Mobility, competition, and Plio-Pleistocene hominid foraging groups

Evidence for carcass access times and levels of early hominid mobility is synthesized using studies of carnivore ethology and theories of interspecific competition to arrive at tentative conclusions about the organization of Plio-Pleistocene hominid foraging groups. The model presented suggests that group foraging tactics, in combination with high mobility, are central to successful confrontational scavenging (interference competition), whereas individual foraging tactics and high mobility are central to successful nonconfrontational scavenging (exploitative competition). In contrast, group or individual foraging tactics and low mobility characterize the acquisition of fresh carcasses in low-competition contexts. Individual foraging tactics and low mobility are employed in response to extreme competition over marginal resources. Preliminary tests with data from Bed I Olduvai Gorge and Koobi Fora suggest that Plio-Pleistocene hominids, like other large-bodied predators, employed flexible foraging tactics involving changes in group size and levels of mobility to gain access to carcasses in both low-and high-competition contexts.     

Hunting and Scavenging by Early Humans: The State of the Debate

During the last 25 years, there has been a shift towards the belief that early humans were scavengers instead of hunters. This revisionist interpretation has brought a reconciliation with the Darwinian paradigm of gradual progressive evolution that has traditionally guided (and very often, misled) an important part of anthropological thinking. However, empirical support for the scavenging hypothesis is still lacking. Recent data based on bone surface modifications from archaeological faunas suggest, in contrast, that hominids were primary agents of carcass exploitation. Meat seems to have been an important part of Plio-Pleistocene hominid diets. Passive scavenging scenarios show that this kind of opportunistic strategy cannot afford significant meat yields. Therefore, the hunting hypothesis has not yet been disproved. This makes the hunting-and-scavenging issue more controversial than before, and calls for a revision of the current interpretive frameworks and ideas about early human behavior.     

The oldowan reassessed: A close look at early stone artifacts

Early Stone Age assemblages called “Oldowan” and early “Developed Oldowan” are discussed, based on the results of a long-term study of Plio-Pleistocene sites at Koobi Fora, Kenya and an extensive experimental research program of replicating and using early stone artifact forms. Five major conclusions are drawn from this investigation: (1) many Oldowan core forms (“core-tools”) are probably simple by-products of flake manufacture rather than representations of stylistic norms; (2) flakes and retouched flakes - were essential tools in Oldowan technology, particularly for activities involving cutting; (3) this simple technology does not necessarily reflect the cognitive abilities of the early hominids that manufactured the stone artifacts; (4) there is evidence to show that Oldowan technology can be viewed as a simple curated one, in which raw material was intentionally carried from place to place for future use; (5) early hominid populations that made and used stone implements were not necessarily dependent upon them for their survival.     

Identifying the Involvement of Multiple Carnivore Taxa with Archaeological Bone Assemblages

Information on the number of carnivore taxa that were involved with archaeological bone assemblages is pertinent to questions of site formation, hominid and carnivore competition for carcasses and the sequence of hominid and carnivore activity at sites. A majority of early archaeological bone assemblages bear evidence that both hominids and carnivores removed flesh and/or marrow from the bones. Whether flesh specialists (felids) or bone-crunchers (hyaenas), or both, fed upon the carcasses is crucial for deciphering the timing of hominid involvement with the assemblages. Here we present an initial attempt to differentiate the tooth mark signature inflicted on bones by a single carnivore species versus multiple carnivore taxa. Quantitative data on carnivore tooth pits, those resembling a tooth crown or a cusp, are presented for two characteristics: the area of the marks in millimetres, and the shape as determined by the ratio of the major axis to the minor axis of the mark. Tooth pits from bones modified by extant East African carnivores and latex impressions of tooth pits from extinct carnivore species are compared to those in the FLK Zinjanthropus bone assemblage. Data on tooth mark shape indicate greater variability in theZinj sample than is exhibited by any individual extant or extinct carnivore species in the comparative sample. Data on tooth mark area demonstrate that bone density is related to the size of marks. Taken together, these data support the inference that felids defleshed bones in the Zinj assemblage and that hyaenas had final access to any grease or tissues that remained.     

Testing the “shift in the balance of power” hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene

C.K. Brain documented two interesting patterns in the Pleistocene faunas of Swartkrans Cave, South Africa: (1) The earliest depositional units, Members 1 and 2, preserve high numbers of hominid fossils, while the numbers drop sharply in the more recent Member 3. (2) Burned bone specimens, which seem to have been altered in fires tended by hominids, appear for the first time in Member 3. It was suggested that 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. A lack of butchered bones in Members 1 and 2 and their presence in Member 3 provided support for the hypothesis. However, we have now identified butchered bones in all three units. Further, our findings reveal a lack of variability in butchery patterns through time at Swartkrans; in all cases hominids appear to have been proficient carcass foragers. The real “shift” at Swartkrans does not appear to be one of eventual hominid dominance over carnivores, but rather one of a predominance of leopards at Swartkrans in Member 1 times to the alternating presence of leopards and hyenas in Members 2 and 3. Consistent leopard presence in Member 1 seems to have discouraged hominid activity in the vicinity of the cave. In contrast, by the time Members 2 and 3 were forming hominids may have temporarily used the cave, taking advantage of those periods of carnivore absence.     

Carnivory, Coevolution, and the Geographic Spread of the Genus Homo

This review traces the colonization of Eurasia by hominids some 1,700,000 years ago and their subsequent evolution there to 10,000 years ago from a carnivorous perspective. Three zooarchaeological trends reflect important shifts in hominid adaptations over this great time span: (1) increasing predation on large, hoofed animals that culminated in prime-adult–biased hunting, a predator–prey relationship that distinguishes humans from all other large predators and is a product of coevolution with them; (2) greater diet breadth and range of foraging substrates exploited in response to increasing human population densities, as revealed by small-game use; and (3) increased efficiency in food capture, processing, and energy retention through technology, and the eventual expansion of technology into social (symbolic) realms of behavior. Niche boundary shifts, examined here in eight dimensions, tend to cluster at 500 thousand years ago (KYA), at 250 KYA, and several in rapid succession between 50 and 10 KYA. Most of these shifts appear to be consequences of competitive interaction, because high-quality, protein-rich resources were involved. Many of the boundary shifts precede major radiations in the equipment devoted to animal exploitation. With a decline in trophic level after 45 KYA, demographic increase irreversibly altered the conditions of natural selection on human societies, from a largely interspecific competitive forum to one increasingly defined by intraspecific pressures. Regionalization of Upper Paleolithic artifact styles is among the many symptoms of this process.     

Preliminary evidence for seasonal deposition patterns from member 2 of the Swartkrans hominid site,South Africa

Frequencies of specimens in juvenile age classes, based on an analysis of tooth eruption and wear sequences, in specimens of an extinct species of springbok, Antidorcas bondi Wells and Cooke, from Member 2 of the Swartkrans hominid site, suggest that the remains of this animal were deposited during summer months. These indications of seasonal activity may offer support for previous suggestions of annual game movements. Such periodic movements have implications for our understanding of the behaviour patterns of the animals, including perhaps the hominids, which are represented in the assemblages from Swartkrans and other sites in the vicinity.     

Re–evaluating Subsistence Skills of Levantine Middle and Upper Palaeolithic Hunters: A Comparison of the Faunal Assemblages

It has long been argued that there were qualitative differences in the procurement strategies of the Middle and Upper Palaeolithic, with the hominids of the earlier period being less capable and efficient hunters than those of the subsequent period. This hypothesis is tested here through an examination of faunal assemblages from the two periods in the Levant by comparing measures of species diversity. It is concluded that no significant differences in hunting can be documented and that the hominids of both periods can be characterized as efficient foragers.     

Anthropogenic Causes, Mechanisms and Effects of Upper Pliocene and Quaternary Extinctinctions of Large Vertebrates

Successive waves of extinction of large vertebrates have swept the globe since the Pliocene. In contrast to such episodes in earlier geological epochs, many of the species of large herbivores and carnivores, flightless birds, and giant tortoises which became extinct during this period were not replaced in these niches by other species. Relying on data from the fossil and archaeological records as well as on ethological and palaeo-ecological arguments, the authors explain why hominids are to be held responsible for this ecological genocide. Possible ecological and climatic consequences of the extinctions are discussed. These considerations cast doubt upon the notion of early hominids as scavengers.     

Possible evidence of bone tool shaping by Swartkrans early hominids

Ever since Dart (J. Phys. Anthrop. 7 (1949) 1) interpreted certain bones from Makapansgat as tools, scientific consensus has fluctuated as to whether some bone objects from early hominid sites should be interpreted as artefacts, or the result of non-human taphonomic processes, which are known to produce pseudo-bone tools morphologically similar to human modified or used artefacts. Here we present possible evidence of bone tool shaping from Swartkrans (Members 1–3; ca. 1.8–1.0 Mya). Four horncores and the proximal end of an ulna used as tools in digging activities also have facets covered by parallel spindle-shaped striations characteristic of grinding. Identification of these traces as possibly resulting from deliberate shaping or re-sharpening of the bone tools is based on the characterisation of the use-wear pattern and other taphonomic modifications observed on the Swartkrans bone tools. This interpretation is also supported by the study of the remainder of the horncores from Swartkrans, horncores from other southern African Plio-Pleistocene sites (Sterkfontein, Makapansgat, Gondolin), modern horncores affected by pre- and post-mortem modification, ethnographic, LSA, African Iron Age and experimental bone tools shaped by grinding. These data suggest that early hominids had the cognitive ability to modify the functional area of bone implements to achieve optimal efficiency.     

Variation in the taphonomic effect of scavengers in semi‐arid Australia linked to rainfall and the El Niño Southern Oscillation

Scavenging is one of the primary taphonomic processes shaping the final composition of fossil faunal assemblages. The taphonomic effect of scavengers is variable and must be understood in the context of the causes of that variation. In this study, we investigated relationships between the El Niño Southern Oscillation (ENSO), variable rainfall and scavenging on 20–40 kg mammal carcasses in semi‐arid New South Wales over four years. Following periods of above‐average rainfall (coincident with the La Niña phase of the ENSO), there was an increased availability of non‐carrion food and scavenging activity was moderate. Following below‐average rainfall (coincident with the El Niño phase of the ENSO), foraging options diminished, leading to a greater importance of carrion in the diet of scavengers and a resultant increase in carcass disturbance, transport and destruction by scavengers. Feral pigs (Sus scrofa) and red foxes (Vulpes vulpes) were the most taphonomically significant scavengers in the study. Australian ravens (Corvus coronoides) and wedge‐tailed eagles (Aquila audax) were active scavengers throughout the period of the study, but had little impact on bone survival. Lace monitors (Varanus varius) also fed mostly on soft tissue and were only present seasonally. We found that climate variability in the form of short‐term oscillation can result in significant variation in the impact of scavengers on carcasses and may be an important consideration when evaluating site formation scenarios and biases in fossil faunal assemblages. Copyright © 2006 John Wiley & Sons, Ltd.     

Fossil marsupial predators of South America (Marsupialia,Borhyaenoidea): bite mechanics and palaeobiological implications

Borhyaenoids were marsupial predators that inhabited South America during the Cenozoic. They were very significant because no other mammals rivaled them as terrestrial hunters of large prey. Here we estimate the bite force of three species of borhyaenoids by two different methods to infer predatory behaviour in extinct taxa. One of the methods uses mainly the skull and only some simple measurements of the mandible; the other uses several measurements within the dentary. The results show that bite forces are very high in comparison to predators of the order Carnivora, a feature manifest by several other living and extinct marsupial predators. Differences in size, bite mechanics and special adaptations among the borhyaenoids suggest a very wide range of predatory behaviours that rival those represented in the extant families of the Order Carnivora.     

The history of stones: behavioural inferences and temporal resolution of an archaeological assemblage from the Middle Palaeolithic

Behavioural issues are a main focus of current Palaeolithic research, especially where the archaeological record of archaic hominids is concerned. Often these issues are approached using archaeological assemblages that are palimpsests defined exclusively by stratigraphic criteria. The aim of this paper is to discuss whether such assemblages are adequate for solving behavioural questions. As a case study, we will present the lithic provisioning strategies documented in level L of the Abric Romaní Middle Palaeolithic site. The results of this study suggest that the number of events and/or the amount of time included in the archaeological assemblages could be relevant when explaining the interassemblage variability, given that palimpsests tend to reduce the behavioural variability. If we want to approach the behavioural domain, we need archaeological assemblages of higher temporal resolution, defined through the identification of single activity events.     

Absolute dating of hominids and palaeolithic artifacts of the cave of La Chaise-de-Vouthon (Charente), France

Two adjacent chambers of the cave of La Chaise, Grotte de Bourgeois-Delaunay (B-D) and Grotte Suard, have been studied. Both were partly filled with detrital sediments containing lower and middle Palaeolithic artifacts and skeletal remains of pre-Neanderthalian hominids. Layers of stalagmitic calcite occur interstratified in the sediments of both chambers. Dates obtained by ²³⁰Th/²³⁴U ratios have provided a time scale for hominid and cultural evolution as represented in this cave.In B-D the lower travertine rests on a breccia containing cranial remains of juvenile Neanderthals. The base of the travertine dates to 151 ± 15 Ky (Ky = 1000 years BP); the top of the travertine yields a date of 112±5 Ky. The travertine contains pollen of an interglacial flora. Overlying detrital sediments 1·2 m in thickness contain artifacts transitional from Acheulian to Mousterian industries. They are capped by a travertine (Layer 7) whose base is dated at 100±6 Ky, and which is capped by stalagmites ranging in age down to 58±7 Ky. Overlying the travertine is sediment containing first Mousterian, and then Aurignacian artifacts.Near the base of the sediments filling Grotte Suard is a stalagmite layer dated to 249±30 Ky. It contains interglacial pollen and presumably dates to the beginning of the isotope stage 7 interglacial. Neanderthaloid hominid teeth and cranial fragments are found scattered through the overlying sediments, up to a capping stalagmitic layer whose base is dated at 101±7 Ky. The best described hominids from Suard are from a section that was probably overlying the capping stalagmite. The capping stalagmite is temporally correlated with layer 7 of B-D.     

Skeletal element abundances in archaeofaunal assemblages: economic utility,sample size,and assessment of carcass transport strategies

Economic utility indices provide a means of interpreting butchery and transport decisions reflected in the relative abundance of skeletal elements. Because of destructive taphonomic processes, interpreting skeletal element abundances in terms of carcass transport strategies requires that faunal analysts consider only those elements which accurately reflect their original abundances following human discard. In this study we use resampling techniques to examine the impact of sample size on correlations between high-survival skeletal element frequencies and economic utility in four simulated population assemblages reflecting distinct carcass transport strategies. Correlations alone do not accurately reflect the true relationship between bone abundance and economic utility as particular transport strategies have a tendency to generate high frequencies of Type II errors as sample size decreases. We show that the Shannon evenness index can be used as a quantitative means of distinguishing between bone assemblages characterized by subtle variations in skeletal element abundances. The evenness index can also be used to evaluate whether observed correlations reflect sampling error. Results from our simulations are applied to three published faunal assemblages to evaluate likely carcass transport strategies.     

Neandertal foraging during the late Mousterian in the Pyrenees: new insights based on faunal remains from Gatzarria Cave

This article presents the initial results of a new study of faunal remains from Gatzarria Cave, a Middle-to-Upper Palaeolithic transition site the Pyrenees of southwestern France (department of the Pyrénées Atlantiques). This study attempts to document diet breadth during the late Mousterian, while paying due attention to recently identified problems regarding the stratigraphic context of the assemblages. The faunal analysis focuses on a subset of late Mousterian faunal remains from layer Cj at the site. Taphonomic analysis suggests that humans were the primary bone accumulators. The assemblage is dominated by a single large-bodied species, red deer; smaller-bodied ungulates are poorly represented. Skeletal part representation indicates that within-bone nutrients contained in marrow were probably a key resource for these foragers. The overall pattern of remains is interpreted as evidence of narrow-spectrum foraging, a pattern which appears to be repeated at other Mousterian sites in the Pyrenees region. This may mean that local Neandertal populations existed at relatively low densities. However, this suggestion must be tempered by the fact that settlement patterns, including occupation seasonalities and site functions, are not yet well understood for this region.     

Presence of the African Saber-toothed FelidMegantereon whitei(Broom, 1937) (Mammalia, Carnivora, Machairodontinae) in Apollonia-1 (Mygdonia Basin, Macedonia, Greece)

We have made a multivariate morphometric study of the fossils ofMegantereonfrom the Apollonia-1 site at the Mygdonia Basin (Macedonia, Greece), using discriminant functions. Results obtained indicate that these specimens belong to the African speciesMegantereon whiteiBroom, which is also found in the Lower Pleistocene of Dmanisi (East Georgia, Caucasus) and Orce (Southern Spain). Morphofunctional studies ofM. whiteisuggest that this saber-toothed felid was an ambush predator with great killing capability in relation to its food requirements, thus leaving enough meat to be scavenged by both hyaenas and hominids.M. whiteimay have played an important ecological role making the first dispersal ofHomoto Eurasia the Lower Pleistocene possible.     

Hiding to eat: the role of carnivores in the early Middle Pleistocene from the TD8 level of Gran Dolina (Sierra de Atapuerca,Burgos, Spain)

Damage generated by large and small carnivores is common in many Middle Pleistocene sites. However, identifying the predator that produces the faunal accumulations is often a difficult task. In order to recognize the main type of carnivore that acts on a faunal assemblage, a combination of several characteristics should be taken into account: taxonomic and skeletal element representation, age profiles, carnivore damage (location, frequencies and dimensions of tooth-marks, bone breakage and digested bones), degree of fragmentation and frequencies of coprolites. But, adding environmental characteristics and the ethology of non-human predators/scavengers is also important. All these aspects are applied to the faunal assemblage from the TD8 level of the Gran Dolina site (Sierra de Atapuerca, Burgos, Spain). Paleomagnetic data combined with ESR and U-series place the TD8 level at the beginning of the Middle Pleistocene, specifically circa 700 kyr ago. The TD8 level contains a large faunal accumulation primarily composed of ungulate skeletal elements, and to a lesser extent carnivore remains. This assemblage is characterized by an overrepresentation of fallow deer (Dama vallonetensis), a skeletal profile biased towards cranial remains and limb bones, diversity of ages at death, a high proportion of carnivore damage and tooth-marks of large size, and an absence of human activity. According to these data, the accumulation seems to have been produced primarily by large carnivores, possibly hyenas. This observation does not rule out the possible occasional activity by other carnivores. Nevertheless, the characteristics of the TD8 assemblage do not correlate entirely with those traditionally used to define carnivore dens. In TD8, there are (1) no immature carnivore remains (remains of just one young Mosbach wolf); (2) scarce traces related to the end stages of consumption and some anatomical connexions; (3) few coprolites; (4) high proportion of adult ungulates and; (5) high quantities of whole bones and epiphyses. From this perspective, the TD8 faunal assemblage seems to correspond to a succession of carnivore occupations that allows the development of a suite of features to identify the activities of several species of predators that may have used the cave in different ways and durations. This study aims to emphasize the importance of these analyzes in order to know the behaviour of different non-human predators/scavengers in the European Middle Pleistocene sites.     

Following the white rabbit: A case of a small game procurement site in the upper palaeolithic (Sala de las Chimeneas,Maltravieso Cave,Spain)

The role of small game in Upper Palaeolithic economies has been examined by several authors over the past few decades. Among the small fauna, rabbits seem to have been a widely exploited resource in certain geographic areas, making them one of the main sources for subsistence in hunter–gatherer groups of southwestern Europe. Examining aspects such as anatomic profiles, demographics and taphonomic modifications (including bone breakage) allows us to approach determining the origins of the accumulation of assemblages and establishing the role of hominids and other processes in their formation. The faunal remains of level A of the Sala de las Chimeneas (Maltravieso Cave, Extremadura, Spain) show a clear predominance of rabbits. Results point to a complex taphonomic history. The assemblage of rabbit remains recovered at the site is of anthropic, exogenous and intrusive origin. The results of anthropogenic modifications of the bones reveal a different pattern than what is usually found in assemblages of the same age. The differences that set this assemblage apart include the absence of burned bones and the scarcity of anthropic breakage of humeri, femora and tibiae. These features, in conjunction with the characteristics of the archaeological context, have allowed us to rule out the possibility that this location was used as a base camp or bivouac. Along with these data, the presence of Pleistocene age warrens in the deposit supports the hypothesis that the space was used by hominids as a resource procurement site. Copyright © 2011 John Wiley & Sons, Ltd.