Mapping nut-cracking in a new population of wild capuchin monkeys (Sapajus libidinosus) at Ubajara National Park, Brazil.

Populations of bearded capuchin monkeys (Sapajus libidinosus) vary in their tool use behaviors, with some of this divergence regarded as culturally determined. The use of stone tools, primarily to crack open encased foods, is widespread among bearded capuchins living in dry habitats (Caatinga and Cerrado). Significant diversity in targets, processed foods, material, and size of tools is observed across populations. However, so far, only a few sites have been systematically studied, and we are still distant from a representative picture of the range of variation in capuchins' culture. In this study, we did a systematic assessment of stone tool use sites in the Ubajara National Park (UNP), in the Caatinga region of Ceará, Brazil, recording and measuring stone tools, processed foods, and available lithic resources as part of an extensive comparative research, the CapCult project. We found indirect and direct evidence that capuchin monkeys at UNP customarily use hammerstones and anvils to process at least two species of palm nuts, macauba (Acrocomia aculeata) and the harder babaçu (Attalea speciosa). Most of the anvils were rock surfaces and had leftovers of only one palm nut species. The hammerstones used to process both palm nuts were not significantly different in weight, although the ones used for Ac. aculeata were longer. We found a higher frequency of nut-cracking sites in the drier lowland area of the park, reflecting differences in the density of the most common palm species, Ac. aculeata, and availability of raw stone material. The stone tool use observed in UNP is within the scope of previously reported in savannah capuchin populations. Our study widens the knowledge of stone tool-use diversity in wild capuchin monkeys, which could contribute to shaping conservation policy, including cultural traits.

Operationalizing niche construction theory with stone tools.

One of the greatest difficulties with evolutionary approaches in the study of stone tools (lithics) has been finding a mechanism for tying culture and biology in a way that preserves human agency and operates at scales that are visible in the archaeological record. The concept of niche construction, whereby organisms actively construct their environments and change the conditions for selection, could provide a solution to this problem. In this review, we evaluate the utility of niche construction theory (NCT) for stone tool archaeology. We apply NCT to lithics both as part of the "extended phenotype" and as residuals or precipitates of other niche-constructing activities, suggesting ways in which archaeologists can employ niche construction feedbacks to generate testable hypotheses about stone tool use. Finally, we conclude that, as far as its applicability to lithic archaeology, NCT compares favorably to other prominent evolutionary approaches, such as human behavioral ecology and dual-inheritance theory.

Fourteen Years of Archaeological and Heritage Research in the Iringa Region, Tanzania.

The Iringa Region is famous among archaeologists for the Acheulean site of Isimila, and among historians as the stronghold where Chief Mkwawa led the Hehe resistance against German colonial forces. However, our research reveals that Iringa has a rich archaeological record that spans the period from the Stone Age into the recent past. This article summarizes the results of 14 years of research by our team, the Iringa Region Archaeological Project (IRAP). Since 2006, IRAP members have recorded 67 sites, and this only scratches the surface of the archaeological potential in the area. These sites, some of which were recorded in conjunction with local participants, have archaeological component characteristic of the Early, Middle, and Later Stone Age, the Iron Age, and the recent past. We consider the archaeological and historical value of Iringa to be high and hope that this work inspires future research, tourism, and conservation efforts in the area.

La région d'Iringa en Tanzanie est. reconnue par les archéologues pour le site acheuléen d'Isimila et parmi les historiens comme le fief où le chef Mkwawa a dirigé la résistance du Hehe contre les forces coloniales allemandes. Cependant, nos recherches révèlent qu'Iringa possède de riches archives archéologiques allant de l'âge de pierre au passé récent. Cet article résume les résultats de quatorze années de recherche de notre équipe, le projet archéologique de la région d'Iringa (PARI). Depuis 2006, les membres du PARI ont enregistré 67 sites, ce qui ne fait qu'effleurer la surface du potentiel archéologique de la région. Les sites identifiés présentent des éléments archéologiques caractéristiques de l'âge de pierre précoce, moyen et postérieur, de l'âge du fer, et du passé historique. En outre, un certain nombre de sites culturels importants ont été enregistrés en collaboration avec des participants locaux. Nous considérons que la valeur archéologique et historique d'Iringa est. élevée et espérons que ces travaux inspireront la recherche, le tourisme et la conservation dans cette région importante.

Manual laterality and cognition through evolution: An archeological perspective.

To understand the evolution of lateralized motor biases and cognitive functions, we rely on archeological methods to give us a window onto the past. Currently, the overwhelming majority of prehistoric data on asymmetry and laterality concern only the hominin lineage, spanning the time period from the presumed evolutionary split with the other great apes around 6-8 million years ago until the present day. We present an overview of these data from paleontology and archeology. Lateralized motor biases and anatomical asymmetries are evident throughout prehistory, showing increases in the predominance of right-handedness over time. Laterality was a key feature of the motor-cognitive development of extinct human ancestors. However, further research in living humans is needed to resolve the extent of colateralization of functions in the human brain, so we urge caution when inferring functional cognitive laterality from behavioral markers of handedness.

Stone tool use by wild capuchin monkeys (Sapajus libidinosus) at Serra das Confusões National Park, Brazil.

Capuchin monkeys (Sapajus spp.) are proficient tool users, and the use of stone tools occurs in several populations, mostly to crack open encased foods. Two well-studied Brazilian populations of Sapajus libidinosus inhabit Fazenda Boa Vista and Serra da Capivara National Park and present different behavioral sets regarding tool use. Serra das Confusões National Park (SCoNP) lies between those sites, but little is known about the capuchin monkey population that lives there. To begin unraveling the capuchin behavior in this area, we conducted a brief survey for tool use sites. We found indirect evidence that capuchin monkeys at SCoNP use stone hammers to crack open at least four species of seeds and fruits. Plant reproductive parts there are processed with stone tools in a similar pattern to the other sites. Further study is needed to directly observe tool use by capuchin monkeys at SCoNP, verify the occurrence of other possible types of tool use in this population, and thus fully compare their tool use repertoire to that of other populations.