Dorothy M Fragaszy
Dados Biográficos
| ID | 123079 |
|---|---|
| NOME | Dorothy M Fragaszy |
| PRENOMES | Dorothy M |
| SOBRENOME | Fragaszy |
| ASSINATURA | FRAGASZY D M |
| AFILIAÇÕES | University of Georgia |
| ORCID | 0000-0002-4010-4993 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 66 |
| TOTAL DE CITAÇÕES | 180 |
| TOTAL COMO AUTOR | 66 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1974 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2026 |
| ÍNDICE H | 8 |
Bimanual Coordination and Right‐Hand Bias in Extractive Foraging by Wild Sapajus libidinosus
Bimanual coordination is considered a crucial factor in the evolution of manual lateralization. Experimental tasks requiring the simultaneous and coordinated use of both hands induce hand preferences at the population level across various nonhuman primate species studied in captive environments. However, to date, research investigating laterality in bimanual coordination within natural settings remains scarce, especially with respect to platyrrhi…
Moving
Examples of realized scientific careers can provide ideas and inspiration for others aiming to pursue such careers. Here I recount in brief the story of my long career in primatology (1973 to the present), focusing on one enduring theme in my research: the nature and genesis of goal‐directed action (evident in movement). The story begins in graduate school, passes through developing my own laboratory, on to pursuing a spectrum of studies with men…
Optional tool use
Tool use in humans can be optional, that is, the same person can use different tools or no tool to achieve a given goal. Strategies to reach the same goal may differ across individuals and cultures and at the intra‐individual level. This is the first experimental study at the intra‐individual level on the optional use of a tool in wild nonhuman primates. We investigated optional tool use by wild bearded capuchins ( Sapajus libidinosus ) of Fazend…
Dexterity and technique in termite fishing by chimpanzees ( Pan troglodytes troglodytes ) in the Goualougo Triangle, Republic of Congo
Although the phenomenon of termite fishing by chimpanzees ( Pan troglodytes ) has historical and theoretical importance for primatology, we still have a limited understanding of how chimpanzees accomplish this activity, and in particular, about details of skilled actions and the nature of individual variation in fishing techniques. We examined movements, hand positions, grips, and other details from remote video footage of seven adult and subadul…
Revisiting the fourth dimension of tool use
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 act…
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 g…
Rare Bearded Capuchin (Sapajus libidinosus) Tool-Use Culture is Threatened by Land use Changes in Northeastern Brazil
Consistent inter-individual differences in susceptibility to bodily illusions
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 hu…
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 …
Perceptual Learning of Tooling Affordances of a Jointed Object via Dynamic Touch
We investigated whether perceptual learning via dynamic touch can facilitate the discovery of tooling affordances. Twelve blindfolded participants manipulated two structurally identical aluminum objects consisting of a blade and a shaft; one object was seven and a half times heavier than and twice as large as the other object. Flexions/extensions at two joints in the shaft changed the configuration and functionality of each object. A rigid shaft …
Manual skills for processing plant underground storage organs by wild bearded capuchins
OBJECTIVES: 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 in…
Foraging and inter‐individual distances of bearded capuchin monkeys
Extractive foraging is a skill young capuchin monkeys learn over time. A key unknown is whether unskilled individuals occupy spatial positions that increase their opportunities to learn. We observed the spatial positions of individuals in a group of capuchin monkeys in Northeastern Brazil. To improve our understanding of the relationship between learning by young capuchin monkeys and inter-individual distance, we investigated the associations bet…
Stone-Tool Use in Wild Monkeys
Handheld tools transform the actor's body into a body-plus-tool system such that the fit of the actor's body, the tool, and the task demand channel movement in action. In this study, we performed a biomechanical analysis of percussive actions in wild bearded capuchin monkeys, Sapajus libidinosus at Fazenda Boa Vista, Brazil, as they cracked open tucum nuts with anvil-and-hammer tools from the frame of reference of the body-plus-tool system. The r…
Coexistence Between Humans and Capuchins (Sapajus libidinosus)
The strategic role of the tail in maintaining balance while carrying a load bipedally in wild capuchins (Sapajus libidinosus)
Body mass in wild bearded capuchins, ( Sapajus libidinosus )
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 …
Wild capuchin monkeys spontaneously adjust actions when using hammer stones of different mass to crack nuts of different resistance
OBJECTIVES: 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. MATERIALS AND METHODS: During a field experiment carried out in FBV (Piauí, Brazil), eight adult wild capuchin monkeys (five males) cracked Orbygnia nuts of varied…
Age‐related variation in the mechanical properties of foods processed by S apajus libidinosus
OBJECTIVES: 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, compare…
Kinetics of bipedal locomotion during load carrying in capuchin monkeys
Multi‐step routes of capuchin monkeys in a laser pointer traveling salesman task
Prior studies have claimed that nonhuman primates plan their routes multiple steps in advance. However, a recent reexamination of multi-step route planning in nonhuman primates indicated that there is no evidence for planning more than one step ahead. We tested multi-step route planning in capuchin monkeys using a pointing device to "travel" to distal targets while stationary. This device enabled us to determine whether capuchins distinguish the …
Grasping in primates
For a long time, humans (genus Homo) were thought to be the only mammalian species capable of dextrous manual grasping. However, grasping is widespread among tetrapods, and among primates, it is associated with a wide range of morphological, dietary and locomotor variation. From an evolutionary perspective, this prompts several questions: is the origin and evolution of grasping in primates derived from requirements associated primarily with feedi…
Use of stone hammer tools and anvils by bearded capuchin monkeys over time and space
Flexible and conservative features of social systems in tufted capuchin monkeys
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…
Fallback foraging as a way of life
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 abilit…
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 …
Indentation as a technique to assess the mechanical properties of fallback foods
A number of living primates feed part‐year on seemingly hard food objects as a fallback. We ask here how hardness can be quantified and how this can help understand primate feeding ecology. We report a simple indentation methodology for quantifying hardness, elastic modulus, and toughness in the sense that materials scientists would define them. Suggested categories of fallback foods—nuts, seeds, and root vegetables—were tested, with accuracy che…
Coexistence Between Humans and Capuchins (Sapajus libidinosus)
Use of stone hammer tools and anvils by bearded capuchin monkeys over time and space
Comparison of Development and Life History in Pan and Cebus
Dynamic in‐hand movements in adult and young juvenile chimpanzees ( Pan troglodytes )
Descriptions of manual function in nonhuman primates have largely focused on static precision and power grasping (as first defined by Napier, 1956 ), while identification and description of dynamic manual function are rare and incomplete. Here, we describe several forms of in‐hand movements used by chimpanzees ( Pan troglodytes ) when manipulating small objects. In‐hand movements are defined as the movement of an object within one hand via manipu…
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…
Age‐related variation in the mechanical properties of foods processed by S apajus libidinosus
OBJECTIVES: 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, compare…
Manual Function in Cebus apella. Digital Mobility, Preshaping, and Endurance in Repetitive Grasping
Hand preferences for a haptic searching task by tufted capuchins (Cebus apella)
Rare Bearded Capuchin (Sapajus libidinosus) Tool-Use Culture is Threatened by Land use Changes in Northeastern Brazil
Grasping in primates
For a long time, humans (genus Homo) were thought to be the only mammalian species capable of dextrous manual grasping. However, grasping is widespread among tetrapods, and among primates, it is associated with a wide range of morphological, dietary and locomotor variation. From an evolutionary perspective, this prompts several questions: is the origin and evolution of grasping in primates derived from requirements associated primarily with feedi…
Integration of New Males into Four Social Groups of Tufted Capuchins (Cebus apella)
Manual skills for processing plant underground storage organs by wild bearded capuchins
OBJECTIVES: 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 in…
Infant socialization in Primates
Wild capuchin monkeys spontaneously adjust actions when using hammer stones of different mass to crack nuts of different resistance
OBJECTIVES: 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. MATERIALS AND METHODS: During a field experiment carried out in FBV (Piauí, Brazil), eight adult wild capuchin monkeys (five males) cracked Orbygnia nuts of varied…
Kinematics of bipedal locomotion while carrying a load in the arms in bearded capuchin monkeys (Sapajus libidinosus)
Revisiting the fourth dimension of tool use
Social Facilitation of Eating Familiar Food in Tufted Capuchins (Cebus apella)
Introduction and integration of strangers into captive groups of tufted capuchins (Cebus apella)
Self-treatment of wounds by a capuchin monkey (Cebus apella)
Infant socialization in Primates
Response to novelty inSaimiri andCallicebus
Longitudinal observations of care and development of infant titi monkeys ( Callicebus moloch )
The purpose of this study was to describe patterns of infant care and development in family groups of the monogamous titi ( Callicebus moloch ). Three infant titis were observed with their natal family groups over the first six months of life. Field observations of extensive male involvement with infants were confirmed. Adult males were clearly the infants' primary social companions, and infants spent more time in contact with adult males at all …
Self-treatment of wounds by a capuchin monkey (Cebus apella)
Capuchin monkey ( Cebus apella ) grooms her infant's wound with tools
After an attack on her 6‐day‐old infant, a capuchin monkey manufactured, modified, and used simple tools to manipulate her infant's head wound, and applied modified plant materials to the wound. The monkey's preparation and use of plant materials were varied and skillful. Several contextual factors probably facilitated the extension of tool‐using behaviors that this female used in treating her own wounds to treating another's wound. We consider t…
Prehension in Cebus and Saimiri
Prehension was examined in tufted capuchins ( Cebus apella ) and squirrel monkeys ( Saimiri sciureus ). Individual subjects were videotaped from frontal and sagittal planes while they grasped small objects presented in several ways (in view, out of view, embedded, moving). Capuchins used a precision grip in 30% of trials and in more than half of trials with stationary objects. Most (54%) of the precision grips used were opposition of the thumb to…
Forelimb dimensions and goniometry of the wrist and fingers in tufted capuchin monkeys ( Cebus apella )
Adult capuchin monkeys use precision grips during manipulation of small objects, although their thumbs have been classified as pseudo‐opposable. We investigated the physical properties of the hands to increase our understanding of manual function in capuchins. Forelimb dimensions and joint mobility (goniometric) measurements were obtained from adult, juvenile, and infant tufted capuchins ( Cebus apella ). Compared to adult squirrel monkeys, adult…
Behavioral sampling in the field
Sampling decisions affect the efficiency and reliability of data collection, and the appropriateness of the data for analyses of group and individual behavior. We evaluate the correspondence between interval sampling of individual behavior at high temporal density (focal interval sampling) with interval sampling of group behavior at lower density (group scan sampling) in two field studies with neotropical primates, capuchins and squirrel monkeys.…
Variation among juvenile capuchins in social influences on exploration
The exploratory or feeding activities of others might influence the timing, the place, or both, of exploratory activities among young group‐living individuals, and this influence might affect the information gained by individuals during exploration. This study examined the temporal and spatial aspects of adults' influence on the exploratory behavior of juvenile capuchins, and on the juveniles' acquisition of a novel behavior. Two experimental app…
Introduction and integration of strangers into captive groups of tufted capuchins (Cebus apella)
Influence of a skilled model on the behavior of conspecific observers in tufted capuchin monkeys ( Cebus apella )
We analyze how the presence of a skilled juvenile capuchin monkey interacting with a mechanical puzzle requiring sequential actions affected the behavior of group‐mates towards the puzzle. Using this study as an example, we suggest a methodological approach to the evaluation of social enhancement of activity and imitation. We suggest that this design could be useful in determining if social and demographic factors influence the occurrence of thes…
Behavioral and cortisol responses to repeated capture and venipuncture in Cebus apella
Behavioral and cortisol responses to repeated capture and venipuncture inCebus apella
Eight capuchins were trained in a capture and venipuncture procedure. Samples taken immediately following capture indicated that subjects experienced rising cortisol levels over the first 5 weeks of training followed by a return to baseline (equivalent to day 1 levels) in the sixth and seventh weeks. After 7 weeks, samples taken 60 min after initial capture revealed that behaviorally habituated animals exhibited significantly lower cortisol level…
Hand preferences for a haptic searching task by tufted capuchins (Cebus apella)
Comparison of Development and Life History in Pan and Cebus
Social context and consumption of unfamiliar foods by capuchin monkeys (Cebus apella) over repeated encounters
Visalberghi and Fragaszy [Animal Behaviour 49:1089–1095, 1995] have shown that social influences affect acceptance of novel foods. However, little is known about the temporal course on which such influences act (e.g., for how long they persist and for how many encounters they are effective). To explore this issue, 11 adult tufted capuchins were observed during ten successive encounters with eight unfamiliar foods (phase 1, in which subjects were …
Social context and consumption of unfamiliar foods by capuchin monkeys (Cebus apella) over repeated encounters
Visalberghi and Fragaszy [Animal Behaviour 49:1089-1095, 1995] have shown that social influences affect acceptance of novel foods. However, little is known about the temporal course on which such influences act (e.g., for how long they persist and for how many encounters they are effective). To explore this issue, 11 adult tufted capuchins were observed during ten successive encounters with eight unfamiliar foods (phase 1, in which subjects were …
Growth and reproduction in captive tufted capuchins (Cebus apella)
We present data on weight and reproduction from a colony of tufted capuchins monkeys (Cebus apella) over a 12 year period. The data constitute a normative record for this species. Weight at birth averages 210 g, and infants gain weight rapidly. Females typically first conceived just after their fifth birthday, and males were fertile by 4 years, 5 months. Interbirth intervals average 576 days. Eighty-seven percent of live-born infants survived pas…
Prehension in infant capuchins (Cebus apella) from six weeks to twenty-four weeks
We analyzed the spontaneous prehensile activity of two infants living with their mothers in social groups, using videotapes taken once weekly from weeks 5 to 24. Prehensile activities were laterally symmetric. Unimanual activity predominated, although bimanual activity appeared at the same ages as unimanual activity. In most bimanual activity the two hands performed the same action, but complementary actions occurred from the onset of bimanual ac…
Manual Function in Cebus apella. Digital Mobility, Preshaping, and Endurance in Repetitive Grasping
Integration of New Males into Four Social Groups of Tufted Capuchins (Cebus apella)
An architecture for comparative cognitive development
Making space for traditions
For quite some time, the question of continuity across species with respect to culture has been linked in the academic world with definitional issues: What is culture, and how we can identify culture in a nonverbal species?1-4 Behavioral scientists agree that behavioral traditions are that aspect of culture we can study in nonhuman animals, and we recognize that traditions are widespread in the animal kingdom (reviewed in Fragaszy and Perry,5 see…
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 shall…
Response to novel housing in two groups of captive tufted capuchin monkeys (Cebus apella)
Primate Behavior and Ecology (59 obras) · Biology (51 obras) · Ecology (33 obras) · Psychology (33 obras) · Animal Vocal Communication and Behavior (30 obras) · Zoology (24 obras) · Computer Science (20 obras) · Communication (17 obras) · Animal Behavior and Reproduction (14 obras) · Engineering (14 obras)