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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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Pavez-Fox MA, Siracusa ER, Ellis S, Kimock CM, Rivera-Barreto N, Negron-Del Valle JE, Phillips D, Ruiz-Lambides A, Snyder-Mackler N, Higham JP, Brent LJ, De Moor D. Socioecological drivers of injuries in female and male rhesus macaques ( Macaca mulatta). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.20.563310. [PMID: 38559204 PMCID: PMC10979908 DOI: 10.1101/2023.10.20.563310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Competition over access to resources, such as food and mates, is believed to be one of the major costs associated with group living. Two socioecological factors suggested to predict the intensity of competition are group size and the relative abundance of sexually active individuals. However, empirical evidence linking these factors to injuries and survival costs is scarce. Here, we leveraged 10 years of data from free-ranging rhesus macaques where injuries inflicted by conspecifics are associated with a high mortality risk. We tested if group size and adult sex ratio predicted the occurrence of injuries and used data on physical aggression to contextualise these results. We found that males were less likely to be injured when living in larger groups, potentially due to advantages in intergroup encounters. Females, instead, had higher injury risk when living in larger groups but this was not explained by within-group aggression among females. Further, male-biased sex ratios predicted a weak increase in injury risk in females and were positively related to male-female aggression, indicating that male coercion during mating competition may be a cause of injuries in females. Overall, our results provide insights into sex differences in the fitness-related costs of competition and empirical evidence for long-standing predictions on the evolution of group living.
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Affiliation(s)
- Melissa A. Pavez-Fox
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, United Kingdom EX4 4QG
- Department of Psychology and Neuroscience, University of St Andrews, United Kingdom KY16 9JP
| | - Erin R. Siracusa
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, United Kingdom EX4 4QG
| | - Samuel Ellis
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, United Kingdom EX4 4QG
| | - Clare M. Kimock
- Department of Anthropology, New York University, New York, NY 10003
- Department of Psychology, Nottingham Trent University, Nottingham, United Kingdom NG1 4FQ
| | - Nahiri Rivera-Barreto
- Caribbean Primate Research Center, University of Puerto Rico, San Juan, Puerto Rico 00936-5067
| | | | - Daniel Phillips
- Center for Evolution and Medicine, Arizona State University, Temple, AZ 85281, United States
| | - Angelina Ruiz-Lambides
- Caribbean Primate Research Center, University of Puerto Rico, San Juan, Puerto Rico 00936-5067
| | - Noah Snyder-Mackler
- Center for Evolution and Medicine, Arizona State University, Temple, AZ 85281, United States
- School of Life Sciences, Arizona State University, Temple, AZ 85281
- School for Human Evolution and Social Change, Arizona State University, Temple, AZ 85281
| | - James P. Higham
- Department of Anthropology, New York University, New York, NY 10003
| | - Lauren J.N. Brent
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, United Kingdom EX4 4QG
| | - Delphine De Moor
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, United Kingdom EX4 4QG
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Thierry B. Studying the Tonkean macaques of Strasbourg, a tale full of sound and fury. Primates 2023; 64:559-572. [PMID: 37597117 DOI: 10.1007/s10329-023-01088-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/08/2023] [Indexed: 08/21/2023]
Abstract
In this paper, I chronicle the Strasbourg population of Tonkean macaques (Macaca tonkeana) over a period of half a century. In 1972, Tonkean macaques were imported from Sulawesi, Indonesia, to eastern France, leading to the establishment of two social groups in the Strasbourg region several years later. Our research team studied the social behavior and cognitive abilities of these Tonkean macaques for four decades. The species is characterized by a high degree of social tolerance. This has proven to be very informative in comparative studies of macaque social behavior, opening a new perspective on the evolution of primate societies. Over the years, the population has grown, and more social groups have been formed. However, the fact that some of the Tonkean macaques were healthy carriers of the herpes B virus led to disagreements over their management and eventually to the elimination of the positive individuals. Many individuals from the Strasbourg population are now kept in sanctuaries, and the number of captive breeding groups is limited. We still have much to learn about Tonkean macaques and there is a need for studies carried out in their native habitat in Sulawesi.
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Affiliation(s)
- Bernard Thierry
- Laboratoire de Psychologie Sociale et Cognitive, Centre National de la Recherche Scientifique, Université Clermont Auvergne, Clermont-Ferrand, France.
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Thierry B. Where do we stand with the covariation framework in primate societies? AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 178 Suppl 74:5-25. [PMID: 36787776 DOI: 10.1002/ajpa.24441] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/21/2021] [Accepted: 11/04/2021] [Indexed: 12/17/2022]
Abstract
Comparative study of the social systems of macaques has revealed correlated variations between species in multiple social traits such as the asymmetry of dominance relationships, preferential treatment of kin, patterns of aggression and reconciliation, modes of socialization, and access to food resources. Macaques can be classified on a scale of four categories of social styles, ranging from the least to the most tolerant species. This led to the development of the covariation framework, which addresses the constraints responsible for the linkages between social traits, and their consequences on the evolution of primate social systems. Decades of research have provided a wealth of information that supports, complements, expands, or challenges the covariation framework. In this article, I review this body of knowledge and consider covariation in its two aspects, that is, as a pattern and as a hypothesis. I first consider the extent to which social styles can be invariant, the strength of correlations between traits, and the possible extension of the framework to nonhuman primates other than macaques. I then discuss how to formulate hypotheses, identify sources of linkage between traits, make predictions about the effects of social constraints, assess the tolerance dimension of social styles, and consider the breaking of linkages between traits. Whereas socioecological studies aim to understand how adaptation to the ecological environment determines the shape of social systems, the covariation framework is a complementary research program that seeks to unravel the internal processes that restrict or channel change in social behavior.
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Affiliation(s)
- Bernard Thierry
- Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Université de Tours, Nouzilly, France
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Morris-Drake A, Kennedy P, Braga Goncalves I, Radford AN. Variation between species, populations, groups and individuals in the fitness consequences of out-group conflict. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210148. [PMID: 35369741 PMCID: PMC8977661 DOI: 10.1098/rstb.2021.0148] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 12/02/2021] [Indexed: 12/30/2022] Open
Abstract
Out-group conflict is rife in the natural world, occurring from primates to ants. Traditionally, research on this aspect of sociality has focused on the interactions between groups and their conspecific rivals, investigating contest function and characteristics, which group members participate and what determines who wins. In recent years, however, there has been increasing interest in the consequences of out-group conflict. In this review, we first set the scene by outlining the fitness consequences that can arise immediately to contest participants, as well as a broader range of delayed, cumulative and third-party effects of out-group conflict on survival and reproductive success. For the majority of the review, we then focus on variation in these fitness consequences of out-group conflict, describing known examples both between species and between populations, groups and individuals of the same species. Throughout, we suggest possible reasons for the variation, provide examples from a diverse array of taxa, and suggest what is needed to advance this burgeoning area of social evolution. This article is part of the theme issue 'Intergroup conflict across taxa'.
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Affiliation(s)
- Amy Morris-Drake
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Patrick Kennedy
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Ines Braga Goncalves
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Andrew N. Radford
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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Dinh HT, Meng Y, Matsumoto J, Setogawa T, Nishimaru H, Nishijo H. Fast Detection of Snakes and Emotional Faces in the Macaque Amygdala. Front Behav Neurosci 2022; 16:839123. [PMID: 35386724 PMCID: PMC8979552 DOI: 10.3389/fnbeh.2022.839123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 02/11/2022] [Indexed: 11/30/2022] Open
Abstract
Primate vision is reported to detect snakes and emotional faces faster than many other tested stimuli. Because the amygdala has been implicated in avoidance and emotional behaviors to biologically relevant stimuli and has neural connections with subcortical nuclei involved with vision, amygdalar neurons would be sensitive to snakes and emotional faces. In this study, neuronal activity in the amygdala was recorded from Japanese macaques (Macaca fuscata) during discrimination of eight categories of visual stimuli including snakes, monkey faces, human faces, carnivores, raptors, non-predators, monkey hands, and simple figures. Of 527 amygdalar neurons, 95 responded to one or more stimuli. Response characteristics of the amygdalar neurons indicated that they were more sensitive to the snakes and emotional faces than other stimuli. Response magnitudes and latencies of amygdalar neurons to snakes and monkey faces were stronger and faster than those to the other categories of stimuli, respectively. Furthermore, response magnitudes to the low pass-filtered snake images were larger than those to scrambled snake images. Finally, analyses of population activity of amygdalar neurons suggest that snakes and emotional faces were represented separately from the other stimuli during the 50–100 ms period from stimulus onset, and neutral faces during the 100–150 ms period. These response characteristics indicate that the amygdala processes fast and coarse visual information from emotional faces and snakes (but not other predators of primates) among the eight categories of the visual stimuli, and suggest that, like anthropoid primate visual systems, the amygdala has been shaped over evolutionary time to detect appearance of potentially threatening stimuli including both emotional faces and snakes, the first of the modern predators of primates.
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Affiliation(s)
- Ha Trong Dinh
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
- Department of Physiology, Vietnam Military Medical University, Hanoi, Vietnam
| | - Yang Meng
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama, Japan
| | - Jumpei Matsumoto
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama, Japan
| | - Tsuyoshi Setogawa
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama, Japan
| | - Hiroshi Nishimaru
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama, Japan
- *Correspondence: Hiroshi Nishimaru,
| | - Hisao Nishijo
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science (RCIBS), University of Toyama, Toyama, Japan
- Hisao Nishijo,
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