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Kerjean E, van de Waal E, Canteloup C. Social dynamics of vervet monkeys are dependent upon group identity. iScience 2024; 27:108591. [PMID: 38299029 PMCID: PMC10829874 DOI: 10.1016/j.isci.2023.108591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 09/22/2023] [Accepted: 11/27/2023] [Indexed: 02/02/2024] Open
Abstract
Traditions are widespread across the animal realm. Here, we investigated inter-group variability of social dynamics in wild vervet monkeys (Chlorocebus pygerythrus). We analyzed 84,704 social interactions involving 247 individuals collected over nine years in three neighboring groups of wild vervet monkeys. We found that in one group - Ankhase - individuals had a higher propensity to be affiliative (i.e., sociality) and grooming interactions were more reciprocal. Despite yearly fluctuations in sociality, differences between groups remained stable over time. Moreover, our statistical model predictions confirmed that these findings were maintained for similar sex ratios, age distributions, and group sizes. Strikingly, our results suggested that dispersing males adapted their sociality to the sociality of the group they integrated with. As a whole, our study sheds light on the existence of stable social dynamics dependent upon group identity in wild vervet monkeys and suggests that at least part of this variability is socially mediated.
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Affiliation(s)
- Elena Kerjean
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Vaud, Switzerland
- Research Center on Animal Cognition, Center of Integrative Biology, University of Toulouse III - Paul Sabatier, Toulouse, France
| | - Erica van de Waal
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Vaud, Switzerland
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu-Natal, South Africa
- Center for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, KwaZulu-Natal, South Africa
- The Sense Innovation and Research Center, Lausanne and Sion, Vaud, Switzerland
| | - Charlotte Canteloup
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Vaud, Switzerland
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu-Natal, South Africa
- Center for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, KwaZulu-Natal, South Africa
- The Sense Innovation and Research Center, Lausanne and Sion, Vaud, Switzerland
- Laboratory of Cognitive & Adaptive Neurosciences, CNRS - UMR 7364, University of Strasbourg, Strasbourg, France
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O’Hearn WJ, Ruiz-Lambides A, Platt ML, Brent LJN. No evidence that grooming is exchanged for coalitionary support in the short- or long-term via direct or generalized reciprocity in unrelated rhesus macaques. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03160-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Abstract
Reciprocity is a prominent explanation for cooperation between non-kin. Studies designed to demonstrate reciprocity often focus on direct reciprocity in the timescale of minutes to hours, whereas alternative mechanisms like generalized reciprocity and the possibility of reciprocation over longer timescales of months and years are less often explored. Using a playback experiment, we tested for evidence of direct and generalized reciprocity across short and longer timescales. We examined the exchange of grooming for coalitionary support between unrelated female rhesus macaques in a population with a complete genetic pedigree. Females that received grooming were not more responsive to calls for coalitionary support from unrelated female group mates compared to control females that received agonism or no interaction — even when the call belonged to a females’ most recent grooming partner. Similarly, females were not more responsive to calls for support from their most frequent unrelated grooming partner of the last two years, nor if they received large amounts of grooming from all other females in their group. We interpret these results as an absence of evidence for direct or generalized reciprocity on any timescale in the exchange of grooming for coalitionary support in rhesus macaques. If grooming is exchanged for support in this population, it is with an intensity below our ability to detect it or over a longer timescale than we examined. We propose by-product explanations may also be at play and highlight the importance of investigating multiple mechanisms when testing apparently cooperative behaviors.
Significance statement
The receipt of help can make some animals more likely to provide help in return, whether it be a singular act, or many acts accumulated over months. Similarly, the receipt of help, be it one act of aid, or a group’s worth of help over time, can make some animals more likely to pay help forward to others. Studies on Old World monkeys suggest females may give grooming and in return receive aid in future physical conflicts. Using a playback experiment, we found female rhesus macaques were not more responsive to calls for intervention in a simulated conflict after being groomed by unrelated females, even if the calling combatant was her most recent, or a long-time grooming partner. Our results suggest females in our study population may be receiving benefits other than support in conflicts for the grooming they provide.
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Sekizawa M, Kutsukake N. Pattern, function and constraint of infant handling in wild Japanese macaques. Ethology 2022. [DOI: 10.1111/eth.13274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maisa Sekizawa
- Department of Evolutionary Studies of Biosystems The Graduate University for Advanced Studies SOKENDAI Kanagawa Japan
| | - Nobuyuki Kutsukake
- Department of Evolutionary Studies of Biosystems The Graduate University for Advanced Studies SOKENDAI Kanagawa Japan
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