| wild capuchin monkeys (cebus libidinosus) use anvils and stone pounding tools. | we conducted an exploratory investigation in an area where nut-cracking by wild capuchin monkeys is common knowledge among local residents. in addition to observing male and female capuchin monkeys using stones to pound open nuts on stone "anvils," we surveyed the surrounding area and found physical evidence that monkeys cracked nuts on rock outcrops, boulders, and logs (collectively termed anvils). anvils, which were identified by numerous shallow depressions on the upper surface, the presence ... | 2004 | 15580579 |
| cross-genus adoption of a marmoset (callithrix jacchus) by wild capuchin monkeys (cebus libidinosus): case report. | we report a case of interspecies adoption of an infant marmoset (callithrix jacchus) by wild capuchin monkeys (cebus libidinosus). the marmoset was an infant when it was first observed in the capuchin group on 3 march 2004. since it first appeared it has been observed informally and frequently. in january 2005 systematic observations were made of the marmoset and a capuchin of similar age. throughout its period of adoption the marmoset appeared to be socially integrated into the group, benefitin ... | 2006 | 16786521 |
| spontaneous tool use by wild capuchin monkeys (cebus libidinosus) in the cerrado. | among primates, only chimpanzees and orang-utans are credited with customary tool use in nature. among monkeys, capuchins stand out with respect to the number of accounts of tool use. however, the majority of capuchin tool use observations reported in nature is anecdotal or idiosyncratic. in this report, we documented the stone pounding of dry fruits (hymenea courbaril and acrocomia aculeata) in two wild free-ranging groups of cebus libidinosus in the brasilia national park, a preserved area rep ... | 2006 | 16912501 |
| characteristics of hammer stones and anvils used by wild bearded capuchin monkeys (cebus libidinosus) to crack open palm nuts. | capuchins living in boa vista (piauì, brazil) crack open hard palm nuts on hard, level surfaces (anvils) using stones (hammers) as percussive tools. this activity leaves diagnostic physical remains: distinctive shallow depressions (pits) on the surface of the anvil, cracked shells, and stone hammers on the anvil. to initiate comparison of percussive stone tool use and interpretation of the artifacts it produces across capuchins, chimpanzees, and hominins, we describe a sample of the anvils and h ... | 2007 | 17177182 |
| response toward novel stimuli in a group of tufted capuchins (cebus libidinosus) in brasília national park, brazil. | we investigated responses toward novel foods and novel objects by wild capuchins that routinely exploit visitors' foods in brasília national park. given the capuchins' daily exposure to human foods and objects, we expected them to be more explorative toward novel foods and objects compared to capuchins that are not habituated to visitors. however, since the safety and palatability of potential foods have to be learned, we also expected the capuchins to be cautious about eating novel foods, as ha ... | 2007 | 17216622 |
| physical properties of palm fruits processed with tools by wild bearded capuchins (cebus libidinosus). | habitually, capuchin monkeys access encased hard foods by using their canines and premolars and/or by pounding the food on hard surfaces. instead, the wild bearded capuchins (cebus libidinosus) of boa vista (brazil) routinely crack palm fruits with tools. we measured size, weight, structure, and peak-force-at-failure of the four palm fruit species most frequently processed with tools by wild capuchin monkeys living in boa vista. moreover, for each nut species we identify whether peak-force-at-fa ... | 2008 | 18618602 |
| kinematics and energetics of nut-cracking in wild capuchin monkeys (cebus libidinosus) in piauí, brazil. | 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 average height of 0.33 m, 60% of body length. then, they rapidly lowered the stone by flexing the lower extremities and the trunk until the stone contacted ... | 2009 | 18785652 |
| the enhanced tool-kit of two groups of wild bearded capuchin monkeys in the caatinga: tool making, associative use, and secondary tools. | 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 purposes. over the course of 701.5 hr of visual contact of two wild capuchin groups we recorded 677 tool use episodes. five hundred and seventeen of thes ... | 2009 | 19051323 |
| distribution of potential suitable hammers and transport of hammer tools and nuts by wild capuchin monkeys. | 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 wild nonhuman primates. wild bearded capuchins (cebus libidinosus) in boa vista (piauí, brazil) routinely crack open palm nuts and other physically we ... | 2009 | 19172379 |
| behavioral flexibility of a group of bearded capuchin monkeys (cebus libidinosus) in the national park of brasília (brazil): consequences of cohabitation with visitors. | increasing urbanization and deforestation have enhanced the opportunities of contact between humans and monkeys and the impact of human activities on primate behavior is receiving growing attention. this study explores whether activity budgets and diet of a group of capuchin monkeys (cebus libidinosus) inhabiting the area of the swimming pools of the national park of brasília is affected by the presence of visitors providing food to them. during one year, both in the dry and the wet seasons, we ... | 2008 | 19197485 |
| first record of tool use by wild populations of the yellow-breasted capuchin monkey (cebus xanthosternos) and new records for the bearded capuchin (cebus libidinosus). | reports on use of stones as hammers and anvils to open hard nuts by wild capuchin monkeys are scarce and limited to cebus libidinosus. here, we report for the first time data on tool use-stones as hammer and anvils to open nuts-in wild c. xanthosternos and a description of new tool using sites for c. libidinosus. our records were made by visiting anvil sites and by information obtained from local residents. we surveyed three different biomes: caatinga (dry forest and thorn scrub), cerrado (brazi ... | 2009 | 19206141 |
| three stones for three seeds: natural occurrence of selective tool use by capuchins (cebus libidinosus) based on an analysis of the weight of stones found at nutting sites. | capuchins (cebus libidinosus) occupy areas of caatinga in northeast brazil. they consume the nuts of several species of difficult-to-open fruits (two species of palmae and one species of euphorbiacea) and are reported to use stones as hammers to crack open the nuts. this article describes the weight of hammers found on anvils and presumably used for nut-cracking by individuals in two groups of wild unprovisioned capuchin monkeys. hammer weights ranged from less than 200 to over 3 kg. based on a ... | 2010 | 19953558 |
| comparative anatomical study of the forearm extensor muscles of cebus libidinosus (rylands et al., 2000; primates, cebidae), modern humans, and other primates, with comments on primate evolution, phylogeny, and manipulatory behavior. | despite its abundance in latin america, and its remarkable ability to use tools, there are only a few myological studies on the capuchin monkey, cebus libidinosus. in the present study, we dissected the forearm extensor muscles of six adult males and two adult females of this species. we describe these muscles and compare them with those of other primates dissected by us and by other authors. the forearm extensor muscles of cebus monkeys are, in general, more similar to those of other platyrrhin ... | 2010 | 21082733 |
| biomarkers of genotoxicity and genomic instability in a non-human primate, cebus libidinosus (cebidae, platyrrhini), exposed to nitroimidazole derivatives. | the genotoxicity of two nitroimidazole derivatives, ornidazole (onz) and metronidazole (mtz) in the peripheral blood lymphocytes of cebus libidinosus (cli) (primates, cebidae) was assessed. endpoints measured included sister chromatid exchange (sce) frequency, cell proliferation kinetics (cpk), replication index (ri), mitotic index (mi), and damage incidence in or near cli heterochromatin regions. mi and sce values following onz or mtz treatments were significantly different (p<0.001) from contr ... | 2011 | 21255674 |
| stone tool use by adult wild bearded capuchin monkeys (cebus libidinosus). frequency, efficiency and tool selectivity. | chimpanzees have been the traditional referential models for investigating human evolution and stone tool use by hominins. we enlarge this comparative scenario by describing normative use of hammer stones and anvils in two wild groups of bearded capuchin monkeys (cebus libidinosus) over one year. we found that most of the individuals habitually use stones and anvils to crack nuts and other encased food items. further, we found that in adults (1) males use stone tools more frequently than females ... | 2011 | 21470663 |
| flexible and conservative features of social systems in tufted capuchin monkeys: comparing the socioecology of sapajus libidinosus and sapajus nigritus. | socioecological models assume that primates adapt their social behavior to ecological conditions, and predict that food availability and distribution, predation risk and risk of infanticide by males affect patterns of social organization, social structure and mating system of primates. however, adaptability and variation of social behavior may be constrained by conservative adaptations and by phylogenetic inertia. the comparative study of closely related species can help to identify the relative ... | 2011 | 21656840 |
| a comparative study of the recombination pattern in three species of platyrrhini monkeys (primates). | homologous chromosomes exchange genetic information through recombination during meiotic synapsis, a process that increases genetic diversity and is fundamental to sexual reproduction. meiotic studies in mammalian species are scarce and mainly focused on human and mouse. here, the meiotic recombination events were determined in three species of platyrrhini monkeys (cebus libidinosus, cebus nigritus and alouatta caraya) by analysing the distribution of mlh1 foci at the stage of pachytene. moreove ... | 2011 | 21735165 |
| risk factors associated with toxoplasma gondii infection in captive sapajus spp. | the aim of this study was to identify risk factors associated with prevalence of toxoplasma gondii infection in captive capuchin monkeys at a facility in the northeastern brazil. serum samples from 116 bearded capuchin (sapajus libidinosus), nine blonde capuchin (sapajus flavius), five black-capped capuchin (sapajus apella), and four capuchin monkeys (sapajus spp.) were tested for t. gondii antibodies using the modified agglutination test (mat, cut-off ≥25); antibodies were found in 85.3% (99/11 ... | 2015 | 25676671 |
| lineage-specific serology confirms brazilian atlantic forest lion tamarins, leontopithecus chrysomelas and leontopithecus rosalia, as reservoir hosts of trypanosoma cruzi ii (tcii). | trypanosoma cruzi, the agent of chagas disease in humans, has a vast reservoir of mammalian hosts in the americas, and is classified into six genetic lineages, tci-tcvi, with a possible seventh, tcbat. elucidating enzootic cycles of the different lineages is important for understanding the ecology of this parasite, the emergence of new outbreaks of chagas disease and for guiding control strategies. direct lineage identification by genotyping is hampered by limitations of parasite isolation and c ... | 2016 | 27846858 |
| effects of habitat structure and fragmentation on diversity and abundance of primates in tropical deciduous forests in bolivia. | habitat structure and anthropogenic disturbance are known to affect primate diversity and abundance. however, researchers have focused on lowland rain forests, whereas endangered deciduous forests have been neglected. we aimed to investigate the relationships between primate diversity and abundance and habitat parameters in 10 deciduous forest fragments southeast of santa cruz, bolivia. we obtained primate data via line-transect surveys and visual and acoustic observations. in addition, we asses ... | 2010 | 20949116 |
| female bearded capuchin monkeys (sapajus libidinosus) use objects to solicit the sexual partner. | female wild bearded capuchins (sapajus libidinosus) living at serra da capivara national park (scnp) that use stone and stick tools during foraging occasionally toss or throw stones at the male during courtship. we report similar behaviors in a different population that uses stones as tools in foraging. we video-recorded the sexual behavior of four females (27 days during nine proceptive periods) belonging to a group of wild capuchins living in fazenda boa vista (fbv), 320 km from scnp. three fe ... | 2017 | 28287755 |
| factors affecting cashew processing by wild bearded capuchin monkeys (sapajus libidinosus, kerr 1792). | cashew nuts are very nutritious but so well defended by caustic chemicals that very few species eat them. we investigated how wild bearded capuchin monkeys (sapajus libidinosus) living at fazenda boa vista (fbv; piauí, brazil) process cashew nuts (anacardium spp.) to avoid the caustic chemicals contained in the seed mesocarp. we recorded the behavior of 23 individuals toward fresh (n = 1282) and dry (n = 477) cashew nuts. adult capuchins used different sets of behaviors to process nuts: rubbing ... | 2016 | 27008439 |
| the strategic role of the tail in maintaining balance while carrying a load bipedally in wild capuchins (sapajus libidinosus): a pilot study. | the ability to carry objects has been considered an important selective pressure favoring the evolution of bipedal locomotion in early hominins. comparable behaviors by extant primates have been studied very little, as few primates habitually carry objects bipedally. however, wild bearded capuchins living at fazenda boa vista spontaneously and habitually transport stone tools by walking bipedally, allowing us to examine the characteristics of bipedal locomotion during object transport by a gener ... | 2016 | 26733456 |
| age-related variation in the mechanical properties of foods processed by sapajus libidinosus. | the diet of tufted capuchins (sapajus) is characterized by annual or seasonal incorporation of mechanically protected foods. reliance on these foods raises questions about the dietary strategies of young individuals that lack strength and experience to access these resources. previous research has demonstrated differences between the feeding competencies of adult and juvenile tufted capuchins. here we test the hypothesis that, compared to adults, juveniles will process foods with lower toughness ... | 2016 | 26381730 |
| wild bearded capuchin monkeys crack nuts dexterously. | dexterous tool use has been crucial in the evolution of hominid percussive technology. according to newell, "dexterity" is the ability of an organism to make goal-directed corrections in movements to optimize effort. dexterous movements are smooth and effective and accomplish the same goal with less energy than less dexterous movements. dexterity develops during the later phases of refining a motor skill as the actor becomes sensitive to the outcome of the preceding movement, or to its modulatio ... | 2015 | 25936553 |
| stone anvil damage by wild bearded capuchins (sapajus libidinosus) during pounding tool use: a field experiment. | we recorded the damage that wild bearded capuchin monkeys (sapajus libidinosus) caused to a sandstone anvil during pounding stone tool use, in an experimental setting. the anvil was undamaged when set up at the fazenda boa vista (fbv) field laboratory in piauí, brazil, and subsequently the monkeys indirectly created a series of pits and destroyed the anvil surface by cracking palm nuts on it. we measured the size and rate of pit formation, and recorded when adult and immature monkeys removed loo ... | 2014 | 25372879 |
| the effect of dietary adaption on cranial morphological integration in capuchins (order primates, genus cebus). | a fundamental challenge of morphology is to identify the underlying evolutionary and developmental mechanisms leading to correlated phenotypic characters. patterns and magnitudes of morphological integration and their association with environmental variables are essential for understanding the evolution of complex phenotypes, yet the nature of the relevant selective pressures remains poorly understood. in this study, the adaptive significance of morphological integration was evaluated through th ... | 2012 | 23110039 |
| comparative anatomy of the hind limb vessels of the bearded capuchins (sapajus libidinosus) with apes, baboons, and cebus capucinus: with comments on the vessels' role in bipedalism. | capuchin monkeys are known to exhibit sporadic bipedalism while performing specific tasks, such as cracking nuts. the bipedal posture and locomotion cause an increase in the metabolic cost and therefore increased blood supply to lower limbs is necessary. here, we present a detailed anatomical description of the capuchin arteries and veins of the pelvic limb of sapajus libidinosus in comparison with other primates. the arterial pattern of the bearded capuchin hind limb is more similar to other qu ... | 2013 | 24396829 |
| wild monkeys flake stone tools. | 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, conchoidally fractured, sharp-edged flakes and cores that have the characteristics and morphology of intentionally produced hominin tools. the producti ... | 2016 | 27760117 |
| pre-columbian monkey tools. | stone tools reveal worldwide innovations in human behaviour over the past three million years [1]. 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) [2]. this anthropocentrism limits our comparative insight into the emergence and development of technology, weakening our evolutionary models [3]. here, we apply archaeological techniques ... | 2016 | 27404235 |
| vertical bipedal locomotion in wild bearded capuchin monkeys (sapajus libidinosus). | 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 occurs often in nature in sapajus libidinosus, the bearded capuchin monkey. the context is transport of small food items from source to site of consu ... | 2016 | 27153820 |
| when and where to practice: social influences on the development of nut-cracking in bearded capuchins (sapajus libidinosus). | the habitual use of tools by wild capuchin monkeys presents a unique opportunity to study the maintenance and transmission of traditions. young capuchins spend several years interacting with nuts before cracking them efficiently with stone tools. using a two-observer method, we quantified the magnitude of the social influences that sustain this long period of practice. during five collection periods (over 26 months), one observer recorded the behavior of 16 immature monkeys, and another observer ... | 2016 | 26932847 |
| the effects of tradition on problem solving by two wild populations of bearded capuchin monkeys in a probing task. | 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 studies have shown that cultural knowledge may influence problem solving in wild populations of chimpanzees. here, we present the results from a field e ... | 2016 | 27881763 |
| wild capuchin monkeys spontaneously adjust actions when using hammer stones of different mass to crack nuts of different resistance. | expert tool users are known to adjust their actions skillfully depending on aspects of tool type and task. we examined if bearded capuchin monkeys cracking nuts with stones of different mass adjusted the downward velocity and the height of the stone when striking palm nuts. | 2016 | 27135182 |
| the fourth dimension of tool use: temporally enduring artefacts aid primates learning to use tools. | all investigated cases of habitual tool use in wild chimpanzees and capuchin monkeys include youngsters encountering durable artefacts, most often in a supportive social context. we propose that enduring artefacts associated with tool use, such as previously used tools, partly processed food items and residual material from previous activity, aid non-human primates to learn to use tools, and to develop expertise in their use, thus contributing to traditional technologies in non-humans. therefore ... | 2013 | 24101621 |
| comparative anatomical analyses of the forearm muscles of cebus libidinosus (rylands et al. 2000): manipulatory behavior and tool use. | the present study describes the flexor and extensor muscles in cebus libidinosus' forearm and compares them with those from humans, chimpanzees and baboons. the data is presented in quantitative anatomical indices for similarity. the capuchin forearm muscles showed important similarities with chimpanzees and humans, particularly those that act on thumb motion and allow certain degree of independence from other hand structures, even though their configuration does not enable a true opposable thum ... | 2011 | 21789230 |
| diversity of nutcracking tool sites used by sapajus libidinosus in brazilian cerrado. | 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 fields, savannas and forest formations. we conducted surveys in 10 of 20 localities where nutcracking by capuchins was reported by the local inhabitants in ... | 2015 | 25676549 |
| sexual bias in probe tool manufacture and use by wild bearded capuchin monkeys. | here we examine data from a two-year research on the use of sticks as probes by two groups of wild capuchin monkeys (sapajus libidinosus) in serra da capivara national park (pi), brazil. the use of sticks as probes is not usually observed among wild tufted capuchin (sapajus spp.) populations, having been reported as a customary behavior only in scnp groups. probe tools are used to access small prey (insects or lizards) in rock cracks or tree trunks, or honey from wasps' nests, and also to poke t ... | 2014 | 25446625 |
| kinematics of bipedal locomotion while carrying a load in the arms in bearded capuchin monkeys (sapajus libidinosus). | understanding the selective pressures that drove the evolution of bipedalism in the human lineage may help inform researchers about the locomotor mode(s) of pre-hominin ancestors. several selective pressures have been hypothesized, including the need to carry food, tools, or infants. bearded capuchin monkeys are an excellent primate in which to examine the hypothesis that carrying supported the evolution of bipedalism because they are morphologically generalized and in some ways similar to mioce ... | 2012 | 23149226 |
| techniques used by bearded capuchin monkeys (sapajus libidinosus) to access water in a semi-arid environment of north-eastern brazil. | the exploratory behaviour and the ability of capuchin monkeys to use tools allows them to thrive at times and places of limited food and water abundance, such as in semi-arid environments. here, we report the behaviours employed by individuals belonging to a wild group of bearded capuchin monkeys (sapajus libidinosus) to access natural water sources in a dry forest of north-eastern brazil. an adult female employed a twig as a tool and her tail to gain access to accumulated rainwater in a tree ho ... | 2017 | 28848101 |
| anatomical description of the main vessels for venipuncture in the black-striped capuchin monkey (sapajus libidinosus, silva junior, 2002). | the scarcity of data on the anatomy of sapajus libidinosus has impeded the execution for appropriate veterinary treatment. the objective of this study was to describe the main peripheral veins of the capuchin monkey, used in venipuncture and indicate the best access route for venipuncture procedures. | 2017 | 28809436 |
| cashew nut positioning during stone tool use by wild bearded capuchin monkeys (sapajus libidinosus). | wild capuchin monkeys (sapajus libidinosus) at serra da capivara national park, brazil, regularly use stone tools to break open cashew nuts (anacardium spp.). here we examine 2 approaches used by the capuchins to position the kidney-shaped cashew nuts on an anvil before striking with a stone tool. lateral positioning involves placing the nut on its flatter, more stable side, therefore requiring less attention from the monkey during placement. however, the less stable and never previously describ ... | 2016 | 28245462 |
| wild capuchin monkeys adjust stone tools according to changing nut properties. | animals foraging in their natural environments need to be proficient at recognizing and responding to changes in food targets that affect accessibility or pose a risk. wild bearded capuchin monkeys (sapajus libidinosus) use stone tools to access a variety of nut species, including otherwise inaccessible foods. this study tests whether wild capuchins from serra da capivara national park in brazil adjust their tool selection when processing cashew (anacardium spp.) nuts. during the ripening proces ... | 2016 | 27624672 |
| growing up tough: comparing the effects of food toughness on juvenile feeding in sapajus libidinosus and trachypithecus phayrei crepusculus. | studies of primate feeding ontogeny provide equivocal support for reduced juvenile proficiency. when immatures exhibit decreased feeding competency, these differences are attributed to a spectrum of experience- and strength-related constraints and are often linked to qualitative assessments of food difficulty. however, few have investigated age-related differences in feeding ability relative to mechanical property variation across the diet, both within and among food types. in this study, we com ... | 2016 | 27544691 |
| body mass in wild bearded capuchins, (sapajus libidinosus): ontogeny and sexual dimorphism. | body mass is fundamental for understanding growth, health, and aspects of life history but records of body mass are rarely available for wild primates. we documented the body mass of all individuals in a group of wild bearded capuchin monkeys (sapajus libidinosus) at annual intervals for seven consecutive years. sexual dimorphism in body mass was more pronounced than reported in the literature for adults in this genus: females in our sample were relatively light (average 2.1 kg), while males had ... | 2015 | 26637804 |
| hand preference during tool use in wild bearded capuchins. | the preferential use of one limb (lateralization) has been observed in many species. this lateralization reflects functional asymmetries of the brain. right-handedness and left-hemisphere dominance seem to be the norm in humans. however, suggestions that vertebrates, particularly non-human primates, show handedness are contentious. tool use could be a driver of handedness. here i investigated hand bias during tool use activities in groups of wild capuchins (sapajus libidinosus). i observed the u ... | 2015 | 26382752 |
| kinetics of bipedal locomotion during load carrying in capuchin monkeys. | facultative bipedalism during load transport in nonhuman primates has been argued to be an important behavior potentially leading to the evolution of obligate, extended limb bipedalism. understanding the biomechanics of such behavior may lead to insights about associated morphology, which may translate to interpretation of features in the fossil record. some populations of bearded capuchin monkeys (sapajus libidinosus) spontaneously carry heavy loads bipedally during foraging activities. this st ... | 2015 | 26073073 |
| computerized spatial delayed recognition span task: a specific tool to assess visuospatial working memory. | a new tablet device version (ios platform) of the spatial delayed recognition span task (sdrst) was developed with the aim of investigating visuospatial working memory (wm) abilities based on touchscreen technology. this new wm testing application will be available to download for free in apple store app ("sdrst app"). in order to verify the feasibility of this computer-based task, we conducted three experiments with different manipulations and groups of participants. we were interested in inves ... | 2015 | 25964758 |
| nasal probe and toothpick tool use by a wild female bearded capuchin (sapajus libidinosus). | we report the first observation of probe tool use by a wild adult female bearded capuchin (sapajus libidniosus), at serra da capivara national park (scnp), brazil. this individual used several stick tools and one grass stem to probe her nostrils, usually triggering a sneeze reaction, and also used stick tools to probe her teeth or gum. both of these behaviours were accompanied by inspection and licking of the tool following use. we have termed these self-directed actions nasal probe and toothpic ... | 2015 | 25864187 |
| comparative anatomy of the pelvic vessels in the bearded capuchin (sapajus libidinosus) and baboons, apes and modern humans. | cebus/sapajus has shown high cognitive and manipulatory behaviour as well as intermittent bipedalism. although the function of the muscles and bones of this genus has been widely investigated, the arterial system that supports these tissues has not been studied in much detail, and a full description of the blood vessels of the pelvis is still missing. therefore, we studied the vessels of the pelvis of sapajus libidinosus in terms of their origin, distribution and muscle irrigation and compared t ... | 2014 | 25377625 |
| epidural anesthesia in capuchin monkeys (sapajus libidinosus). | many primates are kept in breeding for scientific or conservation purposes, but much of the clinical care is represented by trauma. to provide more effective interventions in some of these cases, the present study aimed to evaluate the technique of local anesthesia through the epidural space in capuchin monkeys (sapajus libidinosus). | 2015 | 25348555 |
| does hierarchy stability influence testosterone and cortisol levels of bearded capuchin monkeys (sapajus libidinosus) adult males? a comparison between two wild groups. | testosterone and cortisol are hormones expected to play a major role in competitive behaviours (i.e. aggression), and are related to rank and hierarchical stability. through a non-invasive technique, we analyzed faecal testosterone (ftm(1)) and cortisol (fcm(2)) metabolites of dominant and subordinate males from two wild groups of bearded capuchin monkeys. one group had a stable dominance hierarchy while the other had an unstable hierarchy, with a marked conflict period related to a male take-ov ... | 2014 | 25239540 |
| adaptability in stone tool use by wild capuchin monkeys (sapajus libidinosus). | capuchin monkeys are well known for population variation in the use of stone tools and the types of food items consumed. in order to determine adaptability in stone tool use, we investigated a never before studied population of wild capuchin monkey (sapajus libidinosus) displaying terrestrial habits in a caatinga environment. to carry out this study we recorded physical evidence of the use of stone tools as well as made direct observations through trap cameras. during a 15-month period, we studi ... | 2014 | 24753103 |
| stone throwing as a sexual display in wild female bearded capuchin monkeys, sapajus libidinosus. | 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, vocalizations, stereotyped body postures, and touch-and-run behavior. this study reports stone throwing as a newly-described communicative behavior duri ... | 2013 | 24278147 |
| wild bearded capuchin monkeys (sapajus libidinosus) strategically place nuts in a stable position during nut-cracking. | humans can use hand tools smoothly and effectively in varying circumstances; in other words, skillfully. a few other species of primates crack encased foods using hammer tools and anvils. are they skilled? positioning the food on the anvil so that it does not fall off when struck is a component of skilled cracking. we discovered that bearded capuchin monkeys deliberately place palm nuts in a relatively stable position on the anvil before striking them. in the first experiment, we marked the meri ... | 2013 | 23460793 |
| wild bearded capuchins process cashew nuts without contacting caustic compounds. | complex and flexible food processing was a key element for the evolutionary success of hominins, enlarging the range of exploitable foods while enabling occupation of new habitats. only a few primate species crack open encased food by using percussive tools and/or avoid physical contact with irritant compounds by removing the structures containing them. we describe, for the first time, how a population of bearded capuchin monkeys (sapajus libidinosus) accesses the nutritious kernel of cashew nut ... | 2013 | 23300054 |
| wild bearded capuchin (sapajus libidinosus) select hammer tools on the basis of both stone mass and distance from the anvil. | contemporary optimization models suggest that animals optimize benefits of foraging and minimize its costs. for wild bearded capuchins (sapajus libidinosus), nut-cracking entails cost related to lifting the heavy stone and striking the nut and additional cost to transport the stone if it is not already on the anvil. to assess the role of stone mass and transport distance in capuchins' tool selection, we carried out three field experiments. in experiment 1, we investigated whether transport dista ... | 2012 | 22821007 |
| energetic payoff of tool use for capuchin monkeys in the caatinga: variation by season and habitat type. | in this paper, we analyze predictions from the energetic bottleneck and opportunity models to explain the use of stones to crack open encased fruit by capuchins in dry environments. the energetic bottleneck model argues that tool use derives from the need to crack open hard-encased fruits which are key resources during periods of food scarcity. the opportunity model argues that tool use by capuchins derives from simultaneous access to stones and encased fruits. the study was conducted in the caa ... | 2012 | 22539256 |
| genome size of two cebus species (primates: platyrrhini) with a fertile hybrid and their quantitative genomic differences. | genome size or c-value is defined as the total amount of dna contained within a haploid chromosome set and is regarded as a species-specific constant. speciation among neotropical primates seems to be accompanied by marked quantitative changes in dna content. a direct correlation between genome size and the presence of heterochromatin has also been proposed. in this work, we analyzed the genome of a female fertile hybrid between cebus libidinosus and c. nigritus using interspecies comparative ge ... | 2011 | 21811058 |
| analysis of the heterochromatin of cebus (primates, platyrrhini) by micro-fish and banding pattern comparisons. | the karyotype of the neotropical primate genus cebus (platyrrhini: cebidae), considered the most ancestral one, shows the greatest amount of heterochromatin described among platyrrhini genera. banding techniques and restriction enzyme digestion have previously revealed great variability of quantity and composition of heterochromatin in this genus. in this context, we use fluorescence in situ hybridization (fish) to analyse this genomic region and discuss its possible role in the diversification ... | 2011 | 21677395 |
| food or threat? wild capuchin monkeys (sapajus libidinosus) as both predators and prey of snakes. | 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 on snakes, and humans are one of the few primate species that do. we report here another case, the wild capuchin monkey (sapajus libidinosus), which p ... | 2018 | 28918605 |
| unique perceptuomotor control of stone hammers in wild monkeys. | we analysed the patterns of coordination of striking movement and perceptuomotor control of stone hammers in wild bearded capuchin monkeys,sapajus libidinosusas they cracked open palm nut using hammers of different mass, a habitual behaviour in our study population. we aimed to determine why these monkeys cannot produce conchoidally fractured flakes as do contemporary human knappers or as did prehistoric hominin knappers. we found that the monkeys altered their patterns of coordination of moveme ... | 2018 | 29321246 |
| seroprevalence of selected flaviviruses in free-living and captive capuchin monkeys in the state of pernambuco, brazil. | mosquito-borne diseases such as dengue, yellow fever and, more recently, chikungunya virus (chikv) and zika virus (zikv) have a great impact in the public health. in addition, the presence of such viruses might have an impact on wild animal conservation as well as their possible role as animal reservoir. here, we performed a serological survey searching for antibodies against a panel of flaviviruses [zikv, dengue virus (denv), yellow fever virus (yfv), west nile virus (wnv), saint louis encephal ... | 2018 | 29424106 |
| atlantic-primates: a dataset of communities and occurrences of primates in the atlantic forests of south america. | primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. there are 26 primate species in the atlantic forests of south america, 19 of them endemic. we compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera callithrix and alouatta. the dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates ... | 2019 | 30317556 |
| assessment of the technique of the anesthetic block of the brachial plexus by supraclavicular approach in sapajus libidinosus (spix, 1823). | the aim of study was to evaluate the efficacy of the supraclavicular brachial plexus block technique in sapajus libidinosus. | 2020 | 33053204 |
| anatomy of the dura mater venous sinus of alouatta belzebul. | the anatomy of the dura mater's venous sinuses is important in the veterinary clinical and surgical area, for cranial procedures and interventions of wild animals, in addition to assisting in the management of neurological diseases, which can prevent serious complications. the macroscopic anatomy of the venous sinuses of the dura mater of alouatta belzebul was studied. five adult specimens, males and females, were dissected and fixed in 10% formaldehyde solution. in the dura mater of the alouatt ... | 2020 | 32738181 |
| isotopic and elemental corroborates for wild bearded capuchin (sapajus libidinosus) omnivorous dietary adaptation at fazenda boa vista, brazil. | this study analyzes variability in the diets of wild bearded capuchin monkeys, sapajus libidinosus, by analyzing stable carbon (δ13 c value) and nitrogen (δ15 n values) isotope ratios and elemental concentrations (%c and %n) of fecal samples and food items. developing isotopic and elemental correlates for diets of habituated subjects is a necessary step toward applying similar methods to interpret diets of unhabituated or cryptic subjects. | 2020 | 32526804 |
| adult and juvenile bearded capuchin monkeys handle stone hammers differently during nut-cracking. | wild bearded capuchin monkeys (sapajus libidinosus) habitually use stone hammers to crack open palm nuts and seeds on anvils. this activity requires strength, balance, and precise movement of a large stone with respect to the item placed on an anvil. we explored how well young monkeys cope with these challenges by examining their behavior and the behavior of adults while they cracked palm nuts using a stone. using video records, we compared actions of six juvenile (2-5 years) and six adult (7+ y ... | 2020 | 32458474 |
| compound grips in tufted capuchin monkeys (sapajus spp and sapajus libidinosus). | an experimental study with captive individuals and study of video recordings of wild monkeys explored whether and how tufted capuchin monkeys use onehand to hold one or more objects with multiple grips (compound grips). a task designed to elicit compound grip was presented to five captive tufted capuchin monkeys (sapajus spp). the monkeys held one to four balls in onehand and dropped the balls individually into a vertical tube. multiple simple grips and independent digit movements enabled separa ... | 2020 | 32337763 |
| haematological and biochemical parameters of wild capuchin monkeys in brasília, federal district-brazil. | wild capuchin monkeys (sapajus libidinosus) usually are found in conserved forests near the zoo and the urban areas of brasília city, brazil. in this study, some capuchin monkeys were captured using traps, followed by safe biological procedures for their overall health analysis, based on specific haematological and biochemical tests of blood samples. | 2020 | 32175604 |
| trachea and lung anatomy applied to clinical and surgical procedures in sapajus libidinosus (spix, 1823). | the objective of the present study was to study the anatomy of the respiratory system of sapajus libidinosus. | 2020 | 31960468 |
| face-to-face interactions between mothers and female infants in wild bearded capuchin monkeys (sapajus libidinosus). | once considered uniquely human, mother-infant face-to-face interactions (ff) were observed in a few captive primates. in these studies, ff were correlated to physical contact suggesting a mechanism mediating proximity between mother and infant, as is the case for humans. we investigated this hypothesis in wild capuchin monkeys (sapajus libidinosus) during the first year of life of eight female infants. data were weekly focal-day videos of infants from which we recorded ff with mothers. we expect ... | 2020 | 31891984 |
| positional behavior and substrate use in wild adult bearded capuchin monkeys (sapajus libidinosus). | natural selection for positional behavior (posture and locomotion) has at least partially driven the evolution of anatomical form and function in the order primates. examination of bipedal behaviors associated with daily activity patterns, foraging, and terrestrial habitat use in nonhuman primates, particularly those that adopt bipedal postures and use bipedal locomotion, allows us to refine hypotheses concerning the evolution of bipedalism in humans. this study describes the positional behavior ... | 2019 | 31721259 |
| faecal virome analysis of wild animals from brazil. | the brazilian cerrado fauna shows very wide diversity and can be a potential viral reservoir. therefore, the animal's susceptibility to some virus can serve as early warning signs of potential human virus diseases. moreover, the wild animal virome of this biome is unknown. based on this scenario, high-throughput sequencing contributes a robust tool for the identification of known and unknown virus species in this environment. in the present study, faeces samples from cerrado birds (psittacara le ... | 2019 | 31480274 |
| distinct perceptuomotor features of percussive tooling in humans (homo sapiens) and wild bearded capuchin monkeys (sapajus libidinosus). | adjustment of percussive movements to match the energetic requirements of the task serves as an index of skill in stone-knapping and nut-cracking. in this study, we compared strike-by-strike adjustment of percussive movements in expert bearded capuchin monkeys (sapajus libidinosus) and (novice and expert) humans cracking palm nuts (astrocaryum spp.) using stone hammers of varying mass. the monkeys regulated each strike's amplitude and hammer's velocity at impact to a small degree based on the pr ... | 2020 | 31393142 |
| manual skills for processing plant underground storage organs by wild bearded capuchins. | wild sapajus libidinosus exploit underground storage organs (usos) that require extraction and extensive processing before consumption. since capuchin monkeys are small-sized extractive foragers that cannot perform forceful precision grips, we expected that: (a) they would use other body parts together with their hands, (b) older (and larger) capuchins would be more efficient than younger (and smaller) ones, and (c) capuchins would invest greater effort/time to exploit usos than other foods. | 2019 | 31265758 |
| three thousand years of wild capuchin stone tool use. | 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 monkey stone tools between 2,400 and 3,000 years old and, on the basis of metric and damage patterns, demonstrate that capuchin food processing changed ... | 2019 | 31235926 |
| continuous use of combined hormonal contraceptive and the effect on blood coagulation factors in female capuchin monkeys (sapajus libidinosus). | this study aimed at evaluating the availability of the primate sapajus libidinosus as an animal model for research assessing the physiological effects of the continuous use of combined hormonal contraceptives. in order to do this, six reproductively active female s. libidinosus from the primate research center of the university of brasília were selected to take part in this experiment. every 21 days or so, each female received a single dose of combined hormonal contraceptive (algestone acetophen ... | 2019 | 31001334 |
| electrocardiographic parameters of sapajus libidinosus (spix, 1823) after chemical immobilization with tiletamine-zolazepam. | tiletamine-zolazepam is a widely used as an alternative chemical immobilization method in non-human primates, with a safe application pathway and necessary relaxation. in order to determine the electrocardiographic parameters of sapajus libidinosus after intramuscular tiletamine-zolazepam administration at the dose of 5 mg/kg, nine animals were submitted to anesthesia. | 2019 | 30868585 |
| how bearded capuchin monkeys (sapajus libidinosus) prepare to use a stone to crack nuts. | bearded capuchin monkeys crack nuts with naturally varying stone hammers, suggesting they may tune their grips and muscular forces to each stone. if so, they might use discrete actions on a stone before lifting and striking, and they would likely use these actions more frequently when the stone is larger and/or less familiar and/or when first initiating striking. we examined the behavior of (a) four monkeys (all proficient at cracking nuts) with two larger (1 kg) and two smaller (0.5 kg) stones, ... | 2019 | 30811071 |
| oral microbiota and their antibiotic susceptibility in free-living monkeys in goiás state, brazil: repercussions for injuries in humans. | goiás state, which is in the midwest region of brazil, has several urban forests. this fact, along with the expansion of urban areas within the limits of forest conservation units, increases the contact between humans and wildlife, such as capuchin monkeys. the impulsive behavior of these animals and the scarcity of food cause them to vigorously search for food, leading to direct encounters with park visitors, which can result in scratches and bites and making them potential disseminators of pat ... | 2019 | 30652796 |
| bearded capuchin monkeys use joint synergies to stabilize the hammer trajectory while cracking nuts in bipedal stance. | the transition from occasional to obligate bipedalism is a milestone in human evolution. however, because the fossil record is fragmentary and reconstructing behaviour from fossils is difficult, changes in the motor control strategies that accompanied this transition remain unknown. quadrupedal primates that adopt a bipedal stance while using percussive tools provide a unique reference point to clarify one aspect of this transition, which is maintaining bipedal stance while handling massive obje ... | 2018 | 30333210 |
| determination of baseline values for routine ophthalmic tests in bearded capuchin (sapajus libidinosus). | establish baseline values for ophthalmic diagnostic tests in sapajus libidinosus. | 2019 | 30230553 |
| trypanosoma cruzi transmission in the wild and its most important reservoir hosts in brazil. | trypanosoma cruzi (kinetoplastea: trypanosomatidae) infects all tissues of its hosts, which along with humans, include hundreds of mammalian species in the americas. the epidemiology of t. cruzi has been changing in that currently the majority of the cases and/or outbreaks of chagas disease occur by the ingestion of comestibles contaminated by t. cruzi metacyclic forms. these cases/outbreaks occur in distinct regional scenarios, mainly in the amazon biome and are related to the local interaction ... | 2018 | 30189896 |
| 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 th ... | 2018 | 29550951 |
| intersection as key locations for bearded capuchin monkeys (sapajus libidinosus) traveling within a route network. | there is evidence that wild animals are able to recall key locations and associate them with navigational routes. studies in primate navigation suggest most species navigate through the route network system, using intersections among routes as locations of decision-making. recent approaches presume that points of directional change may be key locations where animals decide where to go next. over four consecutive years, we observed how a wild group of bearded capuchin monkeys used a route network ... | 2018 | 29532262 |