Kanjera South Research Articles

Meat on the menu: GIS spatial distribution analysis of bone surface damage indicates that Oldowan hominins at Kanjera South, Kenya had early access to carcasses

The shift to increased meat consumption is one of the major adaptive changes in hominin dietary evolution. Although meat eating by Oldowan hominins is well evidenced at Pleistocene archaeological sites in eastern Africa by butchery marks on bones, the methods through which carcasses were acquired (i.e., hunting vs. scavenging) and extent of their completeness (fleshed vs. defleshed) is less certain. This study addresses these issues through a geographic information systems (GIS) comparative analysis of bone modification patterns created by hominins and carnivores observed in the ca. 2.0 Ma assemblage from Kanjera South, Kenya and those of several modern, experimentally modified bone assemblages. Comparison of GIS-generated models shows that the pattern of bone preservation at Kanjera South is similar to that found in experimental bone assemblages that were first butchered and hammerstone fractured by humans, and subsequently scavenged by carnivores. The distribution of bone modifications on the Kanjera fauna also suggests hominins had early access to small bovids. Butchery marks appear almost exclusively in ‘hot zones’—areas where flesh does not typically survive lion consumption—further suggesting Kanjera hominins were not scavenging carnivore kills. Our findings support previous claims that the Kanjera assemblage offers the earliest clear evidence of repeated butchery of antelope carcasses by Early Stone Age (Oldowan) hominins and perhaps the earliest evidence for hunting. Kanjera carnivore damage frequencies are lower than those reported for the slightly younger site of FLK Zinj (Olduvai Gorge, Tanzania), suggesting differing competitive regimes at the two sites.

Seasonality and Oldowan behavioral variability in East Africa

The extent, nature, and temporality of early hominin food procurement strategies have been subject to extensive debate. In this article, we examine evidence for the seasonal scheduling of resource procurement and technological investment in the Oldowan, starting with an evaluation of the seasonal signature of underground storage organs, freshwater resources, and terrestrial animal resources in extant primates and modern human hunter-gatherer populations. Subsequently, we use the mortality profiles, taxonomic composition, and taphonomy of the bovid assemblages at Kanjera South (Homa Peninsula, Kenya) and FLK-Zinj (Olduvai Gorge, Tanzania) to illustrate the behavioral flexibility of Oldowan hominins, who were targeting different seasonally vulnerable demographics. In terms of the lithic assemblages, the specific opportunities and constraints afforded by dry season subsistence at FLK-Zinj may have disincentivized lithic investment, resulting in a more expedient toolkit for fast and effective carcass processing. This may have been reinforced by raw material site provisioning during a relatively prolonged seasonal occupation, reducing pressures on the reduction and curation of lithic implements. In contrast, wet season plant abundance would have offered a predictable set of high-quality resources associated with low levels of competition and reduced search times, in the context of perhaps greater seasonal mobility and consequently shorter occupations. These factors appear to have fostered technological investment to reduce resource handling costs at Kanjera South, facilitated by more consistent net returns and enhanced planning of lithic deployment throughout the landscape. We subsequently discuss the seasonality of freshwater resources in Oldowan procurement strategies, focusing on FwJj20 (Koobi Fora, Kenya). Although more analytical studies with representative sample sizes are needed, we argue that interassemblage differences evidence the ability of Oldowan hominins to adapt to seasonal constraints and opportunities in resource exploitation.

Ecological perspectives on technological diversity at Kanjera South

The aspects of hominin behavior responsible for Oldowan stone tool variation are the focus of much debate. There is some consensus that this variation arises from a combination of ecological and cultural factors. The diversity of raw material types and technological strategies present at Kanjera South, Kenya, provide an opportunity to examine the interacting influences of ecology and culture on Oldowan stone tool variation. Here, we combine previous analyses of raw material properties, provenance, and technology with quantitative measures of core reduction intensity and tool utilization to examine the influence of both ecological and technocultural factors on stone tool variation at Kanjera South. The results of this analysis reflect a dynamic relationship between raw material properties, provenance, and hominin mobility. Exotic raw materials are generally more resistant to edge attrition compared with those available locally, which may have incentivized their transport over long distances and more extensive reduction. Cores produced on raw materials from distant sources also exhibit more complex core reduction strategies than locally acquired materials. While this pattern is partially due to the differences in the quality of knappable stone, bifacial centripetal and multifacial core reduction strategies also arise due to the continuous transport and use of exotic raw materials. Moreover, the variation in stone tool reduction is not consistent with neutral models of stone tool transport and discard. These results demonstrate that ecological factors such as raw material provenance and physical properties have strong impacts on reduction intensity and the technological strategies used by hominins.

Exploration of apatite (U[sbnd]Th)/He geochronological analysis of volcanic units in fossil-bearing strata of the Homa Peninsula, southwestern Kenya

Many geological contexts lack suitable material for commonly applied absolute dating methods. Even if some regions contain potentially datable materials, they may be inappropriate for dating by existing geochronological techniques. Paleoanthropological localities on the Homa Peninsula, southwestern Kenya, have yielded important paleoanthropological material. These localities are, however, poorly constrained in time, and few radioisotopic ages have been published, because sediments derived from the Homa Mountain carbonatite complex commonly do not contain zircons for UPb dating or feldspars for 40Ar/39Ar dating. Additionally, apatite grains that are present have failed to produce precise isotope dilution-thermal ionization mass spectrometer (ID-TIMS) results due to their high common lead content. Apatite (UTh)/He dating using single-crystal laser fusion He determinations and the UTh isotope dilution method was applied to three formations with well-constrained ages to test the suitability of this technique for dating sediments on the peninsula. Two of the three Kanam Formation samples provide dates close to the approximately 6 million year age (Ma) provided by 40Ar/39Ar dates. The Abundu Formation was dated to 2.39 ± 0.29 Ma overlapping with the age of the Rawi Formation (C2An.1n Subchron, 3.05–2.59 Ma) to which it has been correlated. The age for the Kanjera South Member 1.54 ± 0.85 Ma overlaps with the expected 2 Ma age, though it has a large uncertainty. The apatite raw (UTh)/He ages are somewhat younger than the expected dates, but the technique shows promise.

Building ED-XRF datasets for sourcing rhyolite and quartzite artifacts: A case study on the Homa Peninsula, Kenya

Determining the provenance of archeological material is essential for documenting the movement of ancient resources and placing fossils and artifacts in the correct stratigraphic context. Non-destructive geochemical compositional analysis with Energy Dispersive X-ray Fluorescence (ED-XRF) spectrometry has the potential to provide a versatile approach to studying the provenance of archeological material. It is possible to build large regional XRF datasets that are useful for understanding the movements of toolmakers because this technique can be applied to a large number of samples non-destructively. However, incorporating new provenance data into existing datasets poses several potential challenges. Expanded provenance datasets often require the comparison of geochemical data across XRF instruments and settings. In particular the addition of different lithologies requires an understanding of diverse degrees of surface weathering and matrix heterogeneity.On the Homa Peninsula in Kenya, Oldowan tools from Kanjera South were previously linked to primary and secondary sources based on trace element geochemistry determined through ED-XRF. In this study, we established comparability across two ED-XRF instruments and incorporated samples from additional sources of quartzite and rhyolite into the existing raw material sourcing dataset. The new sources revealed regional differences in the geochemistry of rhyolite and quartzite that derive from drainages on and around the Homa Peninsula. This demonstrates the compatibility of quartzite and rhyolite materials with non-destructive ED-XRF sourcing and provides a methodological establishment of cross-study comparison in elemental values derived from non-uniform whole rock samples. This study highlights the importance of calibration using overlapping reference standards and linear regressions to determine offsets necessary for direct comparison.

Social evolution in Plio-Pleistocene hominins: Insights from hamadryas baboons and paleoecology

Reconstructions of hominin evolution have long benefited from comparisons with nonhuman primates, especially baboons and chimpanzees. The hamadryas baboon (Papio hamadryas) is arguably one of the best such models, as it exhibits both the male kin bonding and the cross-sex pair bonding thought to have been important in hominin evolution. Here we link processes of behavioral evolution in hamadryas baboons with those in a Plio-Pleistocene hominin, provisionally identified as Homo erectus (sensu lato) – a pivotal species in that its larger body and brain size and wider ranging patterns increased female costs of reproduction, increasing the importance of sociality. The combination of these higher costs of reproduction and shifts in diet and food acquisition have previously been argued to have been alleviated either via strengthening of male-female bonds (involving male provisioning and the evolution of monogamy) or via the assistance of older, post-reproductive females (leading to post-reproductive longevity in females, i.e., the grandmother hypothesis). We suggest that both arrangements could have been present in Plio-Pleistocene hominins if they lived in multilevel societies. Here we expand on our earlier scenario with two sets of recent data in support of it, (1) archaeological data from the 2 million year old Oldowan site of Kanjera South, Kenya and other sites that are suggestive of tool dependent foraging on nutrient dense resources (animal carcasses and plant underground storage organs), cooperation, and food sharing; and (2) a pattern of genetic variation in hamadryas baboons that suggests the operation of kin selection among both males and females at multiple levels of society. Taken together, these two sets of data strengthen our model and support the idea of a complex society linked by male-male, male-female, and female-female bonds at multiple levels of social organization in Plio-Pleistocene hominins.

Bovid mortality patterns from Kanjera South, Homa Peninsula, Kenya and FLK-Zinj, Olduvai Gorge, Tanzania: Evidence for habitat mediated variability in Oldowan hominin hunting and scavenging behavior

The archaeological record has documented Oldowan hominin occupation of habitats ranging from open grasslands to riparian forest by 2.0 Ma. Despite this we have a poor understanding of whether hominin foraging behavior varied in different environmental settings. We compared bovid mortality profiles from the two largest Oldowan zooarchaeological samples, one from a grassland (Excavation 1, Kanjera South, Kenya) and another from a woodland (FLK Zinj, Olduvai Gorge, Tanzania) with bovid mortality samples created by African carnivores in different habitats. Kanjera hominins frequently had early access, likely through hunting, to small (size 1 ≤ 23 kg and size 2 = 24–112 kg) juvenile bovids, creating a mortality pattern similar to that created by grassland dwelling carnivores. Kanjera hominins had more mixed access to large (size 3 = 113–340 kg), often juvenile, bovids and frequently scavenged heads. In contrast, previous work has shown that the few small bovids at FLK-Zinj were predominantly older individuals. Prime adults dominated the FLK-Zinj large bovid sample, leading to a mortality pattern similar to that created by carnivores occupying more closed habitats. Variation in bovid body size and mortality profiles between these archaeological assemblages may reflect the challenges of acquiring fauna in open versus closed habitats with a simple hunting toolkit. The heterogeneous woodland habitat of FLK-Zinj would have provided more opportunities to ambush prey, whereas on grasslands with more limited concealment opportunities Kanjera hominins focused their efforts on vulnerable juvenile prey, some likely acquired after short chases.

Old stones’ song—second verse: use-wear analysis of rhyolite and fenetized andesite artifacts from the Oldowan lithic industry of Kanjera South, Kenya

This paper investigates Oldowan hominin behavioral ecology through use-wear analysis of artifacts from Kanjera South, Western Kenya. It extends development of our experimental use-wear reference collection and analysis of use-wear on the well preserved and unweathered Oldowan tools from this site to include rhyolite, a non-local material of similar durability to previously studied quartz and quartzite tools, and fenetized andesite, a local material with considerably less durability. Variability in rhyolite and fenetized andesite texture, inclusions, and matrix required enhancement of previous methods so we combine the use of stereoscopic, metallographic, and scanning electron microscopy in this study. This study allows us to begin exploration of the links between specific artifactual raw materials and the materials they were used to process. Data assembled so far suggest that tools fashioned from non-local and local stone were, with one possible exception, used to process similar materials. Additionally, experiments carried out with replicas of tools made of rhyolite and fenetized andesite confirm interpretation of reduction sequences that tools made of less durable local material had a shorter use-life and were used expediently compared to the more durable non-local quartz, quartzite, and rhyolite. These new data improve our understanding, of the functional needs, behavioral solutions, and cognitive capacities of Oldowan hominins. Finally, these data show how use-wear analysis, combined with lithic raw material and lithic technology, can be a powerful means for evaluating two key points for human evolution: long-term memory, and planning.

Geochronology and physical context of Oldowan site formation at Kanjera South, Kenya

AbstractOldowan sites in primary geological context are rare in the archaeological record. Here we describe the depositional environment of Oldowan occurrences at Kanjera South, Kenya, based on field descriptions and granulometric analysis. Excavations have recovered a large Oldowan artefact sample as well as the oldest substantial sample of archaeological fauna. The deposits at Kanjera South consist of 30 m of fluvial, colluvial and lacustrine sediments. Magneto- and biostratigraphy indicate the Kanjera South Member of the Kanjera Formation was deposited during 2.3–1.92 Ma, with 2.0 Ma being a likely age for the archaeological occurrences. Oldowan artefacts and associated fauna were deposited in the colluvial and alluvial silts and sands of beds KS1–3, in the margins of a lake basin. Field descriptions and granulometric analysis of the sediment fine fraction indicate that sediments from within the main archaeological horizon were emplaced as a combination of tractional and hyperconcentrated flows with limited evidence of debris-flow deposition. This style of deposition is unlikely to significantly erode or disturb the underlying surface, and therefore promotes preservation of surface archaeological accumulations. Hominins were repeatedly attracted to the site locale, and rapid sedimentation, minimal bone weathering and an absence of bone or artefact rounding further indicate that fossils and artefacts were quickly buried.

Oldowan hominin behavior and ecology at Kanjera South,Kenya.

The Early Stone Age archaeological record does not become persistent and widespread until approximately 2.0-1.7 million years ago, when Oldowan sites spread across Africa and ultimately into Eurasia. However, good records of hominin behavior from this important time interval are uncommon. Here we describe recent findings from the two million year old Oldowan site of Kanjera South, on the Homa Peninsula of southwestern Kenya. Kanjera South is the oldest Oldowan site with large assemblages of stone artifacts and well-preserved archaeological fauna. Our research indicates that hominin activities were situated in an open habitat within a grassland dominated ecosystem, the first documentation of an archaeological site in such an open setting. Hominins selectively collected and transported stone materials (30% of the lithic assemblage) over longer distances (at least 10 km) than is typical for the Oldowan, reflecting their preference for hard, easily-flaked lithologies unavailable on the northern half of the Homa Peninsula. They deployed different technological strategies to more intensively utilize these hard, non-local raw materials. Artifacts were used for a variety of tasks, including butchering small antelopes probably obtained by hunting, working wood, working soft plant material, and processing underground storage organs. These data suggest that the Kanjera hominins utilized a technological system that allowed them to extract nutrient dense animal and plant foods from their environment. This shift towards the acquisition of nutritious, hard-to-acquire foods in packets large enough to be shared may have facilitated brain and body size expansion in the genus Homo.

Old stones' song: Use-wear experiments and analysis of the Oldowan quartz and quartzite assemblage from Kanjera South (Kenya)

Evidence of Oldowan tools by ∼2.6 million years ago (Ma) may signal a major adaptive shift in hominin evolution. While tool-dependent butchery of large mammals was important by at least 2.0 Ma, the use of artifacts for tasks other than faunal processing has been difficult to diagnose. Here we report on use-wear analysis of ∼2.0 Ma quartz and quartzite artifacts from Kanjera South, Kenya. A use-wear framework that links processing of specific materials and tool motions to their resultant use-wear patterns was developed. A blind test was then carried out to assess and improve the efficacy of this experimental use-wear framework, which was then applied to the analysis of 62 Oldowan artifacts from Kanjera South. Use-wear on a total of 23 artifact edges was attributed to the processing of specific materials. Use-wear on seven edges (30%) was attributed to animal tissue processing, corroborating zooarchaeological evidence for butchery at the site. Use-wear on 16 edges (70%) was attributed to the processing of plant tissues, including wood, grit-covered plant tissues that we interpret as underground storage organs (USOs), and stems of grass or sedges. These results expand our knowledge of the suite of behaviours carried out in the vicinity of Kanjera South to include the processing of materials that would be ‘invisible’ using standard archaeological methods. Wood cutting and scraping may represent the production and/or maintenance of wooden tools. Use-wear related to USO processing extends the archaeological evidence for hominin acquisition and consumption of this resource by over 1.5 Ma. Cutting of grasses, sedges or reeds may be related to a subsistence task (e.g., grass seed harvesting, cutting out papyrus culm for consumption) and/or a non-subsistence related task (e.g., production of ‘twine,’ simple carrying devices, or bedding). These results highlight the adaptive significance of lithic technology for hominins at Kanjera.

Earliest Archaeological Evidence of Persistent Hominin Carnivory

The emergence of lithic technology by ∼2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ∼1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ∼2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence – spanning hundreds to thousands of years – and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution.

Estimation of annual effective dose and radiation hazards due to natural radionuclides in Mount Homa, southwestern Kenya

The radiological hazard of naturally occurring radioactive material in Mount Homa in southwestern Kenya was investigated after 210 point measurements and 44 samples were analysed. In situ measured average outdoor absorbed dose rate in air using survey meters was found to vary from 154.8 to 2280.6 nGy h(-1). The mean (range) values of radioactive concentrations measured using an HpGe detection system for (40)K, (226)Ra and (232)Th were 915 ± 3 (64-3017), 195 ± 8 (17-1447) and 409 ± 4 (23-1369) Bq kg(-1), respectively. The calculated range of the annual effective dose for a person living in Homa Mountain area varied from 28.6 to 1681.2, with a mean of 470.4 µSv. All calculated average radiological indices, namely Radium equivalent, Representative level, Gamma activity, External and Internal hazard, were higher than the limits set by various national and international bodies. These results imply that Mount Homa region is a high background radiation area.

Behavioural variability in Oldowan hominins: the case from Kanjera South, Kenya

Behavioural variability in Oldowan hominins: the case from Kanjera South, Kenya

Oldest Evidence of Toolmaking Hominins in a Grassland-Dominated Ecosystem

BackgroundMajor biological and cultural innovations in late Pliocene hominin evolution are frequently linked to the spread or fluctuating presence of C4 grass in African ecosystems. Whereas the deep sea record of global climatic change provides indirect evidence for an increase in C4 vegetation with a shift towards a cooler, drier and more variable global climatic regime beginning approximately 3 million years ago (Ma), evidence for grassland-dominated ecosystems in continental Africa and hominin activities within such ecosystems have been lacking.Methodology/Principal FindingsWe report stable isotopic analyses of pedogenic carbonates and ungulate enamel, as well as faunal data from ∼2.0 Ma archeological occurrences at Kanjera South, Kenya. These document repeated hominin activities within a grassland-dominated ecosystem.Conclusions/SignificanceThese data demonstrate what hitherto had been speculated based on indirect evidence: that grassland-dominated ecosystems did in fact exist during the Plio-Pleistocene, and that early Homo was active in open settings. Comparison with other Oldowan occurrences indicates that by 2.0 Ma hominins, almost certainly of the genus Homo, used a broad spectrum of habitats in East Africa, from open grassland to riparian forest. This strongly contrasts with the habitat usage of Australopithecus, and may signal an important shift in hominin landscape usage.

Raw material quality and Oldowan hominin toolstone preferences: evidence from Kanjera South, Kenya

The role of raw material quality in Oldowan technology has not been fully explored. There are numerous studies suggesting Oldowan hominins preferred certain types of stone for artifact manufacture. Previous studies of the artifact assemblage from the early Pliocene Oldowan locality of Kanjera South (South Rachuonyo District, Kenya) show that raw material selection and transport was an important aspect of Late Pliocene hominin adaptations. Yet the exact properties of stones that hominins were selecting remain enigmatic. Two potentially important features of artifact raw material are durability and fracture predictability. We investigate fracture predictability through mechanical tests of stone and investigations of the affect of stone properties on fracture patterns in archaeological collections. We investigate stone durability with actualistic studies of edge attrition combined with further mechanical tests of various lithologies. Oldowan hominins at Kanjera appear to have selected raw materials based on their durability. The ability for a stone to fracture consistently does not appear to be as important in hominin toolstone preference as previously assumed. Hominins that produced the assemblages at Kanjera South appear to have incorporated an extensive understanding of various attributes of raw material in the transport and production of stone artifacts. When combined with previous research on the transport patterns at Kanjera, the results of this study provide evidence for a more complex raw material acquisition strategy than has previously been suggested for Late Pliocene Oldowan hominins.

Oldowan behavior and raw material transport: perspectives from the Kanjera Formation

The archaeological record of Oldowan hominins represents a diverse behavioral system. It has been suggested that exploitation of lithic resources by Oldowan hominins was simplistic and represented mostly use of local sources of stone. Here we investigate the raw material selection and transport behaviors of Oldowan hominins reflected in the stone artifact assemblages from the Kanjera South Formation, South Rachuonyo District, Kenya. Using geochemical methods (ED-XRF) artifacts are linked to primary and secondary source outcrops throughout southwestern Kenya. These data show that hominins selected raw materials for transport at frequencies that are significantly different from their availability on ancient landscapes. Furthermore, a substantial proportion of the assemblage represents transport over relatively long distances (>10 km). Our study further suggests that in the early stages of stone tool use hominins used a wide variety of raw materials and selected these materials at some distance from their eventual discard locations. Early hominin behavior may have incorporated an understanding of raw material source distributions across a more extensive landscape than has been previously documented. This supports the growing perspective that Oldowan technology represents a more complex behavioral pattern than is usually associated with the beginnings of hominin tool use.

Carnivore tooth-marks, microbial bioerosion, and the invalidation of test of Oldowan hominin scavenging behavior

The shift to increased meat consumption is one of the major adaptive changes in hominin dietary evolution. Although meat eating by Oldowan hominins is well evidenced at Pleistocene archaeological sites in eastern Africa by butchery marks on bones, the methods through which carcasses were acquired (i.e., hunting vs. scavenging) and extent of their completeness (fleshed vs. defleshed) is less certain. This study addresses these issues through a geographic information systems (GIS) comparative analysis of bone modification patterns created by hominins and carnivores observed in the ca. 2.0 Ma assemblage from Kanjera South, Kenya and those of several modern, experimentally modified bone assemblages. Comparison of GIS-generated models shows that the pattern of bone preservation at Kanjera South is similar to that found in experimental bone assemblages that were first butchered and hammerstone fractured by humans, and subsequently scavenged by carnivores. The distribution of bone modifications on the Kanjera fauna also suggests hominins had early access to small bovids. Butchery marks appear almost exclusively in ‘hot zones’—areas where flesh does not typically survive lion consumption—further suggesting Kanjera hominins were not scavenging carnivore kills. Our findings support previous claims that the Kanjera assemblage offers the earliest clear evidence of repeated butchery of antelope carcasses by Early Stone Age (Oldowan) hominins and perhaps the earliest evidence for hunting. Kanjera carnivore damage frequencies are lower than those reported for the slightly younger site of FLK Zinj (Olduvai Gorge, Tanzania), suggesting differing competitive regimes at the two sites.

Recent research into oldowan hominin activities at Kanjera South, Western Kenya

This paper presents the initial results of excavations at Kanjera South, located on the Homa Peninsula in Western Kenya. Since 1995, our exploration of this locality has yielded a combination of artefacts and well preserved faunal remains in a sedimentary context that also allows for environmental reconstruction. Here we examine the history of exploration of Kanjera and its significance in the development of palaeoanthropological research in East Africa. We also summarise our findings from the recently discovered Oldowan site. Taphonomic analyses suggest that the archaeological layers were formed at least partially by hominin activity. Artefacts made from a wide variety of raw materials are abundant, as are animal bones. Results of our first analyses confirm that Oldowan hominins had considerable behavioural flexibility and occupied a range of habitats.

Flake recovery rates and inferences of Oldowan hominin behavior: a response to Kimura 1999, 2002

The aspects of hominin behavior responsible for Oldowan stone tool variation are the focus of much debate. There is some consensus that this variation arises from a combination of ecological and cultural factors. The diversity of raw material types and technological strategies present at Kanjera South, Kenya, provide an opportunity to examine the interacting influences of ecology and culture on Oldowan stone tool variation. Here, we combine previous analyses of raw material properties, provenance, and technology with quantitative measures of core reduction intensity and tool utilization to examine the influence of both ecological and technocultural factors on stone tool variation at Kanjera South. The results of this analysis reflect a dynamic relationship between raw material properties, provenance, and hominin mobility. Exotic raw materials are generally more resistant to edge attrition compared with those available locally, which may have incentivized their transport over long distances and more extensive reduction. Cores produced on raw materials from distant sources also exhibit more complex core reduction strategies than locally acquired materials. While this pattern is partially due to the differences in the quality of knappable stone, bifacial centripetal and multifacial core reduction strategies also arise due to the continuous transport and use of exotic raw materials. Moreover, the variation in stone tool reduction is not consistent with neutral models of stone tool transport and discard. These results demonstrate that ecological factors such as raw material provenance and physical properties have strong impacts on reduction intensity and the technological strategies used by hominins.