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Suire A, Kunita I, Harel R, Crofoot M, Mutinda M, Kamau M, Hassel JM, Murray S, Kawamura S, Matsumoto-Oda A. Estimating individual exposure to predation risk in group-living baboons, Papio anubis. PLoS One 2023; 18:e0287357. [PMID: 37939092 PMCID: PMC10631679 DOI: 10.1371/journal.pone.0287357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 10/16/2023] [Indexed: 11/10/2023] Open
Abstract
In environments with multiple predators, vulnerabilities associated with the spatial positions of group-living prey are non-uniform and depend on the hunting styles of the predators. Theoretically, coursing predators follow their prey over long distances and attack open areas, exposing individuals at the edge of the group to predation risk more than those at the center (marginal predation). In contrast, ambush predators lurk unnoticed by their prey and appear randomly anywhere in the group; therefore, isolated individuals in the group would be more vulnerable to predators. These positions of vulnerability to predation are expected to be taken by larger-bodied males. Moreover, dominant males presumably occupy the center of the safe group. However, identifying individuals at higher predation risk requires both simultaneous recording of predator location and direct observation of predation events; empirical observations leave ambiguity as to who is at risk. Instead, several theoretical methods (predation risk proxies) have been proposed to assess predation risk: (1) the size of the individual 'unlimited domain of danger' based on Voronoi tessellation, (2) the size of the 'limited domain of danger' based on predator detection distance, (3) peripheral/center position in the group (minimum convex polygon), (4) the number and direction of others in the vicinity (surroundedness), and (5) dyadic distances. We explored the age-sex distribution of individuals in at-risk positions within a wild baboon group facing predation risk from leopards, lions, and hyenas, using Global Positioning System collars. Our analysis of the location data from 26 baboons revealed that adult males were consistently isolated at the edge of the group in all predation risk proxies. Empirical evidence from previous studies indicates that adult male baboons are the most frequently preyed upon, and our results highlights the importance of spatial positioning in this.
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Affiliation(s)
- Alexandre Suire
- Faculty of Global and Regional Studies, University of the Ryukyus, Okinawa, Japan
| | - Itsuki Kunita
- Faculty of Engineering, University of the Ryukyus, Okinawa, Japan
| | - Roi Harel
- Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Margaret Crofoot
- Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Maureen Kamau
- Smithsonian Conservation Biology Institute, Global Health Program, Washington, DC, United States of America
- Mpala Research Centre, Nanyuki, Kenya
| | - James M. Hassel
- Smithsonian Conservation Biology Institute, Global Health Program, Washington, DC, United States of America
| | - Suzan Murray
- Smithsonian Conservation Biology Institute, Global Health Program, Washington, DC, United States of America
| | - Shoji Kawamura
- Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Akiko Matsumoto-Oda
- Graduate School of Tourism Sciences, University of the Ryukyus, Okinawa, Japan
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2
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Pfoh R, Tiddi B, Di Bitetti MS, Agostini I. Grooming site preferences in black capuchin monkeys: Hygienic vs. social functions revisited. Am J Primatol 2021; 83:e23336. [PMID: 34612524 DOI: 10.1002/ajp.23336] [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: 03/30/2021] [Revised: 08/11/2021] [Accepted: 09/25/2021] [Indexed: 11/09/2022]
Abstract
When primates groom each other, they tend to concentrate on those parts of the body they cannot efficiently self-groom (i.e., not visually accessible), and prefer to intensify grooming in areas with high hair density, thus suggesting a hygienic function. However, preferences for some body sites over others during social grooming may also result from different degrees of social bonding and relative dominance. To assess the relative importance of physical (hygienic) and social factors, we examined grooming interactions in two groups of wild black capuchin monkeys (Sapajus nigritus) during 15 nonconsecutive months. We evaluated the distribution of social grooming across body sites according to their accessibility by self-grooming and hair density. At the same time, we assessed whether the degree of dyadic social bonding affects the relative body orientation between groomer and groomee and the access to vulnerable body sites (e.g., face, throat, groin) during grooming. As expected, capuchins preferentially groomed inaccessible body sites (e.g., back and head), with a disproportionate effort directed to the tufts of their partners. We found that dyadic social bond strength, together with rank distance, significantly affected the proportion of grooming in ventro-ventral body relative orientation only in dominant-subordinate groomer-groomee dyads. This may indicate that, when two individuals differ in rank but are strongly bonded, the level of uncertainty related to the social context is already resolved and thus grooming per se is no longer perceived by the subordinate as an uncertain/risky situation. We found no effect of social bonding on grooming vulnerable body sites for any type of dyad. Our findings suggest that grooming site preferences in black capuchin monkeys simultaneously reflect hygienic and social functions.
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Affiliation(s)
- Romina Pfoh
- Instituto de Biología Subtropical (IBS), Universidad Nacional de Misiones (UNaM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Puerto Iguazú (Misiones), Argentina.,Asociación Civil Centro de Investigaciones del Bosque Atlántico (CeIBA), Puerto Iguazú, Argentina
| | - Barbara Tiddi
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol, UK.,Division of Human and Social Sciences, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Mario S Di Bitetti
- Instituto de Biología Subtropical (IBS), Universidad Nacional de Misiones (UNaM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Puerto Iguazú (Misiones), Argentina.,Asociación Civil Centro de Investigaciones del Bosque Atlántico (CeIBA), Puerto Iguazú, Argentina.,Facultad de Ciencias Forestales, UNaM, Eldorado, Misiones, Argentina
| | - Ilaria Agostini
- Instituto de Biología Subtropical (IBS), Universidad Nacional de Misiones (UNaM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Puerto Iguazú (Misiones), Argentina.,Asociación Civil Centro de Investigaciones del Bosque Atlántico (CeIBA), Puerto Iguazú, Argentina.,Parque Nacional Nahuel Huapi (CENAC-APN), CONICET, San Carlos de Bariloche, Argentina
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3
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Puga-Gonzalez I, Ostner J, Schülke O, Sosa S, Thierry B, Sueur C. Mechanisms of reciprocity and diversity in social networks: a modeling and comparative approach. Behav Ecol 2018. [DOI: 10.1093/beheco/ary034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ivan Puga-Gonzalez
- Institute for Religion, Philosophy and History, University of Agder, Kristiansand, Gimlemoen, Kristiansand S, Norway
| | - Julia Ostner
- Department for Behavioural Ecology, University of Göttingen, Kellnerweg, Göttingen, Germany
- Primate Social Evolution Group, German Primate Center Göttingen, Kellnerweg, Göttingen, Germany
- Leibniz Science Campus Primate Cognition, Kellnerweg, Göttingen, Germany
| | - Oliver Schülke
- Department for Behavioural Ecology, University of Göttingen, Kellnerweg, Göttingen, Germany
- Primate Social Evolution Group, German Primate Center Göttingen, Kellnerweg, Göttingen, Germany
- Leibniz Science Campus Primate Cognition, Kellnerweg, Göttingen, Germany
| | - Sebastian Sosa
- School of Sociology and Anthropology, Sun Yat-sen University, Guangzhou, PR China
| | - Bernard Thierry
- Ethologie Cognitive et Sociale, Centre National de la Recherche Scientifique, rue du loess, Strasbourg, France
| | - Cedric Sueur
- Université de Strasbourg, CNRS, IPHC UMR, rue Becquerel Strasbourg Cedex, France
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4
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Empirical validation of an agent-based model of wood markets in Switzerland. PLoS One 2018; 13:e0190605. [PMID: 29351300 PMCID: PMC5774711 DOI: 10.1371/journal.pone.0190605] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 12/18/2017] [Indexed: 11/19/2022] Open
Abstract
We present an agent-based model of wood markets and show our efforts to validate this model using empirical data from different sources, including interviews, workshops, experiments, and official statistics. Own surveys closed gaps where data was not available. Our approach to model validation used a variety of techniques, including the replication of historical production amounts, prices, and survey results, as well as a historical case study of a large sawmill entering the market and becoming insolvent only a few years later. Validating the model using this case provided additional insights, showing how the model can be used to simulate scenarios of resource availability and resource allocation. We conclude that the outcome of the rigorous validation qualifies the model to simulate scenarios concerning resource availability and allocation in our study region.
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5
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Farine DR, Strandburg-Peshkin A, Couzin ID, Berger-Wolf TY, Crofoot MC. Individual variation in local interaction rules can explain emergent patterns of spatial organization in wild baboons. Proc Biol Sci 2017; 284:20162243. [PMID: 28424342 PMCID: PMC5413915 DOI: 10.1098/rspb.2016.2243] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 03/20/2017] [Indexed: 11/21/2022] Open
Abstract
Researchers have long noted that individuals occupy consistent spatial positions within animal groups. However, an individual's position depends not only on its own behaviour, but also on the behaviour of others. Theoretical models of collective motion suggest that global patterns of spatial assortment can arise from individual variation in local interaction rules. However, this prediction remains untested. Using high-resolution GPS tracking of members of a wild baboon troop, we identify consistent inter-individual differences in within-group spatial positioning. We then apply an algorithm that identifies what number of conspecific group members best predicts the future location of each individual (we call this the individual's neighbourhood size) while the troop is moving. We find clear variation in the most predictive neighbourhood size, and this variation relates to individuals' propensity to be found near the centre of their group. Using simulations, we show that having different neighbourhood sizes is a simple candidate mechanism capable of linking variation in local individual interaction rules-in this case how many conspecifics an individual interacts with-to global patterns of spatial organization, consistent with the patterns we observe in wild primates and a range of other organisms.
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Affiliation(s)
- D R Farine
- Department of Anthropology, University of California, 1 Shields Avenue, Davis, CA, USA
- Smithsonian Tropical Research Institute, Ancon, Panama
- Edward Grey Institute of Field Ornithology, Department of Zoology, University of Oxford, South Parks Road, Oxford, UK
| | - A Strandburg-Peshkin
- Department of Ecology and Evolutionary Biology, Princeton University, 106A Guyot Hall, Princeton, NJ, USA
| | - I D Couzin
- Department of Collective Behaviour, Max Planck Institute for Ornithology, 78464 Konstanz, Germany
- Chair of Biodiversity and Collective Behaviour, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - T Y Berger-Wolf
- Department of Computer Science, University of Illinois at Chicago, 851 South Morgan Street, Chicago, IL, USA
| | - M C Crofoot
- Department of Anthropology, University of California, 1 Shields Avenue, Davis, CA, USA
- Animal Behavior Graduate Group, University of California, 1 Shields Avenue, Davis, CA, USA
- Smithsonian Tropical Research Institute, Ancon, Panama
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6
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Smith-Aguilar SE, Ramos-Fernández G, Getz WM. Seasonal Changes in Socio-Spatial Structure in a Group of Free-Living Spider Monkeys (Ateles geoffroyi). PLoS One 2016; 11:e0157228. [PMID: 27280800 PMCID: PMC4900631 DOI: 10.1371/journal.pone.0157228] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/26/2016] [Indexed: 11/19/2022] Open
Abstract
Ecological and social factors influence individual movement and group membership decisions, which ultimately determine how animal groups adjust their behavior in spatially and temporally heterogeneous environments. The mechanisms behind these behavioral adjustments can be better understood by studying the relationship between association and space use patterns of groups and how these change over time. We examined the socio-spatial patterns of adult individuals in a free-ranging group of spider monkeys (Ateles geoffroyi), a species with high fission-fusion dynamics. Data comprised 4916 subgroup scans collected during 325 days throughout a 20-month period and was used to evaluate changes from fruit-scarce to fruit-abundant periods in individual core-area size, subgroup size and two types of association measures: spatial (core-area overlap) and spatio-temporal (occurrence in the same subgroup) associations. We developed a 3-level analysis framework to distinguish passive associations, where individuals are mostly brought together by resources of common interest, from active association, where individuals actively seek or avoid certain others. Results indicated a more concentrated use of space, increased individual gregariousness and higher spatio-temporal association rates in the fruit-abundant seasons, as is compatible with an increase in passive associations. Nevertheless, results also suggested active associations in all the periods analyzed, although associations differed across seasons. In particular, females seem to actively avoid males, perhaps prompted by an increased probability of random encounters among individuals, resulting from the contraction of individual core areas. Our framework proved useful in investigating the interplay between ecological and social constraints and how these constraints can influence individual ranging and grouping decisions in spider monkeys, and possibly other species with high fission-fusion dynamics.
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Affiliation(s)
- Sandra E. Smith-Aguilar
- Instituto Politécnico Nacional, Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Oaxaca, Santa Cruz Xoxocotlán, Oaxaca, México
| | - Gabriel Ramos-Fernández
- Instituto Politécnico Nacional, Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Oaxaca, Santa Cruz Xoxocotlán, Oaxaca, México
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Wayne M. Getz
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California, United States of America
- School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa
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7
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Evers E, de Vries H, Spruijt BM, Sterck EH. Intermediate-term emotional bookkeeping is necessary for long-term reciprocal grooming partner preferences in an agent-based model of macaque groups. PeerJ 2016; 4:e1488. [PMID: 26839737 PMCID: PMC4734454 DOI: 10.7717/peerj.1488] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 11/19/2015] [Indexed: 11/29/2022] Open
Abstract
Whether and how primates are able to maintain long-term affiliative relationships is still under debate. Emotional bookkeeping (EB), the partner-specific accumulation of emotional responses to earlier interactions, is a candidate mechanism that does not require high cognitive abilities. EB is difficult to study in real animals, due to the complexity of primate social life. Therefore, we developed an agent-based model based on macaque behavior, the EMO-model, that implements arousal and two emotional dimensions, anxiety-FEAR and satisfaction-LIKE, which regulate social behavior. To implement EB, model individuals assign dynamic LIKE attitudes towards their group members, integrating partner-specific emotional responses to earlier received grooming episodes. Two key parameters in the model were varied to explore their effects on long-term affiliative relationships: (1) the timeframe over which earlier affiliation is accumulated into the LIKE attitudes; and (2) the degree of partner selectivity. EB over short and long timeframes gave rise to low variation in LIKE attitudes, and grooming partner preferences were only maintained over one to two months. Only EB over intermediate-term timeframes resulted in enough variation in LIKE attitudes, which, in combination with high partner selectivity, enables individuals to differentiate between regular and incidental grooming partners. These specific settings resulted in a strong feedback between differentiated LIKE attitudes and the distribution of grooming, giving rise to strongly reciprocated partner preferences that could be maintained for longer periods, occasionally up to one or two years. Moreover, at these settings the individual's internal, socio-emotional memory of earlier affiliative episodes (LIKE attitudes) corresponded best to observable behavior (grooming partner preferences). In sum, our model suggests that intermediate-term LIKE dynamics and high partner selectivity seem most plausible for primates relying on emotional bookkeeping to maintain their social bonds.
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Affiliation(s)
- Ellen Evers
- Department of Animal Ecology, Utrecht University, Utrecht, The Netherlands
| | - Han de Vries
- Department of Animal Ecology, Utrecht University, Utrecht, The Netherlands
| | - Berry M. Spruijt
- Department of Animal Ecology, Utrecht University, Utrecht, The Netherlands
| | - Elisabeth H.M. Sterck
- Department of Animal Ecology, Utrecht University, Utrecht, The Netherlands
- Animal Science Department, Biomedical Primate Research Center, Rijswijk, The Netherlands
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8
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Overduin-de Vries AM, Spruijt BM, de Vries H, Sterck EHM. Tactical deception to hide sexual behaviour: macaques use distance, not visibility. Behav Ecol Sociobiol 2015; 69:1333-1342. [PMID: 26246655 PMCID: PMC4521099 DOI: 10.1007/s00265-015-1946-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 10/25/2022]
Abstract
Although tactical deception (TD) may be employed to hide sexual behaviour, there is as yet no firm evidence for it. Hiding may be guided by cognitive mechanisms consistent with either no, low or high level TD, such as exploiting male peripheral positions (no TD), creating distance (TD level 1) or hiding behind screens (TD level 1.5 which involves visual perspective taking (VPT)). Macaques are capable of VPT in a food context, suggesting that they may employ TD level 1.5. We investigated, in an observational study with temporarily provided hiding screens, which strategy was used to hide sexual behaviour in captive groups of two macaque species (Macaca mulatta and Macaca fascicularis). Sexual behaviour only sporadically took place near screens, and the few copulations near screens were not systematically hidden from the alpha male, precluding TD level 1.5. Instead, both females and non-alpha males were at a larger distance from the alpha male during sexual interactions than otherwise, consistent with TD level 1. Creating peripheral locations (TD level 1) may be effective in improving sexual opportunities in many species.
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Affiliation(s)
- A. M. Overduin-de Vries
- />Utrecht University, Utrecht, The Netherlands
- />Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | | | - H. de Vries
- />Utrecht University, Utrecht, The Netherlands
| | - E. H. M. Sterck
- />Utrecht University, Utrecht, The Netherlands
- />Biomedical Primate Research Centre, Rijswijk, The Netherlands
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9
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Evers E, de Vries H, Spruijt BM, Sterck EHM. Emotional bookkeeping and high partner selectivity are necessary for the emergence of partner-specific reciprocal affiliation in an agent-based model of primate groups. PLoS One 2015; 10:e0118921. [PMID: 25785601 PMCID: PMC4364990 DOI: 10.1371/journal.pone.0118921] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 01/22/2015] [Indexed: 11/29/2022] Open
Abstract
Primate affiliative relationships are differentiated, individual-specific and often reciprocal. However, the required cognitive abilities are still under debate. Recently, we introduced the EMO-model, in which two emotional dimensions regulate social behaviour: anxiety-FEAR and satisfaction-LIKE. Emotional bookkeeping is modelled by providing each individual with partner-specific LIKE attitudes in which the emotional experiences of earlier affiliations with others are accumulated. Individuals also possess fixed partner-specific FEAR attitudes, reflecting the stable dominance hierarchy. In this paper, we focus on one key parameter of the model, namely the degree of partner selectivity, i.e. the extent to which individuals rely on their LIKE attitudes when choosing affiliation partners. Studying the effect of partner selectivity on the emergent affiliative relationships, we found that at high selectivity, individuals restricted their affiliative behaviours more to similar-ranking individuals and that reciprocity of affiliation was enhanced. We compared the emotional bookkeeping model with a control model, in which individuals had fixed LIKE attitudes simply based on the (fixed) rank-distance, instead of dynamic LIKE attitudes based on earlier events. Results from the control model were very similar to the emotional bookkeeping model: high selectivity resulted in preference of similar-ranking partners and enhanced reciprocity. However, only in the emotional bookkeeping model did high selectivity result in the emergence of reciprocal affiliative relationships that were highly partner-specific. Moreover, in the emotional bookkeeping model, LIKE attitude predicted affiliative behaviour better than rank-distance, especially at high selectivity. Our model suggests that emotional bookkeeping is a likely candidate mechanism to underlie partner-specific reciprocal affiliation.
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Affiliation(s)
- Ellen Evers
- Animal Ecology, Utrecht University, Utrecht, the Netherlands
| | - Han de Vries
- Animal Ecology, Utrecht University, Utrecht, the Netherlands
| | | | - Elisabeth H. M. Sterck
- Animal Ecology, Utrecht University, Utrecht, the Netherlands
- Ethology Research, Biomedical Primate Research Center, Rijswijk, the Netherlands
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10
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Vervet (Chlorocebus pygerythrus) Intragroup Spatial Positioning: Dominants Trade-Off Predation Risk for Increased Food Acquisition. INT J PRIMATOL 2015. [DOI: 10.1007/s10764-015-9818-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Puga-Gonzalez I, Butovskaya M, Thierry B, Hemelrijk CK. Empathy versus parsimony in understanding post-conflict affiliation in monkeys: model and empirical data. PLoS One 2014; 9:e91262. [PMID: 24637720 PMCID: PMC3956673 DOI: 10.1371/journal.pone.0091262] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 02/10/2014] [Indexed: 11/18/2022] Open
Abstract
Post-conflict affiliation between former opponents and bystanders occurs in several species of non-human primates. It is classified in four categories of which affiliation received by the former victim, 'consolation', has received most attention. The hypotheses of cognitive constraint and social constraint are inadequate to explain its occurrence. The cognitive constraint hypothesis is contradicted by recent evidence of 'consolation' in monkeys and the social constraint hypothesis lacks information why 'consolation' actually happens. Here, we combine a computational model and an empirical study to investigate the minimum cognitive requirements for post-conflict affiliation. In the individual-based model, individuals are steered by cognitively simple behavioural rules. Individuals group and when nearby each other they fight if they are likely to win, otherwise, they may groom, especially when anxious. We parameterize the model after empirical data of a tolerant species, the Tonkean macaque (Macaca tonkeana). We find evidence for the four categories of post-conflict affiliation in the model and in the empirical data. We explain how in the model these patterns emerge from the combination of a weak hierarchy, social facilitation, risk-sensitive aggression, interactions with partners close-by and grooming as tension-reduction mechanism. We indicate how this may function as a new explanation for empirical data.
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Affiliation(s)
- Ivan Puga-Gonzalez
- Behavioural Ecology and Self-organization, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Marina Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russia
| | - Bernard Thierry
- Départment d'Ecologie, Physiologie & Ethologie, Institut Interdisciplinaire Hubert Curien, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
| | - Charlotte Korinna Hemelrijk
- Behavioural Ecology and Self-organization, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
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12
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Evers E, de Vries H, Spruijt BM, Sterck EHM. The EMO-model: an agent-based model of primate social behavior regulated by two emotional dimensions, anxiety-FEAR and satisfaction-LIKE. PLoS One 2014; 9:e87955. [PMID: 24504194 PMCID: PMC3913693 DOI: 10.1371/journal.pone.0087955] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 01/03/2014] [Indexed: 11/19/2022] Open
Abstract
Agent-based models provide a promising tool to investigate the relationship between individuals' behavior and emerging group-level patterns. An individual's behavior may be regulated by its emotional state and its interaction history with specific individuals. Emotional bookkeeping is a candidate mechanism to keep track of received benefits from specific individuals without requiring high cognitive abilities. However, how this mechanism may work is difficult to study in real animals, due to the complexity of primate social life. To explore this theoretically, we introduce an agent-based model, dubbed EMO-model, in which we implemented emotional bookkeeping. In this model the social behaviors of primate-like individuals are regulated by emotional processes along two dimensions. An individual's emotional state is described by an aversive and a pleasant dimension (anxiety and satisfaction) and by its activating quality (arousal). Social behaviors affect the individuals' emotional state. To implement emotional bookkeeping, the receiver of grooming assigns an accumulated affiliative attitude (LIKE) to the groomer. Fixed partner-specific agonistic attitudes (FEAR) reflect the stable dominance relations between group members. While the emotional state affects an individual's general probability of executing certain behaviors, LIKE and FEAR affect the individual's partner-specific behavioral probabilities. In this way, emotional processes regulate both spontaneous behaviors and appropriate responses to received behaviors, while emotional bookkeeping via LIKE attitudes regulates the development and maintenance of affiliative relations. Using an array of empirical data, the model processes were substantiated and the emerging model patterns were partially validated. The EMO-model offers a framework to investigate the emotional bookkeeping hypothesis theoretically and pinpoints gaps that need to be investigated empirically.
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Affiliation(s)
- Ellen Evers
- Animal Ecology, Utrecht University, Utrecht, the Netherlands
| | - Han de Vries
- Animal Ecology, Utrecht University, Utrecht, the Netherlands
| | | | - Elisabeth H. M. Sterck
- Animal Ecology, Utrecht University, Utrecht, the Netherlands
- Ethology Research, Biomedical Primate Research Center, Rijswijk, the Netherlands
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13
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Neumann C, Agil M, Widdig A, Engelhardt A. Personality of wild male crested macaques (Macaca nigra). PLoS One 2013; 8:e69383. [PMID: 23940517 PMCID: PMC3734184 DOI: 10.1371/journal.pone.0069383] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 06/09/2013] [Indexed: 11/28/2022] Open
Abstract
Animal personalities, i.e. consistent differences in behavior across time and/or context, have received increased attention of behavioral biologists over the last years. Recent research shows that personalities represent traits on which natural and sexual selection work and which can have substantial fitness consequences. The aim of this study is to establish the personality structure of crested macaque (Macaca nigra) males as foundation for future studies on its adaptive value. We collected behavioral data through focal animal sampling and additionally conducted two sets of playback experiments. Results of a factor analysis on the behavioral data revealed a four factor structure with components we labeled Anxiety, Sociability, Connectedness and Aggressiveness. Results from the experiments revealed an additional and independent Boldness factor but the absence of Neophilia. Overall, this structure resembles other macaque and animal species with the exception of Connectedness, which might be a consequence of the species' tolerant social style. Our results thus not only form the basis for future studies on the adaptive value of personality in crested macaques but also contribute an important data point for investigating the evolution of personality structure from a comparative perspective by refining, for example, which personality factors characterized the last common ancestor of hominids and macaques.
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Affiliation(s)
- Christof Neumann
- Junior Research Group of Primate Sexual Selection, German Primate Center, Göttingen, Germany.
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Look before you leap - individual variation in social vigilance shapes socio-spatial group properties in an agent-based model. Behav Ecol Sociobiol 2012; 66:931-945. [PMID: 22661823 PMCID: PMC3353107 DOI: 10.1007/s00265-012-1342-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/26/2012] [Accepted: 02/28/2012] [Indexed: 11/05/2022]
Abstract
Next to predator detection, primate vigilance also serves to keep track of relevant conspecifics. The degree of vigilance towards group members often reflects the dominance rank of an individual: subordinates pay attention to dominants. Although it has been suggested that subordinates’ vigilance may result in spatial centrality of dominants, this has not been addressed in either empirical or modeling studies. Using agent-based models, we determined how social vigilance affects socio-spatial properties of primate groups. A basic model without social vigilance, where individuals avoid potential aggressors (avoidance model), was contrasted with two models that each additionally included a different type of social vigilance: a) monitoring a specific potential aggressor to remain informed on its whereabouts (monitoring model) or b) scanning the whole group to detect potential aggressors (scanning model). Adding monitoring or scanning behavior to the avoidance model reinforced spatial centrality of dominants, a pattern often observed in primates, and resulted in more spread out groups. Moreover, variation in scanning tendency alone was already sufficient to generate spatial centrality of dominants: frequently scanning subordinates could move further away from the group center than dominants, before losing sight of group members. In the monitoring model, two mechanisms caused decreased encounter frequencies among subordinates: a) increased inter-individual distances, and b) frequent monitoring of central dominants. In the scanning model, encounters among subordinates decreased due to increased inter-individual distances. This agent-based model study provides a clear indication that individual variation in social vigilance may be an important structuring feature of primate social groups.
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