 9 (?)</td><td>not yet excavated</td><td>UA 26 to UA 29 (C II inf.)</td></tr></tbody></table>

temporary camps throughout the year (Valensi, 2000; Valensi et al., 2013). Zooarchaeological analysis of ungulate remains indicate majority of bones are anthropogenic, with carnivores primarily taking advantage of remains left by hominin groups (Valensi, 2000). In lower archaeological levels in Subcomplex CII the lithics are assigned as Acheulean lithic assemblages with numerous handaxes and low amounts of Levallois debitage while lithics in Subcomplex CIII have been assigned to the Mousterian culture with low numbers of handaxes (de Lumley et al., 2004; Valensi et al., 2013).

Throughout the continental filling of the Lazaret cave, the large mammal faunas are dominated by *Cervus elaphus* (red deer), a characteristic species of forest ecosystems and still widespread today in Western Europe, with the occasional presence of strictly cold species at the top of the sequence (mainly in sub-complex CIII), such as *Coelodonta antiquitatis* (whooly rhino) and *Rangifer tarandus* (reindeer) (Valensi et al., 2007). The small mammal communities are mostly dominated by the presence of temperate and forested species (such as *Apodemus sylvaticus* (wood mouse) and *Eliomys quercinus* (garden dormouse)), and strictly Mediterranean species, such as *M. (I.) brecciensis* (fossil species of vole) and *M. (T.) savii* (Mediterranean pine vole) with sporadically the presence of strictly cold species, such as *Lasiopodomys gregalis* (narrow-headed vole) in sub-complex CII sup. This phenomenon could be related to the position of the site and suggests that this area may have acted as a “classical refuge” for certain more temperate species during nearly all of MIS 6, as previously mentioned by Valensi et al. (2007), Hanquet et al. (2010), Desclaux (2013), and López-García et al. (2021). Thus, during MIS 6, the Meridional Alps seem to have been a transitional zone between the steppe zones of southern France, located within the limits of permafrost extension, as in levels XX to XVI of Baume Moula-Guercy in the Rhone valley corridor (Defleur et al., 2001, 1998, 2020; Defleur and Desclaux, 2019; Desclaux and Defleur, 1997), and the forest and grassland zones identified in the Italian peninsula, as at Poggetti Vecchi (Benvenuti et al., 2017).

## 1.3. MIS 6 palaeoenvironment and past site-based studies

MIS 6 has been generally characterized by cool and humid climatic conditions with less rainfall than today in the southern European and western Mediterranean region, largely evidenced by marine cores, speleothems and pollen sequences (e.g., Guiot et al., 1993; Guiter et al., 2003; Hodge et al., 2008; Margari et al., 2014; Ponel, 1995; Wainer et al., 2013). Conditions may have been more analogous to those found on the Tibetan Plateau or the Canadian Prairies today, than in any of the biomes found in present day Europe (Guiot et al., 1993). Coleoptera (beetle) and pollen studies in terrestrial contexts in France are also consistent with a cold climate. At La Grande Pile in central France, for example, the Riss pollen chronozone corresponds to MIS 6, and is described as open and extremely cold, similar to arctic tundra. *Pota-monectes grieosctriatus* (a diving water beetle) found near the site suggest open, freshwater sources in the vicinity, although other terrestrial beetle species found indicate rather dry conditions (Ponel 1995: 27). Slightly further south at Les Echets, conditions inferred are similar around 140 ka, but at both sites estimates of mean annual temperature vary considerably. Variations depend on whether palynological data are considered alone or along with other proxies, such as beetles, and range from between approximately 12 °C and 4 °C (Guiot et al., 1993; Ponel, 1995). Pollen and beetle data from deep terrestrial cores appear to be in agreement with speleothem data (for example from Villars Cave), which demonstrate cool and humid conditions (Wainer et al., 2013).

Site based studies, incorporating the analysis of faunal remains, including at Lazaret cave itself have added to this picture. Consisting of large mammal species such as red deer and *Capra ibex* (ibex), as well as birds, small vertebrates and malacofauna, the faunal suite at Lazaret Cave is indicative of a cool but relatively humid environment, dominated by deciduous temperate forest (López-García et al., 2021). Zooarchaeological studies at Lazaret have indicated climatic changes
throughout Complex C. While typically dominated by red deer and ibex throughout the sequence, CII sup. has a zooarchaeological assemblage indicative of a more temperate climate with a high abundance of red deer, relatively less ibex, but also the presence of *Bos primigenius* (aurochs) and *Capreolus capreolus* (roe deer). In comparison, the CIII faunal assemblage reverts to species indicative of colder conditions, including red deer, a higher abundance of ibex compared to CII sup., *Rangifer tarandus* (reindeer) and *Bison priscus* (steppe bison) (Valensi et al., 2007). The large mammal assemblage is supported by marine gastropod assemblages which show a sea temperature cooling in CIII compared to CII (Valensi et al., 2007). Finally, the range of species found within the amphibian, reptile, and bird faunal assemblage also show a cooler climate and more humid, open environmental conditions than today at Lazaret Complex C, and a more temperate climate in CII sup. than CIII (Hanquet et al., 2010).

Recent work on the rodent and herpetofauna assemblages indicate a mixture of both Mediterranean and more strictly cold-adapted species, highlighting an unusual environmental suite that may have characterised this more southerly location, influenced by coastal proximity, and positioned at the interface of warmer Italian forest-grassland environments and the French cold steppe typical of the period. This interpretation supports the idea that Lazaret Cave may have acted as a refugia for temperate species (Desclaux, 2013; López-García et al., 2021). Mean annual temperature (MAT) estimates based on small mammals suggest relatively cooler temperature than today between 8–9 °C, albeit with standard deviations of 6.5–7 °C, throughout Complex C. In contrast, MAT estimates in herpetofauna suggest milder conditions of around 11 °C with standard deviations between 2–3 °C. While the methods used to recreate MAT based on small rodent remains do not consistently show a difference between CII. sup and CIII like other proxies discussed, the presence of relatively colder conditions in CII inf. can be inferred based on the rodent assemblage and the presence of *Lasipodomys gregalis* (narrow-headed vole). These results also persistently show a cooler climate than today with a relatively humid environment dominated by deciduous temperate forests (López-García et al., 2021).

Further analyses on large fauna at Lazaret, including ungulate meso- and micro- wear have served to link the broader climatic and environmental parameters of the region to the specific behaviour of animals. Red deer were demonstrated to have a relatively consistent foraging ecology through the main three subcomplexes, being browsers or (browse-dominated) mixed feeder (Rivals et al., 2023). Although, within Subcomplex CIII, red deer mesowear indicate an increase in grasses which could be caused by niche partitioning and/ or ecological displacement due to competition with other ungulates or potentially changes in mobility. While also being mixed-feeders, ibex diets were distinct from red deer in CII inf. and demonstrated more overlap (increased leaf feeding) into CII sup. and CIII. Aurochs (studied only in CII sup.) were characterised more distinctly as leaf browsers but only by relatively few individuals (Rivals et al., 2023). Analysis of the faunal remains has also helped infer the seasonality of accumulations (i.e. hominin activities) at the site, suggesting differences in the timings of human occupations within Subcomplex CII inf. In Subcomplexes CII sup. and CIII, the remains were accumulated in events lasting more than one season or as a series of shorter events that spanned multiple seasons (Valensi, 2000; Valensi et al., 2013).

## 1.4. Inferring palaeoecology and palaeoenvironment through the isotope analysis of faunal remains

### 1.4.1. Carbonate analysis

The isotope ratios of faunal mineralised tissues are directly related to the isotope ratios of the water and food consumed during life, and thus these approaches can be a useful means of assessing not only an animal's feeding ecology, but also the environment in which they lived and even where they lived (see Stevens et al. 2025). While Late Pleistocene studies

often focus on the analysis of bone collagen, this material is rarely preserved at Middle Pleistocene sites (although see Kuitems et al. 2015; Jones et al. 2001). In such circumstances, tooth enamel becomes the favoured analyte. With its low organic content and densely packed crystalline structure, mammalian tooth enamel is less susceptible to diagenesis than bone mineral (Driessens and Verbeeck, 1990; Hoppe et al., 2003). Unlike bone, tooth enamel in most mammals is not continuously growing, with the chemical and isotopic information contained within relating to the period of growth in early life. A number of approaches have been applied to mammalian tooth enamel to reconstruct past animal diets and behaviours, and to infer aspects of the wider environment, including the carbon isotope analysis of the carbonate component, and the oxygen isotope analysis of the carbonate and phosphate component (Fabre et al., 2011; Feranec et al., 2010; Fernández-García et al., 2024; García-Alix et al., 2012; Scherler et al., 2014). Strontium isotope analysis has also been employed to explore past movements (Britton et al., 2011; Wooler et al., 2021).

The most common isotope analyses undertaken on Pleistocene mammalian tooth enamel are carbon and oxygen, although applications of strontium isotope analysis are also increasing. Carbon isotope ratios can be used to determine the dietary habits of animals, including herbivores, and through this also illuminate the broader ecological and environmental suite at a specific location (e.g. Carvalho et al., 2022). Even in purely C₃-environments, intra-ecosystem carbon isotope ratios of different plant communities or environments (i.e. wooded versus grassland) can differ (Bonafini et al., 2013; Drucker et al., 2008; Van Der Merwe and Medina, 1991). Using multiple species from a faunal assemblage allows for a more complete insights into the dynamics of past faunal communities and allows researchers to distinguish between 'baseline' changes (i.e. variations in faunal isotope values that reflect broad-scale palaeoenvironmental changes) and differences in animal behaviour or resource use (Britton et al., 2023a).

Within mammals, there is an isotope enrichment in tooth enamel δ¹³C values compared to dietary values. In medium to large sized ungulates this enrichment is approximately 14.5 to 12 ± 1.0‰ (Cerling and Harris, 1999; Cerling et al., 2021; Lüdecke et al., 2022; Passey et al., 2005), while in carnivores the enrichment of δ¹³C is ~9‰ (Cerling and Harris, 1999; Tieszen, 1994). Furthermore, predators should have δ¹³C values ~1.3‰ lower than that of their prey (Clementz et al., 2009; Ecker et al., 2013; Fox-Dobbs et al., 2007). Within ungulates, dietary and physiological differences can cause differences in δ¹³C. Grazers, for example, will have more elevated carbonate δ¹³C values compared to browsers, in both mixed C₃-C₄ and exclusively C₃ environments (Eastham and Feranec, 2025; Lüdecke et al., 2022). Ruminants will also have elevated δ¹³C values due to methane production (Cerling and Harris, 1999; Codron et al., 2018; DeSantis et al., 2022; Eastham and Feranec, 2025). Considering the above, the δ¹³C values of herbivores in a purely C₃ environment should be ~−21‰ to −8‰ VPDB. In turn, carnivore δ¹³C will largely depend on their prey-choice, and thus reflect their prey's diet and, through this, the broader environment.

Oxygen isotope ratios of mammalian mineralised tissues are related to that of the water they consume, both in terms of liquids ingested, but also the water (and structural Oxygen-Hydrogen) in their food. Given the relationship between temperature and the δ¹⁸O value of local precipitation, and the relationship between the δ¹⁸O value of body water and that of mineralized tissues, the oxygen isotope analysis of mammalian skeletal tissues can provide valuable insights into past thermal conditions (see Pederzani and Britton 2019 for an overview). When obligate drinking species are targeted, these approaches can provide a means of exploring annual, local mean annual, and even seasonal, climatic conditions. For animals that gain water through their food (either partially or as the major source), such as some cervids, the inference of palaeotemperatures can be more complex (Levin et al., 2006; Pederzani and Britton, 2019; Sponheimer and Lee-Thorp, 1999). Studies on modern red deer (n = 9) on the Isle of Rhum, Scotland, have suggested clear, linear relationships between local environment water,
body water and the δ¹⁸O of mineralised tissues (D'Angela and Longinelli, 1990; Iacumin et al., 1996; Stevens et al., 2011). Based on modern faunal studies and due to the semi-obligate drinking nature of red deer, δ¹⁸O values in red deer tooth enamel are expected to largely reflect the local precipitation. For this reason, red deer tooth enamel has been analysed for δ¹⁸O to reconstruct past temperatures, although caution should be advised as there may be some averaging between drinking and diet water (Drucker et al., 2024; Ecker et al., 2013; Giustini et al., 2024; Szabó et al., 2021).

Carbonate analysis can also be used to analyse faunal behaviours. Altitudinal mobility has been found using intra-tooth serial sampling. As fauna move to higher elevations there is an indirect relationship between δ¹³C values (which increase ~1.2 ± 0.9‰ per 1000 m) and δ¹⁸O values (decrease ~0.3‰ per 100 m) (Körner et al., 1988; Lazzerini et al., 2021; Makarewicz et al., 2017; Mezga et al., 2014; Tornero et al., 2016). δ¹⁸O in tooth enamel carbonates can also provide trophic level details as the enrichment of oxygen isotopes in enamel carbonates from drinking water is ~26‰ (V-SMOW) for herbivores, while carnivores will have slightly more negative δ¹⁸O values compared to their diet (Tieszen, 1994). Differences in δ¹⁸O values between herbivore and carnivore diets is likely due to the different food components in their diet. Carbohydrates – the main components of herbivorous faunal diets and generally lacking in carnivores' diets – are relatively enriched in ¹⁸O relative to water (Schmidt, 1999). This ¹⁸O enrichment can also extend to other naturally biosynthesised plant products that may be present in the diets of herbivores (Schmidt et al., 2001). Thus, low-protein, high plant carbohydrate herbivore diets tend to be ¹⁸O-enriched compared to the high protein diets of carnivores and omnivores (Göhring et al., 2019; Sponheimer and Lee-Thorp, 2001). It is also likely that differences in the amounts of plant- and animal-derived/self-synthesised amino acids or other chemical compounds could account for variations (see Göhring et al. 2019 for discussion). For example, it has been proposed that the greater quantity of plant-derived ¹⁸O-enriched L-tyrosine (a non-essential amino acid) in herbivores, as opposed to that which is self-synthesized, could lead to differences in the δ¹⁸Ocarbonate of herbivorous and carnivorous mammals (Göhring et al., 2019). Finally, within herbivores, dietary niche partitioning, such as browsing versus grazing, can also be potentially identified using carbonate δ¹⁸O data as browsers should have elevated δ¹⁸O values from plant food's water source and because C₃ plant leaves are more depleted in the lighter isotope (Sponheimer and Lee-Thorp, 1999).

Carbonate analysis in tooth enamel is a useful tool for palaeoecological reconstruction which generates δ¹³C data alongside δ¹⁸O data, providing insight into both diet and palaeoenvironment, alongside being more time- and cost-efficient than analysing oxygen in the phosphate moiety (Balasse, 2002; Drucker et al., 2024; Feranec et al., 2010; Koch, 1998; Pellegrini and Snoeck, 2016; Snoeck and Pellegrini, 2015). Through the analysis of carbonates, isotopic niche spaces, i.e., the intersection of carbon isotope and oxygen isotope values in a biplot, can be developed to further interpret dietary niche space results and reconstruct past environments. These methods, originally developed within ecology to calculate isotopic niche spaces using Bayesian Ellipses, are now proving useful for the analysis of dietary and landscape use in the past (Baumann et al., 2020; Bourgon et al., 2020; Britton et al., 2023a; Tessone, 2022). Ecological niches are spaces made up of many different dimensions which can be broken down into independent ecological variables, such as environmental factors which fauna cannot modify but need to survive (scenopoetic) or bionomic factors which fauna can modify, for example trophic feeding, resting, and calving site behaviours (Hutchinson, 1978; Soberón, 2010). As isotope ratios in tooth enamel are highly related to diet and drinking water, these values can represent both bionomic and scenopoetic factors (Jackson et al., 2011). For example, carbon isotopes will reflect trophic level and browsing or grazing alongside carbon sources, i.e. C₃ vs C₄, and woodland vs open air sites, and oxygen can provide temperature and geographical scenopoetic data. As isotopic results are typically shown in

biplots, the intersection between the isotope values, represented in the δ-space, can become the animals isotopic niche space (Newsome et al., 2007). When analysing multiple individuals within a population, these isotopic niche spaces can be widened from a single individual to an entire community (Layman et al., 2007). In this study we use isotopic niche spaces as a proxy to understand past faunal dietary and ecological niche spaces (Newsome et al., 2007; Wißing et al., 2019).

Within carbonate analysis, several approaches can be utilised to characterise and negate potential diagenetic alteration, including assessing the % carbonate content which can indicate recrystallisation (low %) or the addition of exogenous carbonates from the burial environment (high %) (Koch et al., 1997). Mammalian tooth enamel which has not undergone extensive diagenesis is expected to have a carbonate content between 2 to 6% (Ecker et al., 2013; Giustini et al., 2024; Koch et al., 1997; Skippington et al., 2019; Xu et al., 2012). If the carbonate content is within this range and there is no correlation between carbonate content and the δ¹³C and δ¹⁸O values, then it is suggested that the enamel has not been diagenetically altered and can be used for paleoenvironmental reconstruction. Pretreatment techniques, such as using acetic acid, are also frequently used to remove secondary carbonates.

Applications of isotope analysis to Middle Pleistocene faunal remains are comparatively rare to more recent periods, but in the Mediterranean region include sites in northern Spain at Sierra de Atapuerca, and the site of Payre in France. At Payre, Ecker et al. (2013) analysed the carbon and oxygen stable isotopes from carbonates of 14 species including red deer, aurochs and grey wolves in multiple periods, including during MIS 6. The analysis of herbivores here demonstrates clear ecological niches that were unchanging between MIS 8 and MIS 6, indicating niche stability despite the changing global climate of the Middle Pleistocene at this time. The authors suggest that the Mediterranean Sea may have been the prevailing influence on the local faunal palaeoecology, and that the Rhône Valley may have served as a refugium, minimising the impacts of cold phases on fauna (Ecker, et al., 2013).

Isotope zooarchaeology has also been used more directly to explore palaeotemperatures during MIS 6 in this region. At the site of Coudou-lous I, in south-western France, intra-tooth analysis of oxygen (phosphate) from bison teeth in Layer 4 (149 ± 6 ka) characterised both mean annual temperatures and seasonal temperatures at this locale during MIS 6 in the Late Middle Pleistocene (Bernard et al., 2009). A mean annual temperature (MAT) of 9 ± 3 °C was inferred, which is approximately 4 °C less than today (Bernard et al. 2009), implying a relatively ameliorate climate and challenging previous studies that have inferred much colder climatic conditions for this region during the late Middle Pleistocene.

### 1.4.2. Strontium analysis

In addition to providing proxy evidence for dietary niche feeding behaviours and the broader environment, other isotope approaches, such as strontium, can be utilised to explore movements. Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) of skeletal tissues relate directly to that of local lithology, soils and plants, these techniques can provide complementary evidence of individual movement histories (Bentley, 2006; Britton, 2020). Underlying lithology represents the main source of ⁸⁷Sr/⁸⁶Sr variations in terrestrial environments, related to their age and mineral composition, with smaller contributions coming from the atmosphere, aeolian and other local depositional processes (Bentley, 2006; Capo et al., 1998; Dasch, 1969). Most ⁸⁷Sr/⁸⁶Sr in terrestrial environments range from 0.702, in young basalts, to 0.750, in older granites (Bentley, 2006; Erban Kochergina et al., 2021). Sr is released from underlying lithology during natural weathering of bedrock, enters the soils, and plants growing in the soil then absorb the Sr and its associated ⁸⁷Sr/⁸⁶Sr value. When herbivores consume plants, the plants ⁸⁷Sr/⁸⁶Sr then contributes to that of their skeletal tissue. Strontium isotopes show no significant fractionation during these processes, meaning that the ⁸⁷Sr/⁸⁶Sr values in tooth enamel can be used to infer where herbivores were eating during their early life. In overly homogenous lithologies, such as large
areas made of limestone, it can be difficult to tell where a fauna was located as there will be a low amount of variation in the bioavailable $^{87}$Sr/$^{86}$Sr; in these cases, $^{87}$Sr/$^{86}$Sr isotope analysis can better assess where a specimen was not rather than identifying potential origins.

At Lazaret cave itself, a previous isotope study presented local bioavailable strontium alongside intra-tooth strontium, oxygen and carbon data from UA25 (part of Subcomplex II sup.) to explore the palaeoecology of red deer and ibex (Barakat et al., 2023). This study demonstrated a diverse lithological landscape across the French Maritime Alps with both younger and older lithologies (relating to relatively low and high $^{87}$Sr/$^{86}$Sr values) within 50 km of Lazaret Cave (Fig. 2). The site itself has a $^{87}$Sr/$^{86}$Sr value between 0.7082–0.7087 and is situated near a younger carbonate lithology ($^{87}$Sr/$^{86}$Sr ≤ 0.710) although siliciclastic sediments with higher $^{87}$Sr/$^{86}$Sr values (≥ 0.719) can be found within a few kms. $^{87}$Sr/$^{86}$Sr analysis of ungulates showed variations in movements between ibex and red deer. Ibex had low $^{87}$Sr/$^{86}$Sr values with low amounts of variation suggesting they remained within the same lithological zone during tooth mineralisation while $^{87}$Sr/$^{86}$Sr in red deer indicated these ungulates undertook regular (albeit likely small scale) seasonal movements during the occupation of CII sup. (Barakat, et al., 2023).

## 2. Materials and methods

### 2.1. Sampling strategy

Later forming teeth (second and third molars) of ungulates were selected from the stratigraphic Subcomplexes CIII, CII sup., and CII inf., including from ibex, red deer and aurochs for isotope analysis (Table 2). Teeth were selected from individuals already identified to species level. Efforts were made to target molars which are not overly worn to maximise the period of isotopic input represented in each crown. In some cases, two teeth were selected from the same individual to extend that time series. In red deer second and third molars should capture

approximately a five- and thirteen-month period, while ibex molars will capture between six to twelve months (Armaroli et al., 2025; Brown and Chapman, 1991). Due to a lack of representative samples in the assemblage, one of the two samples taken for aurochs was a first molar, which was not ideal, due to a potential residual influencing of nursing (Bernard et al., 2009; Towers et al., 2014). Bovid first molars begin to mineralise in utero and finish mineralising in the first three months of life, while the third molar should begin formation between nine to thirteen months and finish mineralising approximately one year later (Balasse, 2002; Montgomery et al., 2010). In addition to the ungulates, fourth premolars and first molars from six *Canis lupus* (grey wolf) specimens—two from each major subcomplex level—were also analysed for carbonates to reconstruct wolf dietary ecology throughout Complex C. The list of samples analysed, and the mean isotopic values used can be found in the SI Table 1 and 2.

### 2.2. Methods

#### 2.2.1. Carbon and oxygen isotope analysis

Tooth enamel samples were prepared for carbonate analysis at the Archaeological Isotope and Peptide Research Laboratory (AIPRL) at Durham University. Using a diamond-tipped burr, tooth samples still attached to the mandibular and maxillary bone were cleaned to remove any surface dirt and cementum. Tooth enamel was then sampled in bulk by using the diamond-tipped burr across the full height and depth of the tooth enamel. The powdered sample was collected on foil and transferred to a 2 mL microcentrifuge tubes and washed in a 0.1 M acetic acid solution for 10 min as a pretreatment to remove any diagenetic contamination due to the limestone background. The washed samples were then centrifuged and washed with deionised water four times to remove any lingering acetic acid. Finally, cleaned samples were freeze-dried and transferred to Iso-Analytical Ltd (Sandbach, Cheshire, UK) for mass spectrometry.

At Iso-Analytical Ltd, samples were weighed into Exetainer™ tubes

<figure><img src="image_4.png" /><figcaption>**Fig. 2.** Bioavailable $^{87}$Sr/$^{86}$Sr isoscape of the area around Lazaret Cave including an inset map focusing on the area directly surrounding Lazaret Cave from Barakat et al. (2023, Fig. 4A). The black solid lines represent modern day country boundaries. This isoscape was created using kriging with external drift and pre-published plant and soil $^{87}$Sr/$^{86}$Sr data from Willmes et al. (2014), Willmes et al. (2018a), Bataille et al. (2018), and Lugli et al. (2022).</figcaption></figure>
<caption>**Table 2**</caption>

Number of samples analysed for $\delta^{13}$C, $\delta^{18}$O and $^{87}$Sr/$^{86}$Sr from each complex which are included in the results. Samples analysed but not included in the results can be found in Supplementary Table 1. Samples designated with an asterisk come from Barakat et al. (2023).

<table><thead><tr><th>Species</th><th>Complex</th><th>Number of individuals analysed for δ<sup>13</sup>C and δ<sup>18</sup>O</th><th>Number of individuals analysed for <sup>87</sup>Sr/<sup>86</sup>Sr</th></tr></thead><tbody><tr><td rowspan="2">Bos primigenius</td><td>C III</td><td>1</td><td></td></tr><tr><td>CII sup.</td><td>1</td><td></td></tr><tr><td rowspan="3">Canis lupus</td><td>C III</td><td>2</td><td></td></tr><tr><td>CII sup.</td><td>2</td><td></td></tr><tr><td>CII inf.</td><td>2</td><td></td></tr><tr><td rowspan="3">Capra ibex</td><td>C III</td><td>4</td><td>1</td></tr><tr><td>CII sup.</td><td>3</td><td>1*</td></tr><tr><td>CII inf.</td><td>4</td><td>2</td></tr><tr><td rowspan="3">Cervus elaphus</td><td>C III</td><td>5</td><td>2</td></tr><tr><td>CII sup.</td><td>6 + 2*</td><td>2*</td></tr><tr><td>CII inf.</td><td>4</td><td>1</td></tr></tbody></table>

and flushed with 99.995 % helium. Carbonate in the samples was converted to CO₂ by adding phosphoric acid and letting the samples sit overnight for the reaction to occur. Reference materials (IA-R022, NBS-18, and IA-R066) were prepared along the same methods. CO₂ from the samples was then analysed by Continuous Flow-Isotope Ratio Mass Spectrometry (CF-IRMS). The CO₂ was sampled from the Exetainer™ tubes into a continuously flowing He stream using a double holed needle. The CO₂ was resolved on a packed column gas chromatograph and the resultant chromatographic peak carried forward into the ion source of a Europa Scientific 20–20 IRMS where it was ionized and accelerated. The phosphoric acid used for digestion was prepared in accordance with Coplen et al. (1983) and was injected through the septum into the vials. 20 % of samples were run in duplicate. Analytical errors for the analysis were $\delta^{13}$C ± 0.1‰ (1 s.d.) and $\delta^{18}$O ± 0.2‰ (1 s.d.).

### 2.2.2. Strontium isotope analysis

Tooth enamel samples for laser ablation $^{87}$Sr/$^{86}$Sr were removed using a dental drill with an ultra-fine diamond disc to cut narrow enamel slices from selected teeth. The thin slices of enamel were then mounted flat on petrographic glass slides, with 5–6 individual cross-sections per slide. This method exposes the dentine-enamel junction and offers an ideal trajectory to perform laser-ablation mass spectrometry.

$^{87}$Sr/$^{86}$Sr isotope ratios were measured at the University of California Davis Interdisciplinary Center for Plasma Mass Spectrometry using laser-ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). For the Sr isotope analyses a Nd:YAG 213 nm laser (New Wave Research UP213) is coupled to a Nu Plasma HR MC-ICP-MS (Nu032). A line with a 100 µm diameter spot diameter and a run speed of 10 µm/s was used to sample across the entire tooth cross-section. The laser was operated using a 10-Hz frequency and 5–7 J/cm² photon output.

Different methods have been used to account and correct for the different interferences and mass bias present when analysing strontium isotopes using LA-MC-ICP-MS (Horstwood, 2008; Lewis et al., 2014; Müller and Anczkiewicz, 2016; Oxilia et al., 2020; Vroon et al., 2008). The instrument was operated in medium resolution mode (~7500 M/ΔM) to avoid polyatomic spectral interferences, i.e., $^{40}$Ca$^{31}$P$^{16}$O, or $^{40}$Ar$^{31}$P$^{16}$O, which can overlap with $^{87}$Sr, and consequently cause inaccurate results. The $^{87}$Sr/$^{86}$Sr isotope ratio is normalized for instrumental mass discrimination by monitoring the $^{86}$Sr/$^{88}$Sr isotope ratio ($^{86}$Sr/$^{88}$Sr = 0.1194) and $^{87}$Rb is corrected by monitoring the $^{85}$Rb signal and normalized by the same mass bias coefficient as Sr. The Rb correction is considered robust for samples with low $^{85}$Rb:$^{88}$Sr ratios (<0.002), which included all samples in this study. Krypton interference ($^{86}$Kr) originating from the argon supply is corrected using on-peak subtraction before each analysis. Processing of the geochemical data was carried out in IsoFishR (Willmes et al., 2018b). A 5-point average was applied to the raw data collected by the mass spectrometer with an integration time of 0.2 s resulting in 1 datapoint per second. Outliers were removed based on 2 interquartile range (IQR) outlier criterion using a 100-point moving average window.

Accuracy and reproducibility of the LA-MC-ICP-MS were evaluated using an in-house reference material consisting of a modern marine Green Sturgeon (*Acipenser medirostris*) fin ray. Replicate analyses of the in-house reference material yielded 0.70911 ± 0.00016 (n = 21, ±2 s. d.) which is in good agreement with the global average $^{87}$Sr/$^{86}$Sr value of modern seawater of 0.70918 (McArthur et al., 2001; Mokadem et al., 2015).

## 2.3. Statistical analysis and data treatment

### 2.3.1. Data analysis and isotopic niche space

Graphs were produced using R 4.3.0. Statistical analysis to identify significant differences between $\delta^{13}$C and $\delta^{18}$O between species and between the same species through time (Subcomplex CII and Subcomplex CIII) were done using a Kruskal-Wallis test and *post-hoc* Dunn Test. SIBER was used to create $\delta^{13}$C - $\delta^{18}$O niche ellipses areas which help to identify overlap between species (Jackson et al., 2011). Using SIBER, a convex hull is created which outlines all of the data from each species and a core isotope niche area is created using 40 % of the data. The overlap between core niche areas was produced using SIBER, while the total area (convex hull) overlap was created by transforming convex hulls into spatial objects and computing the minimum convex polygons and calculating the intersection proportion of overlap between species (Jackson et al., 2011). Analysis of isotopic niche space between all species through time (global) and between red deer and ibex (for sub-complexes) was conducted in order to explore potential inter-species differences and potential temporal variations. A limitation of this method and study is that SIBER cannot analyse data sets with less than 5 samples. Thus, only red deer and ibex were analysed in subcomplexes as the number of samples for wolves and aurochs was 2 or less and therefore could not be statistically analysed. Small samples sizes also create larger uncertainties in standard ellipse area (SEA), and thus a corrected standard ellipse area (SEAc) which is larger but has less uncertainty is used.

### 2.3.2. Palaeothermal conditions

Although obligate drinkers, such as horses or bovids, are normally selected for reconstructing palaeotemepratures using isotope zooarchaeology (e.g., Pederzani, et al., 2021), carbonate oxygen isotope data from red deer from Pleistocene sites have been used to explore palaeoclimate (e.g. Amanova, 2024; Giustini et al., 2024; Szabó et al., 2021). Red deer are semi-obligate drinkers, and can nurse their young for a protracted period; however, modern studies too have suggested a usefulness and reliability in the use of their isotope data in inferring past palaeotemperatures (Stevens et al., 2011). Indeed, linear relationships have been demonstrated between both the $\delta^{18}$O of body water and the $\delta^{18}$O of bone phosphate, and the $\delta^{18}$O values of local mean meteoric waters in modern European examples (D'Angela and Longinelli, 1990; Iacumin et al., 1996). Here, we utilised conversion equations form these
modern studies to convert averaged δ¹⁸O values to estimates of mean annual temperature (MAT). This was achieved through initially converting the V-PDB reported value to V-SMOW (1) (after Coplen et al. 1983) and then through generating a predicted phosphate δ¹⁸O value (2) which is based on modern mammals, including red deer, in Italy (Pellegrini et al., 2011):

$$ \delta^{18}O_{V-SMOW} = 1.03091 * \delta^{18}O_{V-PDB} + 30.91 \quad (1) $$

$$ \delta^{18}O_{phos} = 0.950(\pm 0.016) \cdot \delta^{18}O_{carb} - 7.51(\pm 0.439) \quad (2) $$

Eq. (2) was selected as Pellegrini et al. (2011) base their work on modern day fauna (including red deer) in a Mediterranean (Italy) context. Furthermore, it has been utilised in studies of Late Pleistocene fauna in the Mediterranean (Giustini et al., 2024; Pellegrini et al., 2011). Newly converted (predicted) phosphate values must then be transformed into drinking water (dw). The following Eq. (3) by D'Angela and Longinelli (1990) was formulated by analysis of living red deer from across national parks in France and Germany. Species-specific equations are important in this step to avoid fractionation rate and physiological differences between various ungulates.

$$ \delta^{18}O_{phos} = 1.13(\pm 0.04) \cdot \delta^{18}O_{dw} + 25.53(\pm 0.38) \quad (3) $$

Finally, mean annual temperature can be calculated between δ¹⁸O values in precipitation (drinking water) to estimate palaeotemperatures using the following equation (4) calculated by Giustini et al. (2024) based on data obtained from the Global Network of Isotope in Precipitation (IAEA/WMO, 2020):

$$ \delta^{18}O_{dw} = 0.27(\pm 0.06) \cdot T_{air} - 10.25(\pm 0.81) \quad (4) $$

Importantly, each step beginning with the transition from V-PDB to V-SMOW have associated uncertainties which must be calculated before moving to the next conversion. This propagates a compound error, which is taken forward (Pryor et al., 2014).

### 2.3.3. Strontium isotope data

Before any statistical analysis, LA-MC-ICP-MS ⁸⁷Sr/⁸⁶Sr data for M1, M2, and M3s were cleaned to remove values below 0.700 and above 0.7300 which occurred at the start and ends of runs (0.19%) when the Sr signal was very low < 0.1 V. Strontium profiles were then created using a 20-point rolling mean, this rolling mean is used to create all graphical analyses. As individual teeth were analysed rather than sets of teeth, box plots were created to identify the range of values between individual molars and between periods. Two red deer and a single ibex from Barakat et al. (2023) were analysed as second and third molar pairs. For these samples, each tooth is treated as an individual sample, and a box plot is created for each tooth. The minimum, first quartile, median, third quartile, and maximum values which are plotted in the boxplots are calculated in R 4.3.0.

## 3. Results

### 3.1. Carbon and oxygen isotopes

In this study, carbon and oxygen isotope data were generated from a total of 34 samples, including aurochs (n = 2), grey wolf (n = 6), ibex (n = 11) and red deer (n = 15). In some cases (n = 2), multiple teeth (M2 and M3 pairs) were sampled from the same individual animal: in such cases, for the purposes of the statistical analysis, an average value for each animal was used (combining values from both teeth analysed, SI Table 2). In the description of the data, and the analyses below, a further 2 samples were added from a previously published study (Barakat, et al., 2023) at the site which included carbonate oxygen isotope data from two red deer, with second and third molars sampled from each individual. As the data from (Barakat et al., 2023) were generated from sequentially sampled teeth, a single intra-tooth average was calculated

for each individual (combining data from the M2 and M3), to allow data to be comparable to that generated in the current study. A subsample, of 40 % of the data were analysed for carbonate content to evaluate the impact of diagenetic alteration. Of the subsample, the average carbonate content was 6.0 ± 0.9 % which is within the expected range of 2 % to 6 % for mammalian tooth enamel (Skippington et al., 2019; Xu et al., 2012), and, while diagenetic alteration cannot ever be ruled out, the carbonate content and the lack of correlation between CaCO₃ content and δ¹³C and δ¹⁸O values indicate it is unlikely that enamel was altered. Furthermore, the intra-specific differences described below are also suggestive that samples retained biogenic signals.

The mean δ¹³C value for wolves (−13.0‰ ± 0.4, n = 6) was lower than the mean δ¹³C value for the herbivores (−10.8‰ ± 0.6, n = 30) (Table 3, Fig. 3). Within herbivores, aurochs had the least negative δ¹³C values (−9.6‰ ± 0.3, n = 2) and red deer had the most negative (−11.0‰ ± 0.5, n = 17). Ibx sat between these two species with a mean δ¹³C value of −10.8‰ ± 0.5 (n = 11). In pairwise comparisons, grey wolves had significantly lower δ¹³C values than all herbivores, but no significant difference was found between the herbivores (SI Table 3).

For oxygen values, ibex had the least negative average δ¹⁸O value (−2.0‰ ± 1.1, n = 11), followed by red deer (−3.8‰ ± 1.3, n = 17), and aurochs had the lowest average δ¹⁸O value (−4.5‰ ± 0.3, n = 2). The mean δ¹⁸O value for the grey wolf was −4.0‰ ± 1.3 (n = 6) with a range of −2.7‰ to −5.8‰. Between species, red deer have significantly lower δ¹⁸O value than ibex. Grey wolves are nearly significantly lower than ibex (p = 0.058) but more samples would be needed to confirm this given the small sample size (SI Table 3).

### 3.2. Stable light isotope data and isotopic niche spacing by subcomplex

Red deer δ¹³C values decrease through time, while ibex and aurochs increase through time (Fig. 4, SI Table 4). In comparison to ungulates, the grey wolf has the lowest δ¹³C values in CII inf. and highest values in CII sup. Furthermore, there is no significant difference between mean δ¹³C values for any of the species studied between subcomplexes. Oxygen isotope ratios of ibex, aurochs, and grey wolf become more negative through time, with CIII having the most negative δ¹⁸O values for these taxa. This is in stark comparison to the red deer δ¹⁸O values, who are the only species in which CII sup. has the least negative δ¹⁸O values and the lowest values in CII inf. While trends appear more prominently in oxygen values, the results still do not significantly change through time (SI Table 5).

In Fig. 5, the total isotopic area of each species is represented by a convex hull shown in dashed lines. The isotopic core niche area for each species is represented by a maximum likelihood standard ellipse (SEAc, to correct for small sample size) in species-specific colours and represents roughly 40% of the data per species. The largest overlap between red deer and ibex core area is in Subcomplex CIII (Fig. 5D) where 37% of ibex's core area overlaps with red deer's core niche area, in CII inf. (Fig. 5B), this overlap is 10%, while in CII sup. (Fig. 5C) ibex and red deer only overlaps at 1%. When all data is combined, the overlap between ibex and red deer core niche area stays relatively small (4% ibex overlap with red deer, SI Table 6). Aurochs and grey wolf statistics were unable to be calculated due to low sample numbers, however the carbonate values for these species remain separated from red deer and ibex throughout time (Fig. 5A).

Finally, using the δ¹⁸O results of red deer, the estimated mean annual temperature (MAT) was calculated through the different subcomplexes. MAT calculations range from 12.4°C ± 5.0°C in CII inf. (n = 4); to 14.5 °C ± 5.5°C in CII sup. (n = 10); and 14.0 ± 5.4 in CIII (n = 5). These results show a wide range of reconstructed temperatures at Lazaret Cave through time, with the warmest reconstructed MAT in Subcomplex CII sup.
<caption>**Table 3**</caption>

Results table with mean δ¹³C and δ¹⁸O isotope values alongside standard deviations for all fauna across time. Please note, the data from two red deer in a previously published study (Barakat et al. 2023) have been included here.

<table><thead><tr><th>Species</th><th>Sample Size</th><th>Mean<br>δ¹³C<sub>V-PDB</sub> values (‰)</th><th>δ¹³C<sub>V-PDB</sub> Standard deviation<br>(‰)</th><th>Mean<br>δ¹⁸O<sub>V-PDB</sub> (‰)</th><th>δ¹⁸O<sub>V-PDB</sub> Standard deviation (‰)</th></tr></thead><tbody><tr><td>Bos primigenius</td><td>2</td><td>-9.6</td><td>0.3</td><td>-4.5</td><td>0.3</td></tr><tr><td>Canis lupus</td><td>6</td><td>-13.0</td><td>0.4</td><td>-4.0</td><td>1.3</td></tr><tr><td>Capra ibex</td><td>11</td><td>-10.8</td><td>0.5</td><td>-2.0</td><td>1.1</td></tr><tr><td>Cervus elaphus</td><td>17</td><td>-11.0</td><td>0.5</td><td>-3.8</td><td>1.3</td></tr></tbody></table>

<figure><img src="image_5.png" /><figcaption>**Fig. 3.** Scatter plot of raw carbonate data for four species at Lazaret across time. The hollow shapes represent raw data, while the filled in shapes are the average value with the bars representing standard deviations. Green squares represent grey wolves, purple triangles are red deer, blue diamonds are ibex, and red circles are aurochs. Please note, data from two additional red deer (from subcomplex CII sup.) are included from a previous study (Barakat, et al., 2023), calculated as mean values of intra-tooth averages.</figcaption></figure>

### 3.3. Strontium isotope data

Red deer and ibex strontium isotopic analysis was performed on first, second and third molars across Subcomplex CIII and CII inf. All teeth were analysed successfully using laser-ablation and profiles across the entire cross section could be reconstructed, although low Sr concentrations increased analytical uncertainties; individual $^{87}$Sr/$^{86}$Sr profiles from these analyses can be found in SI Table 7. As first molars could potentially be impacted by infant nursing, first molars have been removed from further analyses (i.e. boxplots but are included in the individual $^{87}$Sr/$^{86}$Sr profiles in the SI Figs. 1 and 2). In addition to new teeth analysed for strontium, 2 red deer and an ibex second and third molar pairs from Barakat et al. (2023) all from CII sup. were included to compare results through time. These results show a change in $^{87}$Sr/$^{86}$Sr values between both red deer and ibex and within species through time (Fig. 6).

The overall range of red deer $^{87}$Sr/$^{86}$Sr values, excluding outliers, is between 0.7002 and 0.7274 across all Subcomplexes. Due to low Sr concentrations the total range of $^{87}$Sr/$^{86}$Sr outliers is large in CII inf. and CIII when compared to previously published data from CII sup. Despite this, new data from red deer in CII inf. and CIII show narrower interquartile ranges and median values. In comparison to red deer, ibex $^{87}$Sr/$^{86}$Sr values are typically lower and have a smaller range of values than red deer in the same periods. In CII inf. and CIII different individuals have a relatively large range of $^{87}$Sr/$^{86}$Sr values. For example, the single third molar (R11_479) in Subcomplex CIII, has the largest intra-tooth range of values excluding outliers (0.0054) for ibex and the

third largest intra-tooth $^{87}$Sr/$^{86}$Sr range of all fauna analysed. In Subcomplex CII inf., there is an inter-sample difference between the two individuals analysed (median difference = 0.014). When compared to previously published results from CII sup., these new results show more variation in ibex $^{87}$Sr/$^{86}$Sr values.

Based on these results, we can see that red deer have the highest values and widest variation of interquartile $^{87}$Sr/$^{86}$Sr values in Subcomplex CII sup. in comparison to other subcomplexes. In contrast, ibex show a different trend of having more variation in CII inf. and CIII and very little variation in CII sup. While these results show different trends through time and by species, all fauna sampled in this work and in Barakat et al. (2023) have $^{87}$Sr/$^{86}$Sr values which are above the local $^{87}$Sr/$^{86}$Sr range of the area within Lazaret Cave (between ~0.7082–0.7087).

## 4. Discussion

### 4.1. Local environmental and palaeothermal conditions

Carbon and oxygen isotope results from the three ungulate and one carnivore species at Lazaret Cave confirm a C₃-dominated environment surrounding Middle Pleistocene Lazaret Cave throughout Complex C, as all δ¹³C results are below the C₃ boundary of -8‰. When looking at individual fauna, red deer have the lowest δ¹³C values of all ungulates which indicates a woodland environment that is open and mixes into grasslands or steppe environments and is consistent with interpretations from microwear and cenogram results (Rivals et al., 2023; Valensi and Psathi, 2004). The δ¹³C values of red deer stay consistent through time indicating dietary and habitat stability. While only a low number of samples were taken, aurochs δ¹³C values are the least negative and are indicative of a more open environment than seen in other herbivores. The presence of horses, which were not studied here, in the archaeological record alongside the aurochs results suggest access to open habitats near Lazaret was possible. These habitat results are consistent with findings from Rivals et al. (2023) and López-García et al. (2021) who also identified a mosaic habitat with mixed, open forests environments near Lazaret using different methods. Wider analyses of MIS 6 environments in western Europe using palynology have also identified these types of environments more broadly (e.g. Valensi and Psathi (2004); Guiot et al. (1993); Ponel (1995)).

In comparison to habitat reconstruction which matches with various local and wider records, our palaeoclimate reconstructions have similar climatic patterns through time as found in previous studies, but with higher reconstructed values than other natural archives. Based on calculations which use the red deer oxygen isotope results presented here, the coldest period which Lazaret Cave was occupied corresponded to CII inf. (12.4 °C ± 5.0 °C). The reconstructed temperature value then increased in CII sup. (14.5 ± 5.5 °C) before dropping slightly, although remaining a temperate climate in CIII (14.0 ± 5.4 °C). These MAT reconstructions are slightly below the modern estimated MAT for Nice between 1970–2000 (15.0 ± 0.17 °C) (López-García et al., 2021), not including the large uncertainties. While these new values are warmer than previous environmental studies at Lazaret Cave, the results here support the findings of all previously published studies in that the climate during the accumulation of Complex C was cooler than today
<figure><img src="image_6.png" /><figcaption>Fig. 4. Carbon (A) and oxygen (B) isotope ratios of fauna by subcomplex at Lazaret Cave. Please note, data from two additional red deer (from subcomplex CII sup.) are included from a previous study (Barakat, et al., 2023), calculated as mean values of intra-tooth averages.</figcaption></figure>

<figure><img src="image_7.png" /><figcaption>Fig. 5. SIBER plots showing carbon and oxygen stable isotope data for all archaeological samples at Lazaret Cave (global; A) and for ibex and red deer only by subcomplex (B = subcomplex CII inf.; C = subcomplex CII sup. and D = subcomplex CIII) due to sample sizes. Please note, data from two additional red deer (from subcomplex CII sup.) are included from a previous study (Barakat, et al., 2023), calculated as mean values of intra-tooth averages.</figcaption></figure>

and had a mosaic of environments (Hanquet et al., 2010; López-García et al., 2021; Rivals et al., 2023; Valensi et al., 2007; Valensi and Abbassi, 1998).

López-García et al. (2021) also estimated the MAT at Lazaret using small mammals and amphibians, using a variety of approaches. Their findings indicate a colder MAT for all subcomplexes than those
<figure><img src="image_8.png" /><figcaption>**Fig. 6.** Boxplots showing strontium isotope data for red deer (A) and ibex (B) second and third molars at Lazaret Cave. The y-axis represents the 20-point running mean for LA-MC-ICP-MS data. Box plots show the interquartile range with the median value within the box, the extent of $^{87}$Sr/$^{86}$Sr data in black lines and outliers in black dots. The transparent points behind the box plot show the distribution of individual 20 point running $^{87}$Sr/$^{86}$Sr mean values. Please note, data from two additional red deer (from subcomplex CII sup.) are included from a previous study (Barakat, et al., 2023).</figcaption></figure>

calculated using red deer oxygen isotope values (Table 4). Based on these results, López-García et al. (2021) suggest that CII sup. was potentially warmer than CIII and that CII inf. was the coldest period, but

<caption>**Table 4**</caption>

Table showing the climate estimate results from López-García et al. (2021) in comparison to this study in °C. The fauna analysed and methods used are shown in the first column followed by reconstructed temperature estimates and the conclusions from these palaeoclimate results.

<table><thead><tr><th>Species analysed and method</th><th>CII inf. MAT (°C)</th><th>CII sup. MAT (°C)</th><th>CIII MAT (°C)</th><th>Conclusion</th><th>Reference</th></tr></thead><tbody><tr><td>Small mammals / bioclimatic model</td><td>8.8</td><td>8.8</td><td>8.3</td><td>Stability (colder than today)</td><td>López-García et al. (2021)</td></tr><tr><td>Small mammals / quantified ecology</td><td>8.7</td><td>8.6</td><td>8.8</td><td></td><td></td></tr><tr><td>Herpetofauna / mutual ecogeographic range</td><td>11.00</td><td>10.6</td><td>11.2</td><td></td><td></td></tr><tr><td>Herpetofauna / quantified ecology</td><td>10.9</td><td>11.2</td><td>10.5</td><td></td><td></td></tr><tr><td>Cervus elaphus tooth enamel carbonates</td><td>12.4 ± 5.0</td><td>14.5 ± 5.5</td><td>14.0 ± 5.4</td><td>Gradual warming with CII sup. being the most temperate climate (slightly colder than today)</td><td>This study</td></tr></tbody></table>

overall, the climate remained stable during Neanderthal occupation of Lazaret Cave. This corresponds with the results of the current study which show a CII. sup. to be the warmest of all complexes and CII inf. to be coldest.

Discrepancies between the reconstructed temperature estimates could be due to rodents and amphibians representing a more localised temperature reconstruction near the cave site, while red deer will provide a broader temperature reconstruction. Fauna in both studies could also come from different occupation events given the wide time period Lazaret was occupied (~60,000 years). These discrepancies may also be more to do with when during MIS 6 Neanderthals were using the cave site. The origin of ungulate remains in the sequence at Lazaret Cave is undoubtedly anthropogenic, with cut marks, scrape marks and breaks all attesting to hominin processing (de Lumley et al., 2004; Valensi, 2000). However, owls were likely responsible for the accumulation of small mammals, of which rodents are the most abundant (Desclaux et al., 2011; Hanquet, 2011), and amphibians may enter and live in the cave mouth or surrounding area naturally (de Lumley et al., 2004). As a result, rodents and amphibians may be more representative of conditions throughout Complex C, whether or not hominins were present. However, the remains of red deer are evidence of the period in which Neanderthals were active at the cave site, with Neanderthal dispersals into the area throughout MIS 6 perhaps being linked to more ameliorate periods more broadly.

This has been found at other Neanderthal sites in later periods, for example La Ferrassie, where occupations during MIS 4 in Layer 2 suggested more ameliorate conditions than implied by estimates based on pollen and beetle (Coleoptera) data; the marine isotope stage reconstructions; and even site-specific sedimentary evidence (Pederzani et al., 2021; Ponel, 1995; Royer et al., 2013; Van Andel and Tzedakis,
1996). The authors attribute this to millennial scale warm episodes within each MIS, which are captured in the short-term records of faunal stable isotope data from punctuated archaeological occupations. These short-term oscillations are not visible in time-averaged records and are difficult to relate (in terms of date) to variability within speleothem, pollen, and sea surface temperature records in MIS 6 (Pederzani, et al., 2021). While short term climate changes are difficult to see during the period Lazaret Cave was occupied, we can see these in ice core records, i. e. Greenland ice cores, from the past 104,000 years before present and can assume short term climatic changes occurred earlier than our records show (Seierstad et al., 2014; Svensson et al., 2008). This highlights the value of site-specific approaches, especially during glacial phases, where occupations may only be short-lived and zooarchaeological approaches can help understand life on the ground.

Finally, the absolute values for MAT reconstruction from red deer oxygen isotope data should be taken with caution as red deer are semi-obligate drinkers. Carbonate analysis on modern red deer have shown second and third molars should be a reliable proxy for temperature reconstruction (Stevens et al., 2011), but if red deer at Lazaret received more water from their food (i.e. plants, and particularly leaf water which is significantly ¹⁸O-enriched) than from drinking water this could serve to enrich δ¹⁸O values and elevate temperatures in MAT reconstructions (Jeffrey et al., 2015; Kohn et al., 1996; Sponheimer and Lee-Thorp, 1999). While overlapping extensively (given the large, compound uncertainties associated with the conversion calculations), MAT estimates from red deer at Lazaret Cave are elevated relative to those calculated from bison in deposits of a similar age at Coudoulous I (Bernard et al., 2009), for example. However, when compared to MAT calculated from MIS 6 carbonate oxygen isotope data from horses from the nearby site of Payre, values are comparable to those calculated in Britton et al. (2023b, Fig. 9), which ranged from ~13.5 to ~15 °C, based on data presented in Ecker et al. (2013). Providing sufficient materials are available in the future, phosphate oxygen isotope analysis targeting the teeth of obli-gate, non-migratory grazing species from Lazaret Cave, such as horses, will provide a more complete picture of the prevailing climate experi-enced by Neanderthals at Lazaret during the period represented in these subcomplexes.

## 4.2. Dietary isotopic niches of fauna

Red deer have the lowest δ¹³C values of all ungulates which indicates a more browsing-enriched diet in a woodland environment. These δ¹³C values remain consistently low through time, indicating dietary stability. Modern red deer are mixed feeders who can switch between grazing and browsing depending on plant availability (Drucker et al., 2024); and similarly, Late Pleistocene red deer are thought to have been generalist feeder with the capability to eat from many different habitat types (García García et al., 2009; Rivals et al., 2010). At Lazaret, red deer have the largest range in δ¹³C values (1.7‰) among ungulates, which could suggest more flexibility in the foods eaten, but browsing was likely an important part of their diet through time. These dietary results from δ¹³C values are similar to values found at other MIS 6 sites such as Payre, although the oxygen values have a tighter range (Ecker, et al., 2013).

Throughout Complex C at Lazaret, ibex have slightly less negative δ¹³C values than red deer, which could be indicative of a more mixed-feed diet, with a preference for browse. Evidence for browse is found in the high δ¹⁸O values found throughout time. Compared to red deer, modern alpine ibex typically eat more grasses which may have resulted in the less negative δ¹³C values measured here (Brambilla et al., 2020). While ibex δ¹⁸O and δ¹³C values do not statistically change through time, their δ¹³C values are the least negative in CII sup. which could indicate that ibex remain mixed feeders though time but consume more grasses in the warmer period.

These interpretations of red deer and ibex are consistent with microwear results from the same species, including at Lazaret (Rivals, et al., 2023). When looking at isotopic niche spaces made using δ¹³C and

δ¹⁸O values ibex are separate from red deer, with a moderate amount of core area overlap between the two species in Subcomplex CIII. Using mesowear, Rivals et al. (2023) found more evidence of red deer eating a higher proportion of grasses in later levels of CIII than in all earlier stages which they hypothesise could be due to more movement in red deer or a change in diet due to competition with other herbivores. These results indicate that the latter hypothesis could be more likely.

In comparison to red deer and ibex, aurochs δ¹³C values are the least negative and are indicative of a more open environment than seen in other herbivores. These less negative values support a grazing-based diet for aurochs potentially with more monocotyledons or single-leaf grasses. These results match with modern ecological studies on bovines and historical records of aurochs which indicate aurochs tend to be grazing specialists and only become mixed feeders when forced (Noe-Nygaard et al., 2005; van Vuure, 2005). The grazing pattern found using isotopes contrasts with the microwear patterns which identified aurochs in CII sup. as a leaf browser (Rivals et al., 2023). However, as both studies only include a small number of aurochs samples, this could be indicative of sample size, and the ability of this species to mix-feed. Differences between isotope and mesowear/microwear may also stem from the fact that these approaches record diet on different time scales and can therefore be influenced by seasonal and even supra-annual dietary differences.

Finally, the grey wolf carbonate results show lower δ¹³C and δ¹⁸O values than ungulates found within Lazaret Cave. Based on trophic level offsets in carbonates between prey and predator (~1.3‰), it is likely that grey wolves hunted red deer throughout Complex C, although ibex cannot be excluded as a possible food source. The large difference in δ¹³C values between grey wolves and aurochs (on average 3.4‰) suggests grey wolves likely did not hunt aurochs. These isotopic results are supported by zooarchaeological analysis and lack of carnivore marks on aurochs' bones (Valensi, 2000; Valensi and Psathi, 2004). Furthermore, grey wolf low carbonate results are typical of carnivores due to the lack of carbohydrates and high amount of animal-derived amino acids (Göhring et al., 2019; Schmidt, 1999).

The analysis of dietary isotopic niche space conducted in this study does not show any significant change through time signifying dietary and habitat stability during Neanderthal occupations at Lazaret Cave. These results are somewhat contradictory to the results of microwear. This highlights the different natures of these two evidence types, with isotopes providing a longer-term averaged diet (especially when data from multiple teeth are combined) compared to the pits and scratches that mark an animal's tooth in the months before death. The intra-tooth carbon isotope data from the two red deer published in Barakat et al. (2023) do, however, indicate differences in δ¹³C seasonally, corresponding to δ¹⁸O. This may indeed confirm seasonal dietary differences in red deer, that are not here reflected in the 'bulk' stable light isotope data but are apparent in the microwear data. Further intra-tooth δ¹³C work in both red deer and ibex could perhaps better align the isotope data to the microwear data.

## 4.3. Landscape use of red deer and ibex

⁸⁷Sr/⁸⁶Sr isotopic analysis found variation in all teeth analysed which could be indicative of mobility around Lazaret Cave. None of the samples had ⁸⁷Sr/⁸⁶Sr values which clustered around the cave's ⁸⁷Sr/⁸⁶Sr signature (0.7082–0.7087, as defined by Barakat et al. (2023)), suggesting plants consumed were not only those found immediately around the site but came from a broader area and from a mixture of habitats (as also seen from the carbonate data). This also aligns with what is known about the strontium isoscape in the area (Fig. 2) and that – due to the complex lithology around the site – the bioavailable strontium in the area surrounding the cave site is highly variable (Barakat, et al., 2023). Thus while, ⁸⁷Sr/⁸⁶Sr varied in tooth samples between 0.700 and 0.730, these values can all be found within 50 kms of the site. This could indicate faunal ranges which incorporated these
more lithologically-varied areas, or Neanderthals extending their hunting range. It should also be noted that sea level would have been lower in MIS 6 than today and ungulates could have roamed on coastal plains which are submerged today which are not included in the bioavailable $^{87}$Sr/$^{86}$Sr isoscape.

Based on results from the Barakat et al. (2023) study, which analysed strontium in red deer and ibex from UA 25 (CII. sup.) only, we expected red deer to have high (and seasonally varying) $^{87}$Sr/$^{86}$Sr values and ibex to have much tighter $^{87}$Sr/$^{86}$Sr intra-tooth ranges. However, the data from Subcomplex CII inf. and CIII do not align with that of UA25 and paint a more complex picture of ungulate mobility. Red deer in Subcomplexes CII inf. and CIII seem to have a similar amount of variation between IQR as seen in Barakat et al. (2023), but lower values (between 0.710 and 0.713 rather than 0.712–0.716). $^{87}$Sr/$^{86}$Sr values between 0.710–0.713 can be found ~25 km NE or ~16 km west of Lazaret Cave. These results could mean that red deer were moving to a specific area in the landscape in the warmer CII sup. period which is different to areas in the landscape occupied in colder CII inf. and CIII periods. In comparison, ibex $^{87}$Sr/$^{86}$Sr values have a much broader variation in CII inf. and CIII which was not expected. We interpret this change in ibex intra-tooth $^{87}$Sr/$^{86}$Sr variation in CII sup. to be due to reduced movement around the landscape during that warmer period. Further analyses, such as serial sampling carbonates, could provide more information on red deer and ibex movement in the future, such as altitudinal migrations (Körner et al., 1988; Lazzerini et al., 2021; Makarewicz et al., 2017; Mezga et al., 2014; Tornero et al., 2016). Current bulk sample carbonate results show ibex have less negative $\delta^{18}$O values than red deer and no significant difference in $\delta^{13}$C values. To identify fauna living in landscapes with higher elevations, we would expect to see lower $\delta^{18}$O and higher $\delta^{13}$C values relative to fauna at lower elevations. Thus, the results reported here do not provide any evidence that red deer and ibex made use of areas of the landscape with significantly different elevations.

Interestingly, while we see differences in landscape use in CII sup., we do not see the same changes in carbonate isotopic niche space. This could be due to fauna changing their movement patterns and home range sizes based on climatic changes in order to find similar plant foods through time, thus causing dietary stability but range use differences. This reflects the two main responses that ungulates can make in response to resource changes or competition for resources between species: spatially partition or dietarily partitioning. At Lazaret, during MIS 6, red deer and ibex seem to be employing these different strategies in different periods, although it should be noted that disentangling changes in diet and movement due to behavioural or climatic changes, or perhaps both, remains challenging. The micro- and meso- wear study by Rivals et al. (2023) show dietary stability in red deer through time, although more grasses are eaten in upper levels of CIII. Ibex mesowear shows typical mixed feeder results which gradually shifts to eating more browse in CIII. The $^{87}$Sr/$^{86}$Sr variation in ibex potentially support this change. The lowest $^{87}$Sr/$^{86}$Sr values are found in CII inf., followed by the low $^{87}$Sr/$^{86}$Sr variation in CII sup., and the highest $^{87}$Sr/$^{86}$Sr values are in CIII. Unlike red deer who were likely moving potentially to maintain dietary stability, ibex have a very dynamic landscape use. The isotope results, combined with that of meso- and micro- wear, thus show an interplay between ranging ecology and dietary ecology, highlighting the plasticity of red deer and ibex amidst the fluctuating climate of MIS 6.

Isotopic evidence for niche partitioning between ibex and red deer during periods of climatic fluctuation has been found in other Pleistocene Western Europe sites, such as at the Upper Palaeolithic site of La Riera (Cantabria) (Jones et al., 2020). Jones and colleagues argue that ibex were able to change their dietary niche, allowing them to expand to new, less desirable, regions outside of red deer niches. At Lazaret Cave, ibex and red deer isotopic niche spaces have moderate to no overlap, with the lowest amount of overlap in the warmer CII sup. period. The mixed woodland and open environments surrounding Lazaret Cave, as indicated by $\delta^{13}$C values, could have been an environment which allowed both ibex and red deer to thrive year-round with distinct and

specific spatial and dietary niche spaces within 50 kms of the site (Ashcroft, 2010; Jones, 2022; Vos et al., 2008).

The predictable presence of these medium-sized ungulates, alongside tepid mean annual temperatures throughout the sequence during Neanderthal occupations, could indicate a favourable ‘classic’ refugia with environmental and ecological stability within the Meridional Alps coastal area throughout MIS 6. It should be noted that the conditions of the MIS 6 refugia in this region were not constant throughout the Pleistocene, especially for later cold stages of the Late Pleistocene (MIS 4 and 2). For example, during MIS 4, *Mammuthus primigenius* (mammoth) has been identified in level 6 of Grotte du Prince and Foyer III of Grotte du Cavillon at the French-Italian border (Moussous et al., 2014). Mammoths have also been identified in MIS 2 in Liguria, at Arene Candide (Braun and Palombo, 2012) and at Barma Grande (Onoratini et al., 2012). The presence of such cold adapted taxa in Mediterranean coastal areas only during the Late Pleistocene suggests that MIS 6 did not have the same intensity, at least in the Meridional Alps. Thus, based on mammalian communities identified across the region, alongside dietary and spatial niches, and temperature reconstructions, the context of Lazaret Cave during MIS 6 is one of a classic, glacial refugia with desirable environments for red deer, ibex, and Neanderthals.

## 5. Conclusion

Isotopic analyses conducted on ungulates and carnivore tooth enamel, alongside the comparison of data from micro- and meso- wear and palaeoecological studies on terrestrial vertebrates (large and small mammals alongside avian and herpetofauna), in Complex C at Lazaret Cave provide us with a better understanding of the climatic and environmental dynamics on the Mediterranean coast during Neanderthal occupations of MIS 6 in the context of a traditional southern refugia for temperate species (Hewitt, 2001; Stewart et al., 2010). Carbon isotope data confirm the presence of a $C_3$ mixed woodland and open environment surrounding Lazaret Cave between 190,000 and 130,000 years ago. Throughout the accumulation of Complex C, red deer are browsers, ibex are more mixed feeders, aurochs remain grazers, and grey wolves main prey category are red deer. Isotopic niche areas show these taxa had separate dietary niches through time, with only a slight amount of overlap between ibex and red deer in Subcomplex CIII, when Rivals et al. (2023) identified more grasses being included in red deer diets likely due to sympatric ungulate competition. These results likely show dietary and environmental stability in Mediterranean glacial refugia in MIS 6.

Climatic reconstructions based on oxygen isotope data from red deer tooth enamel, evidence colder climatic conditions than today, but palaeotemperature estimates are elevated relative to those inferred by other data types at the site (small mammals and herpetofauna). The results from this study, however, agree with previous temperature reconstructions that CII inf. was the coldest period of Neanderthal occupation, followed by a warming event in CII sup., before the temperature slightly decreased, but remained temperate, in CIII. These results do not reveal any large variations in reconstructed temperature values between MIS 6.4, 6.3, and 6.2, although this may be due to anthropic biases from Neanderthals occupying Lazaret Cave during warmer periods (where temperature reconstructions are based on anthropogenically accumulated faunal remains, rather than naturally accumulated archives). Indeed, the palaeotemperature reconstructions overlap with and are comparable to those that can be calculated from ungulate tooth enamel oxygen isotope data from other MIS 6 sites in southern France (Ecker, et al., 2013 [as calculated by Britton et al. 2023b], Bernard, et al., 2009). Given that reconstructing past habitats and climates is an essential element in understanding the classic Mediterranean refuge areas in southern Europe, and hominin occupations during past glaciations, we suggest further research to investigate mean annual and seasonal palaeotemperatures during the different phases of Complex C, primarily through phosphate analysis of obligate drinkers, could prove fruitful.

Strontium isotopic analysis from red deer and ibex reveal use of the
wider landscape (up to 50 kms) within the vicinity of the site, which largely overlaps in CII inf. and CIII. Movement patterns change in CII sup., with red ibex remain within a range incorporating similar lithology during the time the second and third molars mineralised. This change in movement may be related to the warmer climates in CII sup. and may thus be a response to changing patterns of resources on a landscape level in order to maintain the dietary stability seen in all of the mammals in this study. In the context of a classic southern refuge area, and on the results of the above study, the climatic oscillations that occurred contemporary to Neanderthal occupations at Lazaret Cave during MIS 6 seem to have had a limited, but not non-negligible, impact on mammal communities, allowing Neanderthals to practice specialised hunting of red deer and ibex at the site through time. However, the somewhat ameliorate climate conditions and ecological stability inferred from the isotope zooarchaeology may also, to an extent, be a function of Neanderthal site use being restricted to milder phases of MIS 6. This serves to highlight the intricate relationships between palaeoecology, palaeoenvironment and hominin dispersals in the past, and the nature of the resulting record.

### CRediT authorship contribution statement

**Sarah Barakat:** Writing – review & editing, Writing – original draft, Visualization, Formal analysis. **Kennedy Williams:** Writing – original draft, Visualization, Formal analysis. **Malte Willmes:** Writing – review & editing, Software, Methodology, Formal analysis, Data curation, Conceptualization. **Emmanuel Desclaux:** Writing – review & editing, Project administration, Investigation, Funding acquisition, Data curation, Conceptualization. **Kate Britton:** Writing – review & editing, Writing – original draft, Supervision, Formal analysis.

### Funding

This research is part of the collective research project named "Paleoecology of the Lazaret Cave: human-environment interactions on the coast of the meridional Alps during the late Middle Pleistocene (MIS6)," granted by the DRAC PACA (French Ministry of Culture) and Département des Alpes-Martimes. We thank UKRI, United Kingdom for salary support for SB (QUADRAT DTP NERC (ref: NE/S007377(1)) and KB (ref: EP/Y023641(1)) during production of this manuscript.

### Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.org/10.1016/j.jasrep.2025.105456.

### Data availability

Data will be made available on request.

### References

* Amanova, M., 2024. Isotopic insight into the ecology of red deer from Riparo Tagliente (Italian Pre-Alps) during the Late Epigravettian. Master's thesis. Instituto Politecnico de Tomar, Erasmus Mundus.

* Armaroli, E., Fontani, F., Iacovera, R., Cilli, E., Latorre, A., Luiselli, D., Silvestrini, S., Terlato, G., Dalmeri, G., Fontana, A., Nannini, N., Vonhof, H., Calcagnile, L., Quarta, G., Duches, R., Bortolini, E., Cipriani, A., Benazzi, S., Lugli, F., Romandini, M., 2025. Ecology and demographic structure of an extinct ibex population in Upper Palaeolithic Italian Alps. bioRxiv 2025.04.01.646553. Doi:10.1101/2025.04.01.646553.

* Ashcroft, M.B., 2010. Identifying refugia from climate change. J. Biogeogr. 37, 1407–1413. https://doi.org/10.1111/j.1365-2699.2010.02300.x.

* Bahain, J.J., 1993. Datation par résonance de spin électronique (ESR) de carbonates et d'émail dentaire quaternaires: potentiel et problèmes. Museum national d'histoire naturelle-MNHN PARIS.

* Balasse, M., 2002. Reconstructing dietary and environmental history from enamel isotopic analysis: Time resolution of intra-tooth sequential sampling. Int. J. Osteoarchaeol. 12, 155–165. https://doi.org/10.1002/oa.601.

* Barakat, S., Le Corre, M., Willmes, M., Cohen, J., Vuillien, M., Desclaux, E., Britton, K., 2023. Laser ablation strontium isotopes and spatial assignment show seasonal mobility in red deer (Cervus elaphus) at Lazaret Cave, France (MIS 6). Front. Ecol. Evol. 11. https://doi.org/10.3389/fevo.2023.988837.

* Bataille, C.P., von Holstein, I.C.C., Laffoon, J.E., Willmes, M., Liu, X.-M., Davies, G.R., 2018. A bioavailable strontium isoscape for Western Europe: a machine learning approach. PLoS One 13, e0197386. https://doi.org/10.1371/journal.pone.0197386.

* Baumann, C., Bocherens, H., Drucker, D.G., Conard, N.J., 2020. Fox dietary ecology as a tracer of human impact on Pleistocene ecosystems. PLoS One 15. https://doi.org/10.1371/journal.pone.0235692.

* Bentley, R.A., 2006. Strontium Isotopes from the Earth to the Archaeological Skeleton: a review. J. Archaeol. Method Theory 13, 135–187. https://doi.org/10.1007/s10816-006-9009-x.

* Benvenuti, M., Bahain, J.J., Capalbo, C., Capretti, C., Ciani, F., D'Amico, C., Esu, D., Giachi, G., Giuliani, C., Gliozzi, E., Lazzeri, S., Macchioni, N., Lippi, M.M., Masini, F., Mazza, P.P.A., Pallecchi, P., Revedin, A., Savorelli, A., Spadi, M., Sozzi, L., Vietti, A., Voltaggio, M., Aranguren, B., 2017. Paleoenvironmental context of the early neanderthals of Poggetti Vecchi for the late middle Pleistocene of central Italy. Quat. Res. (United States) 88. https://doi.org/10.1017/qua.2017.51.

* Bernard, A., Daux, V., Lécuyer, C., Brugal, J.P., Genty, D., Wainer, K., Gardien, V., Foulre, F., Jaubert, J., 2009. Pleistocene seasonal temperature variations recorded in the 6180 of Bison priscus teeth. Earth Planet. Sci. Lett. 283, 133–143. https://doi.org/10.1016/j.EPSL.2009.04.005.

* Bocherens, H., 2015. Isotopic tracking of large carnivore palaeoecology in the mammoth steppe. Quat. Sci. Rev. 117, 42–71. https://doi.org/10.1016/j.quascirev.2015.03.018.

* Bonafini, M., Pellegrini, M., Ditchfield, P., Pollard, A.M., 2013. Investigation of the 'canopy effect' in the isotope ecology of temperate woodlands. J. Archaeol. Sci. 40, 3926–3935. https://doi.org/10.1016/j.JAS.2013.03.028.

* Bourgon, N., Jaouen, K., Bacon, A.M., Jochum, K.P., Dufour, E., Duringer, P., Ponche, J. L., Joannes-Boyau, R., Boesch, Q., Antoine, P.O., Hullot, M., Weis, U., Schulzkornas, E., Trost, M., Fiorillo, D., Demeter, F., Patole-Edoumba, E., Shackelford, L.L., Dunn, T.E., Zachwieja, A., Duangthongchit, S., Sayavonkhamdy, T., Sichanthongtip, P., Sihanam, D., Souksavatdy, V., Hublin, J.J., Tütken, T., 2020. Zinc isotopes in Late Pleistocene fossil teeth from a Southeast Asian cave setting preserve paleodietary information. PNAS 117. https://doi.org/10.1073/pnas.1911744117.

* Brambilla, A., Von Hardenberg, A., Nelli, L., Bassano, B., 2020. Distribution, status, and recent population dynamics of Alpine ibex Capra ibex in Europe. Mamm. Rev. 50, 267–277. https://doi.org/10.1111/MAM.12194.

* Braun, I.M., Palombo, M.R., 2012. Mammuthus primigenius in the cave and portable art: an overview with a short account on the elephant fossil record in Southern Europe during the last glacial. Quat. Int. 276–277. https://doi.org/10.1016/j.quaint.2012.07.010.

* Britton, K., 2020. Isotope analysis for mobility and climate studies. Archaeol. Sci. Introduct. 99–124. https://doi.org/10.1017/9781139013826.005.

* Britton, K., Grimes, V., Niven, L., Steele, T.E., McPherron, S., Soressi, M., Kelly, T.E., Jaubert, J., Hublin, J.-J., Richards, M.P., 2011. Strontium isotope evidence for migration in late Pleistocene Rangifer: implications for Neanderthal hunting strategies at the Middle Palaeolithic site of Jonzac, France. J. Hum. Evol. 61, 176–185. https://doi.org/10.1016/j.jhevol.2011.03.004.

* Britton, K., Jimenez, E.L., Le Corre, M., Renou, S., Rendu, W., Richards, M.P., Hublin, J. J., Soressi, M., 2023a. Multi-isotope analysis of bone collagen of Late Pleistocene ungulates reveals niche partitioning and behavioural plasticity of reindeer during MIS 3. Sci. Rep. 13. https://doi.org/10.1038/s41598-023-42199-7.

* Britton, K., Jimenez, E.L., Le Corre, M., Pederzani, S., Daujeard, C., Jaouen, K., Vettese, D., Tütken, T., Hublin, J.J., Moncel, M.H., 2023b. Multi-isotope zoarchaeological investigations at Abri du Maras: the paleoecological and paleoenvironmental context of Neanderthal subsistence strategies in the Rhône Valley during MIS 3. J. Hum. Evol. 174. https://doi.org/10.1016/j.jhevol.2022.103292.

* Brown, W.A.B., Chapman, N.G., 1991. Age assessment of red deer (Cervus elaphus): from a scoring scheme based on radiographs of developing permanent molariform teeth. J. Zool. 225, 85–97. https://doi.org/10.1111/j.1469-7998.1991.tb03803.x.

* Capo, R.C., Stewart, B.W., Chadwick, O.A., 1998. Strontium isotopes as tracers of ecosystem processes: theory and methods. Geoderma 82, 197–225. https://doi.org/10.1016/S0016-7061(97)00102-X.

* Carvalho, M., Jones, E.L., Ellis, M.G., Cascalheira, J., Bicho, N., Meiggs, D., Benedetti, M., Friedl, L., Haws, J., 2022. Neanderthal palaeoecology in the late Middle Palaeolithic of western Iberia: a stable isotope analysis of ungulate teeth from Lapa do Picareiro (Portugal). J. Quat. Sci. 37 (2), 300–319. https://doi.org/10.1002/JQS.3363.

* Cerling, T.E., Harris, J.M., 1999. Carbon isotope fractionation between diet and bioapatite in ungulate mammals and implications for ecological and paleoecological studies. Oecologia 120. https://doi.org/10.1007/s004420050868.

* Cerling, T.E., Bernasconi, S.M., Hofstetter, L.S., Jaggi, M., Wyss, F., Rudolf von Rohr, C., Claus, M., 2021. CH4/CO2 ratios and carbon isotope enrichment between diet and breath in herbivorous mammals. Front. Ecol. Evol. 9, 638568. https://doi.org/10.3389/fevo.2021.638568.

* Clementz, M.T., Fox-Dobbs, K., Wheatley, P.V., Koch, P.L., Doak, D.F., 2009. Revisiting old bones: coupled carbon isotope analysis of bioapatite and collagen as an ecological and palaeoecological tool. Geol. J. 44. https://doi.org/10.1002/gj.1143.

* Codron, D., Claus, M., Codron, J., Tütken, T., 2018. Within trophic level shifts in collagen-carbonate stable carbon isotope spacing are propagated by diet and digestive physiology in large mammal herbivores. Ecol. Evol. 8. https://doi.org/10.1002/ece3.3786.
Coplen, T.B., Kendall, C., Hopple, J., 1983. Comparison of stable isotope reference samples. Nature 302 (5905), 236–238. https://doi.org/10.1038/302236a0.

Dasch, E.J., 1969. Strontium isotopes in weathering profiles, deep-sea sediments, and sedimentary rocks. Geochim. Cosmochim. Acta 33. https://doi.org/10.1016/0016-7037(69)00153-7.

Defleur, A.R., Desclaux, E., 2019. Impact of the last interglacial climate change on ecosystems and neanderthals behavior at Baume Moula-Guerie, Ardèche, France. J. Archaeol. Sci. 104. https://doi.org/10.1016/j.jas.2019.01.002.

Defleur, A., Crégut-Bonnoure, É., Desclaux, E., 1998. Première mise en évidence d'une sequence éémienne à restes humains dans le remplissage de la Baume Moula-Guerie (Soyons, Ardèche). Comptes Rendus de L'académie De Sciences - Serie IIa: Sciences De La Terre et Des Planètes 326. https://doi.org/10.1016/S1251-8050(98)80070-0.

Defleur, A., Crégut-Bonnoure, É., Desclaux, E., Thinon, M., 2001. Présentation paléoenvironnementale du remplissage de la Baume Moula-Guerie à Soyons (Ardeche) : implications paléoclimatiques et chronologique. Anthropologie 105, 369–408. https://doi.org/10.1016/S0003-5521(01)80022-4.

Defleur, A.R., Desclaux, E., Jabbour, R.S., Richards, G.D., 2020. The Eemian: Global warming, ecosystem upheaval, demographic collapse and cannibalism at Moula-Guerie. A reply to Slimak and Nicholson. J. Archaeol. Sci. https://doi.org/10.1016/j.jas.2020.10.0113.

de Lumley, M., 2018. Les restes humains fossiles de la grotte du Lazaret. Des Homo erectus européens évolués en voie de néandertalisation, Nice, Alpes-Maritimes, France.

de Lumley, H., Echassoux, A., Bailon, S., Cauche, D., de Marchi, M.-P., Desclaux, E., El Guennouni, K., Khatib, S., Lacombat, F., Roger, T., Valensi, P., 2004. Le sol d'occupation acheulée de l'unité archéostratigraphique UA 25 de La Grotte du Lazaret. Edisud, Aix-en-Provence.

DeSantis, L.R.G., Feranec, R.S., Southon, J., Cerling, T.E., Harris, J., Binder, W.J., Cohen, J.E., Farrell, A.B., Lindsey, E.L., Meachen, J., Robin O'Keefe, F., Takeuchi, G. T., 2022. On the relationship between collagen- and carbonate-derived carbon isotopes with implications for the inference of carnivore dietary behavior. Front. Ecol. Evol. 10. https://doi.org/10.3389/fevo.2022.1031383.

Desclaux, E., 2013. Evolution des communautés de mammifères dans les Alpes-Maritimes au cours du Pléistocène. Bulletin Du Musée d'Anthropologie préhistorique de Monaco, 9–19.

Desclaux, E., Defleur, A., 1997. Étude préliminaire des micromammifères de la Baume Moula-Guerie à Soyons (Ardeche, France). Systématique, biostratigraphie et paléoécologie [Micromammals from Baume Moula-Guerie (Ardeche, France): systematic, biostratigraphy and palaeoecology. Quaternaire 8. https://doi.org/10.3406/quate.1997.1574.

Desclaux, E., Hanquet, C., El Guenouni, K., 2011. Origine(s) des accumulations de micromammifères dans quelques sites préhistoriques du Pléistocène moyen et supérieur d'Europe méridionale. Référentiels et transferts aux fossiles, Taphonomie des petits vertébrés.

Discamps, E., Jaubert, J., Bachellerie, F., 2011. Human choices and environmental constraints: Deciphering the variability of large game procurement from Mousterian to Aurignacian times (MIS 5-3) in southwestern France. Quat. Sci. Rev. 30. https://doi.org/10.1016/j.quascirev.2011.06.009.

Driessens, F., Verbeeck, R., 1990. Biominerals.

Drucker, F.G., Bridault, A., Hobson, K.A., Szuma, E., Bocherens, H., 2008. Can carbon-13 in large herbivores reflect the canopy effect in temperate and boreal ecosystems? evidence from modern and ancient ungulates. Palaeogeogr. Palaeoclimatol. Palaeoecol. 266, 69–82. https://doi.org/10.1016/j.PALAEO.2008.03.020.

Drucker, D.G., Rivals, F., Nadal, J., Ruffi, I., Soler, J., Soler, N., Maroto, J., 2024. Ecology of large ungulates in the northeastern Iberian Peninsula during the Upper Palaeolithic through stable isotopes and tooth wear analysis. Quat. Environ. Humans 2, 10001. https://doi.org/10.1016/j.QEH.2024.10001.

D'Angela, D., Longinelli, A., 1990. Oxygen isotopes in living mammal's bone phosphate: further results. Chem. Isotope Geosci. Sect. 86, 75–82. https://doi.org/10.1016/0168-9622(90)90007-y.

Eastham, L.C., Feranec, R.S., 2025. Examining potential drivers of variation in the carbonate-collagen stable carbon isotope offset of modern and late pleistocene ungulates from C3-dominant ecosystems. SSRN. https://doi.org/10.2139/ssrn.5151493.

Ecker, M., Bocherens, H., Julien, M.-A., Rivals, F., Raynal, J.-P., Moncel, M.-H., 2013. Middle Pleistocene ecology and Neanderthals subsistence: insights from stable isotope analyses in Payre (Ardeche, southeastern France). J. Hum. Evol. 65, 363–373. https://doi.org/10.1016/j.jhevol.2013.06.013.

Erban Kerghergina, Y.V., Novak, M., Erban, V., Stepanova, M., 2021. 87Sr/86Sr isotope ratios in trees as an archaeological tracer: Limitations of linking plant-biomass and bedrock Sr isotope signatures. J. Archaeol. Sci. 133, 105438. https://doi.org/10.1016/j.JAS.2021.105438.

Fabre, M., Lécuyer, C., Brugal, J.P., Amiot, R., Foulre, F., Martineau, F., 2011. Late Pleistocene climatic change in the French Jura (Gigny) recorded in the 6180 of phosphate from ungulate tooth enamel. Quat. Res. 75, 605–613. https://doi.org/10.1016/j.YQRES.2011.03.001.

Feranec, R., García, N., Díez, J.C., Arsuaga, J.L., 2010. Understanding the ecology of mammalian carnivorous and herbivorous from Valdegoba cave (Burgos, northern Spain) through stable isotope analysis. Palaeogeogr. Palaeoclimatol. Palaeoecol. 297, 263–272. https://doi.org/10.1016/j.PALAEO.2010.08.006.

Fernández-García, M., Pederzani, S., Britton, K., Agudo-Pérez, L., Cicero, A., Geiling, J. M., Daura, J., Sanz, M., Marín-Arroyo, A.B., 2024. Palaeoecology of ungulates in northern Iberia during the Late Pleistocene through isotopic analysis of teeth. Biogeosciences 21, 4413–4437. https://doi.org/10.5194/BG-21-4413-2024.

Flower, L.O.H., Schreve, D.C., Lamb, A.L., 2021. Nature of the beast? complex drivers of prey choice, competition and resilience in Pleistocene wolves (Canis lupus L., 1754). Quat. Sci. Rev. 272. https://doi.org/10.1016/j.quascirev.2021.107212.

Fox-Dobbs, K., Bump, J.K., Peterson, R.O., Fox, D.L., Koch, P.L., 2007. Carnivore-specific stable isotope variables and variation in the foraging ecology of modern and ancient wolf populations: Case studies from Isle Royale, Minnesota, and La Brea. Can. J. Zool. 85. https://doi.org/10.1139/z077-018.

García-Alix, A., Delgado Huertas, A., Martín Suárez, E., 2012. Unravelling the Late Pleistocene habitat of the southernmost woolly mammoths in Europe. Quat. Sci. Rev. 32, 75–85. https://doi.org/10.1016/j.JQUASCIREV.2011.11.007.

García García, N., Feranec, R.S., Arsuaga, J.L., Bermúdez de Castro, J.M., Carbonell, E., 2009. Isotopic analysis of the ecology of herbivores and carnivores from the Middle Pleistocene deposits of the Sierra De Atapuerca, northern Spain. J. Archaeol. Sci. 36, 1142–1151. https://doi.org/10.1016/j.JAS.2008.12.018.

Giustini, F., Iannucci, A., Porcelli, G., Micarelli, I., Brilli, M., Sardella, R., Mecozzi, B., 2024. Taxonomic and stable isotope analyses of mammal remains from the Lateglacial site of Grotta Polesini (central Italy): Paleoenvironmental implications. J. Quat. Sci. 39, 1098–1115. https://doi.org/10.1002/JQS.3655.

Göhring, A., von Carnap-Bornheim, C., Hilberg, V., Mayr, C., Grupe, G., 2019. Diet and species-specific oxygen isotope relationship and isotope spacing between structural carbonate and phosphate in archaeological mammalian bones. Archaeol. Anthropol. Sci. 11, 2467–2487. https://doi.org/10.1007/S12520-018-0704-9/FIGURES/8.

Guiot, J., de Beaulieu, J.L., Cheddadi, R., David, F., Ponel, P., Reille, M., 1993. The climate in Western Europe during the last Glacial/Interglacial cycle derived from pollen and insect remains. Palaeogeogr. Palaeoclimatol. Palaeoecol. 103. https://doi.org/10.1016/0031-0182(93)90053-L.

Guiter, F., Andrieu-Ponel, V., de Beaulieu, J.L., Cheddadi, R., Calvez, M., Ponel, P., Reille, M., Keller, F., Goeury, C., 2003. The last climatic cycles in Western Europe: a comparison between long continuous lacustrine sequences from France and other terrestrial records. Quat. Int. 111. https://doi.org/10.1016/S1040-6182(03)00015-6.

Hanquet, C., 2011. Évolution des paléoenvironnements et des paléoclimats au Pléistocène moyen, en Europe méridionale, d'après l'étude des faunes de micromammifères. Université Montpellier III - Paul Valéry, Montpellier.

Hanquet, C., Valensi, P., Bailon, S., Desclaux, E., El Guennouni, K., Roger, T., De Lumley, H., 2010. Caractérisation du climat et de la biodiversité au Pléistocène moyen final, d'après les faunes de vertèbres de la grotte du Lazaret (Nice, France). Quaternaire 21, 203–214. https://doi.org/10.4000/QUATERNAIRE.5579.

Hewitt, G.M., 2001. Speciation, hybrid zones and phylogeography – or seeing genes in space and time. Mol. Ecol. 10, 537–549. https://doi.org/10.1111/j.1365-294X.2001.01202.x.

Hodge, E.J., Richards, D.A., Smart, P.L., Andreo, B., Hoffmann, D.L., Mattey, D.P., González-Ramón, A., 2008. Effective precipitation in southern Spain (~ 266 to 46 ka) based on a speleothem stable carbon isotope record. Quat. Res. 69. https://doi.org/10.1016/j.iyqres.2008.02.013.

Hoppe, K.A., Koch, P.L., Furutani, T.T., 2003. Assessing the preservation of biogenic strontium in fossil bones and tooth enamel. Int. J. Osteoarchaeol. 13, 20–28. https://doi.org/10.1002/oa.663.

Horstwood, M.S.A., 2008. Data reduction strategies, uncertainty assessment, and resolution of LA-(MC)-ICP-MS isotope data. In: Laser Ablation ICP-MS in the Earth Sciences: Current Practices and Outstanding Issues. Mineralogical Association of Canada, pp. 283–303. https://doi.org/10.3749/9780921294801.C161.

Hutchinson, G.E., 1978. An Introduction to Population Biology. Yale University Press, New Haven.

Iacumin, P., Bocherens, H., Mariotti, A., Longinelli, A., 1996. Oxygen isotope analyses of co-existing carbonate and phosphate in biogenic apatite: a way to monitor diagenetic alteration of bone phosphate? Earth Planet. Sci. Lett. 142, 1–6. https://doi.org/10.1016/0012-821X(96)00093-3.

IAEA/WMO, 2020. Global Network of Isotopes in Precipitation.

Jackson, A.L., Inger, R., Parnell, A.C., Bearhop, S., 2011. Comparing isotopic niche widths among and within communities: SIBER - Stable Isotope Bayesian Ellipses in R. J. Anim. Ecol. 80. https://doi.org/10.1111/j.1365-2656.2011.01806.x.

Jeffrey, A., Denys, C., Stoetzel, E., Lee-Thorp, J.A., 2015. Influences on the stable oxygen and carbon isotopes in gerbillid rodent teeth in semi-arid and arid environments: Implications for past climate and environmental reconstruction. Earth Planet. Sci. Lett. 428, 84–96. https://doi.org/10.1016/j.EPSL.2015.07.012.

Jones, E.L., 2022. What is a refugium? Questions for the Middle–Upper Palaeolithic transition in peninsular southern Europe. J. Quat. Sci. 37, 136–141. https://doi.org/10.1002/jqs.3274.

Jones, A.M., O'Connell, T.C., Young, E.D., Scott, K., Buckingham, C.M., Iacumin, P., Brasier, M.D., 2001. Biogeochemical data from well preserved 200 ka collagen and skeletal remains. Earth Planet. Sci. Lett. 193. https://doi.org/10.1016/S0012-821X(01)00474-5.

Jones, J.R., Marín-Arroyo, A.B., Straus, L.G., Richards, M.P., 2020. Adaptability, resilience and environmental buffering in European Refugia during the Late Pleistocene: Insights from La Riera Cave (Asturias, Cantabria, Spain). Sci. Rep. 10 (1), 1–17. https://doi.org/10.1038/s41598-020-57715-2.

Jrad, A., Quesnel, Y., Rochette, F., Jallouli, C., Khatib, S., Boukbida, H., Demory, F., 2014. Magnetic investigations of buried palaeohearts inside a palaeolithic cave (Lazaret, Nice, France). Archaeol. Prospect. 21, 87–101. https://doi.org/10.1002/arp.1469.

Koch, P.L., 1998. Isotopic reconstruction of past continental environments. Annu. Rev. Earth Planet. Sci. 26, 573–613. https://doi.org/10.1146/annurev.earth.26.1.573.

Koch, P.L., Tuross, N., Fogel, M.L., 1997. The Effects of Sample Treatment and Diagenesis on the Isotopic Integrity of Carbonate in Biogenic Hydroxylapatite. J. Archaeol. Sci. 24, 417–429. https://doi.org/10.1006/jasc.1996.0126.
Kohn, M.J., Schoeninger, M.J., Valley, J.W., 1996. Herbivore tooth oxygen isotope compositions: Effects of diet and physiology. Geochim. Cosmochim. Acta 60. https://doi.org/10.1016/j.quaint.2011.03.0247.

Körner, C., Farquhar, G.D., Roksandic, Z., 1988. A global survey of carbon isotope discrimination in plants from high altitude. Oecologia 74, 623–632. https://doi.org/10.1007/BF00380063/METRICS.

Kuiters, M., van der Plicht, J., Drucker, D.G., Van Kolfschoten, T., Palsta, S.W.L., Bocherens, H., 2015. Carbon and nitrogen stable isotopes of well-preserved Middle Pleistocene bone collagen from Schöningen (Germany) and their paleoecological implications. J. Hum. Evol. 89, 105–113. https://doi.org/10.1016/J.JHEVOL.2015.01.008.

Layman, C.A., Arrington, D.A., Montaña, C.G., Post, D.M., 2007. Can stable isotope ratios provide for community-wide measures of trophic structure? Ecology 88. https://doi.org/10.1890/0012-9658(2007)88[42:CSIRPF]2.0.CO;2.

Lazzerini, N., Coulon, A., Simon, L., Marchina, C., Fiorillo, D., Turbat, T., Bayarkhuu, N., Noös, C., Lepetz, S., Zazzo, A., 2021. The isotope record (δ13C, δ18O) of vertical mobility in incremental tissues (tooth enamel, hair) of modern livestock: a reference set from the Mongolian Altai. Quat. Int. 595, 128–144. https://doi.org/10.1016/J.QUAINT.2021.04.008.

Levin, N.E., Cerling, T., Passey, B.H., Harris, J.M., Ehleringer, J.R., 2006. A stable isotope aridity index for terrestrial environments. PNAS 103, 11201–11205. https://doi.org/10.1073/pnas.060471903.

Lewis, J., Coath, C.D., Pike, A.W.G., 2014. An improved protocol for 87Sr/86Sr by laser ablation multi-collector inductively coupled plasma mass spectrometry using oxide reduction and a customised plasma interface. Chem. Geol. 390, 173–181. https://doi.org/10.1016/j.chemgeo.2014.10.021.

López-García, J.M., Blain, H.A., Sánchez-Bandera, C., Cohen, J., Lebreton, L., Montuire, S., Stewart, J.R., Desclaux, E., 2021. Multi-method approach using small vertebrate assemblages to reconstruct the Marine Isotope Stage 6 climate and environment of the Lazaret cave sequence (Maritime Alps, Nice, France). Palaeogeogr. Palaeoclimatol. Palaeoecol. 577. https://doi.org/10.1016/j.palaeoecol.2021.110529.

Lüdecke, T., Leichtliter, J.N., Aldeias, V., Bamford, M.K., Biro, D., Braun, D.R., Capelli, C., Cybulski, J.D., Duprey, N.N., Ferreira da Silva, M., Foreman, A.D., Habermann, J. M., Haug, G.H., Martínez, F.I., Mathe, J., Mulch, A., Sigman, D.M., Vonhof, H., Bobe, R., Carvalho, S., Martínez-García, A., 2022. Carbon, nitrogen, and oxygen stable isotopes in modern tooth enamel: a case study from Gorongosa National Park, central Mozambique. Front. Ecol. Evol. 10. https://doi.org/10.3389/fevo.2022.958032.

Lugli, F., Cipriani, A., Bruno, L., Ronchetti, F., Cavazzuti, C., Benazzi, S., 2022. A strontium isotope of Italy for provenance studies. Chem. Geol. 587, 120624. https://doi.org/10.1016/j.chemgeo.2021.120624.

Makarewicz, C.A., Arbuckle, B.S., Öztan, A., 2017. Vertical transhumanism of sheep and goats identified by intra-tooth sequential carbon (δ13C) and oxygen (δ18O) isotopic analyses: evidence from Chalcolithic Kösk Höyük, central Turkey. J. Archaeol. Sci. 86, 68–80. https://doi.org/10.1016/j.JAS.2017.01.003.

Margari, V., Skinner, L.C., Hoddell, D.A., Martrat, P., Toucanne, S., Grimalt, J.O., Gibbard, P.L., Lunkka, J.P., Tzedakis, P.C., 2014. Land-ocean changes on orbital and millennial time scales and the penultimate glaciation. Geology 42, 183–186. https://doi.org/10.1130/G35070.1.

McArthur, J.M., Howarth, R.J., Bailey, T.R., 2001. Strontium isotope stratigraphy: LOWESS version 3: best fit to the marine Sr-isotope curve for 0–509 Ma and accompanying look-up table for deriving numerical age. J. Geol. 109, 155–170.

Megga, Z., Urbanc, J., Cerar, S., 2014. The isotope altitude effect reflected in groundwater: a case study from Slovenia. Isot. Environ. Health Stud. 50, 33–51. https://doi.org/10.1080/10256016.2013.826213.

Michel, V., Yokoyama, Y., 2000. Méthodes U-Th/ESR en Préhistoire et problèmes d'altération des matériaux: exemple de la datation des carbonates et apatites de la grotte du Lazaret. In: Barrandon, J.N., Guibert, P., Michel, V. (Eds.), Actes Des XXIe Rencontres Internationales D'archéologie et D'histoire D'antibes. APDCA, Antibes, pp. 187–205.

Michel, V., Shen, G., Valensi, P., de Lumley, H., 2009. ESR dating of dental enamel from Middle Palaeolithic levels at Lazaret Cave, France. Quat. Geochronol. 4, 233–240. https://doi.org/10.1016/j.qageo.2008.07.003.

Mokadem, F., Parkinson, I.J., Hathorne, E.C., Anand, P., Allen, J.T., Burton, K.W., 2015. High-precision radiogenic strontium isotope measurements of the modern and glacial ocean: Limits on glacial-interglacial variations in continental weathering. Earth Planet. Sci. Lett. 415. https://doi.org/10.1016/j.epsl.2015.01.036.

Montgomery, J., Evans, J.A., Horstwood, M.S.A., 2010. Evidence for long-term averaging of strontium in bovine enamel using TIMS and LA-MC-ICP-MS strontium isotope intra-molar profiles. Environ. Archaeol. 15, 32–42. https://doi.org/10.1179/146141010X12640787648694.

Moussous, A., Valensi, P., Simon, P., 2014. Identification de l'ivoire de Probosciidiens des grottes de Balzi Rossi (Ligurie, Italie) à partir de la méthode des lignes de Schrenger. Bull. Mus. Anthropo. Prehist. Monaco 54, 83–90.

Müller, W., Anczkiewicz, R., 2016. Accuracy of laser-ablation (LA)-MC-ICPMS Sr isotope analysis of (bio)apatite-a problem reassessed. J. Anal. At. Spectrom. 31. https://doi.org/10.1039/c5ja00311c.

Newsome, S.D., Del Río, C.M., Bearhop, S., Phillips, D.L., 2007. A niche for isotopic ecology. Front. Ecol. Environ. 429–436. https://doi.org/10.1890/060150.1.

Noe-Nygaard, N., Price, T.D., Hede, S.U., 2005. Diet of aurochs and early cattle in southern Scandinavia: evidence from 15N and 13C stable isotopes. J. Archaeol. Sci. 32. https://doi.org/10.1016/j.jas.2005.01.004.

Onoratini, G., Arellano, A., Del Lucchese, A., Moullé, P.E., Serre, F., 2012. The Barma Grande cave (Grimaldi, Vintimiglia, Italy): from Neandertal, hunter of “Elephas antiquus”, to Sapiens with ornaments of mammoth ivor. Quat. Int. 255. https://doi.org/10.1016/j.quaint.2011.05.015.

Oxilia, G., Bortolini, E., Badino, F., Bernardini, F., Gazzoni, V., Lugli, F., Romandini, M., Radini, A., Terlato, G., Marciani, G., Silvestrini, S., Menghi Sartorio, J.C., Thun Hohenstein, U., Fiorenza, L., Kullmer, O., Tuniz, C., Moggi Cecchi, J., Talamo, S., Fontana, F., Peresani, M., Benazzi, S., Cristiani, E., 2020. Exploring late paleolithic and mesolithic diet in the eastern alpine region of Italy through multiple proxies. Am. J. Phys. Anthropol. 174, 232–253. https://doi.org/10.1002/ajpa.24128.

Pålsdöttr, A.H., Bläuer, A., Rannamäe, E., Boessenkool, S., Hallsson, J.H., 2019. Not a limitless resource: ethics and guidelines for destructive sampling of archaofaunal remains. R. Soc. Open Sci. 6. https://doi.org/10.1098/RSOS.191059.

Passey, B.H., Robinson, T.F., Ayliffe, L.K., Cerling, T.E., Sponheimer, M.F., Dearing, M.D., Roeder, B.L., Ehleringer, J.R., 2005. Carbon isotope fractionation between diet, breath CO₂, and bioapatite in different mammals. J. Archaeol. Sci. 32, 1459–1470. https://doi.org/10.1016/J.JAS.2005.03.015.

Pederzani, S., Britton, K., 2019. Oxygen isotopes in bioarchaeology: Principles and applications, challenges and opportunities. Earth Sci. Rev. 188, 77–107. https://doi.org/10.1016/j.earscirev.2018.11.005.

Pederzani, S., Aldeias, V., Dibble, H.L., Goldberg, P., Hublin, J.J., Madelaine, S., McPherron, S.P., Sandgathe, D., Steele, T.E., Turq, A., Britton, K., 2021. Reconstructing Late Pleistocene paleoclimate at the scale of human behavior: an example from the Neandertal occupation of La Ferrassie (France). Sci. Rep. 11. https://doi.org/10.1038/s41598-020-80777-1.

Pellegrini, M., Snoeck, C., 2016. Comparing bioapatite carbonate pre-treatments for isotopic measurements: Part 2 – Impact on carbon and oxygen isotope compositions. Chem. Geol. 420, 88–96.

Pellegrini, M., Lee-Thorp, J.A., Donahue, R.E., 2011. Exploring the variation of δ18O and δ18Oc relationship in enamel increments. Palaeogeogr. Palaeoclimatol. Palaeoecol. 310, 71–83. https://doi.org/10.1016/J.PALAEOL.2011.02.023.

Ponel, P., 1995. Russian, Eemian and Würmian Coleoptera assemblages from La Grande Pile (Vosges, France). Palaeogeogr. Palaeoclimatol. Palaeoecol. 114, 1–41. https://doi.org/10.1016/j.paleoecol.1995.00182(95)00083-X.

Pryor, A.J.E., Stevens, R.E., O’Connell, T.C., Lister, J.R., 2014. Quantification and propagation of errors when converting vertebrate biomolecular oxygen isotope data to temperature for palaeoclimate reconstruction. Palaeogeogr. Palaeoclimatol. Palaeoecol. 412, 99–107. https://doi.org/10.1016/j.palaeo.2014.07.003.

Rivals, F., Mihlbachler, M.C., Solounias, N., Mol, D., Semprebron, G.M., de Vos, J., Kalthoff, D.C., 2010. Palaeoecology of the Mammoth Steppe fauna from the late Pleistocene of the North Sea and Alaska: Separating species preferences from geographic influence in paleoecological dental wear analysis. Palaeogeogr. Palaeoclimatol. Palaeoecol. 286, 42–54. https://doi.org/10.1016/j.palaeo.2009.12.002.

Rivals, F., Cohen, J., Desclaux, E., 2023. Dietary traits of the ungulates from the Middle Pleistocene sequence of Lazaret Cave: palaeoecological and archaeological implications. Archaeol. Anthropol. Sci. 15, 1–10. https://doi.org/10.1007/S12520-023-01719-2.

Royer, A., Lécuyer, C., Montuire, S., Escarguel, G., Foureul, F., Mann, A., Maureille, B., 2013. Late Pleistocene (MIS 3–4) climate inferred from micromammal communities and δ18O of rodents from Les Pradelles, France. Quat. Res. 80, 113–124. https://doi.org/10.1016/j.qyres.2013.03.007.

Scherler, L., Tütken, T., Becker, D., 2014. Carbon and oxygen stable isotope compositions of late Pleistocene mammal teeth from dolines of Ajoie (Northwestern Switzerland). Quat. Res. 82, 378–387.

Schmidt, H.L., 1999. Isotope Discriminations upon Biosynthesis in Natural Systems: General Causes and Individual Factors of the Different Bioelements. Isot. Environ. Health Stud. 35, 11–18. https://doi.org/10.1080/10256019900234076.

Schmidt, H.L., Werner, R.A., Roßmann, A., 2001. 18O Pattern and biosynthesis of natural plant products. Phytochemistry 58, 9–32. https://doi.org/10.1016/S0031-9422(01)00017-6.

Seierstad, I.K., Abbott, P.M., Bigler, M., Blunier, T., Bourne, A.J., Brook, E., Buchardt, S. L., Buizert, C., Clausen, H.B., Cook, E., Dahl-Jensen, D., Davies, S.M., Guillevic, M., Johnsen, S.J., Pedersen, D.S., Popp, T.J., Rasmussen, S.O., Severinghaus, J.P., Svensson, A., Vinther, B.M., 2014. Consistently dated records from the Greenland GRIP, GISP2 and NGROP ice cores for the past 104 ka reveal regional millennial-scale δ18O gradients with possible Heinrich event imprint. Quat. Sci. Rev. 106, 29–46. https://doi.org/10.1016/J.QUASCIREV.2014.10.032.

Skippington, J., Veth, P., Manne, T., Slack, M., 2019. Preanalytical processing of archaeological mammal apatite carbonates for stable isotope investigations: a comparative analysis of the effect of acid treatment on samples from Northwest Australia. Int. J. Osteoarchaeol. 29, 760–771. https://doi.org/10.1002/oa.2787.

Snoeck, C., Pellegrini, M., 2015. Comparing bioapatite carbonate pre-treatments for isotopic measurements: Part 1—Impact on structure and chemical composition. Chem. Geol. 417, 394–403. https://doi.org/10.1016/j.chemgeo.2015.10.004.

Soberón, J.M., 2010. Niche and area of distribution modeling: a population ecology perspective. Ecography 33. https://doi.org/10.1111/j.1600-0587.2009.06074.x.

Sponheimer, M., Lee-Thorp, J.A., 1999. Oxygen isotopes in enamel carbonate and their ecological significance. J. Archaeol. Sci. 26, 723–728.

Sponheimer, M., Lee-Thorp, J.A., 2001. The oxygen isotope composition of mammalian enamel carbonate from Morea Estate, South Africa. Oecologia 126, 153–157.

Steele, T.E., 2015. The contributions of animal bones from archaeological sites: the past and future of zooarchaeology. J. Archaeol. Sci. 56, 168–176. https://doi.org/10.1016/J.JAS.2015.02.036.

Stevens, R.E., Balasse, M., O’Connell, T.C., 2011. Intra-tooth oxygen isotope variation in a known population of red deer: Implications for past climate and seasonality reconstructions. Palaeogeogr. Palaeoclimatol. Palaeoecol. 301, 64–74. https://doi.org/10.1016/j.palaeo.2010.12.021.
Stevens, R.E., Pederzani, S., Britton, K., Wexler, S.K., 2025. Bones and teeth isotopes as archives for palaeoclimatic, palaeoenviro nmental and palaeoecological data. Quat. Sci. Rev. 357, 109320. https://doi.org/10.1016/j.quascirev.2025.109320.

Stewart, J.R., Lister, A.M., Barnes, I., Dalén, L., 2010. Refugia revisited: individualistic responses of species in space and time. Proc. Biol. Sci. 277, 661–671. https://doi.org/10.1098/rspb.2009.1272.

Svensson, A., Andersen, K.K., Bigler, M., Clausen, H.B., Dahl-Jensen, D., Davies, S.M., Johnsen, S.J., Muscheler, R., Parrenin, F., Rasmussen, S.O., Röthlisberger, R., Seierstad, I., Steffensen, J.P., Vinther, B.M., 2008. A 60 000 year Greenland stratigraphic ice core chronology. Clim. Past 4. https://doi.org/10.5194/cp-4-47-2008.

Szabó, B., Pazonyi, P., Tóth, E., Magyari, E.K., Kiss, G.I., Rinyu, L., Futó, I., Virág, A., 2021. Pleistocene and holocene palaeoenviro nmental reconstruction of the carpathian basin based on multiproxy analysis of cervid teeth. Hist. Biol. 33, 3307–3325. https://doi.org/10.1080/08912963.2020.1863960.

Tessone, A., 2022. Constructing an isotope ecology in southern Patagonia: Herbivore δ13C and δ15N variability from the Andes to Atlantic coast. Quat. Int. 628, 79–87. https://doi.org/10.1016/j.quaint.2022.02.028.

Tieszen, L.L., 1994. Stable isotopes on the plains: vegetation analyses and diet determinations. Skeletal Biology in the Great Plains.

Tornero, C., Balasse, M., Bălăşescu, A., Chataigner, C., Gasparyan, B., Montoya, C., 2016. The altitudinal mobility of wild sheep at the Epigravettian site of Kalavan 1 (Lesser Caucasus, Armenia): evidence from a sequential isotopic analysis in tooth enamel. J. Hum. Evol. 97, 27–36. https://doi.org/10.1016/j.JHEVOL.2016.05.001.

Towers, J., Gledhill, A., Bond, J., Montgomery, J., 2014. An investigation of cattle birth seasonality using δ13C and δ18O profiles within first molar enamel. Archaeometry 56, 208–236. https://doi.org/10.1111/ARCM.12055.

Valensi, P., 2000. The archaeozoology of Lazaret Cave (Nice, France). Int. J. Osteoarchaeol. 10, 357–367. https://doi.org/10.1002/1099-1212(200009/10)10:5<357::AID-OA561>3.0.CO;2-W.

Valensi, P., Abbassi, M., 1998. Reconstitution de paléoenvironnements quaternaires par l'utilisation de diverses méthodes sur une communauté de mammifères - Application à la grotte du Lazaret [the reconstitution of a quaternary palaeoenvironment using different methods on a mammalian fauna - Application of the Lazaret cave]. Quaternaire 9, 291-302. https://doi.org/10.3406/QUATE.1998.1611.

Valensi, P., Psathi, E., 2004. Faunal Exploitation during the Middle Palaeolithic in south-eastern France and north-western Italy. Int. J. Osteoarchaeol. 14, 256–272. https://doi.org/10.1002/oa.760.

Valensi, P., Bailon, S., Michel, V., Desclaux, E., Rousseau, L., Onoratini, G., Genty, D., Blamart, D., de Lumley, H., 2007. Cadre climatique et environnemental des acheuléens de la grotte du Lazaret, à Nice. Données paléontologiques, biogéochimiques et radiométriques établies sur les faunes de vertébrés et d'invertébrés. ArchéoSciences 31, 137–150. https://doi.org/10.4000/archosciences.844.

Valensi, P., Michel, V., El Guennouni, K., Liouville, M., 2013. New data on human behavior from a 160,000 year old Acheulean occupation level at Lazaret cave, south-east France: an archaeozoological approach. Quat. Int. 316, 123–139. https://doi.org/10.1016/j.quaint.2013.10.034.

Van Andel, T.H., Tzedakis, P.C., 1996. Palaeolithic landscapes of Europe and environs, 150,000-25,000 years ago: an overview. Quat. Sci. Rev. 15. https://doi.org/10.1016/0277-3791(96)00028-5.

Van Der Merwe, N., Medina, E., 1991. The canopy effect, carbon isotope ratios and foodwebs in amazonia. J. Archaeol. Sci. 18, 249–259. https://doi.org/10.1016/0305-4403(91)90064-V.

van Vuure, T., 2005. Retracing the Aurochs: History, Morphology and Ecology of an Extinct Wild Ox. Pensoft Publishers.

Vos, C.C., Berry, P., Opdam, P., Baveco, H., Nijhof, B., O'Hanley, J., Bell, C., Kuipers, H., 2008. Adapting landscapes to climate change: examples of climate-proof ecosystem networks and priority adaptation zones. J. Appl. Ecol. 45, 1722–1731. https://doi.org/10.1111/j.1365-2664.2008.01569.x.

Vroon, P.Z., van der Wagt, B., Koornneef, J.M., Davies, G.R., 2008. Problems in obtaining precise and accurate Sr isotope analysis from geological materials using laser ablation MC-ICPMS. Anal. Bioanal. Chem. 390, 465–476. https://doi.org/10.1007/s00216-007-1742-9.

Wainer, K., Genty, D., Blamart, D., Bar-Matthews, M., Quinif, Y., Plagnes, V., 2013. Millennial climatic instability during penultimate glacial period recorded in a southwestern France speleothem. Palaeogeogr. Palaeoclimatol. Palaeoecol. 376, 122–131. https://doi.org/10.1016/j.PALAEO.2013.02.026.

Willmes, M., McMorrow, L., Kinsley, L., Armstrong, R., Aubert, M., Eggins, S., Falguères, C., Maureille, B., Moffat, I., Grün, R., 2014. The IRHUM (Isotopic Reconstruction of Human Migration) database – bioavailable strontium isotope ratios for geochemical fingerprinting in France. Earth Syst. Sci. Data 6 (1), 117–122. https://doi.org/10.5194/essd-6-117-2014.

Willmes, M., Bataille, C.P., James, H.F., Moffat, I., McMorrow, L., Kinsley, L., Armstrong, R., Eggins, S., Grün, R., 2018a. Mapping of bioavailable strontium isotope ratios in France for archaeological provenance studies. Appl. Geochem. 90, 75–86. https://doi.org/10.1016/j.apgeochem.2017.12.025.

Willmes, M., Ransom, K.M., Lewis, L.S., Denney, C.T., Glessner, J.J.G., Hobbs, J.A., 2018b. IsoFishR: an application for reproducible data reduction and analysis of strontium isotope ratios (87Sr/ 86Sr) obtained via laser-ablation MC-ICP-MS. PLoS One 13. https://doi.org/10.1371/journal.pone.0204519.

Wiíng, C., Rougier, H., Baumann, C., Meyne, A., Crevecoeur, I., Drucker, D.G., Gaudzinski-Windheuser, S., Germonpré, M., Gómez-Olivencia, A., Krause, J., Matthies, T., Naito, Y.I., Posth, C., Semal, P., Street, M., Bocherens, H., 2019. Stable isotopes reveal patterns of diet and mobility in the last Neandertals and first modern humans in Europe. Sci. Rep. 9 (1), 4433. https://doi.org/10.1038/s41598-019-41033-3.

Wood, S.N., 2017. Generalized additive models: An introduction with R, second edition. Generalized Additive Models: An Introduction with R, Second Edition, pp. 1–476. https://doi.org/10.1201/9781315370279/.

Wooller, M.J., Bataille, C.P., Druckenmiller, P., Erickson, G.M., Groves, P., Haubenstock, N., Howe, T., Irrgeher, J., Mann, D., Moon, K., Potter, B.A., Prohaska, T., Rasic, J., Reuther, J., Shapiro, B., Spaleta, K.J., Willis, A.D., 2021. Lifetime mobility of an Arctic woolly mammoth. Science 1979 (373), 806–808. https://doi.org/10.1126/science.abg1134.

Xu, C., Reed, R., Gorski, J.P., Wang, Y., Walker, M.P., 2012. The distribution of carbonate in enamel and its correlation with structure and mechanical properties. J. Mater. Sci. 47, 8035–8043. https://doi.org/10.1007/S10853-012-6693-7.