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intimate social behavior in infant interactions in cebus apella.the development and individual stability of three intimate social behaviors (lipsmacking, carrying attempts, and facial inspection) were examined for 43 group-housed cebus apella infants from birth to 2 years of age. occurrence of these behaviors was scored from 10-min videotape samples recorded three times a week over that time. frequency of lipsmacking and carrying attempts by adult males, adult females, and juveniles were all highest in early months and decreased to low levels by the end of t ...200918925645
quality before quantity: rapid learning of reverse-reward contingency by capuchin monkeys (cebus apella).capuchin monkeys (cebus apella) were tested on a reverse-reward task involving different quantities of the same food, or an identical quantity of different foods. all monkeys tested first on the qualitative version spontaneously mastered the task, whereas only one of four spontaneously mastered the quantitative version. no monkey reached criterion when the tasks were switched, although almost all did so following remedial procedures after the study. the results suggest that (a) qualitative rever ...200819014269
grooming, rank, and agonistic support in tufted capuchin monkeys.studies investigating the relation between allogrooming and social rank in capuchin monkeys (genus cebus) have yielded inconsistent results. in this study, we investigated the relation between grooming, agonistic support, aggression and social rank in a captive group of tufted capuchin monkeys (c. apella). differently from most previous studies, we based our analyses on a relatively large database and studied a group with known genealogical relationships. tufted capuchin females did not exchange ...200919025780
ontogeny of manipulative behavior and nut-cracking in young tufted capuchin monkeys (cebus apella): a perception-action perspective.how do capuchin monkeys learn to use stones to crack open nuts? perception-action theory posits that individuals explore producing varying spatial and force relations among objects and surfaces, thereby learning about affordances of such relations and how to produce them. such learning supports the discovery of tool use. we present longitudinal developmental data from semifree-ranging tufted capuchin monkeys (cebus apella) to evaluate predictions arising from perception-action theory linking man ...200819046151
pharmacokinetics and pharmacodynamics of interferon beta 1a in cebus apella.recombinant human interferon (hifn beta) is indicated for the treatment of multiple sclerosis. its effect presents species restriction, thus lacking biological activity on most mammals. although there have been previous studies of the pharmacology of inf beta in old world primates, no data exists on new world primates. therefore, we explored its effect on cebus apella, a new world monkey, describing the pharmacology of this molecule when injected by subcutaneous route in this species.200919054274
navigating two-dimensional mazes: chimpanzees (pan troglodytes) and capuchins (cebus apella sp.) profit from experience differently.we examined whether navigation is impacted by experience in two species of nonhuman primates. five chimpanzees (pan troglodytes) and seven capuchin monkeys (cebus apella) navigated a cursor, using a joystick, through two-dimensional mazes presented on a computer monitor. subjects completed 192 mazes, each one time. each maze contained one to five choices, and in up to three of these choices, the correct path required moving the cursor away from the euclidean direction toward the goal. some subje ...200919148688
does inequity aversion depend on a frustration effect? a test with capuchin monkeys (cebus apella).brosnan and de waal (nature 425:297-299, 2003) reported that if a witness monkey saw a model monkey receive a high-value food, the witness was more inclined to reject a previously acceptable, but low-value food. later work demonstrated that this alleged inequity aversion might be due to frustration induced by switching subjects from their role as models receiving a high-value food to the role of witnesses receiving a low-value food. in the present study, pairs of female capuchins exchanged a tok ...200919184138
social facilitation of exploratory foraging behavior in capuchin monkeys (cebus apella).much of the research on animal social learning focuses on complex cognitive functions such as imitation and emulation. when compelling evidence for such processes is not forthcoming, simpler processes are often assumed but rarely directly tested for. in this study we address the phenomenon of social facilitation, whereby the presence of a feeding conspecific is hypothesized to affect the motivation and behavior of the subject, elevating the likelihood of exploration and discovery in relation to ...200919235756
tufted capuchin monkeys (cebus apella) spontaneously use visual but not acoustic information to find hidden food items.foraging choices in tufted capuchins monkeys are guided by perceptual, cognitive, and motivational factors, but little is known about how these factors might interact. the present study investigates how different types of sensory information affect capuchins' ability to locate hidden food. in two experiments, capuchins were presented with two cups, one baited and one empty. monkeys were given visual, acoustic, or acoustic-visual information related to the baited cup, the empty cup, or both baite ...200919236142
the relative use of proximity, shape similarity, and orientation as visual perceptual grouping cues in tufted capuchin monkeys (cebus apella) and humans (homo sapiens).recent experimental results suggest that human and nonhuman primates differ in how they process visual information to assemble component parts into global shapes. to assess whether some of the observed differences in perceptual grouping could be accounted for by the prevalence of different grouping factors in different species, we carried out 2 experiments designed to evaluate the relative use of proximity, similarity of shape, and orientation as grouping cues in humans (homo sapiens) and capuch ...200919236145
metamemory in tufted capuchin monkeys (cebus apella).whereas evidence for metacognition by nonhuman primates has been obtained in great apes and old world monkeys, it is weaker in new world monkeys. for instance, capuchin monkeys may fail to recognize their own knowledge of the location of invisible bait. in the present study, we tested whether tufted capuchin monkeys would flexibly change their behavior in a delayed matching-to-sample (dmts) test depending upon the strength of their memory trace of the sample. in experiment 1, two monkeys were te ...200919242741
interspecific primate associations in amazonian flooded and unflooded forests.stable associations between two or more primate species are a prominent feature of neotropical forest vertebrate communities and many studies have addressed their prevalence, and their costs and benefits. however, little is known about the influence of different habitat types on the frequency, seasonality, and composition of mixed-species groups in amazonian forest primates. here we examine the features of interspecific primate groups in a large mosaic of flooded (várzea and igapó) and unflooded ...200919242777
is the positive c-kit immunostaining associated with the presence of cells analogous to the intersticial cells of cajal in the ciliary muscle?interstitial cells of cajal were identified in the gastrointestinal tract of several species, with close relation to the enteric nervous system. since it was recognized that interstitial cells of cajal express the gene product of c-kit, we performed immunohistochemistry for c-kit protein in ciliary muscle specimens of monkeys' eyes.200919347121
a comparative study of corpus callosum size and signal intensity in capuchin monkeys (cebus apella) and chimpanzees (pan troglodytes).the evolution of corpus callosum (cc) was integral to the development of higher cognitive processes and hemispheric specialization. an examination of cc morphology and organization across different primate species will further our understanding of the evolution of these specified functions. using magnetic resonance imaging (mri) as a non-invasive technique to measure cc size and to approximate the degree of myelination in the corpus callosum, we report differences in cc morphology and organizati ...200919356692
[study of capability for recognition of complex visual stimuli of different quantities in the lower monkeys].capability of monkeys for identification of quantitative signs has been studied at recognition and comparison of two- and three-dimensional objects in quantities from 1 to 8. the work was carried out on two species of the low monkeys: rhesus macaque (macaca mulatta) and brown capuchins (cebus apella). the studied representatives of the monkeys have been established to be able to differentiate planar images and casts of cherries in various quantity combinations from 1 to 8 and to identify identic ...200919370996
histological findings following the use of a space-making device for bone reformation and implant integration in the maxillary sinus of primates.previous studies have shown that membrane elevation results in predictable bone formation in the maxillary sinus provided that implants can be placed as tent poles. in situations with an extremely thin residual crest which impairs implant placement, it is possible that a space-making device can be used under the sinus membrane to promote bone formation prior to placement of implants.200919392856
face recognition in capuchin monkeys (cebus apella).primates live in complex social groups that necessitate recognition of the individuals with whom they interact. in humans, faces provide a visual means by which to gain information such as identity, allowing us to distinguish between both familiar and unfamiliar individuals. the current study used a computerized oddity task to investigate whether a new world primate, cebus apella, can discriminate the faces of in-group and out-group conspecifics based on identity. the current study, improved on ...200919450022
developmental sources of conservation and variation in the evolution of the primate eye.conserved developmental programs, such as the order of neurogenesis in the mammalian eye, suggest the presence of useful features for evolutionary stability and variability. the owl monkey, aotus azarae, has developed a fully nocturnal retina in recent evolution. description and quantification of cell cycle kinetics show that embryonic cytogenesis is extended in aotus compared with the diurnal new world monkey cebus apella. combined with the conserved mammalian pattern of retinal cell specificat ...200919451636
suppression of ovulation by a synthetic progestin in the capuchin monkey.from the limited research in new world monkeys it is not clear whether they are as sensitive to the antiovulatory effects of synthetic progestins as noted in human beings. we examined whether levonorgestrel prevented ovulation in the capuchin monkey.200919470082
monkeys crying wolf? tufted capuchin monkeys use anti-predator calls to usurp resources from conspecifics.the use of 'tactical deception' is argued to have been important in the cognitive evolution of the order primates, but systematic studies of active deception in wild non-human primates are scant. this study tests whether wild tufted capuchin monkeys (cebus apella nigritus) use alarm calls in a functionally deceptive manner to usurp food resources. if capuchins use alarm calls 'deceptively', it was predicted that false alarms should be: (i) given by subordinates more than by dominants, (ii) more ...200919493903
picture processing in tufted capuchin monkeys (cebus apella).although pictures are frequently used in place of real objects to investigate various aspects of cognition in different non-human species, there is little evidence that animals treat pictorial stimuli as representations of the real objects. in the present study, we carried out four experiments designed to assess picture processing in tufted capuchin monkeys (cebus apella), using a simultaneous matching-to-sample (mts) task. the results of the first three experiments indicate that capuchins are a ...200919501136
tufted capuchin monkeys (cebus apella) show understanding of human attentional states when requesting food held by a human.researchers have investigated to what extent non-human primates understand others' attentional states, as this ability is considered an important prerequisite for theory of mind. however, previous studies using food requesting tasks have failed to show that non-human primates attribute perception to others as a function of their attentional states. one possible reason is that food requesting tasks may require subjects not only to take into account an experimenter's attentional state but also to ...201019517147
effects of follicular phase and oocyte-cumulus complexes quality on the protein profile and in vitro oocyte meiosis competence in cebus apella.to study the protein profile of oocytes and cumulus cells from different sized follicles throughout the follicular phase and to asses the ability of oocytes to progress from the dictyate to metaphase ii (mii) stage.201019560758
the psychological organization of "uncertainty" responses and "middle" responses: a dissociation in capuchin monkeys (cebus apella).some studies of nonhuman animals' metacognitive capacity encourage competing low-level, behavioral descriptions of trial-decline responses by animals in uncertainty-monitoring tasks. to evaluate the force of these behavioral descriptions, the authors presented 6 capuchin monkeys (cebus apella) with 2 density discrimination tasks between sparse and dense stimuli. in one task, difficult trials with stimuli near the middle of the density continuum could be declined through an "uncertainty" response ...200919594282
capuchin monkeys (cebus apella) are sensitive to others' reward: an experimental analysis of food-choice for conspecifics.the issue whether non-human primates have other-regarding preference and/or inequity aversion has been under debate. we investigated whether tufted capuchin monkeys are sensitive to others' reward in various experimental food sharing settings. two monkeys faced each other. the operator monkey chose one of two food containers placed between the participants, each containing a food item for him/herself and another for the recipient. the recipient passively received either high- or low-value food d ...201019609580
ricinus communis biocompatibility histological study in the nose of cebus apella monkeys.bone tissue lesions can be caused by congenital and acquired factors, and result in nasal deformities with cosmetic and functional repercussion. surgical treatment in these cases frequently requires complex reconstructions and the use of biomaterials. the polyurethane derived from castor beans (ricinus communis) has a favorable formulation in terms of ease of processing, flexibility, no emission of toxic vapors and low cost. nonetheless, despite favorable results, studies about the use of castor ...200919649483
histological outcomes on the development of new space-making devices for maxillary sinus floor augmentation.previous studies have pointed out that the mere elevation of the maxillary sinus membrane promotes bone formation without the use of augmentation materials.201119681942
rod bipolar cells in the retina of the capuchin monkey (cebus apella): characterization and distribution.rod bipolar cells in cebus apella monkey retina were identified by an antibody against the alpha isoform of protein kinase c (pkcalpha), which has been shown to selectively identify rod bipolars in two other primates and various mammals. vertical sections were used to confirm the identity of these cells by their characteristic morphology of dendrites and axons. their topographic distribution was assessed in horizontal sections; counts taken along the dorsal, ventral, nasal, and temporal quadrant ...200919709465
folivory or fruit/seed predation for mesopithecus, an earliest colobine from the late miocene of eurasia?here we compare dental microwear textures from specimens of the fossil genus mesopithecus (cercopithecidae, colobinae) from the late miocene of eastern europe with dental microwear textures from four extant primate species with known dietary differences. results indicate that the dental microwear textures of mesopithecus differ from those of extant leaf eaters alouatta palliata and trachypithecus cristatus and instead resemble more closely those of the occasional hard-object feeders cebus apella ...200919733899
living together: behavior and welfare in single and mixed species groups of capuchin (cebus apella) and squirrel monkeys (saimiri sciureus).there are potential advantages of housing primates in mixed species exhibits for both the visiting public and the primates themselves. if the primates naturally associate in the wild, it may be more educational and enjoyable for the public to view. increases in social complexity and stimulation may be enriching for the primates. however, mixed species exhibits might also create welfare problems such as stress from interspecific aggression. we present data on the behavior of single and mixed spec ...201019790191
milk composition of captive tufted capuchins (cebus apella).little is known about the milk composition of nonhuman primates, and it has never been examined in capuchin monkeys (genus cebus). this article reports on the macronutrient milk composition (fat, crude protein (cp), lactose, dry matter (dm), and total gross energy (ge)) of captive housed tufted capuchins (cebus apella) (n=8). c. apella milk averaged 5.22% fat, 2.40% cp, 6.94% lactose, 16.48% dm, and 0.89 kcal/g. fat was the most variable macronutrient and was significantly higher in samples coll ...201019827136
cranial suture morphology and its relationship to diet in cebus.cranial sutures are complex morphological structures. four cebus species (c. albifrons, c. apella, c. capucinus, c. olivaceus) are used here to test the hypothesis that sagittal suture complexity is enhanced in animals that eat materially challenging foods. these primates are ideal for such comparative studies because they are closely related and some are known to exhibit differences in the material properties of the foods they ingest and masticate. specifically, cebus apella is notable among me ...200919833377
'unwilling' versus 'unable': capuchin monkeys' (cebus apella) understanding of human intentional action.a sensitivity to the intentions behind human action is a crucial developmental achievement in infants. is this intention reading ability a unique and relatively recent product of human evolution and culture, or does this capacity instead have roots in our non-human primate ancestors? recent work by call and colleagues (2004) lends credence to the latter hypothesis, providing evidence that chimpanzees are also sensitive to human intentions. specifically, chimpanzees remained in a testing area lon ...200919840049
ontogeny of long bone geometry in capuchin monkeys (cebus albifrons and cebus apella): implications for locomotor development and life history.studies of a diverse array of animals have found that young individuals often have robust bones for their body size (i.e. augmented cross-sectional dimensions), limiting fracture risk despite general musculoskeletal immaturity. however, previous research has focused primarily on precocial taxa (e.g. rodents, lagomorphs, bovids, goats and emu). in this study, we examined the ontogenetic scaling of humeral and femoral cross-sectional robusticity in a mixed-longitudinal sample of two slow-growing, ...201019864273
jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape.tufted capuchins (sensu lato) are renowned for their dietary flexibility and capacity to exploit hard and tough objects. cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. we compared fiber architecture of the masseter and temporalis muscles between c. apella (n=12) and two "untufted" capuchins (c. capucinus ...200919875148
cone photopigment variations in cebus apella monkeys evidenced by electroretinogram measurements and genetic analysis.we investigated the color vision pattern in cebus apella monkeys by means of electroretinogram measurements (erg) and genetic analysis. based on erg we could discriminate among three types of dichromatic males. among females, this classification is more complex and requires additional genetic analysis. we found five among 10 possible different phenotypes, two trichromats and three dichromats. we also found that cebus present a new allele with spectral peak near 552nm, with the amino acid combina ...201019883678
fallback foraging as a way of life: using dietary toughness to compare the fallback signal among capuchins and implications for interpreting morphological variation.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 america, thriving in a range of different habitats. this appears to be a consequence of their ability to exploit obdurate fallback foods. here we comp ...200919890863
postconflict behaviour in brown capuchin monkeys (cebus apella).postconflict affiliation has been mostly studied in old world primates, and we still lack comparative research to understand completely the functional value of reconciliation. cebus species display great variability in social characteristics, thereby providing a great opportunity for comparative studies. we recorded 190 agonistic interactions and subsequent postconflict behaviour in a captive group of brown capuchin monkeys (cebus apella). only 26.8% of these conflicts were reconciled. reconcili ...200919923844
in-group conformity sustains different foraging traditions in capuchin monkeys (cebus apella).decades of research have revealed rich cultural repertoires encompassing multiple traditions in wild great apes, a picture crucially complemented by experimental simulations with captive apes. studies with wild capuchin monkeys, the most encephalized simian species, have indicated a new world convergence on these cultural phenomena, involving multiple traditions and tool use. however, experimental studies to date are in conflict with such findings in concluding that capuchins, like other monkeys ...200919924242
spider monkeys (ateles geoffroyi) and capuchin monkeys (cebus apella) follow gaze around barriers: evidence for perspective taking?gaze following is an adaptive skill that might have been selected in social species, such as many nonhuman primates, to obtain information about food location, predators, and social interactions. the authors investigated the ability of spider monkeys (ateles geoffroyi) and capuchin monkeys (cebus apella) to follow the gaze of a human around barriers and the presence of "looking back" behavior. in the 1st experiment, a human looked to a target location inside the testing room, whereas in the 2nd ...200919929105
monkeys recognize the faces of group mates in photographs.nonhuman primates possess a highly developed capacity for face recognition, which resembles the human capacity both cognitively and neurologically. face recognition is typically tested by having subjects compare facial images, whereas there has been virtually no attention to how they connect these images to reality. can nonhuman primates recognize familiar individuals in photographs? such facial identification was examined in brown or tufted capuchin monkeys (cebus apella), a new world primate, ...200919966230
primate community of the tropical rain forests of saracá-taqüera national forest, pará, brazil.brazil is the richest country in the world in terms of primate species and the amazonian rain forest is one of the richest biomes containing 15 (ca. 90%) of the neotropical primate genera. although considered key elements in conservation strategies, there is only anecdotal information on primates for several protected areas within the region. here we present new data on the community composition of the primates in the saracá-taqüera national forest (429,600 ha), an actively mined, bauxite rich a ...200919967179
how to spend a token? trade-offs between food variety and food preference in tufted capuchin monkeys (cebus apella).humans and non-human animals often choose among different alternatives by seeking variety. here we assessed whether variety-seeking, i.e. the tendency to look for diversity in services and goods, occurs in capuchin monkeys--south-american primates which--as humans--are omnivorous and susceptible to food monotony. capuchins chose between a variety-token, that allowed to select one among 10 different foods (one more-preferred and nine less-preferred) and a monotony-token, that--upon exchange with ...201020026196
[diversity of wild and domestic mammal's intestinal helminths from the caatinga of the parque nacional serra da capivara, southeast of piauí, brazil].biodiversity studies allow ecosystem assessment and monitoring of environmental changes and impacts. parasite diversity could reflect the host/ parasite coevolutionary process and the environment changes that permit the loss, gain or maintenance of species. this survey used species/morphotypes of helminths eggs found in feces from seven wild mammal species (the groups dasypodidae and large cats, and tamandua tetradactyla, cebus apella, alouatta caraya, cerdocyon thous, pecari tajacu) and from tw ...200920040186
mitochondrial divergence between 2 populations of the hooded capuchin, cebus (sapajus) cay (platyrrhini, primates).we analyzed the molecular divergence of 2 separate populations of cebus apella paraguayanus, recently considered a junior synonym of cebus cay, and estimated its time of separation from c. apella. cytochrome b dna from 23 c. cay from brazil and 9 from paraguay showed 24 haplotypes (20 and 4, respectively), accounting for 29 variable sites (19 transitions and 10 transversions), with 40.0%, 26.7%, and 33.0% replacements at first, second, and third codon positions, respectively. genetic distance be ...201020056682
[occurrence of infection leishmania spp. and toxoplasma gondii in monkeys (cebus apella) from campo grande, ms].the aim of this study was research antibodies from infection by leishmania spp. and toxoplasma gondii in nonhuman primates (hnp) and compare the techniques of reaction of indirect immunofluorescence (ifat) and modified agglutination test (mat) for the search of t. gondii. fourteen adults monkeys (cebus apella) were examined, from the centre for rehabilitation of wild animals (cras) from campo grande, ms. the research of anti- leishmania spp. was performed by ifat and research of anti-t. gondii w ...200820059866
prey capture efficiency in brown capuchin monkeys (cebus apella) is influenced by sex and corpus callosum morphology.the diet of capuchin monkeys consists largely of fruits, but these monkeys commonly prey upon insects and other invertebrates as well as vertebrates such as lizards, birds, and fish. capturing small fast-moving prey requires the ability to process complex visuospatial information such as motion detection, shape, and pursuit. here we report the results of an experimental investigation into whether capuchins display sex differences in prey capture efficiency, and whether these differences are asso ...201020077465
gait dynamics of cebus apella during quadrupedalism on different substrates.primates are distinguished from many mammals by emphasizing arboreal lifestyles. primate arboreal adaptations include specializations for enhancing balance and manipulative skills. compliant gait and diagonal sequence (ds) footfalls are hypothesized mechanisms for improving balance during arboreal quadrupedalism (aq), while simultaneously permitting vertical peak force reductions sustained by limbs, particularly forelimbs (fls). capuchin monkeys (cebus apella) are arboreally-adapted quadrupeds t ...201020091854
effects of platelet-rich plasma on healing of alveolar socket: split-mouth histological and histometric evaluation in cebus apella monkeys.the prediction of implant treatment is directly influenced by the quality of the remaining bone after tooth extraction.200920139568
searching in the middle-capuchins' (cebus apella) and bonobos' (pan paniscus) behavior during a spatial search task.in this study we show that bonobos and capuchin monkeys can learn to search in the middle of a landmark configuration in a small-scale space. five bonobos (pan paniscus) and 2 capuchin monkeys (cebus apella) were tested in a series of experiments with the expansion test paradigm. the primates were trained to search in the middle of a 4- or 2-landmark configuration, and were then tested with the same configuration expanded. neither species searched in the middle of the expanded 4-landmark configu ...201020141320
conditional copying fidelity in capuchin monkeys (cebus apella).in the last two decades, it became largely accepted that monkeys show little, if any, copying fidelity. however, some recent studies have begun to challenge this notion. to explore reasons for such contrary findings, we designed a foraging apparatus so that in each of two experiments with capuchin monkeys (cebus apella), a model would demonstrate one of two alternative methods to obtain food. the apparatus had a v-shaped track on which a panel could be slid up left or right from the center to re ...201020175594
the development of the basal ganglia in capuchin monkeys (cebus apella).the basal ganglia are subcortical structures involved in the planning, initiation and regulation of movement as well as a variety of non-motor, cognitive and affective functions. capuchin monkeys share several important characteristics of development with humans, including a prolonged infancy and juvenile period, a long lifespan, and complex manipulative abilities. this makes capuchins important comparative models for understanding age-related neuroanatomical changes in these structures. here we ...201020227397
a capuchin monkey (cebus apella) uses video to find food.we examined the ability of capuchin monkeys to use video without immediate visual-kinaesthetic feedback as a source of information to guide their action in the 3-dimensional world. in experiment 1, 2 capuchins learned to retrieve food under 1 of 2 different objects in 1 cage after watching the experimenter hiding food under 1 of 2 replica objects while in another cage. information space and retrieval space were thus separate. the performance criterion was 71% first correct choices in blocks of 2 ...201020357474
monkeys fail to reciprocate in an exchange task.exchanges form the basis of human economies. animals too can engage in reciprocal interactions but they do not barter goods like humans, which raises the question of the abilities necessary for trading to occur. previous studies have shown that non-human primates can exchange food with human partners. here, we tested the ability of brown capuchin monkeys and tonkean macaques to reciprocate in a task requiring two conspecifics to exchange tokens in order to obtain rewards from an experimenter. we ...201020473699
development of skilled detection and extraction of embedded prey by wild brown capuchin monkeys (cebus apella apella).brown capuchin monkeys (cebus apella apella) in suriname forage on larvae enclosed within healthy bamboo stalks. we applied the searching versus handling dichotomy of optimal foraging models to highlight developmental processes contributing to foraging on embedded prey. larvae acquisition begins with search; selecting an appropriate stalk and locating the embedded larvae; followed by handling, ripping the stalk open, and extracting the larvae. although extraction behaviors were present at low ra ...201020476819
delay of gratification in capuchin monkeys (cebus apella) and squirrel monkeys (saimiri sciureus).in two separate series of experiments four capuchin monkeys (cebus apella) and four squirrel monkeys (saimiri sciureus) were given demonstration trials in which a human transferred six pieces of food, one by one, from out of each monkey's reach to within reach. on test trials the monkey could reach for the transferred food at any time, an action that ended the trial. therefore, it was in the monkey's interest to allow food items to accumulate before reaching for food. no capuchin monkey showed d ...201020476820
hippocampus and dentate gyrus of the cebus monkey: architectonic and stereological study.behavioral, electrophysiological, and anatomical assays of non-human primates have provided substantial evidence that the hippocampus and dentate gyrus are essential for memory consolidation. however, a single anatomical and stereological investigation of these regions has been done in new world primates to complement those assays. the aim of the present study was to describe the cyto-, myelo-, and histochemical architecture of the hippocampus and dentate gyrus, and to use the optical fractionat ...201020558278
identity concept learning in matching-to-sample tasks by tufted capuchin monkeys (cebus apella).the abstract concept of equivalence is considered one of the bases of higher-order cognition, and it has been the subject of considerable research in comparative cognition. this study examined the conditions under which tufted capuchin monkeys (cebus apella) are able to acquire an identity concept. six capuchin monkeys were trained to solve a visual matching-to-sample (mts) task on the basis of perceptual identity. the acquisition of the identity rule was inferred from the subject's ability to s ...201020574839
the ontogeny of handling hard-to-process food in wild brown capuchins (cebus apella apella): evidence from foraging on the fruit of maximiliana maripa.we examined age-related differences in wild brown capuchins' foraging efficiency and the food-processing behaviors directed toward maripa palm fruit (maximiliana maripa). a detailed comparison of the different foraging techniques showed that plucking the fruit from the infructescence constituted the main difficulty of this task. foraging efficiency tended to increase with age, with a threshold at which sufficient strength allowed immatures by the age of three to reach adult-level efficiency. you ...201020575045
preladenant, a selective a(2a) receptor antagonist, is active in primate models of movement disorders.parkinson's disease (pd) and extrapyramidal syndrome (eps) are movement disorders that result from degeneration of the dopaminergic input to the striatum and chronic inhibition of striatal dopamine d(2) receptors by antipsychotics, respectively. adenosine a(2a) receptors are selectively localized in the basal ganglia, primarily in the striatopallidal ("indirect") pathway, where they appear to operate in concert with d(2) receptors and have been suggested to drive striatopallidal output balance. ...201020655910
dioctophyma renale (goeze, 1782) in the abdominal cavity of a capuchin monkey (cebus apella), brazil.this study reports a case of parasitism by dioctophyma renale (goeze, 1762) encysted in the abdominal cavity of a capuchin monkey (cebus apella) coming from the centro nacional de primatas, brazil. the animal was sent to the veterinary clinic sector with an increase in abdominal volume and no occurrence of any other clinical signs. upon palpation, a movable circular mass with a diameter of approximately 10 cm was found. urinalysis, complete blood count and serum biochemistry were performed witho ...201020691541
capuchins (cebus apella) can solve a means-end problem.three capuchin monkeys (cebus apella) were tested on a 2-choice discrimination task designed to examine their knowledge of support, modeled after hauser, kralik, and botto-mahan's (1999) experiments with tamarins. this task involved a choice between 2 pieces of cloth, including 1 with a food reward placed on its surface, and a second cloth with the food reward next to its surface. after reliably solving the basic problem, the capuchins were tested with various alternations of the original food r ...201020695658
learning and generalization of tool use by tufted capuchin monkeys (cebus apella) in tasks involving three factors: reward, tool, and hindrance.we tested 4 captive tufted capuchin monkeys (cebus apella) for their understanding of physical causality in variations of a 2-choice tool use task, 1 alternative of which allowed the monkeys easier access to food. our monkeys, who had been adept at this task involving 2 items, that is, tool and food, quickly learned 3-term problems involving food, tool, and 1 type of hindrance (an obstacle or a trap, which could prevent success). all of the monkeys generalized their performance to new problems w ...201120718553
the effect of environmental enrichment on the behavior of captive tufted capuchin monkeys (cebus apella).the authors provided different forms of environmental enrichment to six old laboratory male tufted capuchin monkeys (cebus apella) and studied the behavior of the monkeys during a baseline period and during three enrichment periods. each observation period lasted 5 d, with an interval of 6 d between periods. during the first enrichment period, the authors provided buster cubes and wood cylinders with drilled holes filled with gum arabic. during the second enrichment period, monkeys were provided ...201020729828
[genetic methods for the reintroduction of primates saguinus, aotus and cebus (primates: cebidae) seized in bogota, colombia].primates are one of more confiscated taxa by the environmental authorities in bogota, colombia. during 2008, 133 monkeys were confiscated; samples from 115 of them were sequenced by the mitochondrial cythocrome oxidase ii gene (mtcoii) and 112 sequences obtained were of high quality. these sequences were compared with those obtained by our research group from individuals directly sampled in the field, with precise geographic origin. so, a more specific geographic area of the colombian territory ...201020737854
can nonhuman primates use tokens to represent and sum quantities?it is unclear whether nonhuman animals can use physical tokens to flexibly represent various quantities by combining token values. previous studies showed that chimpanzees (pan troglodytes) and a macaque (macaca mulatta) were only partly successful in tests involving sets of different-looking food containers representing different food quantities, while some capuchin monkeys (cebus apella) have shown greater success in tests involving sets of various concrete objects representing different food ...201020836596
effects of cannabinoid cb(1) receptor agonism and antagonism on skf81297-induced dyskinesia and haloperidol-induced dystonia in cebus apella monkeys.antipsychotic drugs may cause extrapyramidal symptoms (eps), such as dyskinesia and dystonia. these effects are believed to involve dysfunctional striatal dopamine transmission. patients with schizophrenia show increased prevalence of cannabis abuse and this has been linked to severity of eps. endocannabinoids modulate striatal dopamine activity via type 1 cannabinoid (cb(1)) receptors, and studies in rats and humans suggest beneficial effects of cb(1) ligands on eps. the present study explored ...201021029743
image-based red cell counting for wild animals blood.an image-based red blood cell (rbc) automatic counting system is presented for wild animals blood analysis. images with 2048×1536-pixel resolution acquired on an optical microscope using neubauer chambers are used to evaluate rbc counting for three animal species (leopardus pardalis, cebus apella and nasua nasua) and the error found using the proposed method is similar to that obtained for inter observer visual counting method, i.e., around 10%. smaller errors (e.g., 3%) can be obtained in regio ...201021096766
chemical characterization of oligosaccharides in the milk of six species of new and old world monkeys.human and great ape milks contain a diverse array of milk oligosaccharides, but little is known about the milk oligosaccharides of other primates, and how they differ among taxa. neutral and acidic oligosaccharides were isolated from the milk of three species of old world or catarrhine monkeys (cercopithecidae: rhesus macaque (macaca mulatta), toque macaque (macaca sinica) and hamadryas baboon (papio hamadryas)) and three of new world or platyrrhine monkeys (cebidae: tufted capuchin (cebus apell ...201021127965
semen coagulum liquefaction, sperm activation and cryopreservation of capuchin monkey (cebus apella) semen in coconut water solution (cws) and tes-tris.the objectives of the present study were to test the effect of coconut water solution and tes-tris on the seminal coagulum liquefaction, sperm activation in fresh diluted semen, and on the cryopreservation of semen from capuchin monkeys (cebus apella). semen was collected from six males by electro-ejaculation, diluted in tes-tris or coconut water solution (cws), and incubated at 35°c until the coagulated fraction of the semen was completely liquefied. in the experiment i, after liquefaction, sam ...201021129865
can traditions emerge from the interaction of stimulus enhancement and reinforcement learning? an experimental model.the study of social learning in captivity and behavioral traditions in the wild are two burgeoning areas of research, but few empirical studies have tested how learning mechanisms produce emergent patterns of tradition. studies have examined how social learning mechanisms that are cognitively complex and possessed by few species, such as imitation, result in traditional patterns, yet traditional patterns are also exhibited by species that may not possess such mechanisms. we propose an explicit m ...201021135912
development of maze navigation by tufted capuchins (cebus apella).theories of spatial navigation hypothesize that animals use vector or topological information to choose routes, often including detours, to move objects or themselves to goals. we assessed adult capuchin monkeys' (cebus apella) navigation through 192 virtual two-dimensional mazes that incorporated detour problems. six monkeys initially were significantly less likely to choose the correct paths when detours were required than when not. three of the six monkeys repeatedly practiced the 192 mazes t ...201021138761
cyto-, myelo- and chemoarchitecture of the prefrontal cortex of the cebus monkey.according to several lines of evidence, the great expansion observed in the primate prefrontal cortex (pfc) was accompanied by the emergence of new cortical areas during phylogenetic development. as a consequence, the structural heterogeneity noted in this region of the primate frontal lobe has been associated with diverse behavioral and cognitive functions described in human and non-human primates. a substantial part of this evidence was obtained using old world monkeys as experimental model; w ...201121232115
conceptual thresholds for same and different in old-(macaca mulatta) and new-world (cebus apella) monkeys.learning of the relational same/different (s/d) concept has been demonstrated to be largely dependent upon stimulus sets containing more than two items for pigeons and old-world monkeys. stimulus arrays containing several images for use in same/different discrimination procures (e.g. 16 identical images vs. 16 nonidentical images) have been shown to facilitate and even be necessary for learning of relational concepts (flemming et al., 2007; wasserman et al., 2001; young et al., 1997). in the pre ...201121238555
social traditions and social learning in capuchin monkeys (cebus).capuchin monkeys (genus cebus) have evolutionarily converged with humans and chimpanzees in a number of ways, including large brain size, omnivory and extractive foraging, extensive cooperation and coalitionary behaviour and a reliance on social learning. recent research has documented a richer repertoire of group-specific social conventions in the coalition-prone cebus capucinus than in any other non-human primate species; these social rituals appear designed to test the strength of social bond ...201121357221
the impact of moving to a novel environment on social networks, activity and wellbeing in two new world primates.among the stressors that can affect animal welfare in zoos, the immediate effect of relocation to a novel environment is one that has received little attention in the literature. here, we compare the social network, daily activity and the expression of stress-related behavior in capuchins (cebus apella) and squirrel monkeys (saimiri sciureus) before and just after they were relocated to a new enriched enclosure. results showed similar immediate responses to the move in the two species. both show ...201121381071
susceptibility of cebus apella monkey (primates: cebidae) to experimental leishmania (l.) infantum chagasi-infection.in amazonian brazil, the cebus apella monkey (primates: cebidae) has been associated with the enzootic cycle of leishmania (v.) shawi, a dermotropic parasite causing american cutaneous leishmaniasis (acl). it has also been successfully used as animal model for studying cutaneous leishmaniasis. in this work, there has been investigated its susceptibility to experimental leishmania (l.) infantum chagasi-infection, the etiologic agent of american visceral leishmaniasis (avl). there were used ten c. ...201121412619
perseveration on a reversal-learning task correlates with rates of self-directed behavior in nonhuman primates.in humans and several nonhuman animals, repetitive behavior is associated with deficits on executive function tasks involving response inhibition. we tested for this relationship in nonhuman primates by correlating rates of normative behavior to performance on a reversal-learning task in which animals were required to inhibit a previously learned rule. we focused on rates of self-directed behavior (scratch, autogroom, self touch and manipulation) because these responses are known indicators of a ...201121419808
can monkeys make investments based on maximized pay-off?animals can maximize benefits but it is not known if they adjust their investment according to expected pay-offs. we investigated whether monkeys can use different investment strategies in an exchange task. we tested eight capuchin monkeys (cebus apella) and thirteen macaques (macaca fascicularis, macaca tonkeana) in an experiment where they could adapt their investment to the food amounts proposed by two different experimenters. one, the doubling partner, returned a reward that was twice the am ...201121423777
capuchin monkeys (cebus apella) modify their own behaviors according to a conspecific's emotional expressions.understanding conspecifics' emotional states is important for managing social interactions. we examined whether capuchin monkeys modify their own behaviors in response to a conspecific's emotional expressions. six monkeys saw a demonstrator monkey responding emotionally to an object in a container; the subject monkeys could not see the object. the subjects reached for the container more frequently when the demonstrator showed an emotionally positive expression than when she showed an emotionally ...201121448599
information seeking by rhesus monkeys (macaca mulatta) and capuchin monkeys (cebus apella).animal metacognition is an active, growing research area, and one part of metacognition is flexible information-seeking behavior. in roberts et al. (2009), pigeons failed an intuitive information-seeking task. they basically refused, despite multiple fostering experiments, to view a sample image before attempting to find its match. roberts et al. concluded that pigeons' lack of an information-seeking capacity reflected their broader lack of metacognition. we report a striking species contrast to ...201121459372
the influence of experimental manipulations on chewing speed during in vivo laboratory research in tufted capuchins (cebus apella).even though in vivo studies of mastication in living primates are often used to test functional and adaptive hypotheses explaining primate masticatory behavior, we currently have little data addressing how experimental procedures performed in the laboratory influence mastication. the obvious logistical issue in assessing how animal manipulation impacts feeding physiology reflects the difficulty in quantifying mechanical parameters without handling the animal. in this study, we measured chewing c ...201121469081
cranial ontogeny and sexual dimorphism in two new world monkeys: alouatta caraya (atelidae) and cebus apella (cebidae).pattern of skull development and sexual dimorphism was studied in cebus apella and alouatta caraya using univariate, bivariate, and multivariate statistics. in both species, sexual dimorphism develops because the common growth trajectory in males extends and because of differences in growth rates between sexes. the expectation that the ontogenetic bases of adult dimorphism vary interspecifically is well substantiated by this study. a. caraya exhibits transitional dimorphism in its subadult stage ...201121484855
attention allocation modulates the processing of hierarchical visual patterns: a comparative analysis of capuchin monkeys (cebus apella) and humans.humans show a global advantage when processing hierarchical visual patterns, and they detect the global level of stimulus structure more accurately and faster than the local level in several stimulus contexts. by contrast, capuchins (cebus apella) and other monkey species show a strong local advantage. a key factor which, if manipulated, could cause an inversion of this effect in monkeys is still to be found. in this study, we examined whether it was possible to induce attention allocation to gl ...201121500930
capuchin monkeys are not prosocial in an instrumental helping task.comparative research can shed light on the evolutionary roots and cognitive underpinnings of prosocial behavior by revealing not only positive instances of prosocial motivations in other species, but also the boundary conditions of these motivations. to explore factors that may constrain prosocial behavior, we examined whether brown capuchins (cebus apella), which demonstrate regard for the welfare of conspecifics in other contexts, would behave prosocially in a minimal-cost instrumental helping ...201121505736
i acknowledge your help: capuchin monkeys' sensitivity to others' labor.our society is sustained by wide-ranging cooperation. if individuals are sensitive to others' gains and losses as well as the amount of labor, they can ensure future beneficial cooperative interaction. however, it is still an open question whether nonhuman primates are sensitive to others' labor. we asked this question in tufted capuchin monkeys in an experimental food-sharing situation by comparing conditions with labor by two participants equalized (equal labor condition) or unequalized (unequ ...201121519900
sample stimulus control shaping and restricted stimulus control in capuchin monkeys: a methodological note.this paper reports use of sample stimulus control shaping procedures to teach arbitrary matching-to-sample to 2 capuchin monkeys (cebus apella). the procedures started with identity matching-to-sample. during shaping, stimulus features of the sample were altered gradually, rendering samples and comparisons increasingly physically dissimilar. the objective was to transform identity matching into arbitrary matching (i.e., matching not based on common physical features of the sample and comparison ...201121547073
observer choices during experimental foraging tasks in brown capuchin monkeys (cebus apella).we investigated whether capuchin monkeys (cebus apella) would choose to observe a high- or low-status adult female from their group during experimental foraging tests. the subject was located in the center of a test chamber, with a low- and high-ranking demonstrator on either side of two partitions. a peephole allowed the subject to observe the models by looking through either respective partition. each model was trained on one of the two different methods, lift or pull, for retrieving food from ...201121557285
an inversion effect modified by expertise in capuchin monkeys.the face inversion effect may be defined as the general impairment in recognition that occurs when faces are rotated 180°. this phenomenon seems particularly strong for faces as opposed to other objects and is often used as a marker of a specialized face-processing mechanism. four brown capuchin monkeys (cebus apella) were tested on their ability to discriminate several classes of facial and non-facial stimuli presented in both their upright and inverted orientations in an oddity task. results r ...201121573949
how tufted capuchin monkeys (cebus apella spp) and common chimpanzees (pan troglodytes) align objects to surfaces: insights into spatial reasoning and implications for tool use.this report addresses phylogenetic variation in a spatial skill that underlies tool use: aligning objects to a feature of a surface. fragaszy and cummins-sebree's [behavioral and cognitive neuroscience reviews 4:282-306, 2005] model of relational spatial reasoning and skill development and perception-action theories guided the design of the study. we examined how capuchins and chimpanzees place stick objects of varying shapes into matching grooves on a flat surface. although most individuals ali ...201121608008
the instantaneous center of rotation of the mandible in nonhuman primates.kinematic analyses of mandibular movement in humans demonstrate that the mandibular instantaneous center of rotation (icor) is commonly located near the level of the occlusal plane and varies in its position during a chewing sequence. few data are available regarding the location of the icor in nonhuman primates and it remains unclear how the position of the icor varies in association with mastication and/or gape behaviors. icor was quantified throughout the gape cycle in five species of nonhuma ...201121622946
synteny of human chromosomes 14 and 15 in the platyrrhines (primates, platyrrhini).in order to study the intra- and interspecific variability of the 14/15 association in platyrrhini, we analyzed 15 species from 13 genera, including species that had not been described yet. the dna libraries of human chromosomes 14 and 15 were hybridized to metaphases of alouatta guariba clamitans, a. caraya, a. sara, ateles paniscus chamek, lagothrix lagothricha, brachyteles arachnoides, saguinus midas midas, leontopithecus chrysomelas, callimico goeldii, callithrix sp., cebus apella, aotus nig ...200921637455
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 ...201121656840
capuchin monkeys (cebus apella) use positive, but not negative, auditory cues to infer food location.nonhuman primates appear to capitalize more effectively on visual cues than corresponding auditory versions. for example, studies of inferential reasoning have shown that monkeys and apes readily respond to seeing that food is present ("positive" cuing) or absent ("negative" cuing). performance is markedly less effective with auditory cues, with many subjects failing to use this input. extending recent work, we tested eight captive tufted capuchins (cebus apella) in locating food using positive ...201121681475
social relationships between adult females and the alpha male in wild tufted capuchin monkeys.primates are notable for the widespread presence of long-term female-male associations which go beyond the mating context. however, little attention has been given to the factors that affect within-species variation in female-male relationships, especially among new world primates. although detailed accounts of heterosexual relationships in cebus species are scarce, a few studies have suggested the occurrence of strong associations between adult females and high-ranking males. this study explore ...201121698660
monkeys (macaca mulatta and cebus apella) and human adults and children (homo sapiens) compare subsets of moving stimuli based on numerosity.two monkey species (macaca mulatta and cebus apella) and human children and adults judged the numerousness of two subsets of moving stimuli on a computer screen. two sets of colored dots that varied in number and size were intermixed in an array in which all dots moved in random directions and speeds. participants had to indicate which dot color was more numerous within the array. all species performed at high and comparable levels, including on trials in which the subset with the larger number ...201121716575
anointing variation across wild capuchin populations: a review of material preferences, bout frequency and anointing sociality in cebus and sapajus.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 data into a review of the anointing literature for captive and wild capuchins. using a comparative phylogenetic framework, we test four hypotheses de ...201121769906
polyspecific associations between squirrel monkeys (saimiri sciureus) and other primates in eastern amazonia.one of the most common types of polyspecific association observed in neotropical primate communities is that between squirrel monkeys (saimiri) and capuchins (cebus). the present study focused on association patterns in two saimiri sciureus groups in eastern brazilian amazonia, between march and october, 2009. the associations were analyzed in terms of the species involved, the degree of association, and niche breadth and overlap. the study involved two s. sciureus groups (b4 and gi) on the righ ...201121809365
experimental gastric carcinogenesis in cebus apella nonhuman primates.the evolution of gastric carcinogenesis remains largely unknown. we established two gastric carcinogenesis models in new-world nonhuman primates. in the first model, acp03 gastric cancer cell line was inoculated in 18 animals. in the second model, we treated 6 animals with n-methyl-nitrosourea (mnu). animals with gastric cancer were also treated with canova immunomodulator. clinical, hematologic, and biochemical, including c-reactive protein, folic acid, and homocysteine, analyses were performed ...201121811552
same/different concept learning by capuchin monkeys in matching-to-sample tasks.the ability to understand similarities and analogies is a fundamental aspect of human advanced cognition. although subject of considerable research in comparative cognition, the extent to which nonhuman species are capable of analogical reasoning is still debated. this study examined the conditions under which tufted capuchin monkeys (cebus apella) acquire a same/different concept in a matching-to-sample task on the basis of relational similarity among multi-item stimuli. we evaluated (i) the ab ...201121858225
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