Eduardo Ottoni

University of São Paulo | USP · Department of Experimental Psychology

The last two decades have seen great advances in the study of social learning (learning from others), in part due to efforts to identify it in the wild as the basis of behavioral traditions. Theoretical frameworks suggest that both the dynamics of social tolerance and transmission biases (or social learning strategies) influence the pathways of inf...

Platyrrhines consume many species of arthropods in the order Orthoptera. Some species of orthopterans can produce chemical defenses that render them toxic or unpalatable and thus act as predator deterrents. These species include the stick grasshoppers (family Proscopiidae), which are widely distributed in the Caatinga biome in northeastern Brazil,...

Sapajus libidinosus members of the Pedra Furada group, living in the Serra da Capivara National Park, use stone tools in a wider variety of behaviors than any other living animal, except humans. To rescue the evolutionary history of the Caatinga S. libidinosus and identify factors that may have contributed to the emergence and maintenance of their...

Terrestriality was an essential factor in human evolution. Hominins' extensive use of the ground allowed exploring a new range of environments and their objects, including new resources and potential tool raw materials. Capuchin monkeys are primarily arboreal primates but are also the most prolific tool users among platyrrhines, customarily using s...

There is abundant evidence that allows us to consider wild tufted capuchin monkeys’ toolkits as behavioural traditions. Developmental studies show that infants’ interest in nutcracking and adults’ tolerance of scrounging enhance opportunities for social learning. Field experiments have examined the socially mediated diffusion of new behaviours. The...

Capuchins are highly encephalized New World monkeys (family Cebidae, subfamily Cebinae) living in a variety of forest and savannah habitats, from Central to South America, and currently classified as “gracile” (the Cebus genus) or “robust” (the Sapajus genus). The literature on behavioural plasticity in this taxon highlights purported traditions in...

Examining interactions among sympatric primate species can provide interesting information about competition, cooperation, and avoidance between those species. Those interactions can be neutral, positive, or negative for the species involved. Capuchin monkeys are medium-sized primates that can encounter both larger and smaller primates in their var...

Tufted capuchin monkeys (Sapajus spp.) are the only Neotropical Primates that regularly use tools in the wild, but only one population of bearded capuchin monkeys (Sapajus libidinosus) is known to habitually use sticks as probes. In this population, males are typically the only sex to use stick tools, something unexpected, since there are no obviou...

Many species were reported engaging in homosexual behaviour among mammals, birds, reptiles and insects. In primates, this behaviour seems to be much more frequent among apes and Old World monkeys than in New World monkeys, where only a few species, like squirrel monkeys, tamarins, marmosets, and capuchins, have been observed engaging in same-sex mo...

Overimitation is defined by a tendency to copy all actions executed by a model, even the clearly irrelevant ones. The motivational mechanisms and functionality of overimitation are still not well understood, but its possible adaptive meaning could be related to causal opacity of a great part of socially learned behaviors. This phenomenon has been w...

The human archaeological record changes over time. Finding such change in other animals requires similar evidence, namely, a long-term sequence of material culture. Here, we apply archaeological excavation, dating and analytical techniques to a wild capuchin monkey (Sapajus libidinosus) site in Serra da Capivara National Park, Brazil. We identify m...

Findings from field primatology show that three living primate genera—ape ( Pan ), Old World monkey ( Macaca ), and New World monkey ( Sapajus )—use elementary lithic technology to obtain and process food in nature. All three taxa use stone tools, producing enduring artifacts with distinctive archaeological signatures. In a comparison we show that...

There are already plenty of evidence to consider wild tufted capuchin monkeys' toolkits as behavioral traditions. Developmental studies show that infants' interest in nutcracking and adults' tolerance to scrounging optimize opportunities for socially biased learning. Field experiments provide further evidence on the socially mediated diffusion of n...

Tool use involves the employment of environmental objects for the purpose of altering more efficiently the form, position, or condition of another object, another organism, or the user itself. It was once seen as an exclusively human trait, but is actually widespread throughout the animal kingdom. The use of tools can result from stereotyped, speci...

Fig. 6 Encased foods compared at each of the four research sites. Use of stone hammers to process the encased food by capuchin monkeys at each site indicated by the pentagon icon: [red] stone tool used, [grey] stone tools not used, [white] not enough data. Food resource not present in some sites is indicated by black ‘X’. References used: SCNP (Man...

Capuchin monkeys (Sapajus spp.) are pro cient 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 di erent behavioral sets regarding tool use. Serra das Confusõ...

Snakes present a hazard to primates, both as active predators and by defensive envenomation. This risk might have been a selective pressure on the evolution of primate visual and cognitive systems, leading to several behavioral traits present in human and non-human primates, such as the ability to quickly learn to fear snakes. Primates seldom prey...

Since its inception, archaeology has traditionally focused exclusively on humans and our direct ancestors. However, recent years have seen archaeological techniques applied to material evidence left behind by non-human animals. Here, we review advances made by the most prominent field investigating past non-human tool use: primate archaeology. This...

The idea of nonhuman primates (and other animals) as cultural beings dates back to the classic studies on the diffusion of new behaviours among provisioned Japanese macaques. Comparative studies on behavioural variation between wild primate populations, nevertheless, were the starting point of modern " cultural primatology " : differences in behavi...

Evidence of cultural processes in non-human animals has been growing over the past two decades. An issue that has been debated more recently is the possibility of cumulative culture in non-human animals. Social learning of incremental improvements in technique is considered to be a defining feature of human culture, differentiating it from non-huma...

Capuchin monkeys at Serra da Capivara National Park (SCNP) usually forage on the ground for roots and fossorial arthropods, digging primarily with their hands but also using stone tools to loosen the soil and aid the digging process. Here we describe the stone tools used for digging by two groups of capuchins on SCNP. Both groups used tools while d...

Tool use involves the employment of an environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself, when this user holds and manipulates the tool and is responsible for its proper and effective orientation. It was once seen as an exclusively human trait, but is actually wid...

The effects of culture on individual cognition have become a core issue among cultural primatologists. Field studies with wild populations provide evidence on the role of social cues in the ontogeny of tool use in non-human primates, and on the transmission of such behaviours over generations through socially biased learning. Recent experimental st...

Our understanding of the emergence of technology shapes how we view the origins of humanity. Sharp-edged stone flakes, struck from larger cores, are the primary evidence for the earliest stone technology. Here we show that wild bearded capuchin monkeys (Sapajus libidinosus) in Brazil deliberately break stones, unintentionally producing recurrent, c...

Stone-aided nut-cracking requires the coordination of three elements: the agent must assemble nuts, a "hammer" stone and an "anvil." Under naturalistic settings, nut-cracking sites, constituted of anvil-like surfaces and already containing a hammer stone, can be fairly stable, lasting as long as the "hammer" stays in place. In an experiment with a...

Social learning has been studied in many disciplines, but often lacking in ecological validity. We examine socially-biased learning in two groups (Njb=40; Npf=30) of wild bearded capuchin monkeys, using open-diffusion studies of extractive foraging tasks, and social network data. Thus we describe how patterns of association (social proximity: Njb=5...

Stone tools reveal worldwide innovations in human behaviour over the past three million years. However, the only archaeological report of pre-modern non-human animal tool use comes from three Western chimpanzee (Pan troglodytes verus) sites in Côte d’Ivoire, aged between 4.3 and 1.3 thousand years ago (kya). This anthropocentrism limits our compara...

When carrying objects, nonhuman primates often show bipedal locomotion. Studies of primate bipedality, however, in both nature and captivity, have concentrated on locomotion on horizontal substrates, either terrestrially or arboreally. No observational or experimental study seems to have looked at non-horizontal bipedality, yet we show here that it...

The use of pounding stone tools (PSTs) is a customary behaviour in several wild populations of capuchin monkeys; most of these monkeys use PSTs primarily to open hard palm nuts. Here, we describe the use of PSTs in two not previously studied groups of capuchin monkeys (Sapajus libidinosus) in Serra da Capivara National Park (SCNP), northeastern Bra...

A Análise do Comportamento pode ser entendida como uma perspectiva voltada para o estudo evolucionista do comportamento social e da cultura. A caracterização do comportamento social nessa área e pesquisas recentes sobre metacontingências e macrocontingências são contribuições nesse sentido. Outras perspectivas evolucionistas mais próximas da Biolog...

Robust capuchin monkeys (Sapajus sp.) are the only Neotropical primates that use tools in the wild. Further, the Serra da Capivara National Park (SCNP) capuchins are the only known population that uses stone tools for more purposes than to crack encapsulated fruits and seeds. They also regularly use sticks as probes. Most stone tools are used by bo...

The use of percussive tools to access defended food is widespread among savanna-dwelling bearded The use of percussive tools to access defended food is widespread among savanna-dwelling bearded capuchin monkeys (Sapajus libidinosus). The customary use of tools (usually wooden sticks) to probe arthropod nests or dislodge prey from rock crevices, on...

Capuchin monkeys (Sapajus libidinosus) in several populations use stone tools to crack open encapsulated fruits. One of the resources they process with those tools are cashew nuts. During the maturation changes, the cashew nuts turns easier to crack, because when dry (late season) the husk became more fragile. We know that some wild chimpanzees (Pa...

Cracking nuts with tools is a behavior documented in a small number of populations of tufted capuchins, mainly in semi-arid Caatinga and Caatinga-Cerrado transitional environments of northeastern Brazil. Only one of these populations inhabits the less arid Cerrado in Central Brazil, where environments are composed of a heterogeneous mosaic of field...

Tool use was once a major defining feature of "human nature". If the findings about the spontaneous use of tools by wild chimpanzees (Pan troglodytes) forced us to rethink traditional views on the " unique and exclusive " character of human technological abilities, the discovery of similar behaviors in a few monkey species-one Old World monkey (Mac...

The spontaneous use of stone tools for cracking nuts by tufted capuchin monkeys, now known to be habitual among wild populations in savanna environments, was first described in a semifree group living in the Tietê Ecological Park (SP, Brazil). Nut-cracking at TEP was first observed by our team in 1995 (Ottoni and Mannu in Int J Primatol 22(3):347–3...

Capuchin monkeys, Sapajus Kerr, 1792, are known for their flexible behavior, including tool use, and their ability to survive in urban forests. We observed capuchin juveniles using wood as hammer and anvil and different materials as sponges (four tool-use events) in two geographically distinct urban populations in Brazil, in 2012: two in Goiânia, C...

Wild capuchin monkeys in savanna environments in Central and Northeastern Brazil customarily use tools (usually lithic) to crack open encapsulated fruit. At least one population, though, exhibits a more complex toolkit, including not only percussive stone tools, but also stick probes and the use of stones for digging the soil, cutting/smashing plan...

Probe tool use is, so far, the only known case in which wild capuchin monkeys modify objects used as tools: branches are trimmed off, and tips, thinned. Here we examine data of a two-year research on the use of sticks by two groups in Serra da Capivara National Park (PI), Brazil. This behavior is not usually observed among wild tufted capuchin (Sap...

Capuchin monkeys (Sapajus spp.) in captive settings frequently manipulate and throw objects. In the wild, they may push or drop stones and sticks toward targets during inter- or intraspecific threat displays. In addition, female capuchin monkeys exhibit a broad repertoire of behaviors during their proceptive period, including facial expressions, vo...

Many theoretical and empirical studies overlook the fact that individuals differ in their social experiences. Social network analysis (SNA) can help to take this into account (Sih et al., 2009). Degree is a SNA metric that identifies how many social partners an individual has and may therefore be useful in identifying how females vary in the number...

To determine whether tool use varied in relation to food availability in bearded capuchin monkeys, we recorded anvil and stone hammer use in two sympatric wild groups, one of which was provisioned daily, and assessed climatic variables and availability of fruits, invertebrates and palm nuts. Capuchins used tools to crack open encased fruits, mostly...

The frequency of anointing bouts and the materials used for self- and social anointing vary across capuchin species in captivity, but there is little published data on capuchin anointing in the wild. Here we present previously unpublished data on anointing behaviors from capuchin monkey populations at ten different field sites and incorporate these...

The spontaneous use of stone tools to crack encapsulated food is the rule rather than the exception among wild bearded capuchin monkeys (Sapajus [or Cebus] libidinosus) inhabiting savannah-like environments such as Brazilian cerrado and caatinga. Populations in Serra da Capivara National Park (Piauí, Brazil), furthermore, exhibit a seemingly unique...

Wild bearded capuchin monkeys, Cebus libidinosus, use stone tools to crack palm nuts to obtain the kernel. In five experiments, we gave 10 monkeys from one wild group of bearded capuchins a choice of two nuts differing in resistance and size and/or two manufactured stones of the same shape, volume and composition but different mass. Monkeys consist...

Wild bearded capuchins, Cebus libidinosus, in Fazenda Boa Vista, Brazil crack tough palm nuts using hammer stones. We analysed the contribution of intrinsic factors (body weight, behaviour), size of the nuts and the anvil surface (flat or pit) to the efficiency of cracking. We provided capuchins with local palm nuts and a single hammer stone at an...

We compared the musical judgment and participant's musicality by sex to test different predictions form evolutionary explanations. 202 women and 179 men, responded to a questionnaire after hearing one of three instrumental tunes. The musical judgments were participant's attributions about the tune from 0 to 10, how: "beautiful", "creative", "inspir...

The genus Cebus is one of the best extant models for examining the role of fallback foods in primate evolution. Cebus includes the tufted capuchins, which exhibit skeletal features for the exploitation of hard and tough foods. Paradoxically, these seemingly "specialized" taxa belong to the most ubiquitous group of closely related primates in South...

The use of stones to crack open encapsulated fruit is widespread among wild bearded capuchin monkeys (Cebus libidinosus) inhabiting savanna-like environments. Some populations in Serra da Capivara National Park (Piauí, Brazil), though, exhibit a seemingly broader toolkit, using wooden sticks as probes, and employing stone tools for a variety of pur...

Wild bearded capuchins (Cebus libidinosus, quadrupedal, medium-sized monkeys) crack nuts using large stones. We examined the kinematics and energetics of the nut-cracking action of two adult males and two adult females. From a bipedal stance, the monkeys raised a heavy hammer stone (1.46 and 1.32 kg, from 33 to 77% of their body weight) to an avera...

Appreciation of objects' affordances and planning is a hallmark of human technology. Archeological evidence suggests that Pliocene hominins selected raw material for tool making [1, 2]. Stone pounding has been considered a precursor to tool making [3, 4], and tool use by living primates provides insight into the origins of material selection by hum...

Selection and transport of objects to use as tools at a distant site are considered to reflect planning. Ancestral humans transported tools and tool-making materials as well as food items. Wild chimpanzees also transport selected hammer tools and nuts to anvil sites. To date, we had no other examples of selection and transport of stone tools among...