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Tamura M, Wilfried EEG, Akomo-Okoue EF. Death of a one-armed blackback male due to severe injuries in a group of wild western lowland gorillas (Gorilla gorilla gorilla) in Moukalaba-Doudou National Park, Gabon. Primates 2024:10.1007/s10329-024-01138-4. [PMID: 38809381 DOI: 10.1007/s10329-024-01138-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 05/07/2024] [Indexed: 05/30/2024]
Abstract
The survival of limb-disabled primates in the wild has been widely reported. Nevertheless, their ultimate fate is little documented. It is important to understand the influence of limb disability on primate survival from a conservation perspective, as many African great apes suffer from limb injuries caused by entrapment in snares. Here, we report the death of a one-armed blackback male in a large one-male group of wild western lowland gorillas. The subject was a blackback male (14 years old) named Dodo, who lost his right forearm in August 2008. On 8 December 2019, Dodo was found to have suffered serious bleeding injuries to the front of his body, including large lacerations and puncture wounds. On 14 December his corpse was found in the forest. We provide evidence to suggest that his injuries were more likely caused by intraspecific aggression, though a predatory attack by a leopard could not be completely ruled out. His one-armed disability could have made him more vulnerable to attack from either a gorilla or leopard and led to his fatal injury. This report shows that a gorilla who had previously overcome a disability in one arm in childhood may die prematurely, in part, owing to this disability in young adulthood.
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Affiliation(s)
- Masaya Tamura
- Laboratory of Human Evolution Studies, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan.
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2
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Mouginot M, Wilson ML, Desai N, Surbeck M. Differences in expression of male aggression between wild bonobos and chimpanzees. Curr Biol 2024; 34:1780-1785.e4. [PMID: 38614078 DOI: 10.1016/j.cub.2024.02.071] [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: 06/21/2023] [Revised: 01/22/2024] [Accepted: 02/28/2024] [Indexed: 04/15/2024]
Abstract
Researchers investigating the evolution of human aggression look to our closest living relatives, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes), as valuable sources of comparative data.1,2 Males in the two species exhibit contrasting patterns: male chimpanzees sexually coerce females3,4,5,6,7,8 and sometimes kill conspecifics,9,10,11,12 whereas male bonobos exhibit less sexual coercion13,14 and no reported killing.13 Among the various attempts to explain these species differences, the self-domestication hypothesis proposes negative fitness consequences of male aggression in bonobos.2,15,16 Nonetheless, the extent to which these species differ in overall rates of aggression remains unclear due to insufficiently comparable observation methods.17,18,19,20,21,22,23 We used 14 community-years of focal follow data-the gold standard for observational studies24-to compare rates of male aggression in 3 bonobo communities at the Kokolopori Bonobo Reserve, Democratic Republic of Congo, and 2 chimpanzee communities at Gombe National Park, Tanzania. As expected, given that females commonly outrank males, we found that bonobos exhibited lower rates of male-female aggression and higher rates of female-male aggression than chimpanzees. Surprisingly, we found higher rates of male-male aggression among bonobos than chimpanzees even when limiting analyses to contact aggression. In both species, more aggressive males obtained higher mating success. Although our findings indicate that the frequency of male-male aggression does not parallel species difference in its intensity, they support the view that contrary to male chimpanzees, whose reproductive success depends on strong coalitions, male bonobos have more individualistic reproductive strategies.25.
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Affiliation(s)
- Maud Mouginot
- Institute for Advanced Study in Toulouse (IAST), Toulouse School of Economics, Université Toulouse Capitole, 31000 Toulouse, France; Department of Anthropology, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Michael L Wilson
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA; Institute on the Environment, University of Minnesota, Saint Paul, MN 55108, USA
| | - Nisarg Desai
- Emory National Primate Research Center, Emory University, Atlanta, GA 30329, USA
| | - Martin Surbeck
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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3
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Potel H, Niatou Singa FS, Cipolletta C, Neba Fuh T, Bardino G, Konyal E, Strampelli P, Henschel P, Masi S. Lethal combats in the forest among wild western gorillas. iScience 2024; 27:109437. [PMID: 38523787 PMCID: PMC10960106 DOI: 10.1016/j.isci.2024.109437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/13/2024] [Accepted: 03/04/2024] [Indexed: 03/26/2024] Open
Abstract
Lethal intergroup encounters occur in many species because of sexual selection. While documented in mountain gorillas, they are absent in western gorillas as, instead, it is predicted by their higher feeding (frugivory) and mate competition (single-vs. multi-male groups). We investigate whether the injuries on three dead silverbacks and one adult female from four groups of western gorillas in the Central African Republic, resulted from interactions with gorillas or leopards. We identified two distinct injury patterns caused by gorillas (isolated lacerations, round wounds) and leopards (punctures clustered on head/neck) by analyzing injuries caused by mountain gorillas and leopards to gorillas and non-gorilla species, respectively. The western gorilla injury pattern is similar to that of mountain gorillas suggesting that lethal encounters occur, albeit infrequently, as predicted by sexual selection in a one-male society. While sexual dimorphism and polygynous sociality favored the evolution of violent encounters, multiple males in groups may influence their frequency.
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Affiliation(s)
- Hugo Potel
- Ecoanthropologie, Centre National de la Recherche Scientifique/Muséum National d’Histoire Naturelle, University Paris Diderot, Sorbonne Paris Cité, Musée de l’Homme, Paris, France
| | | | - Chloé Cipolletta
- Dzanga-Sangha Protected Areas, World Wide Fund for Nature, Bangui, Central African Republic
| | - Terence Neba Fuh
- Dzanga-Sangha Protected Areas, World Wide Fund for Nature, Bangui, Central African Republic
| | - Giulia Bardino
- Ecoanthropologie, Centre National de la Recherche Scientifique/Muséum National d’Histoire Naturelle, University Paris Diderot, Sorbonne Paris Cité, Musée de l’Homme, Paris, France
- “La Sapienza” University, Department of Environmental and Evolutionary Biology, Rome, Italy
| | - Emmanuel Konyal
- Dzanga-Sangha Protected Areas, World Wide Fund for Nature, Bangui, Central African Republic
| | | | | | - Shelly Masi
- Ecoanthropologie, Centre National de la Recherche Scientifique/Muséum National d’Histoire Naturelle, University Paris Diderot, Sorbonne Paris Cité, Musée de l’Homme, Paris, France
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4
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Brooker JS, Webb CE, de Waal FBM, Clay Z. The expression of empathy in human's closest relatives, bonobos and chimpanzees: current and future directions. Biol Rev Camb Philos Soc 2024. [PMID: 38597291 DOI: 10.1111/brv.13080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 03/22/2024] [Accepted: 03/26/2024] [Indexed: 04/11/2024]
Abstract
Empathy is a complex, multi-dimensional capacity that facilitates the sharing and understanding of others' emotions. As our closest living relatives, bonobos (Pan paniscus) and chimpanzees (P. troglodytes) provide an opportunity to explore the origins of hominin social cognition, including empathy. Despite certain assumptions that bonobos and chimpanzees may differ empathically, these species appear to overlap considerably in certain socio-emotional responses related to empathy. However, few studies have systematically tested for species variation in Pan empathic or socio-emotional tendencies. To address this, we synthesise the growing literature on Pan empathy to inform our understanding of the selection pressures that may underlie the evolution of hominin empathy, and its expression in our last common ancestor. As bonobos and chimpanzees show overlaps in their expression of complex socio-emotional phenomena such as empathy, we propose that group comparisons may be as or more meaningful than species comparisons when it comes to understanding the evolutionary pressures for such behaviour. Furthermore, key differences, such as how humans and Pan communicate, appear to distinguish how we experience empathy compared to our closest living relatives.
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Affiliation(s)
- Jake S Brooker
- Department of Psychology, Durham University, South Road, Durham, DH1 3LE, UK
| | - Christine E Webb
- Department of Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA, 02138, USA
| | - Frans B M de Waal
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA, 30322, USA
| | - Zanna Clay
- Department of Psychology, Durham University, South Road, Durham, DH1 3LE, UK
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Koops K, Akankwasa W, Camara HD, Fitzgerald M, Keir A, Mamy G, Matsuzawa T, Péter H, Vicent K, Zuberbühler K, Hobaiter C. Flexible grouping patterns in a western and eastern chimpanzee community. Am J Primatol 2024; 86:e23593. [PMID: 38247391 DOI: 10.1002/ajp.23593] [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: 06/16/2023] [Revised: 12/19/2023] [Accepted: 12/27/2023] [Indexed: 01/23/2024]
Abstract
Primate social organizations, or grouping patterns, vary significantly across species. Behavioral strategies that allow for flexibility in grouping patterns offer a means to reduce the costs of group living. Chimpanzees (Pan troglodytes) have a fission-fusion social system in which temporary subgroups ("parties") change in composition because of local socio-ecological conditions. Notably, western chimpanzees (P. t. verus) are described as showing a higher degree of bisexual bonding and association than eastern chimpanzees, and eastern female chimpanzees (P. t. schweinfurthii) are thought to be more solitary than western female chimpanzees. However, reported comparisons in sociality currently depend on a small number of study groups, particularly in western chimpanzees, and variation in methods. The inclusion of additional communities and direct comparison using the same methods are essential to assess whether reported subspecies differences in sociality hold in this behaviorally heterogeneous species. We explored whether sociality differs between two communities of chimpanzees using the same motion-triggered camera technology and definitions of social measures. We compare party size and composition (party type, sex ratio) between the western Gahtoy community in the Nimba Mountains (Guinea) and the eastern Waibira community in the Budongo Forest (Uganda). Once potential competition for resources such as food and mating opportunities were controlled for, subspecies did not substantially influence the number of individuals in a party. We found a higher sex-ratio, indicating more males in a party, in Waibira; this pattern was driven by a greater likelihood in Gahtoy to be in all-female parties. This finding is the opposite of what was expected for eastern chimpanzees, where female-only parties are predicted to be more common. Our results highlight the flexibility in chimpanzee sociality, and caution against subspecies level generalizations.
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Grants
- Newnham College, University of Cambridge
- Royal Zoological Society of Scotland
- Homerton College, University of Cambridge
- Gates Cambridge Trust
- #12002009 Ministry of Education, Culture, Sports, Science and Technology
- #16002001 Ministry of Education, Culture, Sports, Science and Technology
- #20002001 Ministry of Education, Culture, Sports, Science and Technology
- #24000001 Ministry of Education, Culture, Sports, Science and Technology
- #16H06 Ministry of Education, Culture, Sports, Science and Technology
- Stichting Lucie Burgers
- PCEFP3_186967 Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
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Affiliation(s)
- Kathelijne Koops
- Ape Behaviour & Ecology Group, Department of Evolutionary Anthropology, University of Zurich, Zurich, Switzerland
- Department of Archaeology, University of Cambridge, Cambridge, UK
| | | | | | | | - Alex Keir
- Department of Archaeology, University of Cambridge, Cambridge, UK
| | - Gnan Mamy
- Institute de Recherche Environnementale de Bossou, Bossou, Guinea
| | - Tetsuro Matsuzawa
- Division of Humanities and Social Sciences, California Institute of Technology, Pasadena, California, USA
- Department of Pedagogy, Chubu Gakuin University, Gifu, Japan
- College of Life Sciences, Northwest University, Xi'an, China
| | - Hella Péter
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Kizza Vicent
- Budongo Conservation Field Station, Masindi, Uganda
| | - Klaus Zuberbühler
- Budongo Conservation Field Station, Masindi, Uganda
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Catherine Hobaiter
- Budongo Conservation Field Station, Masindi, Uganda
- Wild Minds Lab, School of Psychology & Neuroscience, University of St Andrews, St Andrews, UK
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Hobaiter C, Klein H, Gruber T. Habitual ground nesting in the Bugoma Forest chimpanzees (Pan troglodytes schweinfurthii), Uganda. Am J Primatol 2024; 86:e23583. [PMID: 38037523 DOI: 10.1002/ajp.23583] [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: 06/23/2023] [Revised: 11/05/2023] [Accepted: 11/24/2023] [Indexed: 12/02/2023]
Abstract
We report the presence of habitual ground nesting in a newly studied East African chimpanzee (Pan troglodytes schweinfurthii) population in the Bugoma Central Forest Reserve, Uganda. Across a 2-year period, we encountered 891 night nests, 189 of which were classified as ground nests, a rate of ~21%. We find no preliminary evidence of socio-ecological factors that would promote its use and highlight local factors, such as high incidence of forest disturbance due to poaching and logging, which appear to make its use disadvantageous. While further study is required to establish whether this behavior meets the strict criteria for nonhuman animal culture, we support the argument that the wider use of population and group-specific behavioral repertoires in flagship species, such as chimpanzees, offers a tool to promote the urgent conservation action needed to protect threatened ecosystems, including the Bugoma forest.
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Affiliation(s)
- Catherine Hobaiter
- Wild Minds Lab, School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
- Bugoma Primate Conservation Project, Bugoma Central Forest Reserve, Hoima, Uganda
| | - Harmonie Klein
- Wild Minds Lab, School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - Thibaud Gruber
- Bugoma Primate Conservation Project, Bugoma Central Forest Reserve, Hoima, Uganda
- Faculty of Psychology and Educational Sciences and Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland
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7
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Kawaguchi Y, Tomonaga M. Assessing the motivational value of infant video clips on chimpanzees through discrimination learning task. Dev Psychobiol 2024; 66:e22470. [PMID: 38356136 DOI: 10.1002/dev.22470] [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: 09/27/2023] [Revised: 12/21/2023] [Accepted: 01/26/2024] [Indexed: 02/16/2024]
Abstract
The motivational value of visual infant stimuli in humans is considered to encourage parental behavior. To explore the evolutionary roots of this preference for infants, we examined the reward value of conspecific infant videos compared to adult ones in nine chimpanzees. We employed a novel approach, a simultaneous discrimination task with differential sensory reinforcement. In Experiments 1 and 2, we tested if watching conspecific infant videos is more rewarding than watching adult ones. Participants were required to discriminate between two visual stimuli by a touch panel task. In video reward trials, a video clip featuring a chimpanzee infant followed a correct choice, while one featuring an adult followed an incorrect choice. However, the percentage of correct choices did not significantly differ from chance except in one chimpanzee, indicating that chimpanzees did not exhibit a preference for watching infant videos over those of adult. In Experiment 3, we tested if chimpanzees prefer conspecific videos over a blank screen; however, we did not find evidence either at a group level. These results suggest that the incentive salience of infant stimuli may not be universally compelling across species. Additionally, we discuss the limitations of the task using sensory reinforcement.
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Affiliation(s)
- Yuri Kawaguchi
- Primate Research Institute, Kyoto University, Inuyama, Japan
| | - Masaki Tomonaga
- School of Psychological Sciences, University of Human Environments, Matsuyama, Japan
- Japan Monkey Centre, Inuyama, Japan
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8
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Debetencourt B, Barry MM, Arandjelovic M, Stephens C, Maldonado N, Boesch C. Camera traps unveil demography, social structure, and home range of six unhabituated Western chimpanzee groups in the Moyen Bafing National Park, Guinea. Am J Primatol 2024; 86:e23578. [PMID: 37985945 DOI: 10.1002/ajp.23578] [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: 02/07/2023] [Revised: 11/02/2023] [Accepted: 11/05/2023] [Indexed: 11/22/2023]
Abstract
Precise estimates of population dynamics and social grouping patterns are required for effective conservation of wild animal populations. It is difficult to obtain such information on non-human great apes as they have slow reproductive rates. To gain a better understanding of demography in these populations, previous research has typically involved habituation\, a process that requires years. Here, we collected data continuously over year-long periods to monitor an unhabituated population of critically endangered Western chimpanzees (Pan troglodytes verus) in the Moyen Bafing National Park, Guinea. We used two arrays of 100 camera traps that were placed opportunistically in two distinct 100 km2 sites, named Bakoun and Koukoutamba. We identified 227 individuals in Bakoun and 207 in Koukoutamba through their unique facial features. Our camera trap data make clear that these individuals belong to six and seven closed groups, respectively. Six of those groups were near-completely sampled with an average minimum size of 46.8 individuals (range: 37-58), and a mean adult sex ratio of 1.32 (range: 0.93-2.10). We described the demographic composition of these groups and use Bayesian social network analysis to understand population structure. The network analyses suggested that the social bonds within the two populations were structured by sex homophily, with male chimpanzees being more or equally likely to be observed together than other adult associations. Through estimation of minimum convex polygons, we described the minimum home range for those groups. Compared to other chimpanzee groups living in a similar environment (mosaic savanna-forest), the Moyen Bafing region seems to host a high-density of chimpanzees with small home ranges for their group size. Our research highlights the potential of camera traps for studying the demographic composition of chimpanzee populations with high resolution and obtaining crucial information on several groups in a time-efficient and cost-effective way.
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Affiliation(s)
- Benjamin Debetencourt
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology (MPI-EVA), Leipzig, Germany
- Wild Chimpanzee Foundation, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Mamadou Moussa Barry
- Wild Chimpanzee Foundation, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Mimi Arandjelovic
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology (MPI-EVA), Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv), Leipzig, Germany
| | - Colleen Stephens
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology (MPI-EVA), Leipzig, Germany
| | - Nuria Maldonado
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology (MPI-EVA), Leipzig, Germany
| | - Christophe Boesch
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology (MPI-EVA), Leipzig, Germany
- Wild Chimpanzee Foundation, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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9
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Friederici AD, Wittig RM, Anwander A, Eichner C, Gräßle T, Jäger C, Kirilina E, Lipp I, Düx A, Edwards LJ, Girard-Buttoz C, Jauch A, Kopp KS, Paquette M, Pine KJ, Unwin S, Haun DBM, Leendertz FH, McElreath R, Morawski M, Gunz P, Weiskopf N, Crockford C. Brain structure and function: a multidisciplinary pipeline to study hominoid brain evolution. Front Integr Neurosci 2024; 17:1299087. [PMID: 38260006 PMCID: PMC10800984 DOI: 10.3389/fnint.2023.1299087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/07/2023] [Indexed: 01/24/2024] Open
Abstract
To decipher the evolution of the hominoid brain and its functions, it is essential to conduct comparative studies in primates, including our closest living relatives. However, strong ethical concerns preclude in vivo neuroimaging of great apes. We propose a responsible and multidisciplinary alternative approach that links behavior to brain anatomy in non-human primates from diverse ecological backgrounds. The brains of primates observed in the wild or in captivity are extracted and fixed shortly after natural death, and then studied using advanced MRI neuroimaging and histology to reveal macro- and microstructures. By linking detailed neuroanatomy with observed behavior within and across primate species, our approach provides new perspectives on brain evolution. Combined with endocranial brain imprints extracted from computed tomographic scans of the skulls these data provide a framework for decoding evolutionary changes in hominin fossils. This approach is poised to become a key resource for investigating the evolution and functional differentiation of hominoid brains.
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Affiliation(s)
- Angela D. Friederici
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Roman M. Wittig
- Evolution of Brain Connectivity Project, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Institute for Cognitive Sciences Marc Jeannerod, UMR CNRS, University Claude Bernard Lyon, Bron, France
- Taï Chimpanzee Project, CSRS, Abidjan, Côte d'Ivoire
| | - Alfred Anwander
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Cornelius Eichner
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Tobias Gräßle
- Epidemiology of Highly Pathogenic Microorganisms, Robert Koch Institute, Berlin, Germany
| | - Carsten Jäger
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Medical Faculty, Center of Neuropathology and Brain Research, Paul Flechsig Institute, University of Leipzig, Leipzig, Germany
| | - Evgeniya Kirilina
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Ilona Lipp
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Ariane Düx
- Epidemiology of Highly Pathogenic Microorganisms, Robert Koch Institute, Berlin, Germany
- Helmholtz Institute for One Health, University of Greifswald, Greifswald, Germany
| | - Luke J. Edwards
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Cédric Girard-Buttoz
- Evolution of Brain Connectivity Project, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Institute for Cognitive Sciences Marc Jeannerod, UMR CNRS, University Claude Bernard Lyon, Bron, France
| | - Anna Jauch
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Kathrin S. Kopp
- Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Michael Paquette
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Kerrin J. Pine
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Steve Unwin
- School of Bioscience, University of Birmingham, Birmingham, United Kingdom
| | - Daniel B. M. Haun
- Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Fabian H. Leendertz
- Epidemiology of Highly Pathogenic Microorganisms, Robert Koch Institute, Berlin, Germany
- Helmholtz Institute for One Health, University of Greifswald, Greifswald, Germany
| | - Richard McElreath
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Markus Morawski
- Medical Faculty, Center of Neuropathology and Brain Research, Paul Flechsig Institute, University of Leipzig, Leipzig, Germany
| | - Philipp Gunz
- Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Faculty of Physics and Earth System Sciences, Felix Bloch Institute for Solid State Physics, Leipzig University, Leipzig, Germany
| | - Catherine Crockford
- Evolution of Brain Connectivity Project, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Institute for Cognitive Sciences Marc Jeannerod, UMR CNRS, University Claude Bernard Lyon, Bron, France
- Taï Chimpanzee Project, CSRS, Abidjan, Côte d'Ivoire
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10
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Musgrave S, Koni D, Morgan D, Sanz C. Planning abilities of wild chimpanzees (Pan troglodytes troglodytes) in tool-using contexts. Primates 2023:10.1007/s10329-023-01106-4. [PMID: 38103142 DOI: 10.1007/s10329-023-01106-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 11/15/2023] [Indexed: 12/17/2023]
Abstract
Planning is a type of problem solving in which a course of future action is devised via mental computation. Potential advantages of planning for tool use include reduced effort to gather tools, closer alignment to an efficient tool design, and increased foraging efficiency. Chimpanzees (Pan troglodytes troglodytes) in the Goualougo Triangle use a variety of different types of tools. We hypothesized that procurement strategy (brought to the termite nest, manufactured or acquired at the termite nest, or borrowed from others) reflects planning for current needs, with tool transport behavior varying by tool type and by age and sex class. It is also possible that chimpanzees anticipate the need for tools at future times, which would be evidenced by transporting multiple tool types for a sequential task. One year of video recordings at termite nests were systematically screened for tool procurement; data comprised 299 tool procurement events across 66 chimpanzees. In addition, we screened video recordings of leaf sponging and honey gathering, which resulted in another 38 procurement events. Fishing probes, which are typically used during a single visit, were typically transported to termite nests, while puncturing tools, which are durable and remain on site, were more often acquired at termite nests. Most tools transported in multiples were fishing probes, perhaps in anticipation that a single probe might not last through an entire foraging bout or might be transferred to another chimpanzee. We further documented that chimpanzees transported tool sets, comprising multiple different tool types used in sequence. Mature chimpanzees transported tools more often than did immatures. These observations suggest that chimpanzees plan tool use flexibly, reflecting the availability of raw materials and the likelihood that specific tool types will be needed for particular tasks. Developmental studies and further integration of behavioral, spatial, and archaeological data will help to illuminate the decision making and time depth of planning associated with tool technologies in living primates and hominin ancestors.
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Affiliation(s)
- Stephanie Musgrave
- Department of Anthropology, University of Miami, P.O. Box 248106, Coral Gables, FL, 33124-2005, USA.
| | - David Koni
- Wildlife Conservation Society, Congo Program, B.P. 14537, Brazzaville, Republic of Congo
| | - David Morgan
- Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo, 2001 N. Clark Street, Chicago, IL, 60614, USA
| | - Crickette Sanz
- Wildlife Conservation Society, Congo Program, B.P. 14537, Brazzaville, Republic of Congo
- Department of Anthropology, Washington University in Saint Louis, 1 Brookings Drive, Saint Louis, MO, 63130, USA
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11
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van Leeuwen EJ, Staes N, Brooker JS, Kordon S, Nolte S, Clay Z, Eens M, Stevens JM. Group-specific expressions of co-feeding tolerance in bonobos and chimpanzees preclude dichotomous species generalizations. iScience 2023; 26:108528. [PMID: 38144453 PMCID: PMC10746535 DOI: 10.1016/j.isci.2023.108528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 07/21/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023] Open
Abstract
Bonobos are typically portrayed as more socially tolerant than chimpanzees, yet the current evidence supporting such a species-level categorization is equivocal. Here, we used validated group-level co-feeding assays to systematically test expressions of social tolerance in sixteen groups of zoo- and sanctuary-housed bonobos and chimpanzees. We found that co-feeding tolerance substantially overlaps between the species, thus precluding categorical inference at the species level. Instead, marked differences were observed between groups, with some bonobo communities exhibiting higher social tolerance than chimpanzee communities, and vice versa. Moreover, considerable intergroup variation was found within species living in the same environment, which attests to Pan's behavioral flexibility. Lastly, chimpanzees showed more tolerance in male-skewed communities, whereas bonobos responded less pronounced to sex-ratio variation. We conclude that the pervasive dichotomy between the tolerant bonobo and the belligerent chimpanzee requires quantitative nuance, and that accurate phylogenetic tracing of (human) social behavior warrants estimations of intraspecific group variation.
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Affiliation(s)
- Edwin J.C. van Leeuwen
- Animal Behaviour and Cognition, Department of Biology, Utrecht University, Padualaan 8, Utrecht 3584 CA, the Netherlands
- Behavioural Ecology and Ecophysiology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
- Centre for Research and Conservation, Royal Zoological Society of Antwerp, Koningin Astridplein 26, 2018 Antwerp, Belgium
- Department for Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Nicky Staes
- Behavioural Ecology and Ecophysiology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
- Centre for Research and Conservation, Royal Zoological Society of Antwerp, Koningin Astridplein 26, 2018 Antwerp, Belgium
| | - Jake S. Brooker
- Psychology Department, Durham University, South Road, Durham DH1 3LE, UK
| | - Stephanie Kordon
- Psychology Department, Durham University, South Road, Durham DH1 3LE, UK
| | - Suska Nolte
- Animal Behaviour and Cognition, Department of Biology, Utrecht University, Padualaan 8, Utrecht 3584 CA, the Netherlands
| | - Zanna Clay
- Psychology Department, Durham University, South Road, Durham DH1 3LE, UK
| | - Marcel Eens
- Behavioural Ecology and Ecophysiology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Jeroen M.G. Stevens
- Behavioural Ecology and Ecophysiology Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
- Centre for Research and Conservation, Royal Zoological Society of Antwerp, Koningin Astridplein 26, 2018 Antwerp, Belgium
- SALTO Agro- and Biotechnology, Odisee University College, Hospitaalstraat 23, 9100 Sint Niklaas, Belgium
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12
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Samuni L, Surbeck M. Cooperation across social borders in bonobos. Science 2023; 382:805-809. [PMID: 37972165 DOI: 10.1126/science.adg0844] [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: 12/02/2022] [Accepted: 09/29/2023] [Indexed: 11/19/2023]
Abstract
Cooperation beyond familial and group boundaries is core to the functioning of human societies, yet its evolution remains unclear. To address this, we examined grooming, coalition, and food-sharing patterns in bonobos (Pan paniscus), one of our closest living relatives whose rare out-group tolerance facilitates interaction opportunities between groups. We show that, as in humans, positive assortment supports bonobo cooperation across borders. Bonobo cooperative attitudes toward in-group members informed their cooperative relationships with out-groups, in particular, forming connections with out-group individuals who also exhibited high cooperation tendencies. Our findings show that cooperation between unrelated individuals across groups without immediate payoff is not exclusive to humans and suggest that such cooperation can emerge in the absence of social norms or strong cultural dispositions.
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Affiliation(s)
- Liran Samuni
- Cooperative Evolution Lab, German Primate Center, Göttingen, Germany
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - Martin Surbeck
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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13
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Drummond-Clarke RC, Fryns C, Stewart FA, Piel AK. A case of intercommunity lethal aggression by chimpanzees in an open and dry landscape, Issa Valley, western Tanzania. Primates 2023; 64:599-608. [PMID: 37615802 PMCID: PMC10651548 DOI: 10.1007/s10329-023-01085-6] [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: 12/31/2022] [Accepted: 08/10/2023] [Indexed: 08/25/2023]
Abstract
Intercommunity (lethal) aggression is a familiar component of the behavioural repertoire of many forest-dwelling chimpanzee (Pan troglodytes) communities. However, until now, the absence of intercommunity attacks - including killings - in communities that live in open, mosaic environments has supported hypotheses of reduced resource competition in drier habitats, and informed referential models of early hominin social dynamics in a similar habitat. In June 2020, we observed the first instance of intercommunity lethal aggression, a male-committed infanticide, by the Issa chimpanzee community, which live in a savannah-mosaic habitat in the Issa Valley, western Tanzania. The carcass was recovered by researchers after it was abandoned by the attackers. Here, we give a detailed account of the events leading up to and including the infanticide, and contextualise our observations with what has been described for other chimpanzee communities. Notably, in contrast to the majority of reported intercommunity infanticides, the infant male victim was castrated (and not cannibalised), making this the youngest reported castration. This observation of intercommunity aggression disproves its hypothesised absence in savannah-dwelling chimpanzees, which by extension, has implications for early hominin evolution. We suggest that the near absence of observations of intercommunity aggression in savannah chimpanzee communities is most likely due to the lack of long-term study communities, and in some cases geographic isolation. We hypothesise that food-rich areas within a habitat with otherwise widely distributed food sources may select for intense intercommunity aggression despite the low population density characteristic of savannah communities. Anecdotes such as this add to the comparative database available on intercommunity killings in chimpanzee society, improving our ability to draw inferences about their evolutionary significance.
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Affiliation(s)
| | - Caroline Fryns
- Insitut de Biologie, Université de Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
| | - Fiona A Stewart
- Department of Human Origins, Max Planck Institute of Evolutionary Anthropology, Leipzig, Germany
- Department of Anthropology, University College London, London, UK
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Alex K Piel
- Department of Human Origins, Max Planck Institute of Evolutionary Anthropology, Leipzig, Germany.
- Department of Anthropology, University College London, London, UK.
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14
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Lemoine SRT, Samuni L, Crockford C, Wittig RM. Chimpanzees make tactical use of high elevation in territorial contexts. PLoS Biol 2023; 21:e3002350. [PMID: 37917608 PMCID: PMC10621857 DOI: 10.1371/journal.pbio.3002350] [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: 09/20/2022] [Accepted: 09/26/2023] [Indexed: 11/04/2023] Open
Abstract
Tactical warfare is considered a driver of the evolution of human cognition. One such tactic, considered unique to humans, is collective use of high elevation in territorial conflicts. This enables early detection of rivals and low-risk maneuvers, based on information gathered. Whether other animals use such tactics is unknown. With a unique dataset of 3 years of simultaneous behavioral and ranging data on 2 neighboring groups of western chimpanzees, from the Taï National Park, Côte d'Ivoire, we tested whether chimpanzees make decisions consistent with tactical use of topography to gain an advantage over rivals. We show that chimpanzees are more likely to use high hills when traveling to, rather than away from, the border where conflict typically takes place. Once on border hills, chimpanzees favor activities that facilitate information gathering about rivals. Upon leaving hills, movement decisions conformed with lowest risk engagement, indicating that higher elevation facilitates the detection of rivals presence or absence. Our results support the idea that elevation use facilitated rival information gathering and appropriate tactical maneuvers. Landscape use during territorial maneuvers in natural contexts suggests chimpanzees seek otherwise inaccessible information to adjust their behavior and points to the use of sophisticated cognitive abilities, commensurate with selection for cognition in species where individuals gain benefits from coordinated territorial defense. We advocate territorial contexts as a key paradigm for unpicking complex animal cognition.
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Affiliation(s)
- Sylvain R. T. Lemoine
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Archaeology, University of Cambridge, Cambridge, United Kingdom
| | - Liran Samuni
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Cooperative Evolution Lab, German Primate Center, Göttingen, Germany
| | - Catherine Crockford
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Ape Social Mind Lab, Institut of Cognitive Science Marc Jeannerod, UMR5229, CNRS, Lyon, France
| | - Roman M. Wittig
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d’Ivoire
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Ape Social Mind Lab, Institut of Cognitive Science Marc Jeannerod, UMR5229, CNRS, Lyon, France
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15
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Mouginot M, Cheng L, Wilson ML, Feldblum JT, Städele V, Wroblewski EE, Vigilant L, Hahn BH, Li Y, Gilby IC, Pusey AE, Surbeck M. Reproductive inequality among males in the genus Pan. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220301. [PMID: 37381849 DOI: 10.1098/rstb.2022.0301] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/21/2023] [Indexed: 06/30/2023] Open
Abstract
Reproductive inequality, or reproductive skew, drives natural selection, but has been difficult to assess, particularly for males in species with promiscuous mating and slow life histories, such as bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). Although bonobos are often portrayed as more egalitarian than chimpanzees, genetic studies have found high male reproductive skew in bonobos. Here, we discuss mechanisms likely to affect male reproductive skew in Pan, then re-examine skew patterns using paternity data from published work and new data from the Kokolopori Bonobo Reserve, Democratic Republic of Congo and Gombe National Park, Tanzania. Using the multinomial index (M), we found considerable overlap in skew between the species, but the highest skew occurred among bonobos. Additionally, for two of three bonobo communities, but no chimpanzee communities, the highest ranking male had greater siring success than predicted by priority-of-access. Thus, an expanded dataset covering a broader demographic range confirms that bonobos have high male reproductive skew. Detailed comparison of data from Pan highlights that reproductive skew models should consider male-male dynamics including the effect of between-group competition on incentives for reproductive concessions, but also female grouping patterns and factors related to male-female dynamics including the expression of female choice. This article is part of the theme issue 'Evolutionary ecology of inequality'.
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Affiliation(s)
- Maud Mouginot
- Department of Anthropology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Leveda Cheng
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Michael L Wilson
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
- Institute on the Environment, University of Minnesota, Saint Paul, MN 55108, USA
| | - Joseph T Feldblum
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Veronika Städele
- School of Human Evolution and Social Change, and Institute of Human Origins, Arizona State University, Tempe, AZ 85287, USA
- Cognitive Ethology Laboratory, German Primate Center, Göttingen 37077, Germany
| | - Emily E Wroblewski
- Department of Anthropology, Washington University in St Louis, St Louis, MO 63130, USA
| | - Linda Vigilant
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Beatrice H Hahn
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yingying Li
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ian C Gilby
- School of Human Evolution and Social Change, and Institute of Human Origins, Arizona State University, Tempe, AZ 85287, USA
| | - Anne E Pusey
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Martin Surbeck
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
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16
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Negrey JD, Deschner T, Langergraber KE. Lean muscle mass, not aggression, mediates a link between dominance rank and testosterone in wild male chimpanzees. Anim Behav 2023; 202:99-109. [PMID: 37483564 PMCID: PMC10358427 DOI: 10.1016/j.anbehav.2023.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Testosterone promotes mating effort, which involves intraspecific aggression for males of many species. Therefore, males with higher testosterone levels are often thought to be more aggressive. For mammals living in multimale groups, aggression is hypothesized to link male social status (i.e. dominance rank) and testosterone levels, given that high status predicts mating success and is acquired partly through aggressive intragroup competition. In male chimpanzees, Pan troglodytes, dominance rank has been repeatedly linked to interindividual variation in testosterone levels, but evidence directly linking interindividual variation in testosterone and aggression is lacking. In the present study, we test both aggression levels and lean muscle mass, as measured by urinary creatinine, as links between dominance rank and testosterone levels in a large sample of wild male chimpanzees. Multivariate analyses indicated that dominance rank was positively associated with total rates of intragroup aggression, average urinary testosterone levels and average urinary creatinine levels. Testosterone was positively associated with creatinine levels but negatively associated with total aggression rates. Furthermore, mediation analyses showed that testosterone levels facilitated an association between dominance rank and creatinine levels. Our results indicate that (1) adult male chimpanzees with higher average testosterone levels are often higher ranking but not more aggressive than males with lower testosterone and (2) lean muscle mass links dominance rank and testosterone levels in Ngogo males. We assert that aggression rates are insufficient to explain links between dominance rank and testosterone levels in male chimpanzees and that other social variables (e.g. male-male relationship quality) may regulate testosterone's links to aggression.
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Affiliation(s)
- Jacob D. Negrey
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, U.S.A
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ, U.S.A
- Department of Pathology/Comparative Medicine, Wake Forest University School of Medicine, Winston-
Salem, NC, U.S.A
| | - Tobias Deschner
- Comparative BioCognition, Institute of Cognitive Science, University of Osnabrück, Osnabrück,
Germany
| | - Kevin E. Langergraber
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, U.S.A
- Institute of Human Origins, Arizona State University, Tempe, AZ, U.S.A
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17
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Sarkar A, Wrangham RW. Evolutionary and neuroendocrine foundations of human aggression. Trends Cogn Sci 2023; 27:468-493. [PMID: 37003880 DOI: 10.1016/j.tics.2023.02.003] [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: 11/13/2022] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 04/03/2023]
Abstract
Humans present a behavioural paradox: they are peaceful in many circumstances, but they are also violent and kill conspecifics at high rates. We describe a social evolutionary theory to resolve this paradox. The theory interprets human aggression as a combination of low propensities for reactive aggression and coercive behaviour and high propensities for some forms of proactive aggression (especially coalitionary proactive aggression). These tendencies are associated with the evolution of groupishness, self-domestication, and social norms. This human aggression profile is expected to demand substantial plasticity in the evolved biological mechanisms responsible for aggression. We discuss the contributions of various social signalling molecules (testosterone, cortisol, oxytocin, vasopressin, serotonin, and dopamine) as the neuroendocrine foundation conferring such plasticity.
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Affiliation(s)
- Amar Sarkar
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.
| | - Richard W Wrangham
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
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18
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Koops K, Humle T, Frandsen P, Fitzgerald M, D'Auvergne L, Jackson HA, Børsting C, Siegismund HR, Soumah AG, Hvilsom C. Genetics as a novel tool in mining impact assessment and biomonitoring of critically endangered western chimpanzees in the Nimba Mountains, Guinea. CONSERVATION SCIENCE AND PRACTICE 2023. [DOI: 10.1111/csp2.12898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023] Open
Affiliation(s)
- Kathelijne Koops
- Ape Behaviour & Ecology Group, Department of Evolutionary Anthropology University of Zurich Zurich Switzerland
- Department of Archaeology University of Cambridge Cambridge UK
| | - Tatyana Humle
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation University of Kent Kent UK
| | - Peter Frandsen
- Research and Conservation Copenhagen Zoo Copenhagen Denmark
| | - Maegan Fitzgerald
- Department of Ecology and Conservation Biology Texas A&M University College Station Texas USA
| | - Lucy D'Auvergne
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation University of Kent Kent UK
| | - Hazel A. Jackson
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation University of Kent Kent UK
| | - Claus Børsting
- Department of Forensic Medicine University of Copenhagen Copenhagen Denmark
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19
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Wroblewski EE, Guethlein LA, Anderson AG, Liu W, Li Y, Heisel SE, Connell AJ, Ndjango JBN, Bertolani P, Hart JA, Hart TB, Sanz CM, Morgan DB, Peeters M, Sharp PM, Hahn BH, Parham P. Malaria-driven adaptation of MHC class I in wild bonobo populations. Nat Commun 2023; 14:1033. [PMID: 36823144 PMCID: PMC9950436 DOI: 10.1038/s41467-023-36623-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 02/09/2023] [Indexed: 02/25/2023] Open
Abstract
The malaria parasite Plasmodium falciparum causes substantial human mortality, primarily in equatorial Africa. Enriched in affected African populations, the B*53 variant of HLA-B, a cell surface protein that presents peptide antigens to cytotoxic lymphocytes, confers protection against severe malaria. Gorilla, chimpanzee, and bonobo are humans' closest living relatives. These African apes have HLA-B orthologs and are infected by parasites in the same subgenus (Laverania) as P. falciparum, but the consequences of these infections are unclear. Laverania parasites infect bonobos (Pan paniscus) at only one (TL2) of many sites sampled across their range. TL2 spans the Lomami River and has genetically divergent subpopulations of bonobos on each side. Papa-B, the bonobo ortholog of HLA-B, includes variants having a B*53-like (B07) peptide-binding supertype profile. Here we show that B07 Papa-B occur at high frequency in TL2 bonobos and that malaria appears to have independently selected for different B07 alleles in the two subpopulations.
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Affiliation(s)
- Emily E Wroblewski
- Department of Anthropology, Washington University in St. Louis, Saint Louis, 63130, MO, USA.
| | - Lisbeth A Guethlein
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Aaron G Anderson
- Department of Anthropology, Washington University in St. Louis, Saint Louis, 63130, MO, USA
| | - Weimin Liu
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yingying Li
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sara E Heisel
- Department of Anthropology, Washington University in St. Louis, Saint Louis, 63130, MO, USA
| | - Andrew Jesse Connell
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jean-Bosco N Ndjango
- Department of Ecology and Management of Plant and Animal Resources, Faculty of Sciences, University of Kisangani, BP 2012, Kisangani, Democratic Republic of the Congo
| | - Paco Bertolani
- Institute of Human Sciences, School of Anthropology and Museum Ethnography, University of Oxford, Oxford, UK
| | - John A Hart
- Frankfurt Zoological Society, Lomami National Park Project, Kinshasa, Democratic Republic of the Congo
| | - Terese B Hart
- Frankfurt Zoological Society, Lomami National Park Project, Kinshasa, Democratic Republic of the Congo
| | - Crickette M Sanz
- Department of Anthropology, Washington University in St. Louis, Saint Louis, 63130, MO, USA
- Congo Program, Wildlife Conservation Society, Brazzaville, Republic of the Congo
| | - David B Morgan
- Lester E. Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo, Chicago, IL, 60614, USA
| | - Martine Peeters
- Recherche Translationnelle Appliquée au VIH et aux Maladies Infectieuses, Institut de Recherche pour le Développement, University of Montpellier, INSERM, 34090, Montpellier, France
| | - Paul M Sharp
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, EH9 3FL, UK
- Centre for Immunity, Infection, and Evolution, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Beatrice H Hahn
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Peter Parham
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
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20
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Freymann E, Huffman MA, Muhumuza G, Gideon MM, Zuberbühler K, Hobaiter C. Friends in high places: Interspecific grooming between chimpanzees and primate prey species in Budongo Forest. Primates 2023; 64:325-337. [PMID: 36790568 PMCID: PMC9930027 DOI: 10.1007/s10329-023-01053-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 01/26/2023] [Indexed: 02/16/2023]
Abstract
While cases of interspecies grooming have been reported in primates, no comprehensive cross-site review has been published about this behavior in great apes. Only a few recorded observations of interspecies grooming events between chimpanzees and other primate species have been reported in the wild, all of which have thus far been in Uganda. Here, we review all interspecies grooming events recorded for the Sonso community chimpanzees in Budongo Forest Reserve, Uganda, adding five new observations to the single, previously reported event from this community. A new case of interspecies play involving three juvenile male chimpanzees and a red-tailed monkey is also detailed. All events took place between 1993 and 2021. In all of the six interspecific grooming events from Budongo, the 'groomer' was a female chimpanzee between the ages of 4-6 years, and the 'recipient' was a member of the genus Cercopithecus. In five of these events, chimpanzee groomers played with the tail of their interspecific grooming partners, and except for one case, initiated the interaction. In three cases, chimpanzee groomers smelled their fingers after touching distinct parts of the receiver's body. While a single function of chimpanzee interspecies grooming remains difficult to determine from these results, our review outlines and assesses some hypotheses for the general function of this behavior, as well as some of the costs and benefits for both the chimpanzee groomers and their sympatric interspecific receivers. As allogrooming is a universal behavior in chimpanzees, investigating the ultimate and proximate drivers of chimpanzee interspecies grooming may reveal further functions of allogrooming in our closest living relatives, and help us to better understand how chimpanzees distinguish between affiliative and agonistic species and contexts.
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Affiliation(s)
- Elodie Freymann
- Primate Models for Behavioural Evolution Lab, Department of Anthropology and Museum Ethnography, Institute of Human Sciences, University of Oxford, Oxford, UK. .,Budongo Conservation Field Station, Masindi, Uganda.
| | - Michael A. Huffman
- Wildlife Research Center, Inuyama Campus, Kyoto University, Inuyama, Japan
| | | | | | - Klaus Zuberbühler
- Budongo Conservation Field Station, Masindi, Uganda ,Department of Comparative Cognition, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Catherine Hobaiter
- Wild Minds Lab, School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK ,Budongo Conservation Field Station, Masindi, Uganda
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21
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Gräßle T, Crockford C, Eichner C, Girard‐Buttoz C, Jäger C, Kirilina E, Lipp I, Düx A, Edwards L, Jauch A, Kopp KS, Paquette M, Pine K, Haun DBM, McElreath R, Anwander A, Gunz P, Morawski M, Friederici AD, Weiskopf N, Leendertz FH, Wittig RM, Albig K, Amarasekaran B, Angedakin S, Anwander A, Aschoff D, Asiimwe C, Bailanda L, Beehner JC, Belais R, Bergman TJ, Blazey B, Bernhard A, Bock C, Carlier P, Chantrey J, Crockford C, Deschner T, Düx A, Edwards L, Eichner C, Escoubas G, Ettaj M, Fedurek P, Flores K, Francke R, Friederici AD, Girard‐Buttoz C, Fortun JG, GoneBi ZB, Gräßle T, Gruber‐Dujardin E, Gunz P, Hartel J, Haun DBM, Henshall M, Hobaiter C, Hofman N, Jaffe JE, Jäger C, Jauch A, Kahemere S, Kirilina E, Klopfleisch R, Knauf‐Witzens T, Kopp KS, Kouima GLM, Lange B, Langergraber K, Lawrenz A, Leendertz FH, Lipp I, Liptovszky M, Theron TL, Lumbu CP, Nzassi PM, Mätz‐Rensing K, McElreath R, McLennan M, Mezö Z, Moittie S, Møller T, Morawski M, Morgan D, Mugabe T, Muller M, Müller M, Njumboket I, Olofsson‐Sannö K, Ondzie A, Otali E, Paquette M, Pika S, Pine K, Pizarro A, Pléh K, Rendel J, Reichler‐Danielowski S, Robbins MM, Forero AR, Ruske K, Samuni L, Sanz C, Schüle A, Schwabe I, Schwalm K, Speede S, Southern L, Steiner J, Stidworthy M, Surbeck M, Szentiks C, Tanga T, Ulrich R, Unwin S, van de Waal E, Walker S, Weiskopf N, Wibbelt G, Wittig RM, Wood K, Zuberbühler K. Sourcing high tissue quality brains from deceased wild primates with known socio‐ecology. Methods Ecol Evol 2023. [DOI: 10.1111/2041-210x.14039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Tobias Gräßle
- Epidemiology of highly pathogenic microorganisms Robert Koch‐Institute Berlin Germany
- Helmholtz Institute for One Health Greifswald Germany
| | - Catherine Crockford
- Ape Social Mind Lab Institute of Cognitive Science Marc Jeannerod, UMR 5229, CNRS Lyon France
- Department of Human Behavior, Ecology and Culture Max Planck Institute for Evolutionary Anthropology Leipzig Germany
- Taï Chimpanzee Project Centre Suisse de Recherches Scientifiques en Côte d'Ivoire Abidjan Ivory Coast
| | - Cornelius Eichner
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Cédric Girard‐Buttoz
- Ape Social Mind Lab Institute of Cognitive Science Marc Jeannerod, UMR 5229, CNRS Lyon France
- Department of Human Behavior, Ecology and Culture Max Planck Institute for Evolutionary Anthropology Leipzig Germany
- Taï Chimpanzee Project Centre Suisse de Recherches Scientifiques en Côte d'Ivoire Abidjan Ivory Coast
| | - Carsten Jäger
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
- Paul Flechsig Institute ‐ Center of Neuropathology and Brain Research, Faculty of Medicine Universität Leipzig Germany
| | - Evgeniya Kirilina
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
- Center for Cognitive Neuroscience Berlin Freie Universität Berlin Berlin Germany
| | - Ilona Lipp
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Ariane Düx
- Epidemiology of highly pathogenic microorganisms Robert Koch‐Institute Berlin Germany
- Helmholtz Institute for One Health Greifswald Germany
| | - Luke Edwards
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Anna Jauch
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Kathrin S. Kopp
- Department of Comparative Cultural Psychology Max Planck Institute for Evolutionary Anthropology Leipzig Germany
| | - Michael Paquette
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Kerrin Pine
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Daniel B. M. Haun
- Department of Comparative Cultural Psychology Max Planck Institute for Evolutionary Anthropology Leipzig Germany
| | - Richard McElreath
- Department of Human Behavior, Ecology and Culture Max Planck Institute for Evolutionary Anthropology Leipzig Germany
| | - Alfred Anwander
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Philipp Gunz
- Department of Human Evolution Max Planck Institute for Evolutionary Anthropology Leipzig Germany
| | - Markus Morawski
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
- Paul Flechsig Institute ‐ Center of Neuropathology and Brain Research, Faculty of Medicine Universität Leipzig Germany
| | - Angela D. Friederici
- Department of Neuropsychology Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
| | - Nikolaus Weiskopf
- Department of Neurophysics Max Planck Institute for Human Cognitive and Brain Sciences Leipzig Germany
- Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences Leipzig University Leipzig Germany
| | - Fabian H. Leendertz
- Epidemiology of highly pathogenic microorganisms Robert Koch‐Institute Berlin Germany
- Helmholtz Institute for One Health Greifswald Germany
| | - Roman M. Wittig
- Ape Social Mind Lab Institute of Cognitive Science Marc Jeannerod, UMR 5229, CNRS Lyon France
- Department of Human Behavior, Ecology and Culture Max Planck Institute for Evolutionary Anthropology Leipzig Germany
- Taï Chimpanzee Project Centre Suisse de Recherches Scientifiques en Côte d'Ivoire Abidjan Ivory Coast
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Dialects in leaf-clipping and other leaf-modifying gestures between neighbouring communities of East African chimpanzees. Sci Rep 2023; 13:147. [PMID: 36604445 PMCID: PMC9814361 DOI: 10.1038/s41598-022-25814-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 12/05/2022] [Indexed: 01/06/2023] Open
Abstract
Dialects are a cultural property of animal communication previously described in the signals of several animal species. While dialects have predominantly been described in vocal signals, chimpanzee leaf-clipping and other 'leaf-modifying' gestures, used across chimpanzee and bonobo communities, have been suggested as a candidate for cultural variation in gestural communication. Here we combine direct observation with archaeological techniques to compare the form and use of leaf-modifying gestures in two neighbouring communities of East African chimpanzees. We found that while both communities used multiple forms, primarily within sexual solicitation, they showed a strong preference for a single, different gesture form. The observed variation in form preference between these neighbouring communities within the same context suggests that these differences are, at least in part, socially derived. Our results highlight an unexplored source of variation and flexibility in gestural communication, opening the door for future research to explore socially derived dialects in non-vocal communication.
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Chalyan VG, Meishvili NV, Pachulia IG, Anikaeva EN, Zadorozhnii DV. Lethal Aggression in Captive Monkeys. J EVOL BIOCHEM PHYS+ 2023. [DOI: 10.1134/s0022093023010209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
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Nolte S, Sterck EHM, van Leeuwen EJC. Does tolerance allow bonobos to outperform chimpanzees on a cooperative task? A conceptual replication of Hare et al., 2007. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220194. [PMID: 36686553 PMCID: PMC9810421 DOI: 10.1098/rsos.220194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Across various taxa, social tolerance is thought to facilitate cooperation, and many species are treated as having species-specific patterns of social tolerance. Yet studies that assess wild and captive bonobos and chimpanzees result in contrasting findings. By replicating a cornerstone experimental study on tolerance and cooperation in bonobos and chimpanzees (Hare et al. 2007 Cur. Biol. 17, 619-623 (doi:10.1016/j.cub.2007.02.040)), we aim to further our understanding of current discrepant findings. We tested bonobos and chimpanzees housed at the same facility in a co-feeding and cooperation task. Food was placed on dishes located on both ends or in the middle of a platform. In the co-feeding task, the tray was simply made available to the ape duos, whereas in the cooperation task the apes had to simultaneously pull at both ends of a rope attached to the platform to retrieve the food. By contrast to the published findings, bonobos and chimpanzees co-fed to a similar degree, indicating a similar level of tolerance. However, bonobos cooperated more than chimpanzees when the food was monopolizable, which replicates the original study. Our findings call into question the interpretation that at the species level bonobos cooperate to a higher degree because they are inherently more tolerant.
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Affiliation(s)
- Suska Nolte
- Animal Behaviour and Cognition, Department of Biology, University Utrecht, Utrecht, The Netherlands
- Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Elisabeth H. M. Sterck
- Animal Behaviour and Cognition, Department of Biology, University Utrecht, Utrecht, The Netherlands
- Animal Science Department, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Edwin J. C. van Leeuwen
- Animal Behaviour and Cognition, Department of Biology, University Utrecht, Utrecht, The Netherlands
- Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Weiss A, Feldblum JT, Altschul DM, Collins DA, Kamenya S, Mjungu D, Foerster S, Gilby IC, Wilson ML, Pusey AE. Personality traits, rank attainment, and siring success throughout the lives of male chimpanzees of Gombe National Park. PeerJ 2023; 11:e15083. [PMID: 37123001 PMCID: PMC10135409 DOI: 10.7717/peerj.15083] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 02/25/2023] [Indexed: 05/02/2023] Open
Abstract
Personality traits in many taxa correlate with fitness. Several models have been developed to try to explain how variation in these traits is maintained. One model proposes that variation persists because it is linked to trade-offs between current and future adaptive benefits. Tests of this model's predictions, however, are scant in long-lived species. To test this model, we studied male chimpanzees living in Gombe National Park, Tanzania. We operationalized six personality traits using ratings on 19 items. We used 37 years of behavioral and genetic data to assemble (1) daily rank scores generated from submissive vocalizations and (2) records of male siring success. We tested whether the association between two personality traits, Dominance and Conscientiousness, and either rank or reproductive success, varied over the life course. Higher Dominance and lower Conscientiousness were associated with higher rank, but the size and direction of these relationships did not vary over the life course. In addition, independent of rank at the time of siring, higher Dominance and lower Conscientiousness were related to higher siring success. Again, the size and direction of these relationships did not vary over the life course. The trade-off model, therefore, may not hold in long-lived and/or slowly reproducing species. These findings also demonstrate that ratings are a valid way to measure animal personality; they are related to rank and reproductive success. These traits could therefore be used to test alternative models, including one that posits that personality variation is maintained by environmental heterogeneity, in studies of multiple chimpanzee communities.
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Affiliation(s)
- Alexander Weiss
- National Evolutionary Synthesis Center, Durham, NC, United States of America
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Wildlife Research Center, Kyoto University, Kyoto, Japan
- Scottish Primate Research Group, United Kingdom
| | - Joseph T. Feldblum
- Department of Anthropology, University of Michigan - Ann Arbor, Ann Arbor, MI, United States of America
- Society of Fellows, University of Michigan - Ann Arbor, Ann Arbor, MI, United States of America
- Department of Evolutionary Anthropology, Duke University, Durham, NC, United States of America
| | - Drew M. Altschul
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Scottish Primate Research Group, United Kingdom
- Mental Health Data Science, Edinburgh, United Kingdom
| | | | - Shadrack Kamenya
- Gombe Stream Research Centre, Jane Goodall Institute, Kigoma, Tanzania
| | - Deus Mjungu
- Gombe Stream Research Centre, Jane Goodall Institute, Kigoma, Tanzania
| | - Steffen Foerster
- Department of Evolutionary Anthropology, Duke University, Durham, NC, United States of America
| | - Ian C. Gilby
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, United States of America
- Institute of Human Origins, Arizona State University, Tempe, AZ, United States of America
| | - Michael L. Wilson
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, United States of America
- Institute on the Environment, University of Minnesota, St. Paul, MN, United States of America
| | - Anne E. Pusey
- Department of Evolutionary Anthropology, Duke University, Durham, NC, United States of America
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26
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Glowacki L. The evolution of peace. Behav Brain Sci 2022; 47:e1. [PMID: 36524358 DOI: 10.1017/s0140525x22002862] [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] [Indexed: 12/23/2022]
Abstract
While some species have affiliative and even cooperative interactions between individuals of different social groups, humans are alone in having durable, positive-sum, interdependent relationships across unrelated social groups. Our capacity to have harmonious relationships that cross group boundaries is an important aspect of our species' success, allowing for the exchange of ideas, materials, and ultimately enabling cumulative cultural evolution. Knowledge about the conditions required for peaceful intergroup relationships is critical for understanding the success of our species and building a more peaceful world. How do humans create harmonious relationships across group boundaries and when did this capacity emerge in the human lineage? Answering these questions involves considering the costs and benefits of intergroup cooperation and aggression, for oneself, one's group, and one's neighbor. Taking a game theoretical perspective provides new insights into the difficulties of removing the threat of war and reveals an ironic logic to peace - the factors that enable peace also facilitate the increased scale and destructiveness of conflict. In what follows, I explore the conditions required for peace, why they are so difficult to achieve, and when we expect peace to have emerged in the human lineage. I argue that intergroup cooperation was an important component of human relationships and a selective force in our species history beginning at least 300 thousand years. But the preconditions for peace only emerged in the past 100 thousand years and likely coexisted with intermittent intergroup violence which would have also been an important and selective force in our species' history.
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Affiliation(s)
- Luke Glowacki
- Department of Anthropology, Boston University, Boston, MA, USA ://www.hsb-lab.org/
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Puberty initiates a unique stage of social learning and development prior to adulthood: Insights from studies of adolescence in wild chimpanzees. Dev Cogn Neurosci 2022; 58:101176. [PMID: 36427434 PMCID: PMC9699942 DOI: 10.1016/j.dcn.2022.101176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/28/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022] Open
Abstract
In humans, puberty initiates a period of rapid growth, change, and formative neurobehavioral development. Brain and behavior changes during this maturational window contribute to opportunities for social learning. Here we provide new insights into adolescence as a unique period of social learning and development by describing field studies of our closest living relatives, chimpanzees. Like humans, chimpanzees have a multiyear juvenile life stage between weaning and puberty onset followed by a multiyear adolescent life stage after pubertal onset but prior to socially-recognized adulthood. As they develop increasing autonomy from caregivers, adolescent chimpanzees explore and develop many different types of social relationships with a wide range of individuals in a highly flexible social environment. We describe how adolescent social motivations and experiences differ from those of juveniles and adults and expose adolescents to high levels of uncertainty, risk, and vulnerability, as well as opportunities for adaptive social learning. We discuss how these adolescent learning experiences may be shaped by early life and in turn shape varied adult social outcomes. We outline how future chimpanzee field research can contribute in new ways to a more integrative interdisciplinary understanding of adolescence as a developmental window of adaptive social learning and resilience.
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Resource Scarcity Predicts Women’s Intrasexual Competition: The Role of Trait and State Envy. EVOLUTIONARY PSYCHOLOGICAL SCIENCE 2022. [DOI: 10.1007/s40806-022-00344-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Safryghin A, Cross C, Fallon B, Heesen R, Ferrer-i-Cancho R, Hobaiter C. Variable expression of linguistic laws in ape gesture: a case study from chimpanzee sexual solicitation. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220849. [PMID: 36405634 PMCID: PMC9653249 DOI: 10.1098/rsos.220849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Two language laws have been identified as consistent patterns shaping animal behaviour, both acting on the organizational level of communicative systems. Zipf's law of brevity describes a negative relationship between behavioural length and frequency. Menzerath's law defines a negative correlation between the number of behaviours in a sequence and average length of the behaviour composing it. Both laws have been linked with the information-theoretic principle of compression, which tends to minimize code length. We investigated their presence in a case study of male chimpanzee sexual solicitation gesture. We failed to find evidence supporting Zipf's law of brevity, but solicitation gestures followed Menzerath's law: longer sequences had shorter average gesture duration. Our results extend previous findings suggesting gesturing may be limited by individual energetic constraints. However, such patterns may only emerge in sufficiently large datasets. Chimpanzee gestural repertoires do not appear to manifest a consistent principle of compression previously described in many other close-range systems of communication. Importantly, the same signallers and signals were previously shown to adhere to these laws in subsets of the repertoire when used in play; highlighting that, in addition to selection on the signal repertoire, ape gestural expression appears shaped by factors in the immediate socio-ecological context.
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Affiliation(s)
- Alexandra Safryghin
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
| | - Catharine Cross
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
| | - Brittany Fallon
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
| | | | - Ramon Ferrer-i-Cancho
- Complexity and Quantitative Linguistics Laboratory, Laboratory for Relational Algorithmics, Complexity, and Learning Research Group, Departament de Ciències de la Computació, Universitat Politècnica de Catalunya, 08034 Barcelona, Catalonia, Spain
| | - Catherine Hobaiter
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
- Budongo Conservation Field Station, Masindi, Uganda
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Desai NP, Fedurek P, Slocombe KE, Wilson ML. Chimpanzee pant-hoots encode individual information more reliably than group differences. Am J Primatol 2022; 84:e23430. [PMID: 36093564 PMCID: PMC9786991 DOI: 10.1002/ajp.23430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 12/30/2022]
Abstract
Vocal learning, the ability to modify the acoustic structure of vocalizations based on social experience, is a fundamental feature of speech in humans (Homo sapiens). While vocal learning is common in taxa such as songbirds and whales, the vocal learning capacities of nonhuman primates appear more limited. Intriguingly, evidence for vocal learning has been reported in chimpanzees (Pan troglodytes), for example, in the form of regional variation ("dialects") in the "pant-hoot" calls. This suggests that some capacity for vocal learning may be an ancient feature of the Pan-Homo clade. Nonetheless, reported differences have been subtle, with intercommunity variation representing only a small portion of the total acoustic variation. To gain further insights into the extent of regional variation in chimpanzee vocalizations, we performed an analysis of pant-hoots from chimpanzees in the neighboring Kasekela and Mitumba communities at Gombe National Park, Tanzania, and the geographically distant Kanyawara community at Kibale National Park, Uganda. We did not find any statistically significant differences between the neighboring communities at Gombe or among geographically distant communities. Furthermore, we found differences among individuals in all communities. Hence, the variation in chimpanzee pant-hoots reflected individual differences, rather than group differences. Thus, we did not find evidence of dialects in this population, suggesting that extensive vocal learning emerged only after the lineages of Homo and Pan diverged.
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Affiliation(s)
- Nisarg P. Desai
- Department of AnthropologyUniversity of MinnesotaMinneapolisMinnesotaUSA
| | - Pawel Fedurek
- Division of Psychology, Faculty of Natural SciencesUniversity of StirlingStirlingUK
| | | | - Michael L. Wilson
- Department of AnthropologyUniversity of MinnesotaMinneapolisMinnesotaUSA,Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA,Institute on the EnvironmentUniversity of MinnesotaSt. PaulMinnesotaUSA
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The Association Between the Bared-Teeth Display and Social Dominance in Captive Chimpanzees ( Pan troglodytes). AFFECTIVE SCIENCE 2022; 3:749-760. [PMID: 36217408 PMCID: PMC9535227 DOI: 10.1007/s42761-022-00138-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 06/26/2022] [Indexed: 11/25/2022]
Abstract
Humans use smiles - widely observed emotional expressions - in a variety of social situations, of which the meaning varies depending on social relationship and the context in which it is displayed. The homologue of the human smile in non-human primates - both due to morphological and functional similarities - is the bared-teeth display (BT). According to the power asymmetry hypothesis (PAH), species with strict linear dominance hierarchies are predicted to produce distinct communicative signals to avoid escalations of social conflicts. Hence, while the BT in a despotic species is predicted to be expressed from low- to high-ranking individuals, signaling submission, the BT in a tolerant species is predicted to be expressed in multiple contexts, regardless of rank. We tested this hypothesis in a group of 8 captive chimpanzees (Pan troglodytes), a species commonly characterized as rather despotic. An investigation of 11,774 dyadic social interactions revealed this chimpanzee group to have a linear dominance hierarchy, with moderate steepness. A Bayesian GLMM - used to test the effects of social contexts and rank relationships of dyads on the use of the BT display - indicated multi-contextual use of the BT which is contingent on the rank relationship. We also found that slight morphological and/or acoustic variants (i.e., silent bared-teeth and vocalized bared-teeth) of the BT display may have different communicative meanings. Our findings are in line with the prediction derived from the PAH for a moderately despotic species, and the view that the human smile originated from the primate BT display. Supplementary Information The online version contains supplementary material available at 10.1007/s42761-022-00138-1.
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32
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The form and function of chimpanzee buttress drumming. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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33
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Crouse KN, Desai NP, Cassidy KA, Stahler EE, Lehman CL, Wilson ML. Larger territories reduce mortality risk for chimpanzees, wolves, and agents: Multiple lines of evidence in a model validation framework. Ecol Modell 2022. [DOI: 10.1016/j.ecolmodel.2022.110063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Badihi G, Bodden K, Zuberbühler K, Samuni L, Hobaiter C. Flexibility in the social structure of male chimpanzees ( Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220904. [PMID: 36177197 PMCID: PMC9515636 DOI: 10.1098/rsos.220904] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Individuals of social species experience competitive costs and social benefits of group living. Substantial flexibility in humans' social structure and the combination of different types of social structure with fission-fusion dynamics allow us to live in extremely large groups-overcoming some of the costs of group living while capitalizing on the benefits. Non-human species also show a range of social strategies to deal with this trade-off. Chimpanzees are an archetypical fission-fusion species, using dynamic changes in day-to-day association to moderate the costs of within-group competition. Using 4 years of association data from two neighbouring communities of East African chimpanzees (Pan troglodytes schweinfurthii), we describe an unexplored level of flexibility in chimpanzee social structure. We show that males from the larger Waibira community (N = 24-31) exhibited additional structural levels of semi-stable core-periphery society, while males from the smaller Sonso community (N = 10-13) did not. This novel core-periphery pattern adds to previous results describing alternative modular social structure in other large communities of chimpanzees. Our data support the hypothesis that chimpanzees can incorporate a range of strategies in addition to fission-fusion to overcome costs of social living, and that their social structures may be closer to that of modern humans than previously described.
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Affiliation(s)
- Gal Badihi
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
| | - Kelsey Bodden
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
| | - Klaus Zuberbühler
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
- School of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Budongo Conservation Field Station, Masindi, Uganda
| | - Liran Samuni
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Catherine Hobaiter
- School of Psychology and Neuroscience, University of St Andrews, South Street, St Andrews KY16 9JP, UK
- Budongo Conservation Field Station, Masindi, Uganda
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Sonnweber R, Stevens JMG, Hohmann G, Deschner T, Behringer V. Plasma Testosterone and Androstenedione Levels Follow the Same Sex-Specific Patterns in the Two Pan Species. BIOLOGY 2022; 11:biology11091275. [PMID: 36138754 PMCID: PMC9495489 DOI: 10.3390/biology11091275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/27/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary Generally male mammals are more aggressive than their female peers. In these males, aggressive behavior is linked to levels of androgens; higher levels of testosterone are predictive of higher aggression rates or more severe aggression. There are some species where the pattern of sex-specific aggression is reversed, and it was hypothesized that high levels of androgens may be responsible for social dominance and aggressiveness in these females. Studies so far found that females of species with sex-reversed aggression patterns (e.g., spotted hyenas and ring-tailed lemurs) had lower plasma testosterone levels than their male peers, but a precursor of testosterone, androstenedione, was comparable or even higher in females than in males. This supported the idea that selection for female aggressiveness may be facilitated through augmented androgen secretion. Here we show that in two sister species, bonobos and chimpanzees, that differ in terms of sex-specific aggression patterns, females have lower plasma testosterone levels and higher plasma androstenedione levels than their male peers. Thus, our data do not support a theory of a role of female androgen levels on the expression of sex-specific patterns of aggression. Abstract In most animals, males are considered more aggressive, in terms of frequency and intensity of aggressive behaviors, than their female peers. However, in several species this widespread male-biased aggression pattern is either extenuated, absent, or even sex-reversed. Studies investigating potential neuro-physiological mechanisms driving the selection for female aggression in these species have revealed an important, but not exclusive role of androgens in the expression of the observed sex-specific behavioral patterns. Two very closely related mammalian species that markedly differ in the expression and degree of sex-specific aggression are the two Pan species, where the chimpanzee societies are male-dominated while in bonobos sex-biased aggression patterns are alleviated. Using liquid chromatography–mass spectrometry (LC-MS) methods, we measured levels of plasma testosterone and androstenedione levels in male and female zoo-housed bonobos (N = 21; 12 females, 9 males) and chimpanzees (N = 41; 27 females, 14 males). Our results show comparable absolute and relative intersexual patterns of blood androgen levels in both species of Pan. Plasma testosterone levels were higher in males (bonobos: females: average 0.53 ± 0.30 ng/mL; males 6.70 ± 2.93 ng/mL; chimpanzees: females: average 0.40 ± 0.23 ng/mL; males 5.84 ± 3.63 ng/mL) and plasma androstenedione levels were higher in females of either species (bonobos: females: average 1.83 ± 0.87 ng/mL; males 1.13 ± 0.44 ng/mL; chimpanzees: females: average 1.84 ± 0.92 ng/mL; males 1.22 ± 0.55 ng/mL). The latter result speaks against a role of androstenedione in the mediation of heightened female aggression, as had been suggested based on studies in other mammal species where females are dominant and show high levels of female aggressiveness.
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Affiliation(s)
- Ruth Sonnweber
- Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
- Correspondence:
| | - Jeroen M. G. Stevens
- Behavioral Ecology and Ecophysiology, Department of Biology, University of Antwerp, Campus Drie Eiken, Building D, D1.21, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - Gottfried Hohmann
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
- Max Planck Institute of Animal Behavior, Am Obstberg 1, 78315 Radolfzell/Konstanz, Germany
| | - Tobias Deschner
- Comparative BioCognition, Institute of Cognitive Science, University of Osnabrück, Artilleriestrasse 34, 49090 Osnabrück, Germany
| | - Verena Behringer
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
- Endocrinology Laboratory, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
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Mearing AS, Burkart JM, Dunn J, Street SE, Koops K. The evolutionary drivers of primate scleral coloration. Sci Rep 2022; 12:14119. [PMID: 35982191 PMCID: PMC9388658 DOI: 10.1038/s41598-022-18275-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 08/08/2022] [Indexed: 11/09/2022] Open
Abstract
The drivers of divergent scleral morphologies in primates are currently unclear, though white sclerae are often assumed to underlie human hyper-cooperative behaviours. Humans are unusual in possessing depigmented sclerae whereas many other extant primates, including the closely-related chimpanzee, possess dark scleral pigment. Here, we use phylogenetic generalized least squares (PGLS) analyses with previously generated species-level scores of proactive prosociality, social tolerance (both n = 15 primate species), and conspecific lethal aggression (n = 108 primate species) to provide the first quantitative, comparative test of three existing hypotheses. The 'self-domestication' and 'cooperative eye' explanations predict white sclerae to be associated with cooperative, rather than competitive, environments. The 'gaze camouflage' hypothesis predicts that dark scleral pigment functions as gaze direction camouflage in competitive social environments. Notably, the experimental evidence that non-human primates draw social information from conspecific eye movements is unclear, with the latter two hypotheses having recently been challenged. Here, we show that white sclerae in primates are associated with increased cooperative behaviours whereas dark sclerae are associated with reduced cooperative behaviours and increased conspecific lethal violence. These results are consistent with all three hypotheses of scleral evolution, suggesting that primate scleral morphologies evolve in relation to variation in social environment.
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Affiliation(s)
- Alex S Mearing
- Department of Archaeology, Fitzwilliam Street, University of Cambridge, Cambridge, CB2 1QH, UK.
| | - Judith M Burkart
- Department of Anthropology, University of Zurich, 8057, Zurich, Switzerland
| | - Jacob Dunn
- Department of Archaeology, Fitzwilliam Street, University of Cambridge, Cambridge, CB2 1QH, UK.,School of Life Sciences, Anglia Ruskin University, Cambridge, CB1 1PT, UK.,Department of Cognitive Biology, University of Vienna, 1090, Vienna, Austria
| | - Sally E Street
- Department of Anthropology, University of Durham, Durham, DH1 3LE, UK
| | - Kathelijne Koops
- Department of Archaeology, Fitzwilliam Street, University of Cambridge, Cambridge, CB2 1QH, UK.,Department of Anthropology, University of Zurich, 8057, Zurich, Switzerland
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Macrohistorical and Evolutionary Dynamics of Between-Group Competition, Sociopolitical Complexity, and Differentiation-Integration Effects. EVOLUTIONARY PSYCHOLOGICAL SCIENCE 2022. [DOI: 10.1007/s40806-022-00333-0] [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]
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38
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39
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Wellens KR, Lee SM, Winans JC, Pusey AE, Murray CM. Female chimpanzee associations with male kin: trade-offs between inbreeding avoidance and infanticide protection. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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40
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Girard-Buttoz C, Bortolato T, Laporte M, Grampp M, Zuberbühler K, Wittig RM, Crockford C. Population-specific call order in chimpanzee greeting vocal sequences. iScience 2022; 25:104851. [PMID: 36034222 PMCID: PMC9399282 DOI: 10.1016/j.isci.2022.104851] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/01/2022] [Accepted: 07/25/2022] [Indexed: 11/25/2022] Open
Abstract
Primates rarely learn new vocalizations, but they can learn to use their vocalizations in different contexts. Such “vocal usage learning,” particularly in vocal sequences, is a hallmark of human language, but remains understudied in non-human primates. We assess usage learning in four wild chimpanzee communities of Taï and Budongo Forests by investigating population differences in call ordering of a greeting vocal sequence. Whilst in all groups, these sequences consisted of pant-hoots (long-distance contact call) and pant-grunts (short-distance submissive call), the order of the two calls differed across populations. Taï chimpanzees consistently commenced greetings with pant-hoots, whereas Budongo chimpanzees started with pant-grunts. We discuss different hypotheses to explain this pattern and conclude that higher intra-group aggression in Budongo may have led to a local pattern of individuals signaling submission first. This highlights how within-species variation in social dynamics may lead to flexibility in call order production, possibly acquired via usage learning. Chimpanzees combine pant-grunt and pant-hoot calls into a greeting hoot sequence Call-order of these greeting and contact calls is population specific Pant-grunt is uttered first in the population with higher in-group aggressions Vocal usage learning may lead to these population differences in sequence structure
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41
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A 25-Year Retrospective Review of Mortality in Chimpanzees ( Pan troglodytes) in Accredited U.S. Zoos from a Management and Welfare Perspective. Animals (Basel) 2022; 12:ani12151878. [PMID: 35892528 PMCID: PMC9330555 DOI: 10.3390/ani12151878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/08/2022] [Accepted: 07/19/2022] [Indexed: 12/01/2022] Open
Abstract
Understanding causes of death allows adjustment of health management strategies for animals in managed care. From 224 documented chimpanzee deaths occurring from 1995 to 2019 in 42 accredited U.S. zoos, post-mortem records and necropsy reports were analyzed for the primary cause of death, which were available for 214 individuals. In total, 37 cases of stillbirth and neonatal deaths were assessed (16.5%); however, the focus was otherwise placed on the remaining 177 cases in which the death occurred in individuals aged greater than 1 month. There were no sex-related differences in etiology; however, age variation in the cause of death was statistically significant (p < 0.001). Elderly (35 years and older) chimpanzees tended to die of intrinsic, often degenerative, etiologies, whereas infants, juveniles, and adolescents (less than 15 years) were more likely to be involved in fatal trauma. Overall, there were 27 deaths (15.3% of all post-neonatal deaths) related to trauma and 13 of these were directly or indirectly related to conspecific aggression. Understanding causes of mortality and the interrelation with management can benefit managed populations of chimpanzees.
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42
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Vlaeyen JMR, Heesen R, Kret ME, Clay Z, Bionda T, Kim Y. Bared-teeth displays in bonobos (Pan paniscus): An assessment of the power asymmetry hypothesis. Am J Primatol 2022; 84:e23419. [PMID: 35848310 DOI: 10.1002/ajp.23419] [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: 10/15/2021] [Revised: 06/22/2022] [Accepted: 06/26/2022] [Indexed: 11/10/2022]
Abstract
Facial expressions are key to navigating social group life. The Power Asymmetry Hypothesis of Motivational Emancipation predicts that the type of social organization shapes the meaning of communicative displays in relation to an individual's dominance rank. The bared-teeth (BT) display represents one of the most widely observed communicative signals across primate species. Studies in macaques indicate that the BT display in despotic species is often performed unidirectionally, from low- to high-ranking individuals (signaling submission), whereas the BT display in egalitarian species is usually produced irrespective of dominance (mainly signaling affiliation and appeasement). Despite its widespread presence, research connecting BT displays to the power asymmetry hypothesis outside the Macaca genus remains scarce. To extend this knowledge, we investigated the production of BT in relation to social dominance in dyadic interactions (N = 11,377 events) of 11 captive bonobos (Pan paniscus). Although adult bonobos were more despotic than previously suggested in the literature, BT displays were produced irrespective of dominance rank. Moreover, while adults produced the BT exclusively during socio-sexual interactions, especially during periods of social tension, immature bonobos produced the BT in a wider number of contexts. As such, the results indicate that the communicative meaning of the BT display is consistent with signaling appeasement, especially in periods of social tension. Moreover, the BT display does not seem to signal social status, supporting the prediction for species with a high degree of social tolerance. These results advance our understanding of the origins of communicative signals and their relation to species' social systems.
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Affiliation(s)
- Jolinde M R Vlaeyen
- Animal Behaviour and Cognition, Utrecht University, Utrecht, the Netherlands.,Institute of Cognitive Science Comparative BioCognition, University of Osnabrück, Osnabruck, Germany
| | | | - Mariska E Kret
- Cognitive Psychology Unit, Institute of Psychology, Leiden University, Leiden, the Netherlands
| | - Zanna Clay
- Department of Psychology, Durham University, Durham, UK
| | | | - Yena Kim
- Cognitive Psychology Unit, Institute of Psychology, Leiden University, Leiden, the Netherlands
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43
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Braga Goncalves I, Morris-Drake A, Kennedy P, Radford AN. Fitness consequences of outgroup conflict. eLife 2022; 11:e74550. [PMID: 35833830 PMCID: PMC9282852 DOI: 10.7554/elife.74550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 06/27/2022] [Indexed: 12/13/2022] Open
Abstract
In social species across the animal kingdom, conspecific outsiders threaten the valuable resources of groups and their members. This outgroup conflict is recognised as a powerful selection pressure, but we argue that studies explicitly quantifying the fitness consequences need to be broader in scope: more attention should be paid to delayed, cumulative, and third-party fitness consequences, not just those arising immediately to group members involved in physical contests. In the first part of this review, we begin by documenting how single contests can have survival and reproductive consequences either immediately or with a delay. Then, we step beyond contests to describe fitness consequences that can also result from interactions with cues of rival presence and the general landscape of outgroup threat, and beyond single interactions to describe cumulative effects of territorial pressure and elevated outgroup-induced stress. Using examples from a range of taxa, we discuss which individuals are affected negatively and positively, considering both interaction participants and third-party group members of the same or the next generation. In the second part of the review, we provide suggestions about how to move forward. We highlight the importance of considering how different types of outgroup conflict can generate different selection pressures and of investigating variation in fitness consequences within and between species. We finish by discussing the value of theoretical modelling and long-term studies of natural populations, experimental manipulations, and meta-analyses to develop further our understanding of this crucial aspect of sociality.
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Affiliation(s)
| | - Amy Morris-Drake
- School of Biological Sciences, University of BristolBristolUnited Kingdom
| | - Patrick Kennedy
- School of Biological Sciences, University of BristolBristolUnited Kingdom
| | - Andrew N Radford
- School of Biological Sciences, University of BristolBristolUnited Kingdom
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44
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Dead-infant carrying by chimpanzee mothers in the Budongo Forest. Primates 2022; 63:497-508. [PMID: 35819534 PMCID: PMC9274961 DOI: 10.1007/s10329-022-00999-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 06/24/2022] [Indexed: 11/03/2022]
Abstract
It has been suggested that non-human primates can respond to deceased conspecifics in ways that suggest they experience psychological states not unlike humans, some of which could indicate they exhibit a notion of death. Here, we report long-term demographic data from two East African chimpanzee groups. During a combined 40-year observation period, we recorded 191 births of which 68 died in infancy, mostly within the first year. We documented the post-mortem behaviour of the mothers and describe nine occasions where Budongo chimpanzee mothers carried infants for 1-3 days after their death, usually until the body started to decompose. We also observed three additional cases of extended carrying lasting for more than 2 weeks, one of which was followed by the unusual extended carrying of an object and another which lasted 3 months. In each case, the corpses mummified. In addition, we report four instances of recurring dead-infant carrying by mothers, three of whom carried the corpse for longer during the second instance. We discuss these observations in view of functional hypotheses of dead-infant carrying in primates and the potential proximate mechanisms involved in this behaviour.
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45
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Gielen K, Louwerse AL, Sterck EHM. The Older the Better: Infanticide Is Age-Related for Both Victims and Perpetrators in Captive Long-Tailed Macaques. BIOLOGY 2022; 11:biology11071008. [PMID: 36101389 PMCID: PMC9311617 DOI: 10.3390/biology11071008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/24/2022] [Accepted: 07/01/2022] [Indexed: 12/05/2022]
Abstract
In wild primates, infanticide is a risk that is especially prevalent when a new male takes over the alpha position. Insight into risk factors related to infanticide may decrease the incidence of infanticide in captivity during male introductions. We investigated several risk factors of infanticide derived from hypotheses explaining infanticide in the wild and tested this in captive long-tailed macaques (Macaca fascicularis) using demographic data spanning a 25.5-year period. Factors that are related to infanticide in the wild explained a large proportion, but not all incidences, of infanticide in captivity. Consistent with the wild data, infants young enough to decrease the interbirth interval (<215 days) were at risk of being killed. In contrast to studies from the wild, infanticidal males were more than 2.5 years younger than non-infanticidal males. This indicates that captive settings can lead to new risks since relatively young males may gain the alpha position, promoting infanticide. Therefore, we propose the adolescent male risk hypothesis as a captive risk factor in which subadult males pose a risk of infanticide. In conclusion, the ages of both males and infants are related to infanticide in captivity and have to be taken into account during male introductions.
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Affiliation(s)
- Karlijn Gielen
- Animal Behaviour and Cognition, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands;
- Correspondence: ; Tel.: +31-30-253-5304
| | - Annet L. Louwerse
- Biomedical Primate Research Centre, 2288 GJ Rijswijk, The Netherlands;
| | - Elisabeth H. M. Sterck
- Animal Behaviour and Cognition, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands;
- Biomedical Primate Research Centre, 2288 GJ Rijswijk, The Netherlands;
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Brooks J, Kano F, Kawaguchi Y, Yamamoto S. Oxytocin promotes species-relevant outgroup attention in bonobos and chimpanzees. Horm Behav 2022; 143:105182. [PMID: 35537292 DOI: 10.1016/j.yhbeh.2022.105182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 04/20/2022] [Accepted: 04/22/2022] [Indexed: 11/30/2022]
Abstract
Previous research has found that oxytocin (OT) is associated with intergroup behaviour in humans as well as wild chimpanzees, and that exogenous OT affects Pan social attention. The two Pan species, bonobos and chimpanzees, differ drastically from one another in their intensity of intergroup competition, with lethal intergroup aggression often led by males in chimpanzees and more tolerant associations often centered around females in bonobos. However, it remains unclear how exogenous OT changes the two species' responses to ingroup and outgroup individuals. In this study, after intranasal administration of nebulized OT or placebo control, chimpanzees and bonobos viewed image pairs of ingroup and outgroup conspecifics while their eye movements were tracked with an eye-tracker. Although the overall effect of OT was small, we found that OT shifted bonobos' and chimpanzees' attention to outgroup images of the sex primarily involved in intergroup encounters in each species. Specifically, OT selectively shifted attention towards outgroup photos of female conspecifics in bonobos, and those of outgroup male conspecifics in chimpanzees. This suggests that OT generally promotes outgroup attention in both bonobos and chimpanzees but this effect is restricted to the sex most relevant in intergroup relations. These results suggest that, although OT may have a generally conserved role in hominid intergroup behaviour, it may act in species-relevant ways under the influence of their socio-ecological backgrounds.
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Affiliation(s)
- James Brooks
- Wildlife Research Center, Kyoto University, 6068203 Kyoto, Japan; Kumamoto Sanctuary, Kyoto University, 8693201 Kumamoto, Japan.
| | - Fumihiro Kano
- Kumamoto Sanctuary, Kyoto University, 8693201 Kumamoto, Japan; Center for the Advanced Study of Collective Behaviour, University of Konstanz, 78464 Konstanz, Germany; Max-Planck Institute of Animal Behavior, 78315 Radolfzell, Germany.
| | - Yuri Kawaguchi
- Messerli Research Institute, University of Veterinary Medicine Vienna, A-1210 Vienna, Austria; Japan Society for the Promotion of Science (JSPS), 1020083 Tokyo, Japan; Primate Research Institute, Kyoto University, 4848506 Inuyama, Japan
| | - Shinya Yamamoto
- Wildlife Research Center, Kyoto University, 6068203 Kyoto, Japan; Insitute for Advanced Study, Kyoto University, 6068501 Kyoto, Japan
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Characterization of Pan social systems reveals in-group/out-group distinction and out-group tolerance in bonobos. Proc Natl Acad Sci U S A 2022; 119:e2201122119. [PMID: 35727986 DOI: 10.1073/pnas.2201122119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human between-group interactions are highly variable, ranging from violent to tolerant and affiliative. Tolerance between groups is linked to our unique capacity for large-scale cooperation and cumulative culture, but its evolutionary origins are understudied. In chimpanzees, one of our closest living relatives, predominantly hostile between-group interactions impede cooperation and information flow across groups. In contrast, in our other closest living relative, the bonobo, tolerant between-group associations are observed. However, as these associations can be frequent and prolonged and involve social interactions that mirror those within groups, it is unclear whether these bonobos really do belong to separate groups. Alternatively, the bonobo grouping patterns may be homologous to observations from the large Ngogo chimpanzee community, where individuals form within-group neighborhoods despite sharing the same membership in the larger group. To characterize bonobo grouping patterns, we compare the social structure of the Kokolopori bonobos with the chimpanzee group of Ngogo. Using cluster analysis, we find temporally stable clusters only in bonobos. Despite the large spatial overlap and frequent interactions between the bonobo clusters, we identified significant association preference within but not between clusters and a unique space use of each cluster. Although bonobo associations are flexible (i.e., fission-fusion dynamics), cluster membership predicted the bonobo fission compositions and the spatial cohesion of individuals during encounters. These findings suggest the presence of a social system that combines clear in-group/out-group distinction and out-group tolerance in bonobos, offering a unique referential model for the evolution of tolerant between-group interactions in humans.
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48
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Bshary R, Richter XYL, van Schaik C. Male services during between-group conflict: the 'hired gun' hypothesis revisited. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210150. [PMID: 35369754 DOI: 10.1098/rstb.2021.0150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In many group-living mammals, philopatric females form the stable core of the group and defend food or shelter against other groups of females. Where males are larger, their participation could give their female group the edge. How can females secure the contribution of males that are neither the father of current infants, nor the dominant male expecting to sire the next generation of infants? It has been proposed that females recruit these males as 'hired guns', receiving social support and copulations in exchange for fighting, against the interests of the dominant male. We first develop the logic of this hypothesis in unprecedented detail by considering the potential pay-off consequences for females and males. We then provide empirical evidence for the existence of hired guns in this context in several primate species. The game-theoretical aspects of the phenomenon remain to be studied, as is the distribution across contexts (e.g. predation avoidance) and species of the hired gun phenomenon. This article is part of the theme issue 'Intergroup conflict across taxa'.
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Affiliation(s)
- Redouan Bshary
- Behavioural Ecology Laboratory, Faculty of Science, University of Neuchâtel, Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Xiang-Yi Li Richter
- Behavioural Ecology Laboratory, Faculty of Science, University of Neuchâtel, Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Carel van Schaik
- Department of Anthropology and Anthropological Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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49
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Massaro AP, Gilby IC, Desai N, Weiss A, Feldblum JT, Pusey AE, Wilson ML. Correlates of individual participation in boundary patrols by male chimpanzees. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210151. [PMID: 35369753 DOI: 10.1098/rstb.2021.0151] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Group territory defence poses a collective action problem: individuals can free-ride, benefiting without paying the costs. Individual heterogeneity has been proposed to solve such problems, as individuals high in reproductive success, rank, fighting ability or motivation may benefit from defending territories even if others free-ride. To test this hypothesis, we analysed 30 years of data from chimpanzees (Pan troglodytes) in the Kasekela community, Gombe National Park, Tanzania (1978-2007). We examined the extent to which individual participation in patrols varied according to correlates of reproductive success (mating rate, rank, age), fighting ability (hunting), motivation (scores from personality ratings), costs of defecting (the number of adult males in the community) and gregariousness (sighting frequency). By contrast to expectations from collective action theory, males participated in patrols at consistently high rates (mean ± s.d. = 74.5 ± 11.1% of patrols, n = 23 males). The best predictors of patrol participation were sighting frequency, age and hunting participation. Current and former alpha males did not participate at a higher rate than males that never achieved alpha status. These findings suggest that the temptation to free-ride is low, and that a mutualistic mechanism such as group augmentation may better explain individual participation in group territorial behaviour. This article is part of the theme issue 'Intergroup conflict across taxa'.
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Affiliation(s)
- Anthony P Massaro
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55414, USA
| | - Ian C Gilby
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85281, USA.,Institute of Human Origins, Arizona State University, Tempe, AZ 85281, USA
| | - Nisarg Desai
- Department of Anthropology, University of Minnesota, Minneapolis, MN 55414, USA
| | - Alexander Weiss
- National Evolutionary Synthesis Center, Durham, NC 27705, USA.,Department of Psychology, School of Philosophy, Psychology and Language Sciences, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK
| | - Joseph T Feldblum
- Department of Anthropology, University of Michigan, Ann Arbor, MI 48109, USA.,Society of Fellows, University of Michigan, Ann Arbor, MI 48109, USA
| | - Anne E Pusey
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Michael L Wilson
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55414, USA.,Department of Anthropology, University of Minnesota, Minneapolis, MN 55414, USA.,Institute on the Environment, University of Minnesota, St. Paul, MN 55414, USA
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50
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Glowacki L, McDermott R. Key individuals catalyse intergroup violence. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210141. [PMID: 35369758 DOI: 10.1098/rstb.2021.0141] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Intergroup violence is challenging to understand: why do individuals cooperate to harm members of other groups when they themselves may be killed or injured? Despite progress in understanding the evolutionary and proximate mechanisms that underlie violence, we still have little insight into the processes that lead to the emergence of coalitionary aggression. We argue that an overlooked component is the presence of individuals who have a crucial role in initiating violence. In instigating intergroup violence, these key individuals may expect to face lower costs, receive greater benefits, or garner benefits that have a greater value to them than others. Alternatively, key individuals may be motivated by individual traits such as increased boldness, propensity for aggression or exploratory behaviour. Key individuals catalyse the emergence of coalitionary violence through one of several processes including altering the costs and benefits that accrue to others, paying a greater share of the startup costs, signalling privileged knowledge, or providing coordination, among other factors. Here we integrate diverse lines of empirical research from humans and non-human animals demonstrating that inter-individual variation is an important factor in the emergence of intergroup violence. Focusing on the role of key individuals provides new insights into how and why violence emerges. This article is part of the theme issue 'Intergroup conflict across taxa'.
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Affiliation(s)
| | - Rose McDermott
- Political Science, Brown University, Providence, RI, USA
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