1
|
Arseneau-Robar TJ, Teichroeb JA, Macintosh AJJ, Saj TL, Glotfelty E, Lucci S, Sicotte P, Wikberg EC. When population growth intensifies intergroup competition, female colobus monkeys free-ride less. Sci Rep 2024; 14:14363. [PMID: 38906888 PMCID: PMC11192885 DOI: 10.1038/s41598-024-64188-0] [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: 05/25/2023] [Accepted: 06/06/2024] [Indexed: 06/23/2024] Open
Abstract
Intergroup aggression often results in the production of public goods, such as a safe and stable social environment and a home range containing the resources required to survive and reproduce. We investigate temporal variation in intergroup aggression in a growing population of colobus monkeys (Colobus vellerosus) to ask a novel question: "Who stepped-up to produce these public goods when doing so became more difficult?". Both whole-group encounters and male incursions occurred more frequently as the population grew. Males and females were both more likely to participate in whole-group encounters when monopolizable food resources were available, indicating both sexes engaged in food defence. However, only females increasingly did so as the population grew, suggesting that it was females who increasingly produced the public good of home range defence as intergroup competition intensified. Females were also more active in male incursions at high population densities, suggesting they increasingly produced the public good of a safe and stable social environment. This is not to say that males were chronic free-riders when it came to maintaining public goods. Males consistently participated in the majority of intergroup interactions throughout the study period, indicating they may have lacked the capacity to invest more time and effort.
Collapse
Affiliation(s)
| | - Julie A Teichroeb
- Department of Anthropology, University of Toronto Scarborough, Toronto, Canada
| | | | - Tania L Saj
- Department of Anthropology, University of Calgary, Calgary, Canada
| | - Emily Glotfelty
- Department of Anthropology, University of Texas San Antonio, San Antonio, USA
| | - Sara Lucci
- Department of Anthropology, University of Texas San Antonio, San Antonio, USA
| | - Pascale Sicotte
- Department of Biology, Concordia University, Montreal, QC, Canada
| | - Eva C Wikberg
- Department of Anthropology, University of Texas San Antonio, San Antonio, USA.
| |
Collapse
|
2
|
Montgomery TM, Lehmann KDS, Gregg S, Keyser K, McTigue LE, Beehner JC, Holekamp KE. Determinants of hyena participation in risky collective action. Proc Biol Sci 2023; 290:20231390. [PMID: 38018101 PMCID: PMC10685128 DOI: 10.1098/rspb.2023.1390] [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: 06/22/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023] Open
Abstract
Collective action problems arise when cooperating individuals suffer costs of cooperation, while the benefits of cooperation are received by both cooperators and defectors. We address this problem using data from spotted hyenas fighting with lions. Lions are much larger and kill many hyenas, so these fights require cooperative mobbing by hyenas for them to succeed. We identify factors that predict when hyena groups engage in cooperative fights with lions, which individuals choose to participate and how the benefits of victory are distributed among cooperators and non-cooperators. We find that cooperative mobbing is better predicted by lower costs (no male lions, more hyenas) than higher benefits (need for food). Individual participation is facilitated by social factors, both over the long term (close kin, social bond strength) and the short term (greeting interactions prior to cooperation). Finally, we find some direct benefits of participation: after cooperation, participants were more likely to feed at contested carcasses than non-participants. Overall, these results are consistent with the hypothesis that, when animals face dangerous cooperative dilemmas, selection favours flexible strategies that are sensitive to dynamic factors emerging over multiple time scales.
Collapse
Affiliation(s)
- Tracy M. Montgomery
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
- Department for the Ecology of Animal Societies, Max Planck Institute for Animal Behavior, Bücklestraße 5a, 78467 Konstanz, Germany
- Center for the Advanced Study of Collective Behavior, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
| | - Kenna D. S. Lehmann
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Human Biology Program, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
| | - Samantha Gregg
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
| | - Kathleen Keyser
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
| | - Leah E. McTigue
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Rocky Mountain Research Station, Colorado State University, 240 W Prospect St, Fort Collins, CO 80525, USA
| | - Jacinta C. Beehner
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA
- Department of Anthropology, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109, USA
| | - Kay E. Holekamp
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Context-dependent alarm responses in wild vervet monkeys. Anim Cogn 2023:10.1007/s10071-023-01767-0. [PMID: 36930451 DOI: 10.1007/s10071-023-01767-0] [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: 10/07/2022] [Revised: 02/04/2023] [Accepted: 03/08/2023] [Indexed: 03/18/2023]
Abstract
The alarm calls of nonhuman primates are occasionally cited as functionally equivalent to lexical word meaning in human language. Recently, however, it has become increasingly unlikely that one-to-one relations between alarm call structures and predator categories are the default, mainly because many call types are produced in multiple contexts, requiring more complex notions of meaning. For example, male vervet monkeys produce the same alarm calls during encounters with terrestrial predators and neighbouring groups, suggesting that recipients require additional information to attribute meaning to the calls. We empirically tested the hypothesis that vervet monkeys take contextual information into account when responding to each other's alarm calls. In playback experiments, we exposed subjects to recordings of male alarm barks during actual intergroup encounters (predator unlikely) or when there was no intergroup encounter (predator likely). Subjects responded more strongly in the no intergroup encounter situations, typically associated with discovering a hiding predator, measured in terms of startle responses, vigilance behaviour and gazing towards the presumed caller. We discuss the significance of using contextual information for meaning attribution in nonhuman primate communication.
Collapse
|
5
|
Lerch BA, Smith DA, Koffel T, Bagby SC, Abbott KC. How public can public goods be? Environmental context shapes the evolutionary ecology of partially private goods. PLoS Comput Biol 2022; 18:e1010666. [PMID: 36318525 PMCID: PMC9651594 DOI: 10.1371/journal.pcbi.1010666] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 11/11/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022] Open
Abstract
The production of costly public goods (as distinct from metabolic byproducts) has largely been understood through the realization that spatial structure can minimize losses to non-producing “cheaters” by allowing for the positive assortment of producers. In well-mixed systems, where positive assortment is not possible, the stable production of public goods has been proposed to depend on lineages that become indispensable as the sole producers of those goods while their neighbors lose production capacity through genome streamlining (the Black Queen Hypothesis). Here, we develop consumer-resource models motivated by nitrogen-fixing, siderophore-producing bacteria that consider the role of colimitation in shaping eco-evolutionary dynamics. Our models demonstrate that in well-mixed environments, single “public goods” can only be ecologically and evolutionarily stable if they are partially privatized (i.e., if producers reserve a portion of the product pool for private use). Colimitation introduces the possibility of subsidy: strains producing a fully public good can exclude non-producing strains so long as the producing strain derives sufficient benefit from the production of a second partially private good. We derive a lower bound for the degree of privatization necessary for production to be advantageous, which depends on external resource concentrations. Highly privatized, low-investment goods, in environments where the good is limiting, are especially likely to be stably produced. Coexistence emerges more rarely in our mechanistic model of the external environment than in past phenomenological approaches. Broadly, we show that the viability of production depends critically on the environmental context (i.e., external resource concentrations), with production of shared resources favored in environments where a partially-privatized resource is scarce. Many organisms produce “public goods”, substances that may directly benefit their competitors as well as themselves. Because goods production is costly, understanding the evolutionary stability of public goods production has been a subject of considerable interest: what keeps cheaters from taking over a population and driving producers to extinction? Here, we ask when partial privatization of public goods (that is, when producers retain some portion of the good for their own exclusive use) is sufficient to stabilize production even in the absence of spatial structure, and how this depends on environmental conditions. We derive lower bounds for the amount of privatization needed to stabilize production and find that these bounds depend critically on environmental conditions. We further investigate the case of two public goods, each needed for the acquisition of the other, and each a resource whose availability limits growth. We find that the ecological dynamics of such colimiting resources can interact, with privatization of one resource subsidizing more-public, or even fully public, production of the other. Finally, we offer the perspective that producers are not “losers” in a race of loss-of-function mutations, but rather can do no better than to produce the resource in a given set of conditions.
Collapse
Affiliation(s)
- Brian A. Lerch
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
| | - Derek A. Smith
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Thomas Koffel
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, United States of America
| | - Sarah C. Bagby
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Karen C. Abbott
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, United States of America
| |
Collapse
|
6
|
Williams L, Shultz S, Jensen K. The primate workplace: Cooperative decision-making in human and non-human primates. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.887187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The success of group foraging in primates is not only determined by ecological and social factors. It is also influenced by cognition. Group foraging success is constrained, for instance, by the challenges of coordination, synchrony and decision-making, and it is enhanced by the ability to share, learn from others and coordinate actions. However, what we currently know about the cognition of individuals in groups comes primarily from experiments on dyads, and what we know of the effect of ecological factors on group dynamics comes from larger wild groups. Our current knowledge of primate group behaviour is thus incomplete. In this review, we identify a gap in our knowledge of primate group dynamics between the dyadic studies on primate cooperation and the large group observational studies of behavioural ecology. We highlight the potential for controlled experimental studies on coordination and cooperation in primate groups. Currently, these exist primarily as studies of dyads, and these do not go far enough in testing limits of group-level behaviours. Controlled studies on primate groups beyond the dyad would be highly informative regarding the bounds of non-human primate collaboration. We look to the literature on how humans behave in groups, specifically from organisational psychology, draw parallels between human and non-human group dynamics and highlight approaches that could be applied across disciplines. Organisational psychology is explicitly concerned with the interactions between individuals in a group and the emergent properties at the group-level of these decisions. We propose that some of the major shortfalls in our understanding of primate social cognition and group dynamics can be filled by using approaches developed by organisational psychologists, particularly regarding the effects of group size and composition on group-level cooperation. To illustrate the potential applications, we provide a list of research questions drawn from organisational psychology that could be applied to non-human primates.
Collapse
|
7
|
Bangerter A, Genty E, Heesen R, Rossano F, Zuberbühler K. Every product needs a process: unpacking joint commitment as a process across species. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210095. [PMID: 35876205 PMCID: PMC9310187 DOI: 10.1098/rstb.2021.0095] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/28/2021] [Indexed: 09/14/2023] Open
Abstract
Joint commitment, the feeling of mutual obligation binding participants in a joint action, is typically conceptualized as arising by the expression and acceptance of a promise. This account limits the possibilities of investigating fledgling forms of joint commitment in actors linguistically less well-endowed than adult humans. The feeling of mutual obligation is one aspect of joint commitment (the product), which emerges from a process of signal exchange. It is gradual rather than binary; feelings of mutual obligation can vary in strength according to how explicit commitments are perceived to be. Joint commitment processes are more complex than simple promising, in at least three ways. They are affected by prior joint actions, which create precedents and conventions that can be embodied in material arrangements of institutions. Joint commitment processes also arise as solutions to generic coordination problems related to opening up, maintaining and closing down joint actions. Finally, during joint actions, additional, specific commitments are made piecemeal. These stack up over time and persist, making it difficult for participants to disengage from joint actions. These complexifications open up new perspectives for assessing joint commitment across species. This article is part of the theme issue 'Revisiting the human 'interaction engine': comparative approaches to social action coordination'.
Collapse
Affiliation(s)
- Adrian Bangerter
- Institute of Work and Organizational Psychology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Emilie Genty
- Institute of Work and Organizational Psychology, University of Neuchâtel, Neuchâtel, Switzerland
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | | | - Federico Rossano
- Department of Cognitive Science, University of California, San Diego, CA, USA
| | - Klaus Zuberbühler
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| |
Collapse
|
8
|
Saha P, Bose D, Stebliankin V, Cickovski T, Seth RK, Porter DE, Brooks BW, Mathee K, Narasimhan G, Colwell R, Scott GI, Chatterjee S. Prior exposure to microcystin alters host gut resistome and is associated with dysregulated immune homeostasis in translatable mouse models. Sci Rep 2022; 12:11516. [PMID: 35799048 PMCID: PMC9262933 DOI: 10.1038/s41598-022-15708-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 06/28/2022] [Indexed: 11/09/2022] Open
Abstract
A strong association between exposure to the common harmful algal bloom toxin microcystin and the altered host gut microbiome has been shown. We tested the hypothesis that prior exposure to the cyanotoxin microcystin-LR may alter the host resistome. We show that the mice exposed to microcystin-LR had an altered microbiome signature that harbored antibiotic resistance genes. Host resistome genotypes such as mefA, msrD, mel, ant6, and tet40 increased in diversity and relative abundance following microcystin-LR exposure. Interestingly, the increased abundance of these genes was traced to resistance to common antibiotics such as tetracycline, macrolides, glycopeptide, and aminoglycosides, crucial for modern-day treatment of several diseases. Increased abundance of these genes was positively associated with increased expression of PD1, a T-cell homeostasis marker, and pleiotropic inflammatory cytokine IL-6 with a concomitant negative association with immunosurveillance markers IL-7 and TLR2. Microcystin-LR exposure also caused decreased TLR2, TLR4, and REG3G expressions, increased immunosenescence, and higher systemic levels of IL-6 in both wild-type and humanized mice. In conclusion, the results show a first-ever characterization of the host resistome following microcystin-LR exposure and its connection to host immune status and antimicrobial resistance that can be crucial to understand treatment options with antibiotics in microcystin-exposed subjects in clinical settings.
Collapse
Affiliation(s)
- Punnag Saha
- Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
- NIEHS Center for Oceans and Human Health and Climate Change Interactions, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
- Columbia VA Medical Center, Columbia, SC, 29209, USA
| | - Dipro Bose
- Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
- NIEHS Center for Oceans and Human Health and Climate Change Interactions, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
- Columbia VA Medical Center, Columbia, SC, 29209, USA
| | - Vitalii Stebliankin
- Knight Foundation School of Computing & Information Sciences, Florida International University, Miami, FL, 33199, USA
| | - Trevor Cickovski
- Knight Foundation School of Computing & Information Sciences, Florida International University, Miami, FL, 33199, USA
| | - Ratanesh K Seth
- Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
- Columbia VA Medical Center, Columbia, SC, 29209, USA
| | - Dwayne E Porter
- NIEHS Center for Oceans and Human Health and Climate Change Interactions, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
| | - Bryan W Brooks
- Department of Environmental Science, Baylor University, Waco, TX, 76798, USA
| | - Kalai Mathee
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Giri Narasimhan
- Knight Foundation School of Computing & Information Sciences, Florida International University, Miami, FL, 33199, USA
- Biomolecular Sciences Institute, Florida International University, Miami, FL, 33199, USA
| | - Rita Colwell
- CosmosID Inc, Germantown, MD, 20874, USA
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD, 20742, USA
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, 20742, USA
| | - Geoff I Scott
- NIEHS Center for Oceans and Human Health and Climate Change Interactions, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
| | - Saurabh Chatterjee
- Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA.
- NIEHS Center for Oceans and Human Health and Climate Change Interactions, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA.
- Columbia VA Medical Center, Columbia, SC, 29209, USA.
| |
Collapse
|
9
|
Smith JE, Fichtel C, Holmes RK, Kappeler PM, van Vugt M, Jaeggi AV. Sex bias in intergroup conflict and collective movements among social mammals: male warriors and female guides. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210142. [PMID: 35369756 DOI: 10.1098/rstb.2021.0142] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Intergroup conflict is a major evolutionary force shaping animal and human societies. Males and females should, on average, experience different costs and benefits for participating in collective action. Specifically, among mammals, male fitness is generally limited by access to mates whereas females are limited by access to food and safety. Here we analyse sex biases among 72 species of group-living mammals in two contexts: intergroup conflict and collective movements. Our comparative phylogenetic analyses show that the modal mammalian pattern is male-biased participation in intergroup conflict and female-biased leadership in collective movements. However, the probability of male-biased participation in intergroup conflicts decreased and female-biased participation increased with female-biased leadership in movements. Thus, female-biased participation in intergroup conflict only emerged in species with female-biased leadership in collective movements, such as in spotted hyenas and some lemurs. Sex differences are probably attributable to costs and benefits of participating in collective movements (e.g. towards food, water, safety) and intergroup conflict (e.g. access to mates or resources, risk of injury). Our comparative review offers new insights into the factors shaping sex bias in leadership across social mammals and is consistent with the 'male warrior hypothesis' which posits evolved sex differences in human intergroup psychology. This article is part of the theme issue 'Intergroup conflict across taxa'.
Collapse
Affiliation(s)
- Jennifer E Smith
- Biology Department, Mills College, 5000 MacArthur Boulevard, Oakland, CA 94631, USA
| | - Claudia Fichtel
- Behavioral Ecology and Sociobiology Unit, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Rose K Holmes
- Biology Department, Mills College, 5000 MacArthur Boulevard, Oakland, CA 94631, USA
| | - Peter M Kappeler
- Behavioral Ecology and Sociobiology Unit, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany.,Department Anthropology/Sociobiology, University of Göttingen, Göttingen, Germany
| | - Mark van Vugt
- Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Adrian V Jaeggi
- Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland
| |
Collapse
|
10
|
García MG, de Guinea M, Bshary R, van de Waal E. Drivers and outcomes of between-group conflict in vervet monkeys. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210145. [PMID: 35369750 PMCID: PMC8977665 DOI: 10.1098/rstb.2021.0145] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Neighbouring groups compete over access to resources and territories in between-group encounters, which can escalate into between-group conflicts (BGCs). Both the ecological characteristics of a territory and the rival's fighting ability shape the occurrence and outcome of such contests. What remains poorly understood, however, is how seasonal variability in the ecological value of a territory together with fighting ability related to the likelihood of between-group encounters and the extent to which these escalate into conflicts. To test this, we observed and followed four vervet monkey groups in the wild, and recorded the group structure (i.e. size, composition), the locations and the outcomes of 515 BGCs. We then assessed key ecological measures at these locations, such as vegetation availability (estimated from Copernicus Sentinel 2 satellite images) and the intensity of usage of these locations. We tested to what extent these factors together influenced the occurrence and outcomes of BGCs. We found that the occurrence of BGCs increased at locations with higher vegetation availability relative to the annual vegetation availability within the group's home territory. Also, groups engaging in a BGC at locations far away from their home territory were less likely to win a BGC. Regarding group structure, we found that smaller groups systematically won BGCs against larger groups, which can be explained by potentially higher rates of individual free-riding occurring in larger groups. This study sheds light on how the ecology of encounter locations in combination with a group's social characteristics can critically impact the dynamics of BGCs in a non-human primate species. This article is part of the theme issue ‘Intergroup conflict across taxa’.
Collapse
Affiliation(s)
- Miguel Gareta García
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal 3115, South Africa.,Department of Eco-Ethology, Faculty of Biology, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel 2000, Switzerland
| | - Miguel de Guinea
- Movement Ecology Laboratory, Alexander Silverman Institute of Life Sciences, Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Redouan Bshary
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal 3115, South Africa.,Department of Eco-Ethology, Faculty of Biology, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel 2000, Switzerland
| | - Erica van de Waal
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal 3115, South Africa.,Department of Ecology and Evolution, Faculty of Biology and Medicine, University of Lausanne, Lausanne 1015, Switzerland
| |
Collapse
|
11
|
Predictive value of surveillance cultures for bacteremia caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales among patients with hematological diseases. Infection 2022; 50:753-759. [PMID: 35013943 DOI: 10.1007/s15010-021-01753-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 12/28/2021] [Indexed: 11/05/2022]
Abstract
PURPOSE Due to the increasing prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales, empirical therapies with cefepime or piperacillin/tazobactam for hematology patients with febrile neutropenia have become ineffective. Carbapenems should be administered as soon as possible in such patients with ESBL bacteremia. If the surveillance culture results are consistent with the blood culture findings, the time to adequate treatment initiation can be shortened. METHODS All consecutive patients with Enterobacterales bacteraemia who were admitted from January 2013 to December 2018 at the hematology wards were enrolled in this study. Surveillance rectal swab and blood culture results were compared. RESULTS In total, 67 patients with Enterobacterales bacteremia underwent surveillance culture prior to the onset of infection. Regarding the presence or absence of ESBL-producing Enterobacterales, 64 (95.5%) patients had surveillance results concordant with blood culture results. The positive predictive value of surveillance culture for bacteremia caused by ESBL-producing Enterobacterales was 95.0%. Moreover, the negative predictive value of surveillance culture for bacteremia caused by non-ESBL-producing Enterobacterales was 95.7%. CONCLUSION The concordance rate between the surveillance rectal swab and blood cultures was highly acceptable. Surveillance rectal swab cultures are useful for identifying patients at high risk for ESBL bacteremia.
Collapse
|
12
|
Gareta García M, Farine DR, Brachotte C, Borgeaud C, Bshary R. Wild female vervet monkeys change grooming patterns and partners when freed from feeding constraints. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.08.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Smith JE, von Rueden CR, van Vugt M, Fichtel C, Kappeler PM. An Evolutionary Explanation for the Female Leadership Paradox. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.676805] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Social influence is distributed unequally between males and females in many mammalian societies. In human societies, gender inequality is particularly evident in access to leadership positions. Understanding why women historically and cross-culturally have tended to be under-represented as leaders within human groups and organizations represents a paradox because we lack evidence that women leaders consistently perform worse than men. We also know that women exercise overt influence in collective group-decisions within small-scale human societies, and that female leadership is pervasive in particular contexts across non-human mammalian societies. Here, we offer a transdisciplinary perspective on this female leadership paradox. Synthesis of social science and biological literatures suggests that females and males, on average, differ in why and how they compete for access to political leadership in mixed-gender groups. These differences are influenced by sexual selection and are moderated by socioecological variation across development and, particularly in human societies, by culturally transmitted norms and institutions. The interplay of these forces contributes to the emergence of female leaders within and across species. Furthermore, females may regularly exercise influence on group decisions in less conspicuous ways and different domains than males, and these underappreciated forms of leadership require more study. We offer a comprehensive framework for studying inequality between females and males in access to leadership positions, and we discuss the implications of this approach for understanding the female leadership paradox and for redressing gender inequality in leadership in humans.
Collapse
|
14
|
Sánchez-Amaro A, Ball R, Rossano F. Gibbon strategies in a food competition task. Sci Rep 2021; 11:9312. [PMID: 33927301 PMCID: PMC8085081 DOI: 10.1038/s41598-021-88804-5] [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: 12/08/2020] [Accepted: 04/14/2021] [Indexed: 02/03/2023] Open
Abstract
Social primates face conflicts of interest with other partners when their individual and collective interests collide. Despite living in small, primarily bonded, groups compared to other social primates, gibbons are not exempt from these conflicts in their everyday lives. In the current task, we asked whether dyads of gibbons would solve a conflict of interest over food rewards. We presented dyads of gibbons with a situation in which they could decide whether to take an active role and pull a handle to release food rewards at a distance or take a passive role and avoid action. In this situation, the passive partner could take an advantageous position to obtain the rewards over the active partner. Gibbons participated in three conditions: a control condition with no food rewards, a test condition with indirect food rewards and a test condition with direct food rewards. In both test conditions, five rewards were released at a distance from the handle. In addition, the active individual could obtain one extra food reward from the handle in the direct food condition. We found that gibbons acted more often in the two conditions involving food rewards, and waited longer in the indirect compared to the direct food condition, thus suggesting that they understood the task contingencies. Surprisingly, we found that in a majority of dyads, individuals in the active role obtained most of the payoff compared to individuals in the passive role in both food conditions. Furthermore, in some occasions individuals in the active role did not approach the location where the food was released. These results suggest that while gibbons may strategize to maximize benefits in a competitive food task, they often allowed their partners to obtain better rewards. Our results highlight the importance of social tolerance and motivation as drivers promoting cooperation in these species.
Collapse
Affiliation(s)
- Alejandro Sánchez-Amaro
- grid.266100.30000 0001 2107 4242Department of Cognitive Science, University of California San Diego, La Jolla, USA ,grid.419518.00000 0001 2159 1813Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Robert Ball
- grid.266100.30000 0001 2107 4242Department of Cognitive Science, University of California San Diego, La Jolla, USA ,grid.212340.60000000122985718The Graduate Center, City University of New York, New York, USA
| | - Federico Rossano
- grid.266100.30000 0001 2107 4242Department of Cognitive Science, University of California San Diego, La Jolla, USA
| |
Collapse
|
15
|
Isbell LA, Bidner LR, Loftus JC, Kimuyu DM, Young TP. Absentee owners and overlapping home ranges in a territorial species. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-020-02945-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
16
|
Green PA, Briffa M, Cant MA. Assessment during Intergroup Contests. Trends Ecol Evol 2020; 36:139-150. [PMID: 33187729 DOI: 10.1016/j.tree.2020.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 12/11/2022]
Abstract
Research on how competitors assess (i.e., gather information on) fighting ability and contested resources, as well as how assessment impacts on contest processes and outcomes, has been fundamental to the field of dyadic (one-on-one) contests. Despite recent growth in studies of contests between social-living groups, there is limited understanding of assessment during these intergroup contests. We adapt current knowledge of dyadic contest assessment to the intergroup case, describing what traits of groups, group members, and resources are assessed, and how assessment is manifested in contest processes (e.g., behaviors) and outcomes. This synthesis helps to explain the role of individual heterogeneity in assessment and how groups are shaped by the selective pressure of contests.
Collapse
Affiliation(s)
- P A Green
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK.
| | - M Briffa
- School of Biological and Marine Sciences, Plymouth University, Drake Circus, Plymouth PL3 8AA, UK
| | - M A Cant
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK
| |
Collapse
|
17
|
Lewis RJ, Sandel AA, Hilty S, Barnett SE. The Collective Action Problem but Not Numerical Superiority Explains Success in Intergroup Encounters in Verreaux’s Sifaka (Propithecus verreauxi): Implications for Individual Participation and Free-Riding. INT J PRIMATOL 2020. [DOI: 10.1007/s10764-020-00155-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
18
|
Making ‘my’ problem ‘our’ problem: Warfare as collective action, and the role of leader manipulation. THE LEADERSHIP QUARTERLY 2020. [DOI: 10.1016/j.leaqua.2019.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
19
|
Scarry CJ. Against all odds: Numerical assessment by tufted capuchin monkeys. Am J Primatol 2020; 82:e23094. [PMID: 31961003 DOI: 10.1002/ajp.23094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/06/2019] [Accepted: 12/21/2019] [Indexed: 11/09/2022]
Abstract
When competitors are able to assess the asymmetry in the resource holding potential before interacting, individuals or groups should avoid interacting with stronger opponents, thereby avoiding the energy costs and risk of injury associated with aggressive intergroup encounters. Thus, escalated aggression is expected only between closely matched competitors. Among Argentine tufted capuchin monkeys (Sapajus nigritus), intergroup dominance is decided by the asymmetry in male group size. Using playback experiments, I simulated intergroup encounters with neighboring groups, manipulating both the apparent numerical asymmetry and the resource context. During experimental trials, I recorded the approach behavior of the focal individual, as well as changes in neighbor density and individual travel speed following the presentation of the playback stimulus, to assess whether individual willingness to participate in resource defense was affected by the probability of winning the encounter. In spite of the competitive disadvantage, neither males nor females showed a decreased probability of approach when the numerical odds strongly favored the opposing group. Instead decisions regarding whether to participate appear to be driven primarily by the resource context. Nevertheless, changes in individual behavior during approaches suggest that tufted capuchin monkeys are sensitive to the relative odds. Individuals accelerated less when approaching a larger group, although no changes in neighbor density were apparent. The absence of an effect of the numerical asymmetry on willingness to approach the playback speaker suggests that subordinate groups benefit from engaging in intergroup aggression with larger neighbors, despite the high probability of losing. These encounters may serve to assess the current subjective resource valuation of the neighboring group or limit territorial expansion by large groups by decreasing the marginal value of home range exclusivity. Because these encounters are riskier, however, individuals appear to alter their approaches, becoming more tentative as the numerical odds increasingly favor the opposing group.
Collapse
Affiliation(s)
- Clara J Scarry
- Department of Anthropology, California State University, Sacramento, California.,Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, New York
| |
Collapse
|
20
|
Majolo B, deBortoli Vizioli A, Martínez-Íñigo L, Lehmann J. Effect of Group Size and Individual Characteristics on Intergroup Encounters in Primates. INT J PRIMATOL 2020. [DOI: 10.1007/s10764-019-00119-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
AbstractIntergroup encounters are common in nonhuman primates and can vary from affiliative to aggressive. We extracted data from the literature to test five different hypotheses: 1) where there are group size differences between opposing groups, whether the larger group is more likely to win an intergroup encounter than the smaller group; 2) whether the likelihood of a group engaging in aggressive intergroup encounters increases with group size; and 3–5) whether dominant, older individuals, and/or males are more likely to participate aggressively in intergroup encounters than subordinate, younger individuals and/or females. Our data set comprised 52 studies on 31 primate species (3 lemur species, 5 New World monkeys, 19 Old World monkeys, and 4 apes). We found that the larger group is more likely to win an encounter against a smaller group than vice versa. We found no significant relationship between group size and propensity to be aggressive during intergroup encounters. We found weak/no support for the effect of age, dominance rank, and sex on the frequency of aggression displayed toward outgroup individuals during intergroup encounters. Species- and population-specific differences in inter- and intragroup competition and in the degree of the unequal distribution of resources across group members may explain why age, dominance rank, and sex are not strong predictors of aggression during intergroup encounters.
Collapse
|
21
|
Samuni L, Mielke A, Preis A, Crockford C, Wittig RM. Intergroup Competition Enhances Chimpanzee (Pan troglodytes verus) In-group Cohesion. INT J PRIMATOL 2019. [DOI: 10.1007/s10764-019-00112-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractIn-group cohesion is an essential component of successful intergroup competition in both human and nonhuman animals, likely facilitating group members access to potential benefits. However, when benefits are equally shared among group members, group defense becomes a collective action problem, which might subvert cohesive participation during intergroup competition. There is a lack of consensus across studies and species with regard to the link between in-group cohesion and intergroup competition, likely as a result of species differences in managing the collective action problem. Here, we examine this link in a species with a striking example of collective action during intergroup competition, chimpanzees (Pan troglodytes verus). Using two years of focal-follow data on males and females in two groups at the Taï Forest, Côte d’Ivoire, we investigated the immediate and long-term effects of intergroup competition (border patrols and intergroup encounters) on measures of in-group cohesion, namely modularity, party size, and intergroup aggression. We found that groups’ association patterns were less modular (more cohesive) in months in which they engaged in more border patrols and intergroup encounters. We found that current and greater prior engagement in intergroup competition predicted larger party sizes. Furthermore, current, but not prior engagement in intergroup competition, predicted reduced intragroup aggression by males but not by females. Increased in-group cohesion in chimpanzees likely reduces potential costs of intergroup competition engagement, by facilitating joint participation in current and future intergroup conflicts, overcoming the collective action problem.
Collapse
|
22
|
Mielke A, Crockford C, Wittig RM. Snake alarm calls as a public good in sooty mangabeys. Anim Behav 2019; 158:201-209. [PMID: 31875856 PMCID: PMC6915763 DOI: 10.1016/j.anbehav.2019.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/01/2019] [Accepted: 08/16/2019] [Indexed: 11/10/2022]
Abstract
Transmitting information about the location of a predator in social animal species can be seen as an investment in a public good, where information is the resource and group members benefit from reduced fatalities of kin and cooperation partners in their community. As few empirical tests of this idea exist in natural settings, we conducted a field experiment using snake models in wild sooty mangabeys, Cercocebus atys atys. We tested sooty mangabey alarm-calling patterns when exposed to viper models, investigating whether individuals called to signal fitness, to warn specific group members, or when information about the threat is not public, as would be predicted by public goods games. Strong interindividual differences in the likelihood of alarm calling existed. We found that overlap between callers was rare. Individuals were more likely to call if fewer individuals were present at the encounter site and if they had not heard other alarm calls before arriving at the site, indicating that alarm calls extended the information about the threat to following group members. This group size effect is in line with predictions of the volunteer's dilemma, a public goods game. We found no indications that individuals called specifically to warn ignorant individuals, kin or cooperation partners. Calling when information about the threat was not public allowed individuals to warn following group members while avoiding redundancy. Public goods games have not been employed widely in studies of the evolution of primate cooperation and animal communication in general but may provide useful models for understanding group level cooperation.
Collapse
Affiliation(s)
- Alexander Mielke
- Department of Psychology, University of Portsmouth, Portsmouth, U.K
- Max Planck Institute for Evolutionary Anthropology, Department of Primatology, Leipzig, Germany
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Cote d'Ivoire
- Primate Models for Behavioural Evolution Lab, Institute for Cognitive and Evolutionary Anthropology, Oxford, U.K
| | - Catherine Crockford
- Max Planck Institute for Evolutionary Anthropology, Department of Primatology, Leipzig, Germany
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Cote d'Ivoire
| | - Roman M. Wittig
- Max Planck Institute for Evolutionary Anthropology, Department of Primatology, Leipzig, Germany
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Cote d'Ivoire
| |
Collapse
|
23
|
Morris-Drake A, Christensen C, Kern JM, Radford AN. Experimental field evidence that out-group threats influence within-group behavior. Behav Ecol 2019; 30:1425-1435. [PMID: 31579132 PMCID: PMC6765380 DOI: 10.1093/beheco/arz095] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/20/2019] [Accepted: 05/29/2019] [Indexed: 11/13/2022] Open
Abstract
In social species, conspecific outsiders present various threats to groups and their members. These out-group threats are predicted to affect subsequent within-group interactions (e.g., affiliation and aggression) and individual behavior (e.g., foraging and vigilance decisions). However, experimental investigations of such consequences are rare, especially in natural conditions. We used field-based call playbacks and fecal presentations on habituated wild dwarf mongooses (Helogale parvula)-a cooperatively breeding, territorial species-to examine postinteraction responses to the simulated threat of a rival group. Dwarf mongooses invested more in grooming of groupmates, foraged closer together, and more regularly acted as sentinels (a raised guard) after encountering indicators of rival-group presence compared to control conditions. These behavioral changes likely arise from greater anxiety and, in the case of increased vigilance, the need to seek additional information about the threat. The influence of an out-group threat lasted at least 1 h but individuals of different dominance status and sex responded similarly, potentially because all group members suffer costs if a contest with rivals is lost. Our results provide field-based experimental evidence from wild animals that out-group threats can influence within-group behavior and decision making, and suggest the need for greater consideration of the lasting impacts of social conflict.
Collapse
Affiliation(s)
- Amy Morris-Drake
- School of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Julie M Kern
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Andrew N Radford
- School of Biological Sciences, University of Bristol, Bristol, UK
| |
Collapse
|
24
|
Between-group attack and defence in an ecological setting: Insights from nonhuman animals. Behav Brain Sci 2019; 42:e137. [PMID: 31407982 DOI: 10.1017/s0140525x19000773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Attempts to understand the fundamental forces shaping conflict between attacking and defending groups can be hampered by a narrow focus on humans and reductionist, oversimplified modelling. Further progress depends on recognising the striking parallels in between-group conflict across the animal kingdom, harnessing the power of experimental tests in nonhuman species and modelling the eco-evolutionary feedbacks that drive attack and defence.
Collapse
|
25
|
Morton FB, Altschul D. Data reduction analyses of animal behaviour: avoiding Kaiser's criterion and adopting more robust automated methods. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
26
|
Mirville MO, Ridley AR, Samedi J, Vecellio V, Ndagijimana F, Stoinski TS, Grueter CC. Factors influencing individual participation during intergroup interactions in mountain gorillas. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.08.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
27
|
Arseneau-Robar TJM, Müller E, Taucher AL, van Schaik CP, Bshary R, Willems EP. Male monkeys use punishment and coercion to de-escalate costly intergroup fights. Proc Biol Sci 2018; 285:20172323. [PMID: 29875293 PMCID: PMC6015864 DOI: 10.1098/rspb.2017.2323] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 05/10/2018] [Indexed: 11/12/2022] Open
Abstract
In numerous social species, males direct aggression towards female group members during intergroup fights, and this behaviour is commonly thought to function as mate guarding, even though males often target non-receptive females. In studying intergroup fights in a wild population of vervet monkeys, we found that male intragroup aggression was primarily directed towards individuals who had either just finished exhibiting, or were currently attempting to instigate intergroup aggression. Targeted females were less likely to instigate intergroup aggression in the future, indicating that male intragroup aggression functioned as coercion (when directed towards those who were currently trying to instigate a fight) and punishment (when directed towards those who had recently fought). These manipulative tactics effectively prevented intergroup encounters from escalating into fights and often de-escalated ongoing conflicts. Males who were likely sires were those most likely to use punishment/coercion, particularly when they were wounded, and, therefore, less able to protect vulnerable offspring should a risky intergroup fight erupt. This work, along with our previous finding that females use punishment and rewards to recruit males into participating in intergroup fights, highlights the inherent conflict of interest that exists between the sexes, as well as the role that social incentives can play in resolving this conflict. Furthermore, unlike other studies which have found punishment to be used asymmetrically between partners, these works represent a novel example of reciprocal punishment in a non-human animal.
Collapse
Affiliation(s)
- T Jean M Arseneau-Robar
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal, South Africa
| | - Eliane Müller
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal, South Africa
| | - Anouk L Taucher
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal, South Africa
| | - Carel P van Schaik
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal, South Africa
| | - Redouan Bshary
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal, South Africa
- Department of Zoology, University of Neuchâtel, Rue Emile-Argand 11, 2007 Neuchâtel, Switzerland
| | - Erik P Willems
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal, South Africa
| |
Collapse
|
28
|
Christensen C, Radford AN. Dear enemies or nasty neighbors? Causes and consequences of variation in the responses of group-living species to territorial intrusions. Behav Ecol 2018. [DOI: 10.1093/beheco/ary010] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
| | - Andrew N Radford
- School of Biological Sciences, University of Bristol, Bristol, UK
| |
Collapse
|
29
|
Radford AN, Majolo B, Aureli F. Within-group behavioural consequences of between-group conflict: a prospective review. Proc Biol Sci 2017; 283:rspb.2016.1567. [PMID: 27903869 PMCID: PMC5136580 DOI: 10.1098/rspb.2016.1567] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/31/2016] [Indexed: 02/04/2023] Open
Abstract
Conflict is rife in group-living species and exerts a powerful selective force. Group members face a variety of threats from extra-group conspecifics, from individuals looking for reproductive opportunities to rival groups seeking resources. Theory predicts that such between-group conflict should influence within-group behaviour. However, compared with the extensive literature on the consequences of within-group conflict, relatively little research has considered the behavioural impacts of between-group conflict. We give an overview of why between-group conflict is expected to influence subsequent behaviour among group members. We then use what is known about the consequences of within-group conflict to generate testable predictions about how between-group conflict might affect within-group behaviour in the aftermath. We consider the types of behaviour that could change and how the role of different group members in the conflict can exert an influence. Furthermore, we discuss how conflict characteristics and outcome, group size, social structure and within-group relationship quality might modulate post-conflict behavioural changes. Finally, we propose the need for consistent definitions, a broader range of examined behaviours and taxa, individual-focused data collection, complementary observational and experimental approaches, and a consideration of lasting effects if we are to understand fully the significant influence of between-group conflict on social behaviour.
Collapse
Affiliation(s)
- Andrew N Radford
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Bonaventura Majolo
- School of Psychology, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, UK
| | - Filippo Aureli
- Instituto de Neuroetologia, Universidad Veracruzana, Xalapa 91000 Veracruz, Mexico.,Research Centre in Evolutionary Anthropology and Palaeoecology, Liverpool John Moore University, Liverpool L3 3AF, UK
| |
Collapse
|
30
|
Arseneau-Robar TJM, Taucher AL, Müller E, van Schaik C, Bshary R, Willems EP. Female monkeys use both the carrot and the stick to promote male participation in intergroup fights. Proc Biol Sci 2017; 283:rspb.2016.1817. [PMID: 27881752 DOI: 10.1098/rspb.2016.1817] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/27/2016] [Indexed: 01/24/2023] Open
Abstract
Group-level cooperation often poses a social dilemma in which joint action may be difficult to achieve. Theoretical models and experimental work on humans show that social incentives, such as punishment of defectors and rewarding of cooperators, can promote cooperation in groups of unrelated individuals. Here, we demonstrate that these processes can operate in a non-human animal species, and be used to effectively promote the production of a public good. We took advantage of the fact that intergroup fights in vervet monkeys (Chlorocebus aethiops pygerythrus) are characterized by episodes of intergroup aggression with pauses in-between. During pauses, females selectively groomed males that had participated in the previous aggressive episode, but aggressed male group members that had not. In subsequent (i.e. future) episodes, males who had received either aggression or grooming participated above their personal base-line level. Therefore, female-male aggression and grooming both appear to function as social incentives that effectively promote male participation in intergroup fights. Importantly, females stood to gain much from recruiting males as the probability of winning intergroup fights was dependent on the number of active participants, relative to the number of fighters in the opposing group. Furthermore, females appear to maximize the benefits gained from recruiting males as they primarily used social incentives where and when high-quality food resources, which are the resources primarily limiting to female fitness, were at stake.
Collapse
Affiliation(s)
- T Jean Marie Arseneau-Robar
- Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland .,Inkawu Vervet Project, Mawana Game Reserve, Swart Mfolozi, KwaZulu Natal, South Africa
| | - Anouk Lisa Taucher
- Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland.,Inkawu Vervet Project, Mawana Game Reserve, Swart Mfolozi, KwaZulu Natal, South Africa
| | - Eliane Müller
- Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland.,Inkawu Vervet Project, Mawana Game Reserve, Swart Mfolozi, KwaZulu Natal, South Africa
| | - Carel van Schaik
- Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland.,Inkawu Vervet Project, Mawana Game Reserve, Swart Mfolozi, KwaZulu Natal, South Africa
| | - Redouan Bshary
- Inkawu Vervet Project, Mawana Game Reserve, Swart Mfolozi, KwaZulu Natal, South Africa.,Department of Biology, University of Neuchâtel, Emile-Argand 11, Neuchâtel, Switzerland
| | - Erik P Willems
- Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland.,Inkawu Vervet Project, Mawana Game Reserve, Swart Mfolozi, KwaZulu Natal, South Africa
| |
Collapse
|
31
|
A model for warfare in stratified small-scale societies: The effect of within-group inequality. PLoS One 2017; 12:e0188970. [PMID: 29228014 PMCID: PMC5724843 DOI: 10.1371/journal.pone.0188970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 11/16/2017] [Indexed: 11/19/2022] Open
Abstract
In order to predict the features of non-raiding human warfare in small-scale, socially stratified societies, we study a coalitionary model of war that assumes that individuals participate voluntarily because their decisions serve to maximize fitness. Individual males join the coalition if war results in a net economic and thus fitness benefit. Within the model, viable offensive war ensues if the attacking coalition of males can overpower the defending coalition. We assume that the two groups will eventually fuse after a victory, with ranks arranged according to the fighting abilities of all males and that the new group will adopt the winning group’s skew in fitness payoffs. We ask whether asymmetries in skew, group size and the amount of resources controlled by a group affect the likelihood of successful war. The model shows, other things being equal, that (i) egalitarian groups are more likely to defeat their more despotic enemies, even when these are stronger, (ii) defection to enemy groups will be rare, unless the attacked group is far more despotic than the attacking one, and (iii) genocidal war is likely under a variety of conditions, in particular when the group under attack is more egalitarian. This simple optimality model accords with several empirically observed correlations in human warfare. Its success underlines the important role of egalitarianism in warfare.
Collapse
|
32
|
Group augmentation, collective action, and territorial boundary patrols by male chimpanzees. Proc Natl Acad Sci U S A 2017. [PMID: 28630310 DOI: 10.1073/pnas.1701582114] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
How can collective action evolve when individuals benefit from cooperation regardless of whether they pay its participation costs? According to one influential perspective, collective action problems are common, especially when groups are large, but may be solved when individuals who have more to gain from the collective good or can produce it at low costs provide it to others as a byproduct. Several results from a 20-y study of one of the most striking examples of collective action in nonhuman animals, territorial boundary patrolling by male chimpanzees, are consistent with these ideas. Individuals were more likely to patrol when (i) they had more to gain because they had many offspring in the group; (ii) they incurred relatively low costs because of their high dominance rank and superior physical condition; and (iii) the group size was relatively small. However, several other findings were better explained by group augmentation theory, which proposes that individuals should bear the short-term costs of collective action even when they have little to gain immediately if such action leads to increases in group size and long-term increases in reproductive success. In support of this theory, (i) individual patrolling effort was higher and less variable than participation in intergroup aggression in other primate species; (ii) males often patrolled when they had no offspring or maternal relatives in the group; and (iii) the aggregate patrolling effort of the group did not decrease with group size. We propose that group augmentation theory deserves more consideration in research on collective action.
Collapse
|
33
|
The social organization of Homo ergaster: Inferences from anti-predator responses in extant primates. J Hum Evol 2017; 109:11-21. [PMID: 28688456 DOI: 10.1016/j.jhevol.2017.05.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 04/27/2017] [Accepted: 05/04/2017] [Indexed: 02/02/2023]
Abstract
Patterns of primate socioecology have been used to suggest that the first truly savanna-dwelling hominin, Homo ergaster, lived in sizeable groups. Here, we revisit these estimates and infer additional features of the social organization of these early hominins based on anti-predator responses observed across the primate taxon. We first show that the effect of habitat on primate group size, composition, and sexual dimorphism is negligible after controlling for substrate use and phylogeny: terrestrial species live in larger groups with more and bigger males than arboreal taxa. We next hypothesize that groups can only survive in open habitats if males are able to engage in joint counter-attacks against the large carnivorans typical of such environments. To test this, we analyze reports on primate counter-attacks against known predators and find these are indeed disproportionately frequent in terrestrial taxa living in open habitats, sometimes even involving the use of tentative weapons. If we subsequently only examine the taxa that are particularly adept at this (chimpanzees and baboons), we find an effect of habitat type on group size: groups on the savanna are larger than those in the forest. We thus infer that H. ergaster lived in very large groups with many males that jointly defended the group against carnivorans, and argue that these counter-attacks will readily have turned into confrontational scavenging and cooperative hunting, allowing Homo to move into the niche of social carnivore. These two features (life in very large multi-male groups and a switch to persistent carnivory) shaped the evolution of our lineage to such an extent that the social organization of H. ergaster may already have contained many key elements characterizing modern day foragers: male bonding, incipient male-female friendships with food sharing, a tendency toward endogamy, and the presence of large communities that eventually turned into the ethno-linguistic units we can still recognize today.
Collapse
|
34
|
Radford AN, Bruintjes R. Expanding the Link between Out-Group Threats and In-Group Behavior: (A Reply to Kavaliers and Choleris). Am Nat 2017; 189:459-462. [PMID: 28350494 DOI: 10.1086/690837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In social species, groups and their members face a variety of threats from conspecific outsiders. Such out-group conflict is predicted to influence within-group behavior, with empirical work demonstrating this link in humans, primates, and birds. In our note "Out-Group Threat Promotes Within-Group Affiliation in a Cooperative Fish," appearing in The American Naturalist in February 2016, we provided experimental evidence that simulated territorial intrusions result in subsequent increases in affiliation among groupmates in a cichlid fish (Neolamprologus pulcher). Martin Kavaliers and Elena Choleris, in their comment "Out-Group Threat Responses, In-Group Bias, and Nonapeptide Involvement Are Conserved Across Vertebrates," appearing in this issue, commented on our cichlid-fish article; they consider the conserved nature of the link between out-group threat and in-group behavior and bias in vertebrates, the influence of pathogens in the process, and the potential underpinning hormonal mechanisms. Here, we provide clarification and expansion of some of the core points that are discussed in the comment by Kavaliers and Choleris.
Collapse
|
35
|
Intra- and interindividual differences in the costs and benefits of intergroup aggression in female vervet monkeys. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2016.10.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
36
|
von Rueden C, Gavrilets S, Glowacki L. Solving the puzzle of collective action through inter-individual differences. Philos Trans R Soc Lond B Biol Sci 2016; 370:20150002. [PMID: 26503677 DOI: 10.1098/rstb.2015.0002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Models of collective action infrequently account for differences across individuals beyond a limited set of strategies, ignoring variation in endowment (e.g. physical condition, wealth, knowledge, personality, support), individual costs of effort, or expected gains from cooperation. However, behavioural research indicates these inter-individual differences can have significant effects on the dynamics of collective action. The papers contributed to this theme issue evaluate how individual differences affect the propensity to cooperate, and how they can catalyse others' likelihood of cooperation (e.g. via leadership). Many of the papers emphasize the relationship between individual decisions and socio-ecological context, particularly the effect of group size. All together, the papers in this theme issue provide a more complete picture of collective action, by embracing the reality of inter-individual variation and its multiple roles in the success or failure of collective action.
Collapse
Affiliation(s)
- Chris von Rueden
- Jepson School of Leadership Studies, University of Richmond, Richmond, VA 23173, USA
| | - Sergey Gavrilets
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA Department of Mathematics, University of Tennessee, Knoxville, TN 37996, USA National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, TN 37996, USA
| | - Luke Glowacki
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
37
|
Glowacki L, von Rueden C. Leadership solves collective action problems in small-scale societies. Philos Trans R Soc Lond B Biol Sci 2016; 370:20150010. [PMID: 26503683 DOI: 10.1098/rstb.2015.0010] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Observation of leadership in small-scale societies offers unique insights into the evolution of human collective action and the origins of sociopolitical complexity. Using behavioural data from the Tsimane forager-horticulturalists of Bolivia and Nyangatom nomadic pastoralists of Ethiopia, we evaluate the traits of leaders and the contexts in which leadership becomes more institutional. We find that leaders tend to have more capital, in the form of age-related knowledge, body size or social connections. These attributes can reduce the costs leaders incur and increase the efficacy of leadership. Leadership becomes more institutional in domains of collective action, such as resolution of intragroup conflict, where collective action failure threatens group integrity. Together these data support the hypothesis that leadership is an important means by which collective action problems are overcome in small-scale societies.
Collapse
Affiliation(s)
- Luke Glowacki
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA
| | - Chris von Rueden
- Jepson School of Leadership Studies, University of Richmond, Richmond, VA 23173, USA
| |
Collapse
|
38
|
Jaeggi AV, Boose KJ, White FJ, Gurven M. Obstacles and catalysts of cooperation in humans, bonobos, and chimpanzees: behavioural reaction norms can help explain variation in sex roles, inequality, war and peace. BEHAVIOUR 2016. [DOI: 10.1163/1568539x-00003347] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Our closest living relatives, bonobos and chimpanzees, along with small-scale human societies figure prominently in debates about human nature. Here we emphasize and explain behavioural variation within and among these three species. In the logic of behavioural ecology, individuals have been selected to adjust their behaviour along evolved reaction norms that maximize fitness given current socio-ecological conditions. We discuss variation in three behavioural contexts: relationships between the sexes, hierarchy and inequality, and intergroup interactions. In each context, behavioural variation can be related to two broad socio-ecological conditions: (i) the defensibility of contested resources, and (ii) differences in bargaining power. When defensibility of resources and differences in bargaining power are great, interactions are rife with conflict; when they are minimal, interactions are more harmonious. These socio-ecological conditions therefore constitute key catalysts and obstacles of cooperation. We conclude that human nature should be seen as consisting of evolved reaction norms.
Collapse
Affiliation(s)
- Adrian V. Jaeggi
- aDepartment of Anthropology, University of California Santa Barbara, Humanities and Social Sciences Building (HSSB) 2001, Santa Barbara, CA 93106-3210, USA
| | - Klaree J. Boose
- bDepartment of Anthropology, University of Oregon, 308 Condon Hall, 1321 Kincaid Street, Eugene, OR 97403, USA
| | - Frances J. White
- bDepartment of Anthropology, University of Oregon, 308 Condon Hall, 1321 Kincaid Street, Eugene, OR 97403, USA
| | - Michael Gurven
- aDepartment of Anthropology, University of California Santa Barbara, Humanities and Social Sciences Building (HSSB) 2001, Santa Barbara, CA 93106-3210, USA
| |
Collapse
|