1
|
Pritchard AJ, Bliss-Moreau E, Balasubramaniam KN, Capitanio JP, Marty PR, Kaburu SSK, Arlet ME, Beisner BA, McCowan B. Personality trait structures across three species of Macaca, using survey ratings of responses to conspecifics and humans. PLoS One 2024; 19:e0309946. [PMID: 39241030 PMCID: PMC11379396 DOI: 10.1371/journal.pone.0309946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 08/21/2024] [Indexed: 09/08/2024] Open
Abstract
Comparative studies reliant on single personality surveys to rate wild primates are scarce yet remain critical for developing a holistic comparative understanding of personality. Differences in survey design, item exclusion, and factor selection impede cross-study comparisons. To address these challenges, we used consistently collected data to assess personality trait structures in wild rhesus (Macaca mulatta), bonnet (M. radiata), and long-tailed (M. fascicularis) macaques that varied in their degree of phylogenetic closeness, species-typical social styles, and anthropogenic exposure in urban or urban-rural environments. We administered 51-item personality surveys to familiar raters, and, after reliability and structure screenings, isolated 4-5 factor solutions among the species. Four consistent factors emerged: Confident, Sociable, Active, and Irritable/Equable. This latter factor had differential expression across species. Item composition of the Irritable/Equable factor was consistent with their anticipated differences in social styles, but confounded by cross-site anthropogenic variation. We also administered a 43-item survey confined to human-primate situations which paralleled our findings of social style variation, while also exhibiting variation that aligned with population differences in human density. Our findings indicate that macaque personality trait structures may be emergent outcomes of evolutionary and/or socioecological processes, but further research is needed to parse these processes' relative contributions.
Collapse
Affiliation(s)
- Alexander J Pritchard
- California National Primate Research Center, University of California Davis, Davis, CA, United States of America
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA, United States of America
| | - Eliza Bliss-Moreau
- California National Primate Research Center, University of California Davis, Davis, CA, United States of America
- Department of Psychology, University of California Davis, Davis, CA, United States of America
| | - Krishna N Balasubramaniam
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA, United States of America
- School of Life Sciences, Faculty of Science & Engineering, Anglia Ruskin University, Cambridge, United Kingdom
| | - John P Capitanio
- California National Primate Research Center, University of California Davis, Davis, CA, United States of America
| | - Pascal R Marty
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA, United States of America
- Nature Reserve and Wildlife Park Goldau, Goldau, Switzerland
| | - Stefano S K Kaburu
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA, United States of America
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottingham, United Kingdom
| | - Małgorzata E Arlet
- Institute of Human Biology and Evolution, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Brianne A Beisner
- California National Primate Research Center, University of California Davis, Davis, CA, United States of America
| | - Brenda McCowan
- California National Primate Research Center, University of California Davis, Davis, CA, United States of America
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA, United States of America
| |
Collapse
|
2
|
Wright CI, Majolo B, Schino G, Ventura R, Romero T. Social tension after grooming in wild Japanese macaques (Macaca fuscata yakui) is sex specific and sensitive to social relationships. Am J Primatol 2024; 86:e23664. [PMID: 39034444 DOI: 10.1002/ajp.23664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 05/03/2024] [Accepted: 07/01/2024] [Indexed: 07/23/2024]
Abstract
Changes in the rate of self-directed behavior-a proxy for social tension-offer valuable insights into individuals' experiences of social interactions. Many studies have tested the tension-reduction hypothesis, whereby grooming is expected to reduce social tension in the grooming partners. However, it is still unclear whether responses to grooming are affected by social factors such as an individual's role or social relationship with their partner, and whether responses are similar for females and males. Focussing on same-sex grooming in Yakushima Japanese macaques (Macaca fuscata yakui), we analyzed the effects of two social factors on the change in the rate of self-scratching after receiving grooming: sitting in contact with their partner outside of grooming contexts (as a measure of relationship strength) and rank distance. We collected 10-min postgrooming and matched-control focal samples on recipients of grooming. After controlling for postinhibitory rebound effects, grooming reduced scratching in females (suggesting that grooming was relaxing for the receiver), but not in males. In females, this reduction was associated with increased sitting in contact and increased rank distance: being groomed was more tension-reducing if the grooming partners spent time together outside of grooming contexts, or if their difference in rank was greater and therefore more conspicuous. The reduction effect was mediated by sitting in contact only when females had a higher-ranking-that is, more dominant and potentially aggressive-groomer. Our findings suggest that not all grooming interactions are perceived as equal, which has implications for its use as an index of relationship quality. To our knowledge, this represents the first study of postgrooming social tension in male Japanese macaques and our results highlight the need for caution when generalizing findings from only one sex to the species level.
Collapse
Affiliation(s)
- Chloë India Wright
- Department of Life Sciences, School of Life and Environmental Sciences, College of Health and Science, University of Lincoln, Lincoln, UK
| | - Bonaventura Majolo
- School of Psychology, College of Health and Science, University of Lincoln, Lincoln, UK
| | - Gabriele Schino
- Istituto di Scienze e Tecnologie della Cognizione, Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Raffaella Ventura
- Division of Psychology and Forensic Sciences, University of Abertay Dundee, Dundee, Scotland, UK
| | - Teresa Romero
- Department of Psychology, Centre for Comparative and Evolutionary Psychology, University of Portsmouth, Portsmouth, UK
| |
Collapse
|
3
|
Fichtel C, Dinter K, Ratsoavina F. Benefits but not the dual functions of submissive signals differ between two Malagasy primates. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230197. [PMID: 38768209 DOI: 10.1098/rstb.2023.0197] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 03/05/2024] [Indexed: 05/22/2024] Open
Abstract
Many animals use formalized signals to communicate dominance relationships. In some primates, such as macaques, the function of such signals varies with dominance style. Despotic species produce unidirectional submission signals that have a dual function: in conflict contexts, they signal a willingness to withdraw, whereas in peaceful contexts, they indicate the agreement to subordination. More despotic species produce these calls to a lesser extent than less despotic species. Here, we investigated whether the use of unidirectional submission signals is also related to dominance style in two lemur species and whether signalling subordination stabilizes social relationships at the group level. Ring-tailed lemurs (Lemur catta) exhibit a more despotic dominance hierarchy than Verreaux's sifakas (Propithecus verreauxi). We observed social interactions in 75 dyads of Verreaux's sifakas and 118 dyads of ring-tailed lemurs. Both species used unidirectional submissive calls that have a dual function, potentially suggesting convergent evolution of the function of these signals in independent primate lineages. However, signalling subordination did not stabilize social relationships at the group level in both species. Additionally, subordination occurred more frequently in dyads of the more despotic ring-tailed lemurs than in Verreaux's sifakas, indicating opposite patterns to macaques in the coevolution of social traits with dominance style. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
Collapse
Affiliation(s)
- Claudia Fichtel
- Behavioral Ecology and Sociobiology Unit, German Primate Center, Leibniz Institute for Primate Research , Göttingen 37077, Germany
| | - Klara Dinter
- Behavioral Ecology and Sociobiology Unit, German Primate Center, Leibniz Institute for Primate Research , Göttingen 37077, Germany
| | - Fanomezana Ratsoavina
- Mention Zoologie et Biodiversité Animale, Université d'Antananarivo , Antananarivo, Madagascar
| |
Collapse
|
4
|
Burghardt GM, Pellis SM, Schank JC, Smaldino PE, Vanderschuren LJMJ, Palagi E. Animal play and evolution: Seven timely research issues about enigmatic phenomena. Neurosci Biobehav Rev 2024; 160:105617. [PMID: 38458553 DOI: 10.1016/j.neubiorev.2024.105617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/06/2024] [Accepted: 03/02/2024] [Indexed: 03/10/2024]
Abstract
The nature of play in animals has been long debated, but progress is being made in characterizing play and its variants, documenting its distribution across vertebrate and invertebrate taxa, describing its mechanisms and development, and proposing testable theories about its origins, evolution, and adaptive functions. To achieve a deeper understanding of the functions and evolution of play, integrative and conceptual advances are needed in neuroscience, computer modeling, phylogenetics, experimental techniques, behavior development, and inter- and intra-specific variation. The special issue contains papers documenting many of these advances. Here, we describe seven timely areas where further research is needed to understand this still enigmatic class of phenomena more fully. Growing empirical and theoretical evidence reveals that play has been crucial in the evolution of behavior and psychology but has been underestimated, if not ignored, in both empirical and theoretical areas of evolutionary biology and neuroscience. Play research has important ramifications for understanding the evolution of cognition, emotion, and culture, and research on animals can be both informative and transformative.
Collapse
Affiliation(s)
- Gordon M Burghardt
- Departments of Psychology and Ecology & Evolutionary Biology, University of Tennessee, Knoxville, TN, USA.
| | - Sergio M Pellis
- Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Jeffrey C Schank
- Department of Psychology and Animal Behavior Graduate Group, University of California, Davis, CA, USA
| | - Paul E Smaldino
- Department of Cognitive and Information Sciences, University of California, Merced, CA, USA, and Santa Fe Institute, Santa Fe, NM, USA
| | - Louk J M J Vanderschuren
- Department of Population Health Sciences, Section Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Elisabetta Palagi
- Unit of Ethology, Department of Biology, University of Pisa and Natural History Museum, University of Pisa, Pisa, Italy
| |
Collapse
|
5
|
Testard C, Shergold C, Acevedo-Ithier A, Hart J, Bernau A, Negron-Del Valle JE, Phillips D, Watowich MM, Sanguinetti-Scheck JI, Montague MJ, Snyder-Mackler N, Higham JP, Platt ML, Brent L. Natural disaster alters the adaptive benefits of sociality in a primate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.17.549328. [PMID: 37503170 PMCID: PMC10370068 DOI: 10.1101/2023.07.17.549328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Weather-related disasters can radically alter ecosystems. When disaster-driven ecological damage persists, the selective pressures exerted on individuals can change, eventually leading to phenotypic adjustments. For group-living animals, social relationships are believed to help individuals cope with environmental challenges and may be a critical mechanism enabling adaptation to ecosystems degraded by disasters. Yet, whether natural disasters alter selective pressures on patterns of social interactions and whether group-living animals can, as a result, adaptively change their social relationships remains untested. Here, we leveraged unique data collected on rhesus macaques from 5 years before to 5 years after a category 4 hurricane, leading to persistent deforestation which exacerbated monkeys' exposure to intense heat. In response, macaques increased tolerance for and decreased aggression toward other monkeys, facilitating access to scarce shade critical for thermoregulation. Social tolerance predicted individual survival for 5 years after the hurricane, but not before it, revealing a clear shift in the adaptive function of social relationships in this population. We demonstrate that an extreme climatic event altered selection on sociality and triggered substantial and persistent changes in the social structure of a primate species. Our findings unveil the function and adaptive flexibility of social relationships in degraded ecosystems and identify natural disasters as potential evolutionary drivers of sociality. One-Sentence Summary Testard et al. show that a natural disaster altered selection on sociality in group-living primates triggering persistent changes in their social structure.
Collapse
|
6
|
Wakeford A, Nye JA, Grieb ZA, Voisin DA, Mun J, Huhman KL, Albers E, Michopoulos V. Sex influences the effects of social status on socioemotional behavior and serotonin neurochemistry in rhesus monkeys. Biol Sex Differ 2023; 14:75. [PMID: 37898775 PMCID: PMC10613371 DOI: 10.1186/s13293-023-00562-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 10/19/2023] [Indexed: 10/30/2023] Open
Abstract
BACKGROUND Despite observed sex differences in the prevalence of stress-related psychiatric conditions, most preclinical and translational studies have only included male subjects. Therefore, it has not been possible to effectively assess how sex interacts with other psychosocial risk factors to impact the etiology and maintenance of stress-related psychopathology. One psychosocial factor that interacts with sex to impact risk for stress-related behavioral and physiological deficits is social dominance. The current study was designed to assess sex differences in the effects of social status on socioemotional behavior and serotonin neurochemistry in socially housed rhesus monkeys. We hypothesized that sex and social status interact to influence socioemotional behaviors as well as serotonin 1A receptor binding potential (5HT1AR-BP) in regions of interest (ROIs) implicated in socioemotional behavior. METHODS Behavioral observations were conducted in gonadally intact adult female (n = 14) and male (n = 13) rhesus monkeys. 5HT1AR-BP was assessed via positron emission tomography using 4-(2'-Methoxyphenyl)-1-[2'-(N-2"-pyridinyl)-p[18F]fluorobenzamido]ethylpiperazine ([18F]MPPF). RESULTS Aggression emitted was greater in dominant compared to subordinate animals, regardless of sex. Submission emitted was significantly greater in subordinate versus dominant animals and greater in females than males. Affiliative behaviors emitted were not impacted by sex, status, or their interaction. Anxiety-like behavior emitted was significantly greater in females than in males regardless of social status. Hypothalamic 5HT1AR-BP was significantly greater in females than in males, regardless of social status. 5HT1AR-BP in the dentate gyrus of the hippocampus was significantly impacted by a sex by status interaction whereby 5HT1AR-BP in the dentate gyrus was greater in dominant compared to subordinate females but was not different between dominant and subordinate males. There were no effects of sex, status, or their interaction on 5HT1AR-BP in the DRN and in the regions of the PFC studied. CONCLUSIONS These data have important implications for the treatment of stress-related behavioral health outcomes, as they suggest that sex and social status are important factors to consider in the context of serotonergic drug efficacy.
Collapse
Affiliation(s)
- Alison Wakeford
- Emory National Primate Research Center, Atlanta, GA, 30322, USA
| | - Jonathon A Nye
- Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Zachary A Grieb
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - Dené A Voisin
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - Jiyoung Mun
- Emory National Primate Research Center, Atlanta, GA, 30322, USA
| | - Kim L Huhman
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
- Center for Behavioral Neuroscience, Atlanta, GA, USA
| | - Elliott Albers
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
- Center for Behavioral Neuroscience, Atlanta, GA, USA
| | - Vasiliki Michopoulos
- Emory National Primate Research Center, Atlanta, GA, 30322, USA.
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA.
| |
Collapse
|
7
|
Anand A, Balakrishna N, Singh M, Isbell LA, Sirigeri S, Saikia A, Arlet ME. Infant adoptions in wild bonnet macaques (Macaca radiata). Primates 2022; 63:627-635. [PMID: 36100815 PMCID: PMC9646593 DOI: 10.1007/s10329-022-01017-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/16/2022] [Indexed: 11/29/2022]
Abstract
Though uncommon, adoption of orphaned infants has been observed in both wild and captive non-human primates. In two groups of wild bonnet macaques (Macaca radiata), we observed five instances of infants being cared for after they lost their mothers at a pre-weaning age (< 6 months). Orphaned infants had one or more caregivers (juvenile, subadult, and adult female or male) involved in carrying, grooming, hugging, and protecting them. Adoption did not appear to be related to the age/sex class of the infant, or directly to the mother's rank. Although the dominance rank of the mother of an orphaned infant did not have a direct effect on orphan survivorship, it determined the number of caregivers available to the orphaned infant, and infant survivorship was positively related to the number of caregivers of the orphaned infant. Thus, survivorship was likely a function of the mother's sociality. Two other infants born to high-ranking mothers were also adopted by more individuals and survived longer than the infants of low-ranking mothers.
Collapse
Affiliation(s)
- Ashvita Anand
- Faculty of Biology, Jagiellonian University, Kraków, Poland
| | | | - Mewa Singh
- Zoo Outreach Organization, Coimbatore, India
- Department of Psychology, University of Mysore, Mysuru, India
| | - Lynne A Isbell
- Department of Anthropology and Animal Behavior Graduate Group, University of California, Davis, CA, USA
| | - Sindhuja Sirigeri
- Faculty of Biology, Institute of Human Biology and Evolution, Adam Mickiewicz University in Poznań, Poznań, Poland
| | | | - Małgorzata E Arlet
- Faculty of Biology, Institute of Human Biology and Evolution, Adam Mickiewicz University in Poznań, Poznań, Poland.
| |
Collapse
|
8
|
Mechanisms of expression of object play: A comparative study of stone handling in two captive groups of long-tailed macaques (Macaca fascicularis fascicularis). Behav Processes 2022; 203:104774. [DOI: 10.1016/j.beproc.2022.104774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 10/11/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022]
|
9
|
The effects of allogrooming and social network position on behavioural indicators of stress in female lion-tailed macaques (Macaca silenus). Behav Processes 2022; 202:104740. [PMID: 36038022 DOI: 10.1016/j.beproc.2022.104740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/24/2022]
Abstract
Allogrooming serves an important social function in primates and confers short term benefits such as parasite removal and stress-relief. There is currently mixed evidence as to the immediate impact of allogrooming on an individual's stress levels, which may be influenced by their role in the grooming dyad, position in their social network, or their relationship with their grooming partner. In this study of seven captive adult female lion-tailed macaques (Macaca silenus) in a mixed sex group at Chester Zoo, UK, we found evidence to support a tension-reduction function of allogrooming. Focal animal sampling showed that the duration of self-directed behaviour (SDB), which indicates moderate to high levels of stress, was significantly lower in the five-minute period following allogrooming than the five-minute minute period preceding it for both recipients and groomers. However, when compared to match-control periods, both SDB rates and durations were significantly lower across all individuals in the five-minute period both before and after allogrooming, indicating that although allogrooming reduces stress, it is also more likely to occur when individuals are already in a relatively relaxed state. The rate and duration of SDB post-grooming did not correlate with the strength of a dyad's bond (based on proximity). This suggests that it is the act of allogrooming itself, rather than the identity of the partner, that reduces stress for both parties. Analysis of the proximity network highlighted a clear cost to social integration; node strength, a measure of the number and strength of an individual's direct relationships, positively correlated with the duration of self-directed behaviour, suggesting that more gregarious individuals may experience higher levels of stress. These findings add to the growing body of literature that examines the effect of the individual social environment on primate stress levels, and also highlight the need to further investigate the link between social integration and the stress experienced by group-living animals.
Collapse
|
10
|
Miranda RB, Klaczko J, Tonini JF, Brandão RA. Escaping from predators: a review of Neotropical lizards defence traits. ETHOL ECOL EVOL 2022. [DOI: 10.1080/03949370.2022.2082538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Rogério B. Miranda
- Laboratório de Fauna e Unidades de Conservação, Departamento de Engenharia Florestal, Universidade de Brasília, Brasília (DF), Brazil
| | - Julia Klaczko
- Laboratório de Anatomia Comparada de Vertebrados, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília (DF), Brazil
| | - João F.R. Tonini
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge (MA), USA
| | - Reuber Albuquerque Brandão
- Laboratório de Fauna e Unidades de Conservação, Departamento de Engenharia Florestal, Universidade de Brasília, Brasília (DF), Brazil
| |
Collapse
|
11
|
Thierry B. Where do we stand with the covariation framework in primate societies? AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 178 Suppl 74:5-25. [PMID: 36787776 DOI: 10.1002/ajpa.24441] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/21/2021] [Accepted: 11/04/2021] [Indexed: 12/17/2022]
Abstract
Comparative study of the social systems of macaques has revealed correlated variations between species in multiple social traits such as the asymmetry of dominance relationships, preferential treatment of kin, patterns of aggression and reconciliation, modes of socialization, and access to food resources. Macaques can be classified on a scale of four categories of social styles, ranging from the least to the most tolerant species. This led to the development of the covariation framework, which addresses the constraints responsible for the linkages between social traits, and their consequences on the evolution of primate social systems. Decades of research have provided a wealth of information that supports, complements, expands, or challenges the covariation framework. In this article, I review this body of knowledge and consider covariation in its two aspects, that is, as a pattern and as a hypothesis. I first consider the extent to which social styles can be invariant, the strength of correlations between traits, and the possible extension of the framework to nonhuman primates other than macaques. I then discuss how to formulate hypotheses, identify sources of linkage between traits, make predictions about the effects of social constraints, assess the tolerance dimension of social styles, and consider the breaking of linkages between traits. Whereas socioecological studies aim to understand how adaptation to the ecological environment determines the shape of social systems, the covariation framework is a complementary research program that seeks to unravel the internal processes that restrict or channel change in social behavior.
Collapse
Affiliation(s)
- Bernard Thierry
- Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Université de Tours, Nouzilly, France
| |
Collapse
|
12
|
Monkey visual attention does not fall into the uncanny valley. Sci Rep 2022; 12:11760. [PMID: 35817791 PMCID: PMC9273626 DOI: 10.1038/s41598-022-14615-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/09/2022] [Indexed: 11/08/2022] Open
Abstract
Very humanlike artificial agents can induce feelings of uneasiness in human perceivers. Stimuli that generate this response are said to occupy "the uncanny valley". Given inconsistent findings in the literature, whether or not nonhuman animals experience the uncanny valley is unclear. Here, we recorded the visual attention of eleven male rhesus monkeys as they viewed faces varying in realness across five levels, with visual attention measured by both number and duration of visual fixations on faces as a whole and on areas of interest within the faces (e.g., eyes, mouth). Face stimuli varied in terms of the realism of the image and behavior depicted by the face (lipsmack, threat, bared teeth, and neutral). We largely found no support that rhesus monkeys perceive an uncanny valley when viewing our stimuli; however, monkeys did generally pay more attention to eyes and less attention to mouths in real images compared to less realistic images. Across all stimuli, monkeys' visual attention was drawn to the mouths of images when teeth were visible. These findings suggest that rhesus monkeys in our study did not display an uncanny valley effect when viewing realistic stimuli but did percieve affective information depicted by faces regardless of how real those faces appear.
Collapse
|
13
|
Abstract
AbstractThe evolution of male-male aggression is of interest because at its extreme it can be very energetically costly, leave males vulnerable to preadtors, and give rise to weaponry such as exaggerated traits. In grasshoppers (Acrididae), one group stands out as exceptionally aggressive, the skyhoppers (Kosciuscola) in which males bite, kick, mandible flare, and wrestle each other for access to females or when females are laying eggs. In this study we asked whether there is variation in aggressive behaviour among four skyhopper species and aimed to determine whether the traits used in fighting bear signatures of sexual selection in their size, variability, and allometric scaling. We found clear differences in the numbers and types of aggressive behaviours among species. Kosciuscola tristis and K. usitatus were the most aggressive, K. cognatus was the least aggressive, and K. tristis was the only species that performed the ‘mandible flare’ behaviour. Mandible size was larger among the three species that showed aggressive behaviour, all except K. cognatus, and was negatively allometric for all species possibly suggesting a functional size constraint. Pronotum size was different among most species and K. tristis’ pronotum was the largest and borderline positively allometric perhaps suggesting that pronotum size is related to aggressive behaviour but the nature of that relationship remains obscured. Our study suggests that further work investigates skyhoppers’ aggressive behaviour and how it varies with ecology, and paves the way for establishing them as a model system in the evolution of aggressive behaviour.
Collapse
|
14
|
|
15
|
Balasubramaniam KN, Beisner BA, McCowan B, Bloomsmith MA. Female social structure influences, and is influenced by, male introduction and integration success among captive rhesus macaques ( Macaca mulatta). BEHAVIOUR 2021; 158:1007-1042. [PMID: 36176722 PMCID: PMC9518721 DOI: 10.1163/1568539x-bja10109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
Animal social structure is influenced by multiple socioecological factors. Of these, the links between changes to group demography through the arrival of new individuals and residents' social structure remain unclear. Across seven groups of captive rhesus macaques (Macaca mulatta), we examine how male introductions may be influenced by, and in-turn influence, aspects of female social structure. GLMMs revealed that males integrated more successfully into groups in which females showed more 'despotic' social structures, i.e., higher aggression rates, steeper dominance hierarchies, and greater rank-skew in allogrooming network connectedness. Yet during periods that followed males' social integration, females increased their social tolerance (decreased aggression and shallower hierarchies) and group cohesivity (less clustered allogrooming networks), but retained their tendencies to groom dominants. Our findings, independent of group size and matrilineal relatedness, help better understand how dispersal/immigration may influence social structure, and how assessing changes to social structure may inform macaque welfare and management.
Collapse
Affiliation(s)
- Krishna N. Balasubramaniam
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California at Davis, Davis CA 95616, USA
| | - Brianne A. Beisner
- Department of Animal Resources, Yerkes National Primate Research Center Field Station, Emory University, Lawrenceville, GA 30043, USA
| | - Brenda McCowan
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California at Davis, Davis CA 95616, USA
| | - Mollie A. Bloomsmith
- Department of Animal Resources, Yerkes National Primate Research Center Field Station, Emory University, Lawrenceville, GA 30043, USA
| |
Collapse
|
16
|
Zannella A, Stanyon R, Maglieri V, Palagi E. Not all yawns tell the same story: The case of Tonkean macaques. Am J Primatol 2021; 83:e23263. [PMID: 33955009 PMCID: PMC8365700 DOI: 10.1002/ajp.23263] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 04/04/2021] [Accepted: 04/09/2021] [Indexed: 12/21/2022]
Abstract
Here we show for the first time that the plasticity in morphology and duration of yawning in Macaca tonkeana can be associated with different functional contexts. Macaca tonkeana is classified as a tolerant macaque species characterized by social interactions minimally constrained by dominance rank or kinship. Tonkean macaques, as other egalitarian species, rely on a complex facial communicative system. We found that the degree of mouth opening (ranging from covered to uncovered tooth yawns) and the duration of yawning were not strictly dependent. The shortest uncovered tooth yawns were associated with an intense locomotor/physical activity and peaked immediately after stressful social events thus indicating an increase in arousal. In contrast, longer yawns, independently from teeth exposure, were primarily associated with a relaxed state of the subject. In conclusion, our study suggests that to explore the potential different functions of yawning, it is necessary to focus on the variability of its expression both in terms of morphology and duration, because not all yawns tell the same story.
Collapse
Affiliation(s)
- Alessandra Zannella
- Anthropology Laboratories, Department of BiologyUniversity of FlorenceFlorenceItaly
- Natural History MuseumUniversity of PisaPisaItaly
| | - Roscoe Stanyon
- Anthropology Laboratories, Department of BiologyUniversity of FlorenceFlorenceItaly
| | | | - Elisabetta Palagi
- Natural History MuseumUniversity of PisaPisaItaly
- Unit of Ethology, Department of BiologyUniversity of PisaPisaItaly
| |
Collapse
|
17
|
Cléry JC, Hori Y, Schaeffer DJ, Menon RS, Everling S. Neural network of social interaction observation in marmosets. eLife 2021; 10:e65012. [PMID: 33787492 PMCID: PMC8024015 DOI: 10.7554/elife.65012] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 03/29/2021] [Indexed: 11/13/2022] Open
Abstract
A crucial component of social cognition is to observe and understand the social interactions of other individuals. A promising nonhuman primate model for investigating the neural basis of social interaction observation is the common marmoset (Callithrix jacchus), a small New World primate that shares a rich social repertoire with humans. Here, we used functional magnetic resonance imaging acquired at 9.4 T to map the brain areas activated by social interaction observation in awake marmosets. We discovered a network of subcortical and cortical areas, predominately in the anterior lateral frontal and medial frontal cortex, that was specifically activated by social interaction observation. This network resembled that recently identified in Old World macaque monkeys. Our findings suggest that this network is largely conserved between New and Old World primates and support the use of marmosets for studying the neural basis of social cognition.
Collapse
Affiliation(s)
- Justine C Cléry
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western OntarioLondonCanada
| | - Yuki Hori
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western OntarioLondonCanada
| | - David J Schaeffer
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western OntarioLondonCanada
- University of Pittsburgh, Department of NeurobiologyPittsburghUnited States
| | - Ravi S Menon
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western OntarioLondonCanada
- Department of Physiology and Pharmacology, The University of Western OntarioLondonCanada
| | - Stefan Everling
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western OntarioLondonCanada
- Department of Physiology and Pharmacology, The University of Western OntarioLondonCanada
| |
Collapse
|
18
|
Nioche A, Rougier NP, Deffains M, Bourgeois-Gironde S, Ballesta S, Boraud T. The adaptive value of probability distortion and risk-seeking in macaques' decision-making. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190668. [PMID: 33423627 PMCID: PMC7815430 DOI: 10.1098/rstb.2019.0668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2020] [Indexed: 12/26/2022] Open
Abstract
In humans, the attitude toward risk is not neutral and is dissimilar between bets involving gains and bets involving losses. The existence and prevalence of these decision features in non-human primates are unclear. In addition, only a few studies have tried to simulate the evolution of agents based on their attitude toward risk. Therefore, we still ignore to what extent Prospect theory's claims are evolutionarily rooted. To shed light on this issue, we collected data from nine macaques that performed bets involving gains or losses. We confirmed that their overall behaviour is coherent with Prospect theory's claims. In parallel, we used a genetic algorithm to simulate the evolution of a population of agents across several generations. We showed that the algorithm selects progressively agents that exhibit risk-seeking, and has an inverted S-shape distorted perception of probability. We compared these two results and found that monkeys' attitude toward risk is only congruent with the simulation when they are facing losses. This result is consistent with the idea that gambling in the loss domain is analogous to deciding in a context of life-threatening challenges where a certain level of risk-seeking behaviour and probability distortion may be adaptive. This article is part of the theme issue 'Existence and prevalence of economic behaviours among non-human primates'.
Collapse
Affiliation(s)
- A. Nioche
- Department of Communications and Networking, Aalto University, Espoo, Finland
| | - N. P. Rougier
- Inria Bordeaux Sud-Ouest, 33405 Talence, France
- Institut des Maladies Neurodégénératives, Université de Bordeaux, 33000 Bordeaux, France
- Institut des Maladies Neurodégénératives, CNRS, UMR, 5293, 33000 Bordeaux, France
- LaBRI, Université de Bordeaux, INP, CNRS, UMR, 5800, 33405 Talence, France
| | - M. Deffains
- Institut des Maladies Neurodégénératives, Université de Bordeaux, 33000 Bordeaux, France
- Institut des Maladies Neurodégénératives, CNRS, UMR, 5293, 33000 Bordeaux, France
| | - S. Bourgeois-Gironde
- Laboratoire d’Economie Mathématique et de Microéconomie Appliquée, Université Panthéon-Assas, 75006 Paris, France
- Institut Jean Nicod, Département d’Etudes Cognitives, ENS, EHESS, PSL Research University, 75005 Paris, France
- Institut Jean Nicod, CNRS, UMR 8129, 75005, Paris, France
| | - S. Ballesta
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR, 7364, 67000 Strasbourg, France
- Centre de Primatologie de l’Université de Strasbourg, 67207 Niederhausbergen, France
| | - T. Boraud
- Institut des Maladies Neurodégénératives, Université de Bordeaux, 33000 Bordeaux, France
- Institut des Maladies Neurodégénératives, CNRS, UMR, 5293, 33000 Bordeaux, France
- Centre Expert Parkinson, CHU Bordeaux, 33000 Bordeaux, France
| |
Collapse
|
19
|
Modeling social styles in macaque societies applied to a semi-free-ranging group of Macaca tonkeana. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-02965-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
20
|
Female fertile phase synchrony, and male mating and reproductive skew, in the crested macaque. Sci Rep 2021; 11:4251. [PMID: 33608592 PMCID: PMC7896048 DOI: 10.1038/s41598-021-81163-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 12/03/2020] [Indexed: 01/31/2023] Open
Abstract
High social status is the primary determinant of reproductive success among group-living male mammals. Primates living in multimale-multifemale groups show the greatest variation in the strength of this link, with marked variation in reproductive skew by male dominance among species, dependent on the degree of female fertile phase synchrony, and the number of competing males. Here, we present data on two groups of wild crested macaques (Macaca nigra), living in the Tangkoko Reserve, Sulawesi, Indonesia. We investigated male monopolization of fertile females in 31 cycles of 19 females, and genetic paternity of 14 offspring conceived during the study period. We show that female fertile phase synchrony was low, that females had few mating partners in their fertile phase, and that dominant males monopolized a high proportion of consortships and matings, resulting in marked and steep mating and reproductive skew. We conclude that female cycle asynchrony provides the opportunity for strong direct male-male competition in crested macaques, resulting in monopolization of females by dominant males, consistent with their marked sexual dimorphism. Our study provides a test of the underlying factors that determine the relative occurrence and strength of different mechanisms of sexual selection, and the phenotypes that evolve as a result.
Collapse
|
21
|
Macaque species with varying social tolerance show no differences in understanding what other agents perceive. Anim Cogn 2021; 24:877-888. [PMID: 33590410 DOI: 10.1007/s10071-021-01485-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 01/21/2021] [Accepted: 02/01/2021] [Indexed: 12/12/2022]
Abstract
A growing body of work demonstrates that a species' socioecology can impact its cognitive abilities. Indeed, even closely related species with different socioecological pressures often show different patterns of cognitive performance on the same task. Here, we explore whether major differences in social tolerance in two closely related macaque species can impact a core sociocognitive ability, the capacity to recognize what others see. Specifically, we compared the performance of Barbary macaques (Macaca sylvanus, n = 80) and rhesus macaques (Macaca mulatta, n = 62) on a standard test of visual perspective understanding. In contrast to the difference in performance, one might expect from these species' divergent socioecologies that our results show similar performance across Barbary and rhesus macaques, with both species forming expectations about how another agent will act based on that agent's visual perspective. These results suggest that differences in socioecology may not play as big of a role in the evolution of some theory of mind capacities as they do in other decision-making or foraging contexts.
Collapse
|
22
|
Correia-Caeiro C, Holmes K, Miyabe-Nishiwaki T. Extending the MaqFACS to measure facial movement in Japanese macaques (Macaca fuscata) reveals a wide repertoire potential. PLoS One 2021; 16:e0245117. [PMID: 33411716 PMCID: PMC7790396 DOI: 10.1371/journal.pone.0245117] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/23/2020] [Indexed: 02/01/2023] Open
Abstract
Facial expressions are complex and subtle signals, central for communication and emotion in social mammals. Traditionally, facial expressions have been classified as a whole, disregarding small but relevant differences in displays. Even with the same morphological configuration different information can be conveyed depending on the species. Due to a hardwired processing of faces in the human brain, humans are quick to attribute emotion, but have difficulty in registering facial movement units. The well-known human FACS (Facial Action Coding System) is the gold standard for objectively measuring facial expressions, and can be adapted through anatomical investigation and functional homologies for cross-species systematic comparisons. Here we aimed at developing a FACS for Japanese macaques, following established FACS methodology: first, we considered the species' muscular facial plan; second, we ascertained functional homologies with other primate species; and finally, we categorised each independent facial movement into Action Units (AUs). Due to similarities in the rhesus and Japanese macaques' facial musculature, the MaqFACS (previously developed for rhesus macaques) was used as a basis to extend the FACS tool to Japanese macaques, while highlighting the morphological and appearance changes differences between the two species. We documented 19 AUs, 15 Action Descriptors (ADs) and 3 Ear Action Units (EAUs) in Japanese macaques, with all movements of MaqFACS found in Japanese macaques. New movements were also observed, indicating a slightly larger repertoire than in rhesus or Barbary macaques. Our work reported here of the MaqFACS extension for Japanese macaques, when used together with the MaqFACS, comprises a valuable objective tool for the systematic and standardised analysis of facial expressions in Japanese macaques. The MaqFACS extension for Japanese macaques will now allow the investigation of the evolution of communication and emotion in primates, as well as contribute to improving the welfare of individuals, particularly in captivity and laboratory settings.
Collapse
Affiliation(s)
| | - Kathryn Holmes
- School of Psychology, University of Lincoln, Lincoln, Lincolnshire, United Kingdom
| | | |
Collapse
|
23
|
Ostner J, Wilken J, Schülke O. Social contagion of affiliation in female macaques. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201538. [PMID: 33614085 PMCID: PMC7890474 DOI: 10.1098/rsos.201538] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
Social contagion of non-interactive behaviour is widespread among animals including humans. It is thought to facilitate behavioural synchronization and consequently group cohesion, coordination and opportunities for social learning. Contagion of interactive behaviour-particularly affiliation-has received much less attention. Here, we investigated in female rhesus macaques (Macaca mulatta) the effect of observing group members groom on a subject's subsequent grooming behaviour and the potential modulation of contagion by relationship quality and social status. We recorded behaviour after subjects witnessed a grooming event and compared it to behaviour in a control condition with the same individuals in proximity but in the absence of a stimulus grooming event. Compared to the control condition, after observing others groom, females engaged in a grooming interaction sooner, and were more likely to be the initiator and to take on the active groomer role. Dominance rank of the focal individual and more weakly also of the stimulus individuals affected the latency to the next grooming interaction of the focal subject. Latency to the next grooming interaction decreased with increasing rank of the subject potentially reflecting lower social constraints faced by high ranking individuals in this highly despotic species. Relationship quality between the subject and the stimulus individuals had no effect on latency to grooming. Collectively, our findings provide evidence for visual contagion of affiliation in rhesus macaques. Future studies should explore the systematic variation in contagion of interactive behaviour in relation to a gradient of social tolerance.
Collapse
Affiliation(s)
- Julia Ostner
- Department Behavioral Ecology, University of Goettingen, Goettingen, Germany
- Primate Social Evolution Group, German Primate Centre, Leibniz Institute for Primate Research, Goettingen, Germany
- Leibniz ScienceCampus Primate Cognition, Goettingen, Germany
| | - Jana Wilken
- Department Behavioral Ecology, University of Goettingen, Goettingen, Germany
| | - Oliver Schülke
- Department Behavioral Ecology, University of Goettingen, Goettingen, Germany
- Primate Social Evolution Group, German Primate Centre, Leibniz Institute for Primate Research, Goettingen, Germany
- Leibniz ScienceCampus Primate Cognition, Goettingen, Germany
| |
Collapse
|
24
|
Dhawale AK, Kumar MA, Sinha A. Changing ecologies, shifting behaviours: Behavioural responses of a rainforest primate, the lion-tailed macaque Macaca silenus, to a matrix of anthropogenic habitats in southern India. PLoS One 2020; 15:e0238695. [PMID: 32966281 PMCID: PMC7511024 DOI: 10.1371/journal.pone.0238695] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 08/22/2020] [Indexed: 11/18/2022] Open
Abstract
With the uncontrolled expansion of anthropogenic modifications of the environment, wildlife species are forced to interact with humans, often leading to conflict situations that have detrimental effects for both wildlife and humans. Such interactions are escalating globally, making it crucial for us to devise strategies for both, the management of conflict and the conservation of these often-threatened species. We studied a case of potentially detrimental human-wildlife interactions between an endemic, habitat-specialist primate, the lion-tailed macaque Macaca silenus and resident human communities that has developed in recent years in the Western Ghats mountains of southern India. Primates provide useful model systems to understand the extent and nature of behavioural changes exhibited by wildlife in response to anthropogenic habitats with varying degrees of human influence. We documented behaviours, including foraging and intra-species social interactions, to examine the decisions made by the macaques as they exploited four human-modified habitats, which, for the purpose of this study, have been qualitatively characterised to include structural features of the habitat, type of food resources available and the presence of humans. Access to human-origin food, either cooked or packaged, acquired directly from homes or garbage pits, in the human-dominated habitat appeared to significantly reduce active foraging and searching for food, allowing them to engage in other behavioural activities, such as resting. Furthermore, patterns of reciprocated affiliation dissipated in certain human-dominated habitats, with individuals seeming to have adopted novel behavioural strategies, leading to altered social dynamics in the troop, possibly in response to provisioning. This study thus highlights the importance of understanding behavioural changes displayed by animals in response to human interactions; such knowledge could be crucial for the planning and implementation of management and conservation strategies for endangered species such as the lion-tailed macaque and possibly other wildlife in the increasingly anthropogenic landscapes of the tropical world.
Collapse
Affiliation(s)
- Ashni Kumar Dhawale
- Wildlife Biology and Conservation, WCS-NCBS Programme, National Centre for Biological Sciences, Bangalore, India
- School of Natural and Engineering Sciences, National Institute of Advanced Studies, Indian Institute of Science Campus, Bangalore, India
- University of Trans-Disciplinary Health Sciences and Technology, Bangalore, India
| | | | - Anindya Sinha
- School of Natural and Engineering Sciences, National Institute of Advanced Studies, Indian Institute of Science Campus, Bangalore, India
- Indian Institute of Science Education and Research Kolkata, Mohanpur, India
- Cotton University, Guwahati, India
| |
Collapse
|
25
|
Clark PR, Waller BM, Burrows AM, Julle-Danière E, Agil M, Engelhardt A, Micheletta J. Morphological variants of silent bared-teeth displays have different social interaction outcomes in crested macaques (Macaca nigra). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:411-422. [PMID: 32820559 DOI: 10.1002/ajpa.24129] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 07/02/2020] [Accepted: 07/08/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVES While it has been demonstrated that even subtle variation in human facial expressions can lead to significant changes in the meaning and function of expressions, relatively few studies have examined primate facial expressions using similarly objective and rigorous analysis. Construction of primate facial expression repertoires may, therefore, be oversimplified, with expressions often arbitrarily pooled and/or split into subjective pigeonholes. Our objective is to assess whether subtle variation in primate facial expressions is linked to variation in function, and hence to inform future attempts to quantify complexity of facial communication. MATERIALS AND METHODS We used Macaque Facial Action Coding System, an anatomically based and hence more objective tool, to quantify "silent bared-teeth" (SBT) expressions produced by wild crested macaques engaging in spontaneous behavior, and utilized discriminant analysis and bootstrapping analysis to look for morphological differences between SBT produced in four different contexts, defined by the outcome of interactions: Affiliation, Copulation, Play, and Submission. RESULTS We found that SBT produced in these contexts could be distinguished at significantly above-chance rates, indicating that the expressions produced in these four contexts differ morphologically. We identified the specific facial movements that were typically used in each context, and found that the variability and intensity of facial movements also varied between contexts. DISCUSSION These results indicate that nonhuman primate facial expressions share the human characteristic of exhibiting meaningful subtle differences. Complexity of facial communication may not be accurately represented simply by building repertoires of distinct expressions, so further work should attempt to take this subtle variability into account.
Collapse
Affiliation(s)
- Peter R Clark
- Department of Psychology, University of Portsmouth, Portsmouth, UK.,Macaca Nigra Project, Tangkoko Reserve, Indonesia
| | - Bridget M Waller
- Department of Psychology, University of Portsmouth, Portsmouth, UK
| | - Anne M Burrows
- Department of Physical Therapy, Duquesne University, Pittsburgh, Pennsylvania, USA.,Department of Anthropology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | - Muhammad Agil
- Macaca Nigra Project, Tangkoko Reserve, Indonesia.,Faculty of Veterinary Medicine, Agricultural University of Bogor, Bogor, Indonesia
| | - Antje Engelhardt
- Macaca Nigra Project, Tangkoko Reserve, Indonesia.,School of Philosophy and Natural Sciences, Liverpool John Moores University, Liverpool, UK
| | - Jérôme Micheletta
- Department of Psychology, University of Portsmouth, Portsmouth, UK.,Macaca Nigra Project, Tangkoko Reserve, Indonesia
| |
Collapse
|
26
|
Kawazoe T. Male-male social bonds predict tolerance but not coalition formation in wild Japanese macaques. Primates 2020; 62:91-101. [PMID: 32572696 DOI: 10.1007/s10329-020-00838-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 06/13/2020] [Indexed: 12/01/2022]
Abstract
Social bonds have been construed as differentiated and enduring affiliative relationships. Strong bonds will improve fitness through interchanging with coalition formation or tolerance over resources. Social bonds have been found in a variety of taxa and predict the formation of coalitions even amongst males. However, in species exhibiting steeply linear dominance hierarchies, coalitions are hypothesized to be suppressed due to severe competition amongst males, and thus strong bonds may manifest in other forms of behavior, notably social tolerance. The aim of this study was to examine the effects of male-male social bonds and dominance on agonistic supports and aggressive interaction in one of the most despotic primate species, Japanese macaques. I conducted focal samples on male individuals, recording their grooming, proximity to other members, agonistic supports and membership, and aggressive interactions over a 2-year observation period. Male macaques formed differentiated affiliative relationships across dyads and those relationships showed positive relations between the non-mating and the mating seasons. Steep dominance hierarchies were found amongst males. The occurrence of agonistic supports was not explained by the strength of social bonds but by the dominance of the participants, whereas strong bonds predicted less frequent aggressive interaction. These results are in line with the hypothesis that dominance is a major mechanism underlying coalition formation amongst males. Unlike more egalitarian species, strong bonds do not predict coalition formation but rather tolerance in despotic species. These results suggest male-male social bonds will bring alternative consequences according to dominance structures.
Collapse
Affiliation(s)
- Tatsuro Kawazoe
- Research Institute for Languages and Cultures of Asia and Africa, Tokyo University of Foreign Studies, 3-11-1, Asahi-cho, Fuchu, Tokyo, 1838534, Japan. .,School of Sociology and Anthropology, Sun Yat-sen University, No. 135, XingangXi Road, Guangzhou, 510275, Guangdong, People's Republic of China.
| |
Collapse
|
27
|
Cronin KA, Tank A, Ness T, Leahy M, Ross SR. Sex and season predict wounds in zoo-housed Japanese macaques (Macaca fuscata): A multi-institutional study. Zoo Biol 2020; 39:147-155. [PMID: 31990090 DOI: 10.1002/zoo.21533] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/19/2019] [Accepted: 01/14/2020] [Indexed: 11/11/2022]
Abstract
Japanese macaque societies are characterized by frequent intragroup conflict both in free-ranging and zoo-housed conditions. In zoos, understanding the factors that contribute to wounding is of interest because this knowledge can aid in proactive husbandry and management planning that can minimize the negative impacts wounding can have on individual welfare. This study sought to determine whether the variables sex, season and age predicted wounding rates. Data were collected for 24 months on 119 Japanese macaques living in 10 zoos, and we analyzed the contribution of variables using generalized linear mixed models. A total of 1,007 wounds were reported, and the best model included the interaction between sex and season. Follow-up analyses revealed that females incurred more wounds than males, and this sex difference was more pronounced during the breeding compared to the nonbreeding season. On average, individuals received 4.67 (±SEM: 0.55) wounds per year and 77.31% of the population incurred at least one wound in the study period. The majority of wounds were superficial and did not require veterinary intervention. Wound locations were not randomly distributed across body regions and were most often reported on the face. Finally, macaques living in larger social groups experienced more wounds, on average. This study represents the first quantification of wounding in this species and may provide insight to help inform husbandry and management strategies in zoos.
Collapse
Affiliation(s)
- Katherine A Cronin
- Department of Animal Care & Horticulture, Animal Welfare Science Program, Lincoln Park Zoo, Chicago, Illinois.,Animal Care & Horticulture Department, Lincoln Park Zoo, Chicago, Illinois
| | - Amy Tank
- Animal Care & Horticulture Department, Lincoln Park Zoo, Chicago, Illinois
| | - Tom Ness
- Biological Programs, Minnesota Zoo, Apple Valley, Minnesota
| | - Maureen Leahy
- Department of Animal Care & Horticulture, Animal Welfare Science Program, Lincoln Park Zoo, Chicago, Illinois.,Animal Care & Horticulture Department, Lincoln Park Zoo, Chicago, Illinois
| | - Stephen R Ross
- Department of Conservation & Science, Lester E. Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo, Chicago, Illinois
| |
Collapse
|
28
|
Kappeler PM, Pozzi L. Evolutionary transitions toward pair living in nonhuman primates as stepping stones toward more complex societies. SCIENCE ADVANCES 2019; 5:eaay1276. [PMID: 32064318 PMCID: PMC6989303 DOI: 10.1126/sciadv.aay1276] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 10/30/2019] [Indexed: 06/03/2023]
Abstract
Nonhuman primate societies vary tremendously in size and composition, but how and why evolutionary transitions among different states occurred remains highly controversial. In particular, how many times pair living evolved and the social states of the ancestors of pair- and group-living species remains contentious. We examined evolutionary transitions in primate social evolution by using new, independent categorizations of sociality and different phylogenetic hypotheses with a vastly expanded dataset. Using Bayesian phylogenetic comparative methods, we consistently found the strongest support for a model that invokes frequent transitions between solitary ancestors and pair-living descendants, with the latter giving rise to group-living species. This result was robust to systematic variation in social classification, sample size, and phylogeny. Our analyses therefore indicate that pair living was a stepping stone in the evolution of structurally more complex primate societies, a result that bolsters the role of kin selection in social evolution.
Collapse
Affiliation(s)
- Peter M. Kappeler
- Behavioral Ecology and Sociobiology Unit, German Primate Center–Leibniz Institute for Primate Research, Göttingen, Germany
- Department of Sociobiology/Anthropology, University of Göttingen, Göttingen, Germany
| | - Luca Pozzi
- Department of Anthropology, The University of Texas at San Antonio, San Antonio, TX, USA
| |
Collapse
|
29
|
Weinberg-Wolf H, Chang SWC. Differences in how macaques monitor others: Does serotonin play a central role? WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2019; 10:e1494. [PMID: 30775852 PMCID: PMC6570566 DOI: 10.1002/wcs.1494] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 01/11/2019] [Accepted: 01/11/2019] [Indexed: 01/22/2023]
Abstract
Primates must balance the need to monitor other conspecifics to gain social information while not losing other resource opportunities. We consolidate evidence across the fields of primatology, psychology, and neuroscience to examine individual, population, and species differences in how primates, particularly macaques, monitor conspecifics. We particularly consider the role of serotonin in mediating social competency via social attention, aggression, and dominance behaviors. Finally, we consider how the evolution of variation in social tolerance, aggression, and social monitoring might be explained by differences in serotonergic function in macaques. This article is categorized under: Economics > Interactive Decision-Making Psychology > Comparative Psychology Neuroscience > Behavior Cognitive Biology > Evolutionary Roots of Cognition.
Collapse
Affiliation(s)
| | - Steve W C Chang
- Department of Psychology, Yale University, New Haven, Connecticut
- Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut
- Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, Connecticut
| |
Collapse
|
30
|
The Social Rank of Zoo-Housed Japanese Macaques is a Predictor of Visitor-Directed Aggression. Animals (Basel) 2019; 9:ani9060316. [PMID: 31159468 PMCID: PMC6617189 DOI: 10.3390/ani9060316] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/22/2019] [Accepted: 05/29/2019] [Indexed: 11/23/2022] Open
Abstract
Simple Summary Millions of people visit zoological parks around the world every year. As a result, there has been significant interest in how the presence of these visitors affects the behavior and wellbeing of zoo animals, of which primates are a group that has been extensively studied in this regard. However, many studies fail to consider the possibility that group dynamics, particularly social rank, may affect an individual animal’s reaction to visitors. We investigated how visitor presence, both crowd size and activity level, along with the individual rank of zoo-housed monkeys (Japanese macaques) influenced the occurrence of behavior directed toward the visitors. Behaviors directed toward visitors were predominantly threatening. The results revealed that the social rank of a monkey was a significant predictor of visitor-directed aggression, and lower-ranked individuals displayed more frequent aggression toward visitors. We think it is likely that this finding is a result of low ranking individuals redirecting their aggression to visitors as safe targets. Furthermore, the activity level of the visitors affected visitor-directed aggression by the monkeys more so than the size of the crowd. These findings highlight that although environmental factors impact the behavior of animals at the zoo, social rank is also important to consider when understanding how animals may react to zoo visitors. Abstract The effect that visitors have on the behavior and welfare of animals is a widely-studied topic in zoo animal welfare. Typically, these studies focus on how the presence or activity levels of visitors affect animals. However, for many species, and particularly primates, social factors, such as social rank, can also have a large impact on behavior. Here, we considered the influence of both the role of visitors (crowd size and activity levels) and rank on the occurrence of visitor-directed aggression by zoo-housed Japanese macaques (Macaca fuscata, N = 12). We conducted 52 weeks of observation (443.8 h) of macaques living in a large outdoor habitat and recorded 1574 events of visitor-directed behavior, 94.2% of which was characterized as aggressive. We calculated rank using the Elo-rating method. GLMM comparisons indicate that rank was a significant predictor of visitor-directed aggression, with lower-ranked individuals displaying more frequent aggression towards visitors. Additionally, visitor-directed aggression differed by crowd activity levels, but not crowd size. These results support our prediction that rank is associated with differences in visitor-directed aggression, and we interpret this pattern as lower-ranking macaques redirecting aggression toward zoo visitors as safe targets. This work emphasizes how factors emanating from the zoo environment can combine with social dynamics to influence primate response to human presence in the zoo setting.
Collapse
|
31
|
Krause ET, Kjaer JB, Dudde A, Schrader L, Phi-van L. Fear but not social behaviour is affected by a polymorphism in the 5'-flanking region of the serotonin transporter (5-HTT) gene in adult hens. Behav Brain Res 2019; 361:50-53. [PMID: 30562569 DOI: 10.1016/j.bbr.2018.12.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/29/2018] [Accepted: 12/14/2018] [Indexed: 10/27/2022]
Abstract
The serotonin transporter gene (5-HTT) is involved in the regulation of the neural serotonin. Polymorphisms in the 5-HTT gene have been described in many species to be involved in physiological processes and emotions. A functional polymorphism in the 5´-flanking region of the 5-HTT gene is known from chickens, with a deletion-allele (D), which is associated with an increased 5-HTT expression, in comparison to the wild-type-allele (W). In domestic populations, the majority of hens carry the W-allele. The regulatory changes of the 5-HTT are accompanied in chickens, as in humans, by modulations of fear. Beside these effects on fear, the understanding of potential functional consequences on the social behaviour in the gregarious chicken is lacking. Thus, we here investigated whether the 5-HTT polymorphism with three genotypes (WW, WD, DD), is not only linked to fear-related behaviour, but affects also socio-positive and -negative behaviours of adult hens. Our data confirmed the effects on fear-related behaviour. WW hens showed highest levels of fear. Interestingly, no differences in the social behaviours were present between the hens of the different 5-HTT genotypes. We further discuss implications for potential evolutionary pathways via natural selection and / or artificial selection through domestication of the 5-HTT polymorphism, which might have enabled a stable social lifestyle in the wild ancestors of modern chickens.
Collapse
Affiliation(s)
- E Tobias Krause
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut, Dörnbergstraße 25/27, 29223 Celle, Germany.
| | - Joergen B Kjaer
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut, Dörnbergstraße 25/27, 29223 Celle, Germany
| | - Anissa Dudde
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut, Dörnbergstraße 25/27, 29223 Celle, Germany; Department of Animal Behaviour, University of Bielefeld, Konsequenz 45, 33615 Bielefeld, Germany
| | - Lars Schrader
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut, Dörnbergstraße 25/27, 29223 Celle, Germany
| | - Loc Phi-van
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut, Dörnbergstraße 25/27, 29223 Celle, Germany.
| |
Collapse
|
32
|
Jacobson SL, Kwiatt AC, Ross SR, Cronin KA. The effects of cognitive testing on the welfare of zoo-housed Japanese macaques (Macaca fuscata). Appl Anim Behav Sci 2019. [DOI: 10.1016/j.applanim.2018.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
33
|
Lea AJ, Akinyi MY, Nyakundi R, Mareri P, Nyundo F, Kariuki T, Alberts SC, Archie EA, Tung J. Dominance rank-associated gene expression is widespread, sex-specific, and a precursor to high social status in wild male baboons. Proc Natl Acad Sci U S A 2018; 115:E12163-E12171. [PMID: 30538194 PMCID: PMC6310778 DOI: 10.1073/pnas.1811967115] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In humans and other hierarchical species, social status is tightly linked to variation in health and fitness-related traits. Experimental manipulations of social status in female rhesus macaques suggest that this relationship is partially explained by status effects on immune gene regulation. However, social hierarchies are established and maintained in different ways across species: While some are based on kin-directed nepotism, others emerge from direct physical competition. We investigated how this variation influences the relationship between social status and immune gene regulation in wild baboons, where hierarchies in males are based on fighting ability but female hierarchies are nepotistic. We measured rank-related variation in gene expression levels in adult baboons of both sexes at baseline and in response to ex vivo stimulation with the bacterial endotoxin lipopolysaccharide (LPS). We identified >2,000 rank-associated genes in males, an order of magnitude more than in females. In males, high status predicted increased expression of genes involved in innate immunity and preferential activation of the NF-κB-mediated proinflammatory pathway, a pattern previously associated with low status in female rhesus macaques. Using Mendelian randomization, we reconcile these observations by demonstrating that high status-associated gene expression patterns are precursors, not consequences, of high social status in males, in support of the idea that physiological condition determines who attains high rank. Together, our work provides a test of the relationship between social status and immune gene regulation in wild primates. It also emphasizes the importance of social context in shaping the relationship between social status and immune function.
Collapse
Affiliation(s)
- Amanda J Lea
- Department of Biology, Duke University, Durham, NC 27708;
| | - Mercy Y Akinyi
- Department of Biology, Duke University, Durham, NC 27708
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
| | - Ruth Nyakundi
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
| | - Peter Mareri
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
| | - Fred Nyundo
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
| | - Thomas Kariuki
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
| | - Susan C Alberts
- Department of Biology, Duke University, Durham, NC 27708
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708
| | - Elizabeth A Archie
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556
| | - Jenny Tung
- Department of Biology, Duke University, Durham, NC 27708;
- Institute of Primate Research, National Museums of Kenya, Nairobi 00502, Kenya
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708
- Duke University Population Research Institute, Duke University, Durham, NC 27708
| |
Collapse
|
34
|
Kawazoe T, Sosa S. Social networks predict immigration success in wild Japanese macaques. Primates 2018; 60:213-222. [DOI: 10.1007/s10329-018-0702-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023]
|
35
|
Social style and resilience of macaques' networks, a theoretical investigation. Primates 2018; 60:233-246. [PMID: 30242533 DOI: 10.1007/s10329-018-0684-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 08/31/2018] [Indexed: 10/28/2022]
Abstract
Group-living animals rely on efficient transmission of information for optimal exploitation of their habitat. How efficient and resilient a network is depend on its structure, which is a consequence of the social interactions of the individuals that comprise the network. In macaques, network structure differs according to dominance style. Networks of intolerant species are more modular, more centralized, and less connected than those of tolerant ones. Given these structural differences, networks of intolerant species are potentially more vulnerable to fragmentation and decreased information transmission when central individuals disappear. Here we studied network resilience and efficiency in artificial societies of macaques. The networks were produced with an individual-based model that has been shown to reproduce the structural features of networks of tolerant and intolerant macaques. To study network resilience, we deleted either central individuals or individuals at random and studied the effects of these deletions on network cohesiveness and efficiency. The deletion of central individuals had more negative effects than random deletions from the networks of both tolerant and intolerant artificial societies. Central individuals thus appeared to aid in the maintenance of network cohesiveness and efficiency. Further, the networks of both intolerant and tolerant societies appeared to be robust to the loss of individuals, as network fragmentation was never observed. Our results suggest that despite differences in network structure, networks of tolerant and intolerant macaques may be equally resilient.
Collapse
|
36
|
Sueur C, Romano V, Sosa S, Puga-Gonzalez I. Mechanisms of network evolution: a focus on socioecological factors, intermediary mechanisms, and selection pressures. Primates 2018; 60:167-181. [PMID: 30206778 DOI: 10.1007/s10329-018-0682-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/19/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Cédric Sueur
- Université de Strasbourg, CNRS, IPHC, UMR 7178, Strasbourg, France.
| | - Valéria Romano
- Kyoto University Primate Research Institute, Inuyama, Japan
| | - Sebastian Sosa
- Primates and Evolution Anthropology Laboratory, Anthropology Department, Sun Yat-sen University, Guangzhou, China
| | - Ivan Puga-Gonzalez
- Institute for Religion, Philosophy and History, University of Agder, Kristiansand, Norway
| |
Collapse
|
37
|
Dickinson E, Fitton LC, Kupczik K. Ontogenetic changes to muscle architectural properties within the jaw-adductor musculature of Macaca fascicularis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 167:291-310. [PMID: 30168867 DOI: 10.1002/ajpa.23628] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 05/18/2018] [Accepted: 05/19/2018] [Indexed: 11/12/2022]
Abstract
OBJECTIVES Changes to soft- and hard-tissue components of the masticatory complex during development can impact functional performance by altering muscle excursion potential, maximum muscle forces, and the efficiency of force transfer to specific bitepoints. Within Macaca fascicularis, older individuals exploit larger, more mechanically resistant food items and more frequently utilize wide-gape jaw postures. We therefore predict that key architectural and biomechanical variables will scale during ontogeny to maximize bite force and gape potential within older, larger-bodied individuals. MATERIALS AND METHODS We analyzed 26 specimens of M. fascicularis, representing a full developmental spectrum. The temporalis, superficial masseter, and deep masseter were dissected to determine muscle mass, fiber length, and physiologic cross-sectional area (PCSA). Lever-arm lengths were also measured for each muscle, alongside the height of the temporomandibular joint (TMJ) and basicranial length. These variables were scaled against two biomechanical variables (jaw length and condyle-molar length) to determine relative developmental changes within these parameters. RESULTS During ontogeny, muscle mass, fiber length, and PCSA scaled with positive allometry relative to jaw length and condyle-molar length within all muscles. TMJ height also scaled with positive allometry, while muscle lever arms scaled with isometry relative to jaw length and with positive allometry (temporalis) or isometry (superficial and deep masseter) relative to condyle-molar length. CONCLUSION Larger individuals demonstrate adaptations during development towards maximizing gape potential and bite force potential at both an anterior and posterior bitepoint. These data provide anatomical evidence to support field observations of dietary and behavioral differences between juvenile and adult M. fascicularis.
Collapse
Affiliation(s)
- Edwin Dickinson
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Centre for Anatomical and Human Sciences Hull York Medical School, York, United Kingdom
| | - Laura C Fitton
- Centre for Anatomical and Human Sciences Hull York Medical School, York, United Kingdom
| | - Kornelius Kupczik
- Max Planck Weizmann Center for Integrative Archaeology and Anthropology Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| |
Collapse
|
38
|
Joly M, Micheletta J, De Marco A, Langermans JA, Sterck EHM, Waller BM. Comparing physical and social cognitive skills in macaque species with different degrees of social tolerance. Proc Biol Sci 2018; 284:rspb.2016.2738. [PMID: 28904133 DOI: 10.1098/rspb.2016.2738] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 08/01/2017] [Indexed: 11/12/2022] Open
Abstract
Contemporary evolutionary theories propose that living in groups drives the selection of enhanced cognitive skills to face competition and facilitate cooperation between individuals. Being able to coordinate both in space and time with others and make strategic decisions are essential skills for cooperating within groups. Social tolerance and an egalitarian social structure have been proposed as one specific driver of cooperation. Therefore, social tolerance is predicted to be associated with enhanced cognitive skills that underpin communication and coordination. Social tolerance should also be associated with enhanced inhibition, which is crucial for suppressing automatic responses and permitting delayed gratification in cooperative contexts. We tested the performance of four closely related non-human primate species (genus Macaca) characterized by different degrees of social tolerance on a large battery of cognitive tasks covering physical and social cognition, and on an inhibitory control task. All species performed at a comparable level on the physical cognition tasks but the more tolerant species outperformed the less tolerant species at a social cognition task relevant to cooperation and in the inhibitory control task. These findings support the hypothesis that social tolerance is associated with the evolution of sophisticated cognitive skills relevant for cooperative social living.
Collapse
Affiliation(s)
- Marine Joly
- Centre for Comparative and Evolutionary Psychology, University of Portsmouth, Portsmouth, UK
| | - Jérôme Micheletta
- Centre for Comparative and Evolutionary Psychology, University of Portsmouth, Portsmouth, UK
| | - Arianna De Marco
- Fondazione Ethoikos, Radicondoli, Italy.,Parco Faunistico di Piano dell'Abatino, Poggio San Lorenzo, Italy
| | | | - Elisabeth H M Sterck
- Biomedical Primate Research Center, Rijswijk, The Netherlands.,Animal Ecology, University of Utrecht, Utrecht, The Netherlands
| | - Bridget M Waller
- Centre for Comparative and Evolutionary Psychology, University of Portsmouth, Portsmouth, UK
| |
Collapse
|
39
|
Liao Z, Sosa S, Wu C, Zhang P. The influence of age on wild rhesus macaques' affiliative social interactions. Am J Primatol 2017; 80. [PMID: 29266298 DOI: 10.1002/ajp.22733] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 11/08/2017] [Accepted: 11/17/2017] [Indexed: 01/18/2023]
Abstract
The social relationships that individuals experience at different life stages have a non-negligible influence on their lives, and this is particularly true for group living animals. The long lifespan of many primates makes it likely that these animals have various tactics of social interaction to adapt to complex changes in environmental or physical conditions. The different strategies used in social interaction by individuals at different life stages, and whether the position (central or peripheral) or role (initiator or recipient) of an individual in the group social network changes with age, are intriguing questions that remain to be investigated. We used social network analysis to examine age-related differences in social interaction patterns, social roles, and social positions in three affiliative social networks (approach, allogrooming, and social play) in a group of wild rhesus macaques (Macaca mulatta). Our results showed that social interaction patterns of rhesus macaques differ between age classes in the following ways: i) young individuals tend to allocate social time to a high number of groupmates, older individuals prefer to focus on fewer, specific partners; ii) as they grow older, individuals tend to be recipients in approach interactions and initiators in grooming interactions; and iii) regardless of the different social interaction strategies, individuals of all ages occupy a central position in the group. These results reveal a possible key role played by immature individuals in group social communication, a little-explored issue which deserves closer investigation in future research.
Collapse
Affiliation(s)
- Zhijie Liao
- School of Life Sciences, Sun Yat-sen University, GuangZhou, China
| | - Sebastian Sosa
- School of Sociology and Anthropology, Sun Yat-sen University, GuangZhou, China
| | - Chengfeng Wu
- School of Sociology and Anthropology, Sun Yat-sen University, GuangZhou, China
| | - Peng Zhang
- School of Sociology and Anthropology, Sun Yat-sen University, GuangZhou, China
| |
Collapse
|
40
|
Shimada M, Sueur C. Social play among juvenile wild Japanese macaques (Macaca fuscata) strengthens their social bonds. Am J Primatol 2017; 80. [PMID: 29194704 DOI: 10.1002/ajp.22728] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/26/2022]
Abstract
Social play and grooming are typical affiliative interactions for many primate species, and are thought to have similar biological functions. However, grooming increases with age, whereas social play decreases. We proposed the hypothesis that both social grooming and social play in juveniles strengthen their social bonds in daily activities. We carried out field research on the social relationships among juvenile wild Japanese macaques in a troop in Kinkazan, Miyagi Prefecture, Japan, from fall 2007 to spring 2008 to investigate this hypothesis. We evaluated three relationships among juveniles, play indices (PI), grooming indices (GI), and 3-m-proximity indices (3mI) of each dyad (i.e., interacting pair), and compared these social networks based on the matrices of the indices. The play and grooming networks were correlated with the association network throughout the two research periods. The multiple network level measurements of the play network, but not the grooming network, resembled those of the association network. Using a causal step approach, we showed that social play and grooming interactions in fall seem to predict associations in the following spring, controlling for the PI and GI matrix in spring, respectively. Social play and grooming for each juvenile were negatively correlated. The results partially support our predictions; therefore, the hypothesis that the biological function of social play among immature Japanese macaques is to strengthen their social bonds in the near future and develop their social life appears to be correct. For juvenile macaques, social play, rather than grooming, functions as an important social mechanism to strengthen affiliative relationships.
Collapse
Affiliation(s)
- Masaki Shimada
- Department of Animal Sciences, Teikyo University of Science, Uenohara, Yamanashi, Japan
| | - Cédric Sueur
- Université de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg, France
| |
Collapse
|
41
|
Balasubramaniam KN, Beisner BA, Berman CM, De Marco A, Duboscq J, Koirala S, Majolo B, MacIntosh AJ, McFarland R, Molesti S, Ogawa H, Petit O, Schino G, Sosa S, Sueur C, Thierry B, de Waal FBM, McCowan B. The influence of phylogeny, social style, and sociodemographic factors on macaque social network structure. Am J Primatol 2017; 80. [PMID: 29140552 DOI: 10.1002/ajp.22727] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 09/30/2017] [Accepted: 11/02/2017] [Indexed: 11/11/2022]
Abstract
Among nonhuman primates, the evolutionary underpinnings of variation in social structure remain debated, with both ancestral relationships and adaptation to current conditions hypothesized to play determining roles. Here we assess whether interspecific variation in higher-order aspects of female macaque (genus: Macaca) dominance and grooming social structure show phylogenetic signals, that is, greater similarity among more closely-related species. We use a social network approach to describe higher-order characteristics of social structure, based on both direct interactions and secondary pathways that connect group members. We also ask whether network traits covary with each other, with species-typical social style grades, and/or with sociodemographic characteristics, specifically group size, sex-ratio, and current living condition (captive vs. free-living). We assembled 34-38 datasets of female-female dyadic aggression and allogrooming among captive and free-living macaques representing 10 species. We calculated dominance (transitivity, certainty), and grooming (centrality coefficient, Newman's modularity, clustering coefficient) network traits as aspects of social structure. Computations of K statistics and randomization tests on multiple phylogenies revealed moderate-strong phylogenetic signals in dominance traits, but moderate-weak signals in grooming traits. GLMMs showed that grooming traits did not covary with dominance traits and/or social style grade. Rather, modularity and clustering coefficient, but not centrality coefficient, were strongly predicted by group size and current living condition. Specifically, larger groups showed more modular networks with sparsely-connected clusters than smaller groups. Further, this effect was independent of variation in living condition, and/or sampling effort. In summary, our results reveal that female dominance networks were more phylogenetically conserved across macaque species than grooming networks, which were more labile to sociodemographic factors. Such findings narrow down the processes that influence interspecific variation in two core aspects of macaque social structure. Future directions should include using phylogeographic approaches, and addressing challenges in examining the effects of socioecological factors on primate social structure.
Collapse
Affiliation(s)
- Krishna N Balasubramaniam
- Department of Population Health and Reproduction, School of Veterinary Medicine, UC Davis, Davis, California
| | - Brianne A Beisner
- Department of Population Health and Reproduction, School of Veterinary Medicine, UC Davis, Davis, California.,California National Primate Research Center, University of California Davis, Davis, California
| | - Carol M Berman
- Department of Anthropology, Graduate Program in Evolution, Ecology and Behavior, University at Buffalo, Buffalo, New York
| | | | - Julie Duboscq
- Wildlife Research Center, Kyoto University, Inuyama, Japan.,Primate Research Institute, Kyoto University, Inuyama, Japan
| | - Sabina Koirala
- Small Mammal Conservation and Research Foundation (SMCRF), Kathamandu, Nepal
| | | | - Andrew J MacIntosh
- Wildlife Research Center, Kyoto University, Inuyama, Japan.,Primate Research Institute, Kyoto University, Inuyama, Japan
| | - Richard McFarland
- Department of Anthropology, University of Wisconsin-Madison, Madison, Wisconsin
| | | | - Hideshi Ogawa
- School of International Liberal Studies, Chukyo University, Toyota, Japan
| | - Odile Petit
- Ethologie Cognitive et Sociale, Centre National de la Recherche Scientifique, Strasbourg, France
| | - Gabriele Schino
- Istituto di Scienze e Tecnologie della Cognizione, Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Sebastian Sosa
- Anthropology Department, Sun-Yat sen University, Guang Zhou, China
| | - Cédric Sueur
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France
| | - Bernard Thierry
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France
| | | | - Brenda McCowan
- Department of Population Health and Reproduction, School of Veterinary Medicine, UC Davis, Davis, California.,California National Primate Research Center, University of California Davis, Davis, California
| |
Collapse
|
42
|
Engelhardt A, Muniz L, Perwitasari-Farajallah D, Widdig A. Highly Polymorphic Microsatellite Markers for the Assessment of Male Reproductive Skew and Genetic Variation in Critically Endangered Crested Macaques ( Macaca nigra). INT J PRIMATOL 2017; 38:672-691. [PMID: 28845069 PMCID: PMC5550527 DOI: 10.1007/s10764-017-9973-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 05/11/2017] [Indexed: 11/24/2022]
Abstract
Genetic analyses based on noninvasively collected samples have become an important tool for evolutionary biology and conservation. Crested macaques (Macaca nigra), endemic to Sulawesi, Indonesia, are important for our understanding of primate evolution as Sulawesi macaques represent an exceptional example of primate adaptive radiation. Crested macaques are also Critically Endangered. However, to date we know very little about their genetics. The aim of our study was to find and validate microsatellite markers useful for evolutionary, conservation, and other genetic studies on wild crested macaques. Using fecal samples of 176 wild macaques living in the Tangkoko Reserve, Sulawesi, we identified 12 polymorphic microsatellite loci through cross-species polymerase chain reaction amplification with later modification of some of these primers. We tested their suitability by investigating and exploring patterns of paternity, observed heterozygosity, and evidence for inbreeding. We assigned paternity to 63 of 65 infants with high confidence. Among cases with solved paternity, we found no evidence of extragroup paternity and natal breeding. We found a relatively steep male reproductive skew B index of 0.330 ± 0.267; mean ± SD) and mean alpha paternity of 65% per year with large variation across groups and years (29–100%). Finally, we detected an excess in observed heterozygosity and no evidence of inbreeding across our three study groups, with an observed heterozygosity of 0.766 ± 0.059 and expected heterozygosity of 0.708 ± 0.059, and an inbreeding coefficient of −0.082 ± 0.035. Our results indicate that the selected markers are useful for genetic studies on wild crested macaques, and possibly also on other Sulawesi and closely related macaques. They further suggest that the Tangkoko population of crested macaques is still genetically variable despite its small size, isolation, and the species’ reproductive patterns. This gives us hope that other endangered primate species living in small, isolated populations may also retain a healthy gene pool, at least in the short term.
Collapse
Affiliation(s)
- Antje Engelhardt
- School of Natural Sciences and Psychology, Liverpool John Moores University, L3 3AF, Liverpool, UK.,Junior Research Group of Primate Sexual Selection, German Primate Center, 37077 Göttingen, Germany.,Courant Research Center Evolution of Social Behavior, Georg August University, 37077 Göttingen, Germany
| | - Laura Muniz
- Junior Research Group of Primate Kin Selection, Department of Primatology, Max-Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany.,Research Group of Behavioural Ecology, Institute of Biology, University of Leipzig, 04103 Leipzig, Germany
| | - Dyah Perwitasari-Farajallah
- Primate Research Centre, Bogor Agricultural University, Bogor, Indonesia.,Department of Biology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Bogor, Indonesia
| | - Anja Widdig
- Junior Research Group of Primate Kin Selection, Department of Primatology, Max-Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany.,Research Group of Behavioural Ecology, Institute of Biology, University of Leipzig, 04103 Leipzig, Germany.,German Center for Integrative Biodiversity Research, 04103 Leipzig, Germany
| |
Collapse
|
43
|
Hannibal DL, Bliss-Moreau E, Vandeleest J, McCowan B, Capitanio J. Laboratory rhesus macaque social housing and social changes: Implications for research. Am J Primatol 2017; 79:1-14. [PMID: 26848542 PMCID: PMC5436575 DOI: 10.1002/ajp.22528] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 11/30/2015] [Accepted: 01/04/2016] [Indexed: 12/21/2022]
Abstract
Macaque species, specifically rhesus (Macaca mulatta), are the most common nonhuman primates (NHPs) used in biomedical research due to their suitability as a model of high priority diseases (e.g., HIV, obesity, cognitive aging), cost effective breeding and housing compared to most other NHPs, and close evolutionary relationship to humans. With this close evolutionary relationship, however, is a shared adaptation for a socially stimulating environment, without which both their welfare and suitability as a research model are compromised. While outdoor social group housing provides the best approximation of a social environment that matches the macaque behavioral biology in the wild, this is not always possible at all facilities, where animals may be housed indoors in small groups, in pairs, or alone. Further, animals may experience many housing changes in their lifetime depending on project needs, changes in social status, management needs, or health concerns. Here, we review the evidence for the physiological and health effects of social housing changes and the potential impacts on research outcomes for studies using macaques, particularly rhesus. We situate our review in the context of increasing regulatory pressure for research facilities to both house NHPs socially and mitigate trauma from social aggression. To meet these regulatory requirements and further refine the macaque model for research, significant advances must be made in our understanding and management of rhesus macaque social housing, particularly pair-housing since it is the most common social housing configuration for macaques while on research projects. Because most NHPs are adapted for sociality, a social context is likely important for improving repeatability, reproducibility, and external validity of primate biomedical research. Am. J. Primatol. 79:e22528, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Darcy L Hannibal
- California National Primate Research Center, University of California, Davis, California
- Department of Population Health and Reproduction, University of California, Davis, California
| | - Eliza Bliss-Moreau
- California National Primate Research Center, University of California, Davis, California
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, California
| | - Jessica Vandeleest
- California National Primate Research Center, University of California, Davis, California
| | - Brenda McCowan
- California National Primate Research Center, University of California, Davis, California
- Department of Population Health and Reproduction, University of California, Davis, California
| | - John Capitanio
- California National Primate Research Center, University of California, Davis, California
- Department of Psychology, University of California, Davis, California
| |
Collapse
|
44
|
Valomy M, Hayes LD, Schradin C. Social organization in Eulipotyphla: evidence for a social shrew. Biol Lett 2016; 11:rsbl.2015.0825. [PMID: 26559515 DOI: 10.1098/rsbl.2015.0825] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Shrews and their close relatives (order Eulipotyphla) are typically considered to be solitary. This impacts our understanding of mammalian social evolution: (i) the ancestor of mammals is believed to have been shrew-like, and even though Eulipotyphla are not more basal than other mammalian orders, this might have been one reason why the first mammals have been assumed to be solitary-living; (ii) Eulipotyphla are the third largest mammalian order, with hundreds of species entering comparative analyses. We review primary field studies reporting the social organization of Eulipotyphla, doing a literature research on 445 species. Primary literature was only available for 16 of the 445 species. We found 56% of the studied species to be social (38% were living in pairs), which is in sharp contrast to the 0.5 and 8% reported in other databases. We conclude that the available information indicates that shrews are more sociable than generally believed. An interesting alternative hypothesis is that the mammalian ancestor might have been pair-living. To understand the social evolution of mammals, comparative studies must be based on reliable and specific information, and more species of all orders must be studied in the field.
Collapse
Affiliation(s)
- M Valomy
- Département de Licence Sciences de la Vie, Université Pierre et Marie Curie, UPMC, 75252 Paris Cedex 05, France IPHC-DEPE, Université de Strasbourg, 67087 Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France
| | - L D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - C Schradin
- IPHC-DEPE, Université de Strasbourg, 67087 Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa
| |
Collapse
|
45
|
Pekár S, Brabec M. Marginal Models Via GLS: A Convenient Yet Neglected Tool for the Analysis of Correlated Data in the Behavioural Sciences. Ethology 2016. [DOI: 10.1111/eth.12514] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stano Pekár
- Department of Botany and Zoology; Faculty of Science; Masaryk University; Brno Czech Republic
| | - Marek Brabec
- Department of Nonlinear Modelling; Institute of Computer Science; The Czech Academy of Sciences; Praha 8 Czech Republic
| |
Collapse
|
46
|
Bernstein SK, Sheeran LK, Wagner RS, Li JH, Koda H. The vocal repertoire of Tibetan macaques (Macaca thibetana): A quantitative classification. Am J Primatol 2016; 78:937-49. [PMID: 27243451 DOI: 10.1002/ajp.22564] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 05/14/2016] [Accepted: 05/14/2016] [Indexed: 11/10/2022]
Abstract
Vocal repertoires are basic and essential components for describing vocal communication in animals. Studying the entire suite of vocal signals aids investigations on the variation of acoustic structure across social contexts, comparisons on the complexity of communication systems across taxa, and in exploration of the evolutionary origins of species-specific vocalizations. Here, we describe the vocal repertoire of the largest species in the macaque genus, Macaca thibetana. We extracted thirty acoustic parameters from call recordings. Post hoc validation through quantitative analyses of the a priori repertoire classified eleven call types: coo, squawk, squeal, noisy scream, growl, bark, compound squeak, leap coo, weeping, modulated tonal scream, and pant. In comparison to the rest of the genus, Tibetan macaques uttered a wider array of vocalizations in the context of copulations. Previous reports did not include modulated tonal screams and pants during harassment of copulatory dyads. Furthermore, in comparison to the rest of the genus, Tibetan macaque females emit acoustically distinct copulation calls. The vocal repertoire of Tibetan macaques contributes to the literature on the emergence of species-specific calls in the genus Macaca with potential insights from social, reproductive, and ecological comparisons across species. Am. J. Primatol. 78:937-949, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Sofia K Bernstein
- Department of Ecology and Social Behavior, Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan
| | - Lori K Sheeran
- Department of Anthropology and Museum Studies, Central Washington University, Ellensburg, Washington.,Primate Behavior and Ecology Program, Central Washington University, Ellensburg, Washington
| | - R Steven Wagner
- Primate Behavior and Ecology Program, Central Washington University, Ellensburg, Washington.,Department of Biological Sciences, Central Washington University, Ellensburg, Washington
| | - Jin-Hua Li
- School of Life Science, Hefei Normal University, Hefei, China
| | - Hiroki Koda
- Department of Cognitive Sciences, Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan
| |
Collapse
|
47
|
|
48
|
Mother-male bond, but not paternity, influences male-infant affiliation in wild crested macaques. Behav Ecol Sociobiol 2016; 70:1117-1130. [PMID: 27478299 PMCID: PMC4954837 DOI: 10.1007/s00265-016-2116-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 11/16/2022]
Abstract
Abstract In promiscuous primates, interactions between adult males and infants have rarely been investigated. However, recent evidence suggests that male affiliation towards infants has an influence on several aspects of the infants’ life. Furthermore, affiliations may be associated with male reproductive strategy. In this study, we examined which social factors influenced male-infant affiliation initiated by either male or infant, in wild crested macaques (Macaca nigra). We combined behavioral data and genetic paternity analysis from 30 infants living in three wild groups in Tangkoko Reserve, Indonesia. Our results indicate that adult males and infants do not interact at random, but rather form preferential associations. The social factors with the highest influence on infant-initiated interactions were male rank and male association with the infant’s mother. While infants initiated affiliations with males more often in the absence of their mothers, adult males initiated more affiliations with infants when their mothers were present. Furthermore, males initiated affiliations more often when they were in the same group at the time the infant was conceived, when they held a high dominance rank, or when they had a close relationship with the mother. Interestingly, paternity did not affect male-infant affiliation despite being highly skewed in this species. Overall, our results suggest that adult males potentially associate with an infant to secure future mating with the mother. Infants are more likely to associate with a male to receive better support, suggesting a strategy to increase the chance of infant survival in a primate society with high infant mortality. Significance statement We explore social relationships between males and infants in a promiscuous primate, the wild crested macaque. Our novel approach addresses the nature of affiliations both from males’ and infants’ perspectives. The results show that males and infants form preferential associations. Male-female affiliation, but not paternity, was a significant predictor of interactions initiated both by males and infants. Males initiated more interactions towards infants when the mother was in proximity, while infants initiated more interactions in her absence. Finally, high-ranking males were more likely to initiate interactions towards infants. We demonstrated that paternity is not a good predictor of male-infant affiliations, even in a species with a high reproductive skew and a relatively high confidence of paternity. Our paper is one of the first to show that infants are active agents in establishing and maintaining preferential relationships with males. Electronic supplementary material The online version of this article (doi:10.1007/s00265-016-2116-0) contains supplementary material, which is available to authorized users.
Collapse
|
49
|
Sosa S. The Influence of Gender, Age, Matriline and Hierarchical Rank on Individual Social Position, Role and Interactional Patterns in Macaca sylvanus at 'La Forêt des Singes': A Multilevel Social Network Approach. Front Psychol 2016; 7:529. [PMID: 27148137 PMCID: PMC4834345 DOI: 10.3389/fpsyg.2016.00529] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 03/30/2016] [Indexed: 11/13/2022] Open
Abstract
A society is a complex system composed of individuals that can be characterized by their own attributes that influence their behaviors. In this study, a specific analytical protocol based on social network analysis was adopted to investigate the influence of four attributes (gender, age, matriline, and hierarchical rank) on affiliative (allogrooming) and agonistic networks in a non-human primate species, Macaca sylvanus, at the park La Forêt des Singes in France. The results show significant differences with respect to the position (i.e., centric, peripheral) and role (i.e., implication in the network cohesiveness) of an individual within a social network and hence interactional patterns. Females are more central, more active, and have a denser ego network in the affiliative social network tan males; thus, they contribute in a greater way to the cohesive structure of the network. High-ranking individuals are likely to receive fewer agonistic behaviors than low-ranking individuals, and high-ranking females receive more allogrooming. I also observe homophily for affiliative interactions regarding all attributes and homophily for agonistic interactions regarding gender and age. Revealing the positions, the roles, and the interactional behavioral patterns of individuals can help understand the mechanisms that shape the overall structure of a social network.
Collapse
Affiliation(s)
- Sebastian Sosa
- Formerly affiliated with Grupo de Conducta Adaptativa e Interacción, Psychology Faculty, University of BarcelonaBarcelona, Spain
| |
Collapse
|
50
|
Borgi M, Majolo B. Facial width-to-height ratio relates to dominance style in the genus Macaca. PeerJ 2016; 4:e1775. [PMID: 27019780 PMCID: PMC4806626 DOI: 10.7717/peerj.1775] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/17/2016] [Indexed: 11/20/2022] Open
Abstract
Background. Physical, visual, chemical, and auditory cues signalling fighting ability have independently evolved in many animal taxa as a means to resolve conflicts without escalating to physical aggression. Facial width-to-height ratio (fWHR, i.e., the relative width to height of the face) has been associated with dominance-related phenotypes both in humans and in other primates. In humans, faces with a larger fWHR are perceived as more aggressive. Methods. We examined fWHR variation among 11 species of the genus Macaca. Macaques have been grouped into four distinct categories, from despotic to tolerant, based on their female dominance style. Female dominance style is related to intra- and inter-sexual competition in both males and females and is the result of different evolutionary pressure across species. We used female dominance style as a proxy of intra-/inter-sexual competition to test the occurrence of correlated evolution between competitive regimes and dominance-related phenotypes. fWHR was calculated from 145 2D photographs of male and female adult macaques. Results. We found no phylogenetic signal on the differences in fWHR across species in the two sexes. However, fWHR was greater, in females and males, in species characterised by despotic female dominance style than in tolerant species. Discussion. Our results suggest that dominance-related phenotypes are related to differences in competitive regimes and intensity of inter- and intra-sexual selection across species.
Collapse
Affiliation(s)
- Marta Borgi
- School of Psychology, University of Lincoln, Lincoln, United Kingdom; Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | | |
Collapse
|