Raphaël Hanon
email: raphael.hanon@edu.mnhn.fr

Jean-Baptiste Fourvel

Christine Steininger

Carnivores and hominins contributions to the Early Pleistocene bone accumulation of Cooper's D, South Africa

Carnivores has long been identified as one of the most important taphonomical agent of the Plio-Pleistocene hominin-bearing caves of South Africa. Cooper's D is an eroded cave deposit dated between 1.3 -1.0 Ma and has yielded an abundant and diverse large mammal faunal assemblage. It has been previously argued that brown hyenas (Parahyaena brunnea) were the main accumulator agent. However, more recently the involvement of hominins has also been identified in the accumulation of at least a part of the assemblage. In this paper, we first describe the composition of the carnivore paleoguild from Cooper's D, which permits to highlight an important taxonomic diversity. The completeness indexes indicate a good retention of bone material in our analysis. The carnivore ravaging index pointed out the relative moderate impact of carnivores in the destruction of the bone assemblage. Through skeletal part representation, mortality profiles and bone surface modifications, we argue that large felids, and especially leopards, can in fact be identified as the most probable main taphonomic agents. Moreover, we confirmed the involvement of hyenids but also canids in the accumulation and modification of the assemblage. Based on the multiple carnivore taphonomic signal, we proposed that the cave was not used as a carnivore den on a regular basis. Thus, we argue that Cooper's D faunal assemblage is the result of the independent accumulations of both hominins and carnivores.

Introduction

Carnivores, and especially hyenas, have long been identified as one of the main taphonomic agent of the accumulation and modification of Plio-Pleistocene large mammal assemblages. [START_REF] Buckland | Account of an assemblage of fossil teeth and bones of Elephant, Rhinoceros, Hippopotamus, Bear, Tiger, and Hyaena, and siwteen other animalx; Discovered in a cave at Kirkdale, Yorkshire, in the year 1821: with a comparative view of five similar caverns in various parts of England, and others on the continent[END_REF] was the first to characterize a prehistoric hyena den from the study of the bone accumulation at Kirkland, Yorkshire, and therefore bring back to light the potential role of carnivores in archaeological bone accumulations. His research was extended in Europe by Zapfe (1939), [START_REF] Brunner | Beobachtungen zu den Lebensspuren der Hyänen an den Knochen der Huftiere aus dem Unterpliozän von Pikermi[END_REF] and [START_REF] Thenius | Hyänenfraßspuren aus dem Pleistozän von Kärnten. Ein Beitrag zur Frage der sog[END_REF], who recorded feeding traces left by hyenas as well as bone fracture patterns. At the same time in South Africa, Dart (1956;[START_REF] Dart | The osteodontokeratic culture of Australopithecus prometheus[END_REF] was conducted his research on the Australopithecus site of Makapansgat. He suggested that the large mammal bone accumulation was the result of hominin rather than carnivore activity. Some researchers were opposed to the hominin origin scenario for Makapansgat bone accumulation proposed by Dart, and rather attributed the presence of bovid bones associated with the hominin remains to the action of hyenas and other carnivores instead [START_REF] Broom | The South African fossil ape-men: the Australopithecinae[END_REF][START_REF] Oakley | Dawn of man in South Africa[END_REF][START_REF] Koenigswald | The Australopithenicae and Pithecanthropus[END_REF]. Even if Dart (1956) argued for an anthropic origin of these assemblages, the first systematic taphonomic studies conducted by Brain (e.g. 1969;1978;1981) pointed out that early Pleistocene hominins were more susceptible to be hunted by large carnivores than accomplished hunters. From this point, most of the South African Plio-Pleistocene large mammal bone assemblages were attributed to carnivore activity: Gondolin GD2 [START_REF] Adams | Taphonomy of the Gondolin GD 2 in situ Deposits and its Bearing on Interpretations of South African Plio-Pleistocene Karstic Fossil Assemblages[END_REF], Sterkfontein Member 4 (Pickering et al., 2004c), Kromdraai Member 2 (Fourvel et al., 2018b) and Swartkrans Members 1 to 3 [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF]. Interestingly, most of the attention has been given to felids and hyenids, leading to a gap of knowledge about the role of potential smaller carnivores such as canids, viverrids or mustelids [START_REF] Domínguez-Rodrigo | On meat eating and human evolution: A taphonomic analysis of BK4b (Upper Bed II, Olduvai Gorge, Tanzania), and its bearing on hominin megafaunal consumption[END_REF]Fourvel et al., 2018a).

Recent taphonomic investigations of South African caves have provided evidence for the involvement of hominins in the accumulation of at least part of bone assemblage [START_REF] Brain | Swartkrans. A Cave's Chronicle of Early Man[END_REF]Pickering et al., 2004b;2007;2008). On one hand, based on the anatomical distribution of butchery marks along limb bones, [START_REF] Pickering | Carcass foraging by early hominids at Swartkrans cave (South Africa): a new investigation of the zooarchaeology and taphonomy of member 3[END_REF] argue that hominins did have an early access to bovid carcasses during the Swartkrans Member 3 time period (0.96±0.09 Ma; [START_REF] Gibbon | Cosmogenic nuclide burial dating of hominin-bearing Pleistocene cave deposits at Swartkrans, South Africa[END_REF]. On the other hand, carnivores were importantly active at this time in the cave, specifically leopards and hyenids [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF]. Similarly, [START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF] and Hanon et al. (2022) recently described the presence of hominin butchery marks at the Cooper's D site.

Moreover, one definitive bone tool has been described at Cooper's D [START_REF] Hanon | New evidence of bone tool use by Early Pleistocene hominins from Cooper's D, Bloubank Valley, South Africa[END_REF], which reinforce the hypothesis of hominin involvement in the bone accumulation processes.

However, the relationship between these hominins and carnivores at that site remains unexplored. This raises questions about faunal accumulations of early archaeological sites in South Africa, the competition and interaction between hominins and carnivores at that time, as well as Plio-Pleistocene hominin subsistence behaviours.

In this paper, we used multivariate taphonomic evidence obtained from the study of large mammal assemblage of Cooper's D in order to explore the carnivores and hominins respective contributions to the bone accumulation. Our study provides further conclusions on the hominin subsistence behaviors during the Early Pleistocene of South Africa.

The Cooper's cave site

The Cooper's Cave site is situated in the Cradle of Humankind, approximately 45 km northwest of Johannesburg (Fig. 1). Excavations were conducted by Berger andSteininger in 2001 (Berger et al., 2003;[START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF] and were focused on the decalcified sediments of the D deposit. These excavations yielded an abundant assemblage of both micro and macrofauna (n > 50,000), stone tools (n = 49) and seven hominin remains, six of them attributed to Paranthropus robustus, the last one remains unidentified [START_REF] Berger | Preliminary results of excavations at the newly investigated Coopers D deposit, Gauteng, South Africa[END_REF][START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF][START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF][START_REF] Sutton | Early Pleistocene stone artefacts from Cooper's cave, South Africa[END_REF].

Cooper's D consists of two localities -Cooper's D East and Westwhich correspond to two distinct parts of the cave [START_REF] Berger | Preliminary results of excavations at the newly investigated Coopers D deposit, Gauteng, South Africa[END_REF][START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF]. The fossiliferous deposit rests on dolomitic floor on which several types of speleothems formed before the cave opened (ibid.). The western deposit (facies B and C), which makes up the lower major part of the sequence, is made up of fine sand and contains an abundant assemblage of micromammals (de [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF]. The fossil breccia corresponds to an accumulation slope characteristic of cave deposits with a vertical (or subvertical) opening. The deposit is separated in two by a stalagmite floor. The presence of different calcite formations within the western deposit, such as stalagmites, flows or floors associated with the low proportion of dolomitic clasts from the collapse of the roof, indicates that the deposit accumulated when the cave was relatively well closed. Cooper's D East is made up of large clasts, sometimes greater than 50 cm (facies A).

These dolomitic clasts originated from the collapsed roof. No preferential orientation of dolomitic clasts or cherts is observed, while the bone remains seem to more or less align horizontally (de [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF]. Most of the large mammal bone remains have been recovered from the finer-grained portions of the faces A and B.

The interbedded stalagmitic floors within the breccias of the West and East deposits have been dated by the Uranium-Lead method (de [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF]. The stalagmitic floor on which all the deposits rests yielded an age of 1.526 ± 0.088 Ma. The horizontal layer cutting the deposits into two sets has been dated to a minimum of 1.413 Ma and a maximum of 1.671 Ma.

Given the age of 1.526 ± 0.088 Ma of the basal floor, the age of the upper floor is dated between 1.413 and 1.526 ± 0.088 Ma (de Ruiter et al., 2009). All the sediments in the lower part of the deposits must have accumulated between 1.5 and 1.4 Ma. Subsequently, a new study undertook to recalculate the ages, in particular for the sample which provided the date of 1.526 ± 0.088 (CDD1). This sample is now estimated at 1.375 ± 0.113 Ma (Pickering et al., 2019). Based on both radiometric dates and biochronological data, Hanon et al. (2022b) suggest that the faunal assemblage from both West and East parts of the cave accumulated between 1.3 and 1.0 Ma.

Several paleontological studies have been conducted on the Cooper's D large mammal fauna. This is the case for the Primates [START_REF] Berger | A Plio-Pleistocene hominid upper central incisor from the Cooper's site, South Africa[END_REF][START_REF] Steininger | A partial skull of Paranthropus robustus from Cooper's Cave, South Africa[END_REF][START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF][START_REF] Desilva | Cercopithecoid primate postcranial fossils from Cooper's D, South Africa[END_REF][START_REF] Folinsbee | New craniodental fossils of papionin monkeys from Cooper's D, South Africa: Papionin Monkeys from Cooper's D[END_REF], Carnivores [START_REF] Hartstone-Rose | A sabre-tooth felid from Coopers Cave (Gauteng, South Africa) and its implications for Megantereon (Felidae: Machairodontinae) taxonomy[END_REF][START_REF] Adams | Taphonomy of the Gondolin GD 2 in situ Deposits and its Bearing on Interpretations of South African Plio-Pleistocene Karstic Fossil Assemblages[END_REF][START_REF] O'regan | Mustelid and viverrid remains from the Pleistocene site of Cooper's D, Gauteng, South Africa[END_REF][START_REF] Kuhn | Fossil Hyaenidae from Cooper's Cave, South Africa, and the palaeoenvironmental implications[END_REF][START_REF] O'regan | Felidae from Cooper's Cave, South Africa (Mammalia: Carnivora)[END_REF],Equidae [START_REF] Badenhorst | The Equidae from Cooper's D, an early Pleistocene fossil locality in Gauteng, South Africa[END_REF] and Bovidae (Hanon et al., 2022b).

In addition, with palaeontological studies, previous taphonomic studies have been conducted on large mammal Cooper's assemblage ( [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF][START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF][START_REF] Parkinson | Traces of Insect Activity at Cooper's D Fossil Site (Cradle of Humankind, South Africa)[END_REF][START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF]. Based on the study of a sub-sample (NISP = 8488), [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF] identified the brown hyena (Parahyaena brunnea) as the main accumulating agent of the assemblage, although the leopard is also mentioned. Through the study of large-bodied non-hominin primates and the eight coprolite fragments recovered from Cooper's D, [START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF] also suggest the role of brown hyena and felids. Subsequently, Hanon et al. (2022a) has identified 31 bone remains bearing butchery marks.

Based on the study of the morphology and anatomical location of these marks, the authors argued that hominins exploited a diversity of bovid size classes, from small to large animals [START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF]Hanon et al., 2022a). Moreover, [START_REF] Hanon | New evidence of bone tool use by Early Pleistocene hominins from Cooper's D, Bloubank Valley, South Africa[END_REF] described the presence of one definitive bone tool at the site, similar to those find at Sterkfontein, Swartkrans, Kromdraai and Drimolen [START_REF] Brain | Swartkrans. A Cave's Chronicle of Early Man[END_REF]Backwell and d'Errico, 2003;2008;d'Errico and Backwell, 2003;[START_REF] Val | The macrovertebrate fossil assemblage from the Name Chamber, Sterkfontein: taxonomy, taphonomy and implications for site formation processes[END_REF][START_REF] Stammers | The first bone tools from Kromdraai and stone tools from Drimolen, and the place of bone tools in the South African Earlier Stone Age[END_REF]. Thus, the faunal assemblage recovered at Cooper's D is characterized by an important presence of diverse carnivores and also by a great impact of carnivores on at least a large part of the bone assemblage as well as evidence of large mammal exploitation by hominins (de [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF][START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF]Hanon et al., 2022a). Here, through a multivariate taphonomic approach, we seek to identify the respective role of carnivore taxa and hominins in the accumulation and modification of the large mammal bone assemblage of Cooper's D.

Material and methods

The primary taphonomic data, upon which our analyses are based, derive from the study of the Cooper's D large mammal assemblage (n = 21,193), which has been described in length before [START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF]. Within that sample, 741 specimens are attributed to carnivores. Moreover, 5,558 specimens are attributed to bovids and constitute the base of the skeletal element and mortality profile analyses presented in this paper.

The collection comes from the excavations of decalcified sediments conducted from 2001 to 2009 by Lee R. Berger and Christine Steininger on both west and east side of the site [START_REF] Berger | Preliminary results of excavations at the newly investigated Coopers D deposit, Gauteng, South Africa[END_REF][START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF]. The Cooper's collection is stored and curated at the Evolutionary Studies Institute of the University of Witwatersrand, Johannesburg. As a comparative material, we used the modern and archaeological collections housed at the Evolutionary Studies Institute of the University of Witwatersrand, Johannesburg, as well as the collections of the Ditsong National Museum of Natural History of Pretoria.

3.1.Quantification

In this study, we use four quantification units (see [START_REF] Lyman | Vertebrate Taphonomy[END_REF] for a detailed description): NISP (number of identified specimens), MNE (minimum number of elements), MAU (minimum animal unit) and MNI (minimum number of individuals).

Our estimation of the MNE follows the method described by [START_REF] Marean | Impact of Carnivore Ravaging on Zooarchaeological Measures of Element Abundance[END_REF] which derived from the bone fraction record system developed by Klein and Cruz-Uribe (1984:108). Thus, we recorded the bone portion (e.g. proximal epiphysis, proximal shaft, shaft fragment, distal shaft, distal epiphysis) and the bone preservation fraction (e.g. < 0.25, 0.25-0.5, 0.5-0.75, >0.75, 1) for each specimen. Then, we summed the fraction values for each element and portion. The obtained value is rounded up to obtain an estimation of the MNE [START_REF] Lyman | Vertebrate Taphonomy[END_REF]. This method has produced efficient results and has the advantage to take into account long bone shaft specimens in the estimation [START_REF] Marean | Impact of Carnivore Ravaging on Zooarchaeological Measures of Element Abundance[END_REF].

We obtain the MAU by dividing the MNE value of each specific bone element by the number of times that element occurred in a complete skeleton [START_REF] Binford | Nunamiut Ethnoarchaeology[END_REF][START_REF] Binford | Butchering, sharing, and the archaeological record[END_REF]. The percentage of MAU (MAU%) is obtained by dividing the MAU of each bone element by the highest MAU value.

The MNI is calculated by combination (MNIc) as defined by Poplin (1976). It represents the most represented anatomical element in the assemblage for a given taxon, considering the age estimation, the side and the size class.

3.2.Animal size classes

As described by [START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF], four bovid size-classes are commonly recognized: "Class I" (less than 20 kg), "Class II" (from 20 to 100 kg), "Class III" (from 100 to 300 kg) and "Class IV" (more than 300 kg). Following Fourvel et al. (2018b), we combined class III and IV into one class ("large-sized bovids") and considered the following distinction: "small-sized bovids" (Brain's class I), "medium-sized bovids" (Brain's class II) and the "large-sized bovids" (Brain's class III and larger).

3.3.Measure of completeness and degree of ravaging

It has been previously shown that the Cooper's D faunal assemblage depicts a bone density mediated attrition (Hanon et al., 2022a). For that reason, we conducted an estimation of the assemblage completeness and of the carnivore ravaging. [START_REF] Marean | Skeletal Element Equifinality in Zooarchaeology Begins with Method: The Evolution and Status of the "Shaft Critique[END_REF] demonstrated that completely retained faunal assemblages, which means that all the bone flakes have been studied (retained), tend to have a high frequency of incomplete circumference long bone shafts.

In an incompletely retained assemblage, most of the shaft fragments are discard and the assemblage is characterized by a high frequency of epiphysis with complete circumference shaft attached to them. We first apply the circumference index using the long limb bone circumference types used by [START_REF] Bunn | Comparative analysis of modern bone assemblages from a San Huntergatherer camp in the Kalahari desert, Botswana, and from a spotted hyena den near Nairobi, Kenya[END_REF] as follows: (1) less than half circumference preserved; (2) more than half circumference preserved; (3) complete circumference preserved.

We provide the distribution of long bone fragments (NISP) by circumference types and bovid size classes to estimate the level of assemblage completeness. [START_REF] Marean | Skeletal Element Equifinality in Zooarchaeology Begins with Method: The Evolution and Status of the "Shaft Critique[END_REF] also provided the "end versus shaft" index, by NISP, as a measure of the completeness of an assemblage. Completely retained assemblages always preserve shaft remains at higher rate than ends. Moreover, we measure the carnivore ravaging process by applying the axial bones:limb bones ratio by MNE [START_REF] Domínguez-Rodrigo | Deconstructing Olduvai: A Taphonomic Study of the Bed I Sites[END_REF][START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF]. If a carcass has been deposited complete and did not suffer from carnivore ravaging, then we expect to find much more axial than appendicular remains. The ratio range between 4.25 (complete skeleton) to 0 (completely ravaged skeleton).

3.4.Skeletal part representation

Skeletal part representation is commonly regarded as indicative of the impact of taphonomic processes (e.g. [START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF][START_REF] Marean | Impact of Carnivore Ravaging on Zooarchaeological Measures of Element Abundance[END_REF][START_REF] Stiner | Food procurement and transport by human and non human predators[END_REF]2002;[START_REF] Lyman | Vertebrate Taphonomy[END_REF][START_REF] Pickering | Importance of limb bone shaft fragments in zooarchaeology: a response to "On in situ attrition and vertebrate body part profiles[END_REF]Domínguez-Rodrigo and Pickering, 2010). It has been previously

showed that the Cooper's D bone assemblage is biased by a bone-density mediated attrition from pre-and post-depositional processes [START_REF] Hanon | New evidence of bone tool use by Early Pleistocene hominins from Cooper's D, Bloubank Valley, South Africa[END_REF]. Here, we further analyze skeletal part representation of preys in order to quantify the potential involvement of the different carnivore taxa in the selection of bone elements. We study the relative distribution of skeletal elements for each bovid size class according to NISP, MNE and MAU. It includes all the specimens identified to a skeletal element and a bovid size class. For the purpose of the analysis, we exclude unidentified specimens and isolated teeth. We compare our dataset to modern carnivore assemblages provided by Domínguez-Rodrigo and Pickering (2010) using multiple correspondence analysis (CA) for counted data (MNE). In order to test the results obtained with the CA, we perform a hierarchical clustering analysis using the Ward's method, which minimizes the sum of squares variance at each step of the process [START_REF] Borcard | Numerical Ecology with R[END_REF].

The multiple correspondence and hierarchical clustering analyses are performed under the PAST software version 4.05 [START_REF] Hammer | PAST: Paleontological Statistics Software Package for Education and Data Analysis[END_REF]. The original dataset is provided in the Supplementary Material 1.

3.5.Mortality profiles

We investigate prey mortality profiles through the ternary graph method developed by [START_REF] Stiner | The use of mortality patterns in archaeological studies of hominid predatory adaptations[END_REF], [START_REF] Steele | The Modified Triangular Graph: A Refined Method for Comparing Mortality Profiles in Archaeological Samples[END_REF], [START_REF] Bunn | Comparative analysis of modern bone assemblages from a San Huntergatherer camp in the Kalahari desert, Botswana, and from a spotted hyena den near Nairobi, Kenya[END_REF]Pickering (2010), and[START_REF] Weaver | Cross-platform program for likelihood-based statistical comparisons of mortality profiles on a triangular graph[END_REF]. We estimate age of individuals based on eruption stages and tooth wear patterns defined by Bunn and Pickering (2010). Concerning the carnivores, we used a modified version [START_REF] Mills | Notes on age determination, growth and measurements of brown hyaenas Hyaena brunnea from the Kalahari Gemsbok National Park[END_REF], where juveniles have unworn to well-worn deciduous premolars with erupting molars (classes 1 and 2), adults with a full permanent dentition (class 3) and old individuals with well-worn permanent dentition (classes 4 and 5). We exclude young juvenile individuals as they could biased mortality profiles (Bunn and Pickering, 2010b;2010a). The ternary graphs are produced with the Triangle version 2.0 Program using the likelihood method [START_REF] Weaver | Cross-platform program for likelihood-based statistical comparisons of mortality profiles on a triangular graph[END_REF].

3.6.Bone surface modifications

Each bone specimen was carefully observed under binocular microscope Olympus SZ2-ILST (x10 -x40) in order to record bone surface modifications (rodent gnawing marks, root etching, carnivore tooth marks, cut marks, percussion marks). The distinction between carnivore, trampling and stone tools damage was made by using the criteria developed by several researchers [START_REF] Binford | Bones: Ancient men and modern myths[END_REF][START_REF] Potts | Cutmarks made by stone tools on bones from Olduvai Gorge, Tanzania[END_REF][START_REF] Shipman | Early hominid hunting, butchering, and carcass-processing behaviors: Approaches to the fossil record[END_REF][START_REF] Behrensmeyer | Trampling as a cause of bone surface damage and pseudo-cutmarks[END_REF][START_REF] Blumenschine | Percussion marks on bone surfaces as a new diagnostic of hominid behaviour[END_REF][START_REF] Olsen | Surface modification on bone: Trampling versus butchery[END_REF][START_REF] Fiorillo | An experimental study of trampling[END_REF][START_REF] Lyman | Vertebrate Taphonomy[END_REF][START_REF] Patou-Mathis | Les marques de boucherie au Paléolithique[END_REF][START_REF] Blasco | A new element of trampling: an experimental application on the Level XII faunal record of Bolomor Cave (Valencia, Spain)[END_REF][START_REF] Domínguez-Rodrigo | A new protocol to differentiate trampling marks from butchery cut marks[END_REF][START_REF] Adams | Taphonomy of the Gondolin GD 2 in situ Deposits and its Bearing on Interpretations of South African Plio-Pleistocene Karstic Fossil Assemblages[END_REF]. Percussion marks were identified using the criteria described by Blumenschine et al. (1996). We used the different criteria available in the literature for identified carnivore tooth marks [START_REF] Maguire | The Makapansgat limeworks gray breccia: hominids, hyaenas, hystricids or hill wash[END_REF][START_REF] Binford | Bones: Ancient men and modern myths[END_REF][START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF][START_REF] Cruz-Uribe | Distinguishing Hyena from Hominid Bone Accumulations[END_REF][START_REF] Ruiter | Leopards as Taphonomic Agents in Dolomitic Caves-Implications for Bone Accumulations in the Hominid-bearing Deposits of South Africa[END_REF][START_REF] Pickering | Reconsideration of criteria for differentiating faunal assemblages accumulated by hyenas and hominids[END_REF]Pickering et al., 2004a;Domínguez-Rodrigo and Pickering, 2010;[START_REF] Kuhn | Examining criteria for identifying and differentiating fossil faunal assemblages accumulated by hyenas and hominins using extant hyenid accumulations[END_REF][START_REF] Fourvel | Hyénidés modernes et fossiles d'Europe et d'Afrique : taphonomie comparée de leurs assemblages osseux[END_REF]. We recorded punctures, pits, crenulated edges, scoring, furrowing and digestion traces as defined by Fourvel (2012:151).

Digestion has been recorded as slight (stage 1: small digestion pits present), moderate (stage 2: digestion pits cover most of the bone surface, edges are abraded and polished) or heavy (stage 3: original shape of the bone could not be determinable, digestion penetrates deep into the bone which could create deep perforations). We recorded presence and absence of bone modifications by bone section (e.g. proximal epiphysis, middle shaft, distal epiphysis).

We undertook to record the dimensions (maximum length and width) of 64 pits due to carnivore bites visible at the bone surface using a digital DinoLite microscope (Dino-Lite AD7013MTL) and the DinoCapture 2.0 software. If any mark is still ambiguous after a carefully observation, we decided to record it as « indeterminate », and to not include it in our analysis. Pits on epiphysis were not measured because it was shown that their dimensions were much more variable than on the diaphysis and presented a strong overlap [START_REF] Andrés | A study of dimensional differences of tooth marks (pits and scores) on bones modified by small and large carnivores[END_REF].

We measured only well-preserved tooth pits visible on diaphysis of long bones (NISP = 64/143 = 45%). We compared our results with experimental data obtained from [START_REF] Selvaggio | Carnivore tooth marks and stone tool butchery marks on scavenged bones: archaeological implications[END_REF][START_REF] Domı Ńguez-Rodrigo | The use of tooth pits to identify carnivore taxa in tooth-marked archaeofaunas and their relevance to reconstruct hominid carcass processing behaviours[END_REF]and Pickering et al., 2004.

Results

4.1.Composition of the carnivore paleoguild

Carnivores are an important component of the Cooper's D faunal assemblage (25% of the total MNI), representing the second most represented order after the Cetartiodactyla. At Cooper's D, the order of carnivores is dominated by the felid family (MNI = 32%; Fig. 2; Table 1), followed by the Canidae (MNI = 25%) and then the Hyaenidae (MNI = 22%).

Considering only medium to large-sized species (excluding all species smaller than Lupullela, such as Otocyon, Vulpes, Felis, Herpestidae and Viverridae), these frequencies increase up to 40%MNI in felid, 31%MNI in hyenid, 27%MNI in canid and 1%MNI in mustelid. Carnivores (Table 2) [START_REF] Adams | Taphonomy of the Gondolin GD 2 in situ Deposits and its Bearing on Interpretations of South African Plio-Pleistocene Karstic Fossil Assemblages[END_REF]Fourvel et al., in prep.). At the genus level, Lupulella is the most represented carnivore in the whole Cooper's large mammal assemblage (Fig. 2).

4.2.Estimating the post-depositional destruction

We applied the circumference and ends versus shafts indices (Fig. 3). Both show that, regardless of the bovid size class, the shafts and the flakes preserving less than half of their original circumference largely dominate the assemblage. This result indicates that the assemblage is relatively complete and doesn't reflect analytical bias through element selection.

We obtain low values for the axial:appendicular ratios for each prey size classes, but not as low as for Swartkrans Members 1 -3 (Table 3). This result reflects the moderate role of carnivore in the destruction of the bone assemblage at Cooper's D.

4.3.Prey skeletal part representation

Most of bovid skeletal elements are present at Cooper's D, even the most fragile and small specimens such as ribs or patella (Supplementary Material 1) although they are not common according to the axial:limb ratios calculated above. We observe a relatively similar distribution pattern of skeletal elements between each bovid size classes (Fig. 4). However, through a series of Kolmogorov-Smirnov tests, we find a statistically significant difference between small and medium-sized bovids (D = 0.62, p-value = < 0.01) as well as between medium and large-sized bovids (D = 0.62, p-value = 0.01). We do not find any significant difference of skeletal part distribution between small and large-sized bovids (D = 0.15, p-value = 0.1). We note that medium-sized bovids differ from small and large-sized bovids through the higher proportion of ribs and a less proportion of some limb bone elements (i.e. radioulna, metacarpal and tibia). This observation can explain the higher value of axial:limb bone ratios observed among medium-sized bovids.

The correspondence analysis shows that all Cooper's D bovids, regardless of their size, have a skeletal profile closer to the accumulations created by modern leopards than hyenas (Fig. 5; Supplementary Material 2). We observe that leopard's accumulations are characterized by a higher proportion of vertebrae and compact bones. In contrast, hyena's bone accumulations include more long bones. The phenetic analysis performed on the row scores of the correspondence analysis shows a clear distinction between a 'leopard-like' and 'hyena-like' assemblage clusters. The Cooper's D material is once again closer to modern accumulations made by leopards.

4.4.Prey mortality profiles

Each bovid size class is characterized by an 'adult-dominant' pattern of mortality profiles at Cooper's D (Fig. 6). Small-sized bovid mortality pattern is statistically similar to large sized modern felid (Fig. 6A) and wild dog accumulations (Fig. 6B). However, they differ from spotted hyena accumulations. Large-sized bovids show a marked 'adult-dominant' mortality profile which do not correspond to any of our comparative dataset, whether the assemblage is accumulated by carnivore or natural flow (Fig. 6C-D).

4.5.Carnivore tooth marks

We identified 1,081 specimens with carnivore tooth marks, which correspond to approximately 5% of the total NISP (NISP = 1,081:21,193) and 11% of the post-cranial assemblage (NISP = 1,081:9,534). We observed carnivore tooth marks on 318 identifiable bovid bone specimens (Table 4). Carnivore tooth pits have been identified on small, medium and large bovids (Fig. 7; Table 4). Among bone specimens bearing carnivore tooth pits, we can observe that lower limb (28 to 45% NISPtooth-marked) and axial bones (26 to 32% NISPtoothmarked) are much more impacted, regardless of bovid size classes (Fig. 8).

Looking at more precisely the distribution of tooth marks on long bovid limb bones (Fig. 9,Table 4), we observe that metapodials are much more impacted than intermediate and upper limb bones. For both small and medium-sized bovids, tooth marks are more abundant on lower limb bones. However, tooth marks on large-sized bovid bones are more frequently find on intermediate limb bones. For the small-sized bovids, the most impacted long limb bone section is the metapodial shaft, followed by the radio-ulna shaft. For the medium-sized bovids, the metapodial shaft is also the more impacted by carnivore tooth marks, followed by humerus shaft and both proximal radio-ulna and femur shaft. Large-sized bovids show a sparser pattern, with the radio-ulna shaft, metapodials shaft and distal tibia bearing most of the tooth marks.

In order to test whether the distribution of tooth pits depends on the differential conservation of bovid bones, we applied a Spearman's correlation test between the total NISP and the number of tooth-marked elements by size class (Supplementary Material 4). This allowed us to highlight a positive and statistically significant correlation between the skeletal representation (in terms of NISP) and the number of pits per skeletal element for small (rs = 0.62, p-value = 0.01) and medium bovids (rs = 0.74, p-value = 0.001). However, it is not the case for large bovids (rs = 0.17, p-value = 0.54). It therefore means that the distribution of the tooth pits reflects differential bone preservation for small and medium sized bovids.

Overall, tooth marks are more abundant on long limb bone shafts than ends on small and medium-sized bovids which differs from large-sized bovids, since we find more tooth marks on their long limb bone ends than on their shafts (Table 5).

We measured a total of 64 tooth pits observed on bovid bones from Cooper's D (Table 6; Supplementary Material 5). We compared our data to the measurements obtained from the literature on archaeological and modern assemblages (Fig. 10). We note that carnivore tooth pits are large, with a maximum mean width > 1.5 mm and a maximum mean length > 2 mm for all bovid size classes. For all the bovid size classes, we observe that pits have dimensions close to what we find in some modern spotted hyena or lion bone accumulations.

Discussion

5.1.Which carnivore taxa are involved in the Cooper's D bone assemblage accumulation?

In a previous taphonomic investigations of a large mammal sub-sample from Cooper's D, [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF] suggested that brown hyenas (Parahyaena brunnea) were the most probable accumulated agent. This assumption was based on the high carnivores:ungulates ratio (26%) and the relative high representation of small carnivores (viverrids, mustelids and canids).

Subsequently, [START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF] argued that, based on the attritional mortality profiles, largebodied primates were mostly occupying the cave. However, the dimensions and location of the few carnivore marks observed on primate bones, as well as the presence of eight coprolites, lead the authors to conclude that both leopards and hyaenas could be involved in part of the accumulation and modification of the primate bone assemblages at Cooper's D.

By looking at some general characteristics of the Cooper's D bone assemblage (mainly taxonomy and bone surface modification), it is obvious that carnivores contributed to the taphonomic history of the large mammal assemblage. From a taxonomic point of view, carnivores are well represented at Cooper's, and very diverse, representing the second most abundant mammal order after Cetartiodactyla. The carnivore fauna is composed by both extinct and extant felids, hyenids and canids.

At the Cooper's D site, two extinct felid species are present, Megantereon whitei and Dinofelis aronoki. Several authors have hypothesized that saber-toothed cats participated in the accumulation of the bones of large mammals from the Plio-Pleistocene caves of South Africa [START_REF] Vrba | Some evidence of chronology and palaeoecology of Sterkfontein, Swartkrans and Kromdraai from the fossil Bovidae[END_REF][START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF][START_REF] Brain | Swartkrans. A Cave's Chronicle of Early Man[END_REF][START_REF] Marean | Sabertooth cats and their relevance for early hominid diet and evolution[END_REF]. The false saber-toothed cat Dinofelis (estimated between 155 and 230 kg for the species D. barlowi and D. piveteaui) was probably in competition with the lions (O' Regan and Reynolds, 2009). Nevertheless, it is stated that Dinofelis species were less cursorial predators than modern lions and were probably ambush specialized carnivores [START_REF] Werdelin | A revision of the genus Dinofelis (Mammalia, Felidae)[END_REF]. According to O'Regan and Reynolds (2009) the most reasonable approach given the few individuals found on archaeological sites would be to consider them as solitary animals. The study of their mode of locomotion, mainly carried out via measurements of the bones of their limbs, indicates that the species of the genera Dinofelis and Megantereon occupied the dense forests [START_REF] Marean | Sabertooth cats and their relevance for early hominid diet and evolution[END_REF]. [START_REF] Vrba | The fossil Bovidae of Sterkfontein, Swartkrans and Kromdraai[END_REF][START_REF] Vrba | Some evidence of chronology and palaeoecology of Sterkfontein, Swartkrans and Kromdraai from the fossil Bovidae[END_REF] suggests that most bovids in cave sites in South Africa were too large for leopards to be the source of their accumulation. This same argument has been made by [START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF]. However, current observations by [START_REF] Ruiter | Leopards as Taphonomic Agents in Dolomitic Caves-Implications for Bone Accumulations in the Hominid-bearing Deposits of South Africa[END_REF] have shown that leopards were able to transport and accumulate large animals such as eland. Thus, they consider that the accumulation capacity of leopards has been underestimated and that it is not necessary to invoke the involvement of saber-toothed tigers in order to explain the accumulation of large species in South African caves. Although this is correct, we believe here that their presence in bone assemblages allows us to question their role in the large mammal bone accumulation.

Especially since, as suggested by [START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF], and on the basis of current observations of leopard behavior, it is quite possible to consider that saber-toothed cats, as leopards themselves, may have occupied the caves as a lair for the reproduction or feeding.

Hyenids are also well represented and diverse at Cooper's D. We can notice the presence of the extinct hunting hyena Chasmaporthetes. However, the genera Crocuta and Parahyaenna are more abundant. Also, the only juvenile hyena individual recovered from Cooper's D is attributed to the brown hyena (P. brunnea), based on post-cranial material. It is recognized that hyenas occupy caves with their cubs, and that they frequently die in or near the den [START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF][START_REF] Pickering | Taphonomic interpretations of the Sterkfontein Early Hominid site (Gauteng, South Africa) reconsidered in light of recent evidence[END_REF]2002;[START_REF] Kuhn | Examining criteria for identifying and differentiating fossil faunal assemblages accumulated by hyenas and hominins using extant hyenid accumulations[END_REF]. By principle of parsimony, we consider that the hyenas occasionally came into the cave of Cooper's D. According to [START_REF] Kuhn | Examining criteria for identifying and differentiating fossil faunal assemblages accumulated by hyenas and hominins using extant hyenid accumulations[END_REF], spotted hyena dens are characterized by a carnivore:ungulate ratio of less than 13 %, that of striped hyena over 30 %, and that of brown hyena around 20 %. At Cooper's D, the carnivore:ungulate ratio is exceptionally high, up to almost 37% (Hanon et al., 2022a). In our point of view, this could be a result of a taphonomical palimpsest, in which several carnivore occupations blur the signal. Nevertheless, the presence of coprolites associated with juvenile hyena remains strong evidence for a hyena den [START_REF] Cruz-Uribe | Distinguishing Hyena from Hominid Bone Accumulations[END_REF][START_REF] Pickering | Reconsideration of criteria for differentiating faunal assemblages accumulated by hyenas and hominids[END_REF][START_REF] Kuhn | Examining criteria for identifying and differentiating fossil faunal assemblages accumulated by hyenas and hominins using extant hyenid accumulations[END_REF][START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF]. Furthermore, according to [START_REF] Brugal | Comparative study of bone assemblages made by recent and Pleistocene hyenids[END_REF], Pleistocene hyenas could accumulate larger ungulate carcasses than current felids and hyenas (size class 3 or higher). It seems that felids can also leave digested bone fragments as well as bone cylinders, which makes it difficult to identify with certainty a hyena den [START_REF] Kuhn | Examining criteria for identifying and differentiating fossil faunal assemblages accumulated by hyenas and hominins using extant hyenid accumulations[END_REF]. However, according to the review of all the criteria by Fourvel (2012), it appears that the presence of coprolites associated with strongly digested bones is the only character really indicative of a hyena den. Beyond the current hyenas, several extinct taxa such as the running and hunting hyena Chasmaporthetes or the giant hyena Pachycrocuta were probably able to contribute to the formation of bone assemblage. Nonetheless, the characterization of their assemblage and their ability to occupy a cave can only be speculative.

Cooper's D canids are incredibly abundant and diverse. This is particularly the case for Lupulella mesomelas, the black-backed jackal, which are relatively abundant in the deposit and for the large and robust extinct species Lycaon sekowei preserved at Cooper's D [START_REF] Hartstone-Rose | The Plio-Pleistocene ancestor of wild dogs, Lycaon sekowei n. sp[END_REF]. These canids present at Cooper's D, wild dogs (Lycaon sekowei) and jackals (Lupulella mesomelas), are likely to have participated in the bone accumulation of large mammals. Modern African wild dogs are gregarious hunters, with a body mass ranging from 20 to 25 kg [START_REF] Creel | Communal hunting and pack size in African wild dogs, Lycaon pictus[END_REF]. Although wild dogs' hunting ability is probably correlated with pack size, a single individual appears to be able to hunt and consume prey as large as an adult female kudu [START_REF] Courchamp | Small pack size imposes a tradeoff between hunting and pop-guarding in the painted hunting dog Lycaon pictus[END_REF]. According to the review by Hayward et al., (2006a), the current wild dogs have a preference spectrum for the body masses of their preys of bimodal form, the first peak preferably located between 16 and 32 kg, the second between 120 and 140 kg. Nevertheless, [START_REF] Creel | Communal hunting and pack size in African wild dogs, Lycaon pictus[END_REF] indicate that their major prey are ungulates ranging from 15 to 200 kg. In general, the impala (Aepyceros melampus), the great kudu (Tragelaphus strepsiceros), the bushbuck (Tragelaphus scriptus) and the Thompson's gazelle (Eudorcas thompsonii) are the preferred prey [START_REF] Hayward | Prey preferences of the African wild dog Lycaon pictus (Canidae: Carnivora): ecological requirements for conservation[END_REF]. Very little data is available on the taphonomic signature of wild dog accumulations. They appear to have a limited impact on the bones, with more than 50 % of the appendicular bones showing tooth marks but no more than 10 marks per bones [START_REF] Domínguez-Rodrigo | On meat eating and human evolution: A taphonomic analysis of BK4b (Upper Bed II, Olduvai Gorge, Tanzania), and its bearing on hominin megafaunal consumption[END_REF]. They also produce fractures and consume long limb bone shaft fragments (Fourvel et al., 2018a).

Thus, from a taxonomic point of view, it appears that all felids, hyenids and canids had the ability to contribute to the bone accumulation of Cooper's D. Then, we have to investigate the taphonomic signature of the fauna in order to identify which carnivore taxa were involved in the taphonomic history of the assemblage. Previous skeletal element analysis of bovid specimens indicated that Cooper's D bone assemblage is characterized by a density-mediated attrition (Hanon et al., 2022). That result suggests the possible role of carnivore ravaging process in the skeletal part representation and in situ destruction at Cooper's D [START_REF] Cleghorn | Distinguishing selective transport and in situ attrition: A critical review of analytical approaches[END_REF]. Our results obtained from carnivore ravaging ratio (axial:appendicular), indicate a moderate carnivore ravage. Indeed, Cooper's D appears to be much less ravaged than Swartkrans Members 1 -3 (Table 3), which have been interpreted as both leopard (Member 1) and leopard+hyena (Members 2 and 3) accumulations [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF]. This relatively moderate carnivore ravage observed at Cooper's D is much consistent with both leopard and canid activities rather than hyenas. Thus, Cooper's D bovid bone assemblage is characterized by bone-density mediated attrition, regardless of the bovid size class (Hanon et al., 2022), but also by a relatively moderate carnivore ravage (axial:appendicular ratio). These observations lead us to favor the hypothesis of a post-depositional destruction of bovid skeletal elements rather than carnivore activity.

Through the study of the completeness of the assemblage, we observed a predominance of long bone shaft fragments preserving less than half of their original circumference. This indicates that our assemblage is relatively unbiased by selective retention [START_REF] Marean | Skeletal Element Equifinality in Zooarchaeology Begins with Method: The Evolution and Status of the "Shaft Critique[END_REF][START_REF] Domínguez-Rodrigo | Deconstructing Olduvai: A Taphonomic Study of the Bed I Sites[END_REF]. However, we noted that there is a fewer proportion of long bone shaft (52%) identified for large-sized mammals compared to ends (48%). Moreover, large animals are characterized by a good representation of complete circumference long bone fragments (31%). These results indicate that large mammals tend to be better preserved at Cooper's D which is consistent with our previous taphonomic study which pointed out a bone density-mediated attrition (Hanon et al., 2022). Indeed, it seems that even if our assemblage shows a good level of completeness, it has been largely impacted by post-depositional processes. Our multiple taphonomic analysis of the prey skeletal part representation points out similarity in Cooper's D bone preservation and modern leopard accumulations, regardless of bovid size class. However, three cautionary remarks have to be made at this point. First, the absence of comparative data on the skeletal part composition of an assemblage made by African canids, such as wild dogs. Second, all the modern comparative data are setting in open sites environments comparable with East African sites (Domínguez-Rodrigo and Pickering, 2010). Third, as pointed out before, it is highly probable that our bovid skeletal part representation is the result of post-depositional destruction rather than carnivore activity.

Therefore, skeletal part representation cannot be used alone as a good indicator of the original accumulator agent.

Regarding mortality profiles, [START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF] already show the predominance of adult individuals among the bovid assemblage at Cooper's D. Our results indicate a similarity in the mortality distribution of small-sized bovids (size class 1 and 2) between Cooper's D and large felid accumulations as well as wild dog accumulated assemblage. In contrary, mortality pattern of large-sized bovids from Cooper's D (size class 3 and larger) differs from modern carnivore and natural accumulations. The 'prime adult predominance' pattern is frequently observed in archaeological contexts [START_REF] Bunn | Prey mortality profiles indicate that Early Pleistocene Homo at Olduvai was an ambush predator[END_REF] where it is often associated with anthropogenic activity, especially when the proportion of adults exceeds 70% [START_REF] Stiner | The use of mortality patterns in archaeological studies of hominid predatory adaptations[END_REF][START_REF] Bunn | Prey mortality profiles indicate that Early Pleistocene Homo at Olduvai was an ambush predator[END_REF]. However, adult individuals also exceed 70% of the MNI in modern leopard accumulation (Bunn and Pickering, 2010a). They also dominate in other South African archaeological assemblages (Supplementary Material 3; [START_REF] Vrba | The fossil Bovidae of Sterkfontein, Swartkrans and Kromdraai[END_REF][START_REF] Adams | Taphonomy of the Gondolin GD 2 in situ Deposits and its Bearing on Interpretations of South African Plio-Pleistocene Karstic Fossil Assemblages[END_REF]Fourvel et al., 2018b), whether for small (Kromdraai Mb2 = 43%; Gondolin GD2 = 48%; Sterkfontein Main Quarry = 50%; Swartkrans Mb1 = 57%; Swartkrans Mb2 = 49%) or large-sized bovids (Kromdraai Mb2 = 64%; Sterkfontein Main Quarry = 52%; Swartkrans Mb1 = 60%). Ambush or hunting predators (lion, leopard, probably Megantereon, Dinofelis and Chasmaporthetes for the largest preys) also tend to create profiles similar to the structures of living populations, but with a greater representation of adult individuals [START_REF] Stiner | The use of mortality patterns in archaeological studies of hominid predatory adaptations[END_REF]. The bone density mediated attrition observed at Cooper's D, associated with post-depositional bone surface modifications (e.g. manganese coating, decalcification, abrasion and corrosion), indicate that most of the fragile juvenile bones could have been discarded by post-depositional processes. It is also highly probable that mortality profiles from other South African cave sites have been driven by post-depositional processes rather than carnivore and hominin activities.

From the observation of bone surface modifications, it is convincing that carnivores contributed to the accumulation and history of bone assemblage in large mammals at the Cooper's D site. Indeed, more than 5% of the total NISP bear marks attributable to carnivores, and up to 11% of the NISP if we exclude dental material. It is highly probable that the small percentage of carnivore marks is the result of the important presence of manganese coating on the bone surface (Hanon et al., 2022a), which is directly correlated to post-depositional processes and altered the reading of most of the cortical surfaces. Our reanalysis of the assemblage indicates that among specimens bearing carnivore tooth pits, we observed that most of them are attributed to axial (28 to 45% NISPtooth-marked) or lower limb bones (> 26 to 32% NISPtooth-marked), regardless of the bovid size class. Concerning long limb bones, tooth marks (scores + pits) are found more frequently on metapodials shafts as well as on radio-ulna shafts.

Moreover, among limb bones, tooth marks are more abundant on shafts, except for large-sized bovids. On one hand, the presence of tooth marks on both axial bones and metapodials is a characteristic of hyenid scavenging damage [START_REF] Pobiner | A Taphonomic Perspective on Oldowan Hominid Encroachment on the Carnivoran Paleoguild[END_REF]Domínguez-Rodrigo and Pickering, 2010). On the other hand, the scarcity of tooth marks and their presence on intermediate limb bone shaft fragments can be attributed to felid type damage. However, we also show that the distribution of tooth marks along bone elements reflects the differential preservation. Then, it is difficult to make assumptions based only on tooth mark distribution.

Regarding to tooth pit dimensions measured on the small (size class I) and large (size class III and IV) bovids at Cooper's D, although they fall within the range of variation of many modern carnivore taxa (lion, leopard, cheetah, spotted hyena, jackals). According to [START_REF] Selvaggio | Identifying the Involvement of Multiple Carnivore Taxa with Archaeological Bone Assemblages[END_REF], a greater degree of variation than the overall dimensions of the cupules of modern carnivores would indicate the action of several taxa. However, Domı ńguez-Rodrigo and Piqueras (2003) demonstrated that there is no direct link between the strong variation in the length:width ratio of the pits and the number of taxa involved in the accumulation of a bone assemblage. According to [START_REF] Andrés | A study of dimensional differences of tooth marks (pits and scores) on bones modified by small and large carnivores[END_REF], this variation could be explained by the small sample size. We can however observe that the leopard (average ratio = 1.83, σ = 0.73), which presents an average ratio close to that of the large sized mammals from Cooper's D (average ratio = 1.65, σ = 0.77), also has a very strong variation like the Dinofelis genus (mean ratio = 2.84, σ = 0.7). However, the latter has a much higher average ratio than the leopard and the pits observed on the surface of large sized mammal bones from Cooper's D. Although the leopard sometimes hunts and consumes large bovids (kudu, eland or waterbuck), most of its diet consists of small to medium prey [START_REF] Pienaar | Predator-prey relationships amongst the larger mammals of the Kruger National Park[END_REF][START_REF] Ruiter | Leopards as Taphonomic Agents in Dolomitic Caves-Implications for Bone Accumulations in the Hominid-bearing Deposits of South Africa[END_REF]. According to data collected by [START_REF] Brain | The Hunters or the Hunted? An Introduction to African Cave Taphonomy[END_REF], size II antelopes represent between 44.8 to 83.1 % of the leopard's diet, against 8.6 to 26.2% for those of size III. The carnivore pits observed on the surface of the bones of medium-sized mammals (size class II) of Cooper's D are on average smaller dimensions than those observed on small and large mammals. It should be noted that the results obtained for medium-sized mammals are close to those obtained for medium-sized mammals observed in Swartkrans member 3. Pickering et al (2004c) consider that they have were mainly accumulated by leopards, unlike size III mammals, which have been accumulated by several different taxa of carnivores (large canids, spotted hyena and lion).

Despite the difficulty of the identification of carnivore taxa using taphonomic modifications [START_REF] Selvaggio | Identifying the Involvement of Multiple Carnivore Taxa with Archaeological Bone Assemblages[END_REF], we attempt to discuss which carnivore taxa could be responsible for the accumulation of ungulate at Cooper's D. Hyenas activity, and particularly brown hyena (Parahyaena brunnea), is supported by the presence of juvenile individuals, bone surface modifications, tooth pits dimension, the presence of some bone cylinder and by the coprolites [START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF]. However, based on the current evidence, we can argue that large felids such as leopard and extinct large felids, also contributed to the accumulation, at least for a part of the ungulate remains, if is not for the main part. This is notably corroborated by the abundance of felid remains (de [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF][START_REF] O'regan | Felidae from Cooper's Cave, South Africa (Mammalia: Carnivora)[END_REF], the skeletal part representation, the bovid mortality profiles, bone surface modifications and the variation of tooth pit dimensions.

It is important to note that the involvement of canid taxa cannot also be excluded for now.

In particular, a diet overlap has been demonstrated between black-backed jackals (Lupullela mesomelas) and brown hyenas (Parahyaena brunnea) as they usually are in competition for carcass scavenging [START_REF] Merwe | An Assessment of Diet Overlap of Two Mesocarnivores in the North West Province, South Africa[END_REF][START_REF] Yarnell | The Influence of Large[END_REF]. Because of the important presence of Lupullela, and canids in general, at Cooper's D, it is therefore expected that they contributed to the accumulation or the modification of the bone assemblage. Moreover, based on the faunal list and taphonomic alterations, [START_REF] Campmas | Which predators are responsible for faunal accumulations at the Late Pleistocene layers of El Harhoura 2 Cave (Témara, Morocco)[END_REF] and [START_REF] Campmas | Co-évolution Hommes-Canidés en Afrique du Nord-Ouest : une longue histoire[END_REF] identified several north African Pleistocene sites as the result of large canid activity. For the future, more attention should be given to the Canid assemblage in order to identify if they play a role into the accumulation of South African fossil cave sites.

In summary, we argue that large felids (specifically leopard) should be regard as the main accumulating agent of the bovid bone assemblage at Cooper's D. Hyenas (spotted and brown hyenas), and probably canids, also contributed significantly to the constitution of the assemblage as secondary agent, mostly through scavenging.

5.2.Hominin and carnivore contributions at Cooper's D

After Sterkfontein (Member 5 East Oldowan, Name Chamber; [START_REF] Pickering | Taphonomic interpretations of the Sterkfontein Early Hominid site (Gauteng, South Africa) reconsidered in light of recent evidence[END_REF][START_REF] Val | The macrovertebrate fossil assemblage from the Name Chamber, Sterkfontein: taxonomy, taphonomy and implications for site formation processes[END_REF] and Swartkrans (Members 1 -3; [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF]), Cooper's D represents only the third Early Pleistocene site in South Africa that provide hominin remains (NISP = 7; [START_REF] Ruiter | New Australopithecus robustus fossils and associated U-Pb dates from Cooper's Cave (Gauteng, South Africa)[END_REF] associated with stone tool industry (n = 49; [START_REF] Sutton | Early Pleistocene stone artefacts from Cooper's cave, South Africa[END_REF] and butchery marks (NISP = 31;[START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF]. It makes this site a unique case for studying hominin and carnivore respective contribution to the bone assemblage.

In this study, we noticed the absence of hominin and carnivore marks co-occurrence on large mammal bones at Cooper's D. Moreover, we observe the presence of tooth marks preferentially on axial skeleton and on lower limb bones (attributed to hyenid-like scavenging damage) and less importantly on intermediate and upper limb bones (attributed to felid-like kill damage).

Whatever from who hyenas obtain their carcassesnatural death, felids or hominins killsit appears that carnivores did have early access to bovid carcasses at some point. Nevertheless, [START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF] describe the presence of hominin butchery marks (cut and percussion) on ungulate bones from all size classes and note the absence of carnivore and hominin marks cooccurrence on bone surfaces. By crossing these results, we can argue that Cooper's D large mammal accumulation is the result of a relatively independent taphonomic signatures of both carnivores and hominins. This hypothesis of distinct events of butchery and carnivore activity has been previously proposed in other African Plio-Pleistocene sites, such as Swartkrans Members 1 -3 [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF], FLK "Zinj", Olduvai (Domínguez-Rodrigo, [START_REF] Domínguez-Rodrigo | Deconstructing Olduvai: A Taphonomic Study of the Bed I Sites[END_REF] or at the 'Grotte des Rhinocéros', Morocco [START_REF] Daujeard | Earliest African evidence of carcass processing and consumption in cave at 700 ka, Casablanca, Morocco[END_REF].

We agree with [START_REF] Egeland | Disentangling Early Stone Age palimpsests: determining the functional independence of hominidand carnivore-derived portions of archaeofaunas[END_REF] that this observation does not necessarily imply that the hominin-carnivore competition was inexistent. Indeed, these authors observed an independently derived hominin and carnivore component of bone accumulation at several Early Pleistocene sites in Africa, especially at Swartkrans Member 3. The capacity of hominins to avoid intense competition and to process a complete exploitation of ungulate carcasses can then be explains by different non-exclusive hypotheses. ( 1) Hominins could have occupied environments setting in a low competition context such as tree-covered woodland-like habitats. Indeed, experimental studies point out that long limb bone refuses can remain undisturbed for several days (up to 16 days) in a riverine woodland [START_REF] Blumenschine | An experimental model of the timing of hominid and carnivore influence on archaeological bone assemblages[END_REF]. Moreover, complete limb bones are more frequently encountered in low competition areas [START_REF] Blumenschine | A landscape taphonomic model of the scale of prehistoric scavenging opportunities[END_REF].

In this case, it could be easy for hominins to intensively exploited a carcass without being preoccupied by the presence of scavengers. (2) Hominins could have developed specific foraging strategies in order to reduce competition, such as body part transport in hiding places [START_REF] Blumenschine | Hominid carnivory and foraging strategies, and the socioeconomic function of early archaeological sites[END_REF], refuge or "central places" model [START_REF] Isaac | Bones in contention: competing explanations for the juxtaposition of early Pleistocene artifacts and faunal remains[END_REF]. (3) The hominin toolkit or technological advanced could have played a role in their ability to avoid carnivores. For example, the use and domestication of fire could provide a "shift in the balance of power", allowing an optimal exploitation of the environments by hominins without the carnivore competition pressure [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF]. As indicated by [START_REF] Egeland | Disentangling Early Stone Age palimpsests: determining the functional independence of hominidand carnivore-derived portions of archaeofaunas[END_REF], the geological context of South African caves limited our ability to conclude about the origin of independent hominins and carnivores taphonomic signatures. As in Swartkrans Member 3, the Cooper's D faunal assemblage derives from decalcified sediments which implies a secondarily deposit of the material coming from the calcified bone breccia. Hanon et al. (2022b) has showed through the analysis of bovid assemblage from Cooper's D that the environment surrounding the cave was probably a composite of grassland and sparse covered habitat close to a water source which is consistent with the first scenario. Moreover, the karstic environment of the Sterkfontein Valley provides an important source of hiding places for food storage making the second hypothesis plausible.

In South Africa, evidence for a control of fire by hominins appears around 1 Ma at Swartkrans Member 3 [START_REF] Brain | Evidence from the Swartkrans cave for the earliest use of fire[END_REF][START_REF] Pickering | What's new is old: Comments on (more) archaeological evidence of one-million-year-old fire from South Africa[END_REF] and Wonderwerk [START_REF] Berna | Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa[END_REF]. It has been proposed that "the mastery of fire provided a "shift in the balance of power", allowing hominids to carry out activities in the cave for the first time unmolested by predators", and that the shift occurred at the Swartkrans Member 3 [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF].

However, based on the study of sub-samples from Swarktrans Members 1-3, [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF] has showed that there are no significant differences between large mammal exploitation by hominins between the three deposits. Then, for these authors, the control of fire did not seem to provide an important increase of success in carcass foraging. Moreover, the toolkit of hominins at Cooper's D is mainly composed by quartzite flakes and cores [START_REF] Sutton | Early Pleistocene stone artefacts from Cooper's cave, South Africa[END_REF], which are unlikely to be used in the primary acquisition of ungulate carcasses, although they can be used to cut pieces of carcasses for transport. Keeping a parsimonious approach of these observations, we argue that the two first hypotheses, which are the low competition environment and the adaptation of hominin foraging strategies in order to avoid competition, are the most probable explanation for the independent taphonomic signals of both hominins and carnivores observed at Cooper's D.

Conclusion

In this paper, we provided the first taphonomic investigation of carnivore and hominin contributions at the Early Pleistocene site of Cooper's D. The aim was to explore the potential role of carnivores in the origin of large mammal bone accumulation from Cooper's D and to characterize their relationship with hominins. Previous taphonomic studies permit to identified mainly hyena, and possibly leopard, as the main accumulator agents of the large mammal assemblage of Cooper's D [START_REF] Val | New taphonomic analysis of large-bodied primate assemblage from Cooper's D, Bloubank Valley, South Africa[END_REF][START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF]. Our results presented here permit to better understand the taphonomic history of this assemblage. Based on taxonomic composition, skeletal part representation and bone surface modifications, it appears that leopards, or large felids, are the main accumulator agents of all-sized bovids. However, careful investigation of the faunal list, the presence of coprolites and bone surface modifications also permit to show the independent impact of both large canids and hyenids.

Compared with other Plio-Pleistocene archaeological assemblages, we argue that carnivores and hominins did not interact directly at Cooper's D site but mostly visited the cave alternatively. Thus, our work has demonstrated the role of three major taphonomic agents in the bone accumulation of Cooper's D. The first is the leopard, or by extension the big cats. Indeed, we cannot rule out with certainty the role that saber-toothed tigers may have played.

The seconds are the hyenas, probably the brown hyena (Parahyaena brunnea), and canids, which accumulated and scavenged some carcasses and even briefly occupied the cave. Finally, hominins constitute the third agent, but the time of access to the carcass remains uncertain for now [START_REF] Hanon | New evidence of bone tool use by Early Pleistocene hominins from Cooper's D, Bloubank Valley, South Africa[END_REF]. The large mammal assemblage of Cooper's D represents a taphonomic palimpsest corresponding to a mixed accumulation by carnivores and hominins.

Then, we observe that both carnivore and hominins had a primary access to large mammal carcasses. This interpretation of our results implies that carnivore and hominins were not interdependent for each other. In other words, competition for food supply was not important enough to avoid primary access. Our results are consistent with previous conclusions drawn about hominin subsistence behaviours observed at other Plio-Pleistocene African deposits -Swartkrans Members 1 -3, South Africa [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF]; FLK "Zinj", Olduvai, Tanzania (Domínguez-Rodrigo, [START_REF] Domínguez-Rodrigo | Deconstructing Olduvai: A Taphonomic Study of the Bed I Sites[END_REF]BK4b, Olduvai, Tanzania (Domínguez-Rodrigo et al., 2014);FwJj14A, FwJj14B and GaJi14, Koobi Fora, Kenya (Pobiner et al., 2008); Konso, Ethiopia [START_REF] Echassoux | Comportements de subsistence et modifications osseuses à l'aube de l'Acheuléen à Konso, Ethiopie[END_REF]; Kanjera, Kenya [START_REF] Ferraro | Earliest archaeological evidence of persistent hominin carnivory[END_REF]; El-Kherba, Ain Hanech, Algeria [START_REF] Sahnouni | The first evidence of cut marks and usewear traces from the Plio-Pleistocene locality of El-Kherba (Ain Hanech), Algeria: implications for early hominin subsistence activities circa 1.8 Ma[END_REF]; Ain Boucherit, Algeria [START_REF] Pickering | Testing the "shift in the balance of power" hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene[END_REF].

  are mainly represented by adult individuals. However, we were able to identify postcranial remains of juvenile individuals in both Felidae and Hyenidae. The Felidae are the most represented but also the most diverse carnivores at the Cooper's D site. In terms of MNI, we observe that the Panthera genus (MNI = 6), especially leopard (Panthera pardus, MNI = 2), is well-represented within the assemblage. Both the false sabertoothed cat Dinofelis (MNI = 4) and Megantereon are also well represented (MNI = 4). The other taxa are represented by only one individual. Hyenids are very diverse at Cooper's D. Indeed, Kuhn et al. (2017) identify a minimum of 5 genera and 6 species. We can observe that the brown hyena (Parahyaena brunnea) is represented by 3 individuals, including one juvenile. The extinct species Crocuta ultra is represented by 2 individuals. All the other taxa (Chasmaporthetes, Crocuta crocuta, Hyaena, Proteles) are represented by a single individual. The Canidae are represented by 4 genera (Lupulella, Lycaon, Vulpes and Otocyon) and 4 species, 216 remains, representing a minimum of at least 17 individuals (Hartstone-Rose et al.

Table 4 .

 4 Distribution of carnivore tooth marks (punctures, pits, furrowings and scorings) according to each bovid size class. Data represent NISP with at least one carnivore modification. Numbers in brackets represent percentage of the total NISP modified by carnivores. Table 5. Distribution of carnivore tooth marks (punctures, pits, furrowings and scorings) according to their location on each bovid limb bone part. Data represent NISP with at least one carnivore modification. Numbers in brackets represent percentage of the total NISP modified by carnivores.Table 6. Summary statistics of tooth pits dimensions according to the ungulate size classes from Cooper's D.

Figure 1 .

 1 Figure 1. A: Location of Cooper's Cave and other Early Pleistocene main sites in South

Figure 2 .

 2 Figure 2. Representation of the different large carnivore families and genera at Cooper's D.

Figure 3 .

 3 Figure 3. Measure of the completeness of the Cooper's bone assemblage. (A) Percentage of

Figure 4 .

 4 Figure 4. Skeletal part representation (MNE) according to bovid size class at Cooper's D.

Figure 5 .

 5 Figure 5. Correspondence analysis conducted on bovid remains (MNE) from Cooper's D

Figure 6 .

 6 Figure 6. Ternary graphs of mortality profiles for each bovid size class at Cooper's D. (A)

Figure 7 .

 7 Figure 7. Bone surface modifications attributed to carnivore activity observed on large

  Figure 3.

  Figure 4.

  Figure 8.

Figure 9 .

 9 Figure 9.

Table 1 .

 1 List of carnivore taxa identified at Cooper's D (after[START_REF] Hanon | Comportements de subsistance des hominines du Pléistocène inférieur d'Afrique du Sud : analyse archéozoologique du site de Cooper's D (Bloubank Valley)[END_REF].

Table 2 .

 2 Large carnivore mortality profiles from Cooper's D.

Table 3 .

 3 Axial:Appendicular ratio values (in MNE) obtained for each bovid size class at Cooper's D. Comparative data for Swartkrans from

Table 5 .

 5

	1095
	1096
	1097
	1098
	1099
	1100
	1101
	1102

Table 6 .

 6

	Part	Small-sized bovids	Medium-sized bovids	Large-sized bovids
	Shafts	31 (58)		84 (64)		28 (40)
	Ends	22 (42)		47 (36)		42 (60)
	Total	53 (100)		131 (100)		70 (100)
	1103
	Sample		n	Mean ratio	s.d.	Mean length	s.d.	Mean width	s.d.
	Small-sized bovids	23	1.66	0.30	2.64	1.17	1.62	0.73
	Medium-sized bovids	23	1.41	0.40	3.35	1.83	2.44	1.40
	Large-sized bovids	18	1.65	0.77	4.10	2.58	2.43	1.05
	1104
	1105

Acknowledgments

We thank Bernhard Zipfel from University of the Witwatersrand as well as Stephany Potze, Mirriam Tawane, Heidi Fourie and Lazarus Kgasi from the Ditsong Museum, Pretoria, for access to collections. C. S. acknowledges the funding contribution of the Centre of Excellence in Palaeosciences (CoE-Palaeo) and the Palaeontological Scientific Trust (PAST). R. H. would like to acknowledge the ATM MNHN "Paranthropus Diet. Régime alimentaire et comportement de subsistance des Paranthropes sud-africains" (resp. S. Prat) and the UMR 7194/MNHN for the funding support. RH would like to address a special thanks to Camille Daujeard for her comments on an early draft of the paper.

 [START_REF] Sahnouni | 1.9-million-and 2.4-million-year-old artifacts and stone tool-cut marked bones from Ain Boucherit, Algeria[END_REF]; 'Grotte des Rhinocéros', Morocco [START_REF] Daujeard | Earliest African evidence of carcass processing and consumption in cave at 700 ka, Casablanca, Morocco[END_REF] Crushed pit observed on a thoracic vertebra of a medium-sized bovid (CD.6903). D: Crushed pit on a left scapula proximal fragment of a medium-sized bovid (CD.8188). E: Perforation on a complete proximal phalanx of a small-sized bovid (CD.3336). F: Perforation observed on an indeterminate fragment (CD.330). Photos and measurements taken with a Dino-Lite (AD7013MTL) and the DinoCapture 2.0 software. [START_REF] Selvaggio | Identifying the Involvement of Multiple Carnivore Taxa with Archaeological Bone Assemblages[END_REF][START_REF] Domı Ńguez-Rodrigo | The use of tooth pits to identify carnivore taxa in tooth-marked archaeofaunas and their relevance to reconstruct hominid carcass processing behaviours[END_REF]Pickering et al., 2004a).


Carlos Canudas-De-Wit

Martin Rodriguez-Vega

Giovanni De Nunzio

Bassel Othman

A new model for electric vehicle mobility and energy consumption in urban traffic networks

Keywords: Urban mobility, Electric vehicles, Energy requirements

This paper introduces a new model for electric vehicle mobility and energy consumption in urban traffic networks. The model couples the vehicle mobility described by a set of ODEs over a graph capturing the Origin-destination motion for urban networks,and the energy consumption associate to this mobility patterns. This model is illustrated in a simple pedagogic example showing its capabilities, such as keeping track of the vehicle state of charge, current energy and available storage.

INTRODUCTION

As concerns for environmental protection become a major concern, Electric Vehicles (EVs) have started to rise as one of the main components of sustainable traffic systems in cities worldwide. Indeed, some countries have started to incorporate plans to phase-out conventional fuel vehicles in the following years, in efforts to reduce carbon emissions. However, this shift towards an electrified traffic network implies several challenges that need to be solved for EVs to become mainstream. From the consumer side, one of the most common complaints about EVs is the lack of sufficient charging stations so that they can conveniently have their day-to-day life. From the side of city officials and stakeholders, EVs could have a large impact on the power network infrastructure by overloading congested nodes, but at the same time, EVs can be actively used to benefit the power network if Vehicle-to-Grid connections become standard. Initiatives in that directions have been already taken in cities like Utrecht, which has become a proving ground for the bidirectionalcharging techniques that have the rapt interest of automakers, engineers, city managers, and power utilities the world over (see https://spectrum.ieee.org/vehicle-to-grid)

To be able to address these problems, it is first needed to model the power needs and energy consumption of EVs in time and space, which are linked to the mobility patterns of people in urban areas as they go through their regular lives. In this paper, we propose a model that couples urban human mobility, the separation of people flows into several transportation modes including EVs, and an energy model, such that a holistic view of EVs can be given. The model is described and instantiated using a simple network of only two nodes, however, the model is general and applicable to any dimension. In simulations, we show the evolution of people flows, population, power losses, current energy and available storage in each location.

METHODOLOGY

To understand the energy needs and effects of a given penetration rate of EVs, we must first understand the space-and-time-dependent mobility patterns of people in an urban area. For this purpose we consider the mobility model first proposed in [START_REF] Niazi | Optimal Control of Urban Human Mobility for Epidemic Mitigation[END_REF], which considers the mobility between two location types: origins and destinations. The former corresponds to areas where people reside, whereas the latter corresponds to locations that people visit during the day for different activities such as work, education, leisure, commerce, etc. Consider the simple example in Fig. 1 consisting of only one origin (node 1) and one destination (node 2). The mobility model allows to describe the evolution of the population in each node N 1 (t), N 2 (t), and the flows of people between them at each time. The model is based in a set of coupled conservation Ordinary Differential Equations (ODEs) of the form

N 1 (t) N 2 (t) φ 1,2 (t) 1 , v 1 φ 2,1 (t) 2 , v 2
Ṅ1 (t) = φ 2,1 (t) -φ 1,2 (t) , Ṅ2 (t) = φ 1,2 (t) -φ 2,1 (t) (1)
where the parameters i and v i (i = 1, 2) describe the distance and average speed of each trajectory between the nodes, and φ 1,2 is the flow (people per hour) going from node 1 to node 2. This flow is defined as

φ 1,2 (t) = min{D 1,2 (t), S 2 (t)} (2)
where the Demand of the origin 1 to the destination 2 D 1,2 is given by

D 1,2 (t) = δ 1,2 (t)M 1,2 (3)
where δ 1,2 (t) ∈ [0, 1] is called the demand gating function and describe the time window during the day where the population start to leave to destination. M 1,2 is the number of people that want to go from 1 to 2 during the day. Similarly, the Supply of node 2 S 2 (t) is given by

S 2 (t) = ψ 2 (t)φ max 2 if N 2 (t) < N max 2 0 else (4)
where ψ 2 (t) ∈ [0, 1] is the supply gating function indicating the time window where destination is available during the day. δ 1,2 (t) and ψ 2 (t) can be different during the working days and the weekends. N max 2 is the capacity of node 2, and φ max 2 is the maximum inflow to node 2. The flow from node 2 to 1 φ 2,1 is defined analogously. Although here we only describe the equations for 2 nodes, this model is applicable to any number of origin and destination nodes. An extended version of the model and its application, parameter calibration, and discretization strategy for the case of the city of Grenoble in France can be found in [START_REF] Pratap | Where , when and how people move in large-scale urban networks : the Grenoble saga[END_REF].

To use the information regarding the mobility flows for the case of EVs, it is required to determine what is the proportion of people making each trip using a private car, public transport, cycling, walking, etc. This problem is known as the modal choice (or mode choice) analysis, for which there is a lot of interest and attention in the literature, see of instance [START_REF] Bouscasse | A new family of qualitative choice models: An application of reference models to travel mode choice[END_REF] and [START_REF] Mondal | A spatial rank-ordered probit model with an application to travel mode choice[END_REF]. We consider in this work the well-known logit model, which computes the probability that a person uses their private vehicle as

p car (x, β 1 , . . . , β m ) = 1 1 + m n=1 exp(β n • x) (5)
where x ∈ R q are descriptor variables related to the trip properties (traveling time per mode, distance, trip cost per mode, etc.), β n ∈ R q (n = 1, 2, . . . , m) are mode-dependent parameters for each of the other transport modes (public transport, bicycle, etc.), and m is the number of modes other than the private car. For real applications, parameter calibration is done using data from public household surveys.

Once the number of cars doing each trip is known, the corresponding number of EVs can be computed using the penetration rate η EV . Thus, we can describe the number of EVs at node 1 (N EV 1 ) as

Ṅ EV 1 (t) = φ EV 2,1 (t) -φ EV 1,2 (t) (6)
where

φ EV 1,2 (t) = η EV p car (x 1,2 , β 1 , . . . , β m )φ 1,2 (t). (7)
The flow φ EV 2,1 and the number of EVs at node 2 N EV 2 are defined using analogous equations with the corresponding changes in subindices.

Furthermore, it is required to model available electric vehicle energy and power consumption in each location. We denote the average state of charge of vehicles at node 1 as ε 1 ∈ [0, 1], and the average battery net capacity of all EVs in the network as C (kWh). The energy in each node is then defined as

E 1 (t) = CN 1 (t)ε 1 (t) , E 2 (t) = CN 2 (t)ε 2 (t). ( 8
)
The evolution of the energy in each location can also be described using a conservation ODE,

Ė1 (t) = P in 1 (t) -P out 1 (t) , Ė2 (t) = P in 2 (t) -P out 1 (t). ( 9
)
where P in i (kW) is the power flow entering node i, and P out i (kW) is the power flow exiting node i, for i = 1, 2. As EVs consume energy by traveling, the power exiting one node is not the same as the power entering the other. The power losses in each link are defined as

∆P 1,2 = P out 1 -P in 2 , ∆P 2,1 = P out 2 -P in 1 . (10)
The relation between the power flows, power losses and energy are visualized in Fig. 2. The power flow leaving each node can be described in terms of the vehicle flow and state of charge,

E 1 (t) E 2 (t) P out 1 (t) P in 2 (t) ∆P 1,2 (t) P out 2 (t) P in 1 (t) ∆P 2,1 (t
P out 1 (t) = Cφ EV 1,2 (t)ε 1 (t) , P out 2 (t) = Cφ EV 1,2 (t)ε 2 (t). (11)
To describe the power losses in each link, we consider first the energy lost per vehicle by traversing the link. Let F (v) be the force applied by each vehicle to maintain a constant speed v against friction, air drag, and other forces. Multiple definitions for this force can be obtained (see [START_REF] Othman | Ecological traffic management: A review of the modeling and control strategies for improving environmental sustainability of road transportation[END_REF])), and a common form can be written as

F (v) = (sin θ + µ cos θ)mg + βv + 1 2 ρ air Ac d v 2 (12)
where the coefficients m and A are the mass and cross-sectional area of the vehicle, g is the acceleration due to gravity, θ is the road inclination, µ and c d are the friction and air drag coefficients. Thus, the energy lost by each vehicle is the work done by this force during the trip length , which becomes F (v) . Additional terms can be added, such as to model the capacity of EVs to recover energy while going downhill. Thus, the power loss in each link is

∆P 1,2 (t) = φ EV 1,2 (t)F (v 1 ) 1 , ∆P 2,1 (t) = φ EV 2,1 (t)F (v 2 ) 2 . ( 13
)
Using the previous equations, the state of charge dynamics for node 1 can be expressed as

ε1 (t) = φ EV 2,1 (t) N 1 (t) ε 2 (t) -ε 1 (t) - F (v 2 ) 2 C , (14)
and an analogous expression for the state of charge in node 2 ε 2 by switching the corresponding sub indices. Note that the mobility and energy models are coupled in a cascading way: the mobility model can be run independently, and the energy model requires as inputs the population at each node and the arc flows. Although here we have focused on simplicity in a simple case with two nodes, this model can be extended for any number network size, where each node has two equations, one for the population and the other for the state of charge.

RESULTS AND DISCUSSION

To showcase the model, we consider the simple case with one origin and one destination of Figs. 1 and2. In this scenario, vehicles go from origin to destination around 8h00, and return to their homes at 18h00. The simulation is done between 5h00 and 22h00, with a time step of 30 seconds. The initial conditions are N 1 (0) = 100, N 2 (0) = 0, ε 1 (0) = 1, ε 2 (0) = 0. The battery capacity is set to C = 50kW h, and the energy losses at the arcs are set as F (v 1 ) 1 /C = 0.2, and F (v 2 ) 2 /C = 0.1. For simplicity, we consider only the movement of EVs.

The vehicle mobility is shown in Fig. 3, where the left plot shows the population N (t) of each node during each moment of the day, and the right plot shows the flow of vehicles moving in each direction according to the specified profile. Figure 4 shows the energy profiles at each location during the day. The left plot shows the energy held by the EVs in each location. This is shown by the width of the corresponding colored region on the y-axis: e.g. at 6h00, all energy is in the origin node, as seen in the dark green color in Fig. 4 going from 0 to 5000 kWh. As vehicles move, the dark green area decreases while the light green area increases, as energy moves towards the destination. Some energy is lost as shown by the yellow area. At 10h00, the light green region goes from 670 to 4500 kWh, so the energy at the destination is 3830 kWh. Finally, after the vehicles come back to their origin, no more energy is stored in the light green region, and the energy has either return to the dark green region or has been lost in transit.

The plot on the right of Fig. 4, shows the available storage of EVs, calculated as CN i (t)(1-ε i (t)). This can be interpreted as how much energy is needed to fill the battery of all EVs in each location Figure 4: Energy consumption of EVs during one day. to 100%. Thus, at 6h00 there is no available storage as all vehicles are at 100%. As move to the destination, there is some storage as energy has been depleted. However, there is available storage at the origin as the vehicles that remained are still at 100%. Finally, at the end of the day, all available storage is at the origin.

CONCLUSIONS AND PERSPECTIVES

In this work, we have introduced a new model for the mobility and energy consumption of electric vehicles in the case of urban networks. This model takes into account the mobility patterns of people going to different destination categories, multiple modes of transport, and the energy losses in transport by the EVs. The model was exemplified using a simple network of one origin and one destination. This type of model is required to study the number, location, and power definition of charging stations, as well as to understand the possible space-and-time-dependent effect of EVs in the power network.

For future work, we are currently working on the coupling with a charging station model, and the parameter estimation for more complex networks such as the case of the city of Grenoble, France. This will be used to study the effect of varying penetration rates of EVs in the city, and their effect on the power infrastructure.

Figure 1 :

 1 Figure 1: Simple network example: mobility between one origin and one destination

Figure 2 :

 2 Figure 2: Energy balance between origin and destination.

Figure 3 :

 3 Figure 3: Mobility of electric vehicles during one day.

Acknowledgements

This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement 694209).