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Holmes KG, Krützen M, Ridley AR, Allen SJ, Connor RC, Gerber L, Flaherty Stamm C, King SL. Juvenile social play predicts adult reproductive success in male bottlenose dolphins. Proc Natl Acad Sci U S A 2024; 121:e2305948121. [PMID: 38857400 PMCID: PMC11194510 DOI: 10.1073/pnas.2305948121] [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: 04/14/2023] [Accepted: 03/14/2024] [Indexed: 06/12/2024] Open
Abstract
For over a century, the evolution of animal play has sparked scientific curiosity. The prevalence of social play in juvenile mammals suggests that play is a beneficial behavior, potentially contributing to individual fitness. Yet evidence from wild animals supporting the long-hypothesized link between juvenile social play, adult behavior, and fitness remains limited. In Western Australia, adult male bottlenose dolphins (Tursiops aduncus) form multilevel alliances that are crucial for their reproductive success. A key adult mating behavior involves allied males using joint action to herd individual females. Juveniles of both sexes invest significant time in play that resembles adult herding-taking turns in mature male (actor) and female (receiver) roles. Using a 32-y dataset of individual-level association patterns, paternity success, and behavioral observations, we show that juvenile males with stronger social bonds are significantly more likely to engage in joint action when play-herding in actor roles. Juvenile males also monopolized the actor role and produced an adult male herding vocalization ("pops") when playing with females. Notably, males who spent more time playing in the actor role as juveniles achieved more paternities as adults. These findings not only reveal that play behavior provides male dolphins with mating skill practice years before they sexually mature but also demonstrate in a wild animal population that juvenile social play predicts adult reproductive success.
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Affiliation(s)
- Kathryn G. Holmes
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
| | - Michael Krützen
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich8057, Switzerland
| | - Amanda R. Ridley
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
| | - Simon J. Allen
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich8057, Switzerland
- School of Biological Sciences, University of Bristol, BristolBS8 1TQ, United Kingdom
| | - Richard C. Connor
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- Biology Department, University of Massachusetts Dartmouth, North Dartmouth, MA02747
- Department of Biological Sciences and Institute of Environment, Florida International University, North Miami, FL33181
| | - Livia Gerber
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich8057, Switzerland
- Australian National Wildlife Collection, National Research Collections Australia, Commonwealth Scientific and Industrial Research Organisation, Canberra, ACT2601, Australia
| | | | - Stephanie L. King
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- School of Biological Sciences, University of Bristol, BristolBS8 1TQ, United Kingdom
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2
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Matrai E. Experiments with a set of cooperative enrichment devices used by groups of Indo-Pacific bottlenose dolphins. Biol Futur 2024; 75:193-197. [PMID: 38710982 DOI: 10.1007/s42977-024-00218-2] [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: 01/04/2024] [Accepted: 04/10/2024] [Indexed: 05/08/2024]
Abstract
Dolphins in the wild cooperate to find food, gain and maintain access to mating partners, look after their young ones, or for the sheer joy of play. Under human care, environmental enrichments provide mental and physical stimulation and opportunities for the dolphins to practice their natural abilities. In this review, I focus on a set of enrichment devices we designed for cooperative problem-solving. They allowed the dolphins to utilize and improve their cognitive skills, leading to improved socialization within the group. While the devices provided appropriate challenges to the dolphins, they also allowed the investigation of the impact of demographic and social factors on the cooperative actions. We found that age and relatedness had no impact on cooperation; in turn, cooperation increased with group size. In addition, during the use of these cognitive enrichments, partner preference and intersexual differences were revealed in cooperative actions. The novel multi-partner devices were not only used by dolphin pairs but also by dolphin trios and quartets, providing evidence for group-level cooperation. In addition, a novel food-sharing device was used prosocially by dolphin pairs. Finally, the introduction of these cognitive enrichments leads to measurable short- and long-term welfare improvement. Thus, the use of these cognitive enrichments paired with systematic data collection bridged science with welfare. Future studies will investigate intersexual differences in independent groups, the emergence and function of cooperative interactions, and the socio-dynamics using cognitive enrichments.
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Affiliation(s)
- Eszter Matrai
- Research Department, Ocean Park Hong Kong, 180 Wong Chuk Hang Road, Aberdeen, Hong Kong S.A.R..
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3
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Freiburger T, Miller N, Skinner M. Olfactory self-recognition in two species of snake. Proc Biol Sci 2024; 291:20240125. [PMID: 38565155 PMCID: PMC10987230 DOI: 10.1098/rspb.2024.0125] [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: 01/15/2024] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Mark tests, in which an animal uses a mirror to locate and examine an otherwise unnoticeable mark on its own body, are commonly used to assess self-recognition, which may have implications for self-awareness. Recently, several olfactory-reliant species have appeared to pass odour-based versions of the mark test, though it has never been attempted in reptiles. We conducted an odour-based mark test on two species of snakes, Eastern gartersnakes and ball pythons, with widely divergent ecologies (i.e. terrestrial foragers that communally brumate versus semi-arboreal ambush predators that do not). We find that gartersnakes, but not ball pythons, pass the test, and a range of control tests suggest this is based on self-recognition. Gartersnakes are more social than ball pythons, supporting recent suggestions that social species are more likely to self-recognize. These results open the door to examination of the ecology of self-recognition, and suggest that this ability may evolve in response to species-specific ecological challenges, some of which may align with complexity of social structures.
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Affiliation(s)
- Troy Freiburger
- Department of Psychology, Wilfrid Laurier University, Waterloo, ON, Canada N2L 3C5
| | - Noam Miller
- Department of Psychology, Wilfrid Laurier University, Waterloo, ON, Canada N2L 3C5
| | - Morgan Skinner
- Department of Psychology, Wilfrid Laurier University, Waterloo, ON, Canada N2L 3C5
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4
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Friedman WR, Krützen M, King SL, Allen SJ, Gerber L, Wittwer S, Connor RC. Inter-group alliance dynamics in Indo-Pacific bottlenose dolphins (Tursiops aduncus). Anim Cogn 2023; 26:1601-1612. [PMID: 37391478 PMCID: PMC10442264 DOI: 10.1007/s10071-023-01804-y] [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: 01/10/2023] [Revised: 06/16/2023] [Accepted: 06/18/2023] [Indexed: 07/02/2023]
Abstract
The social intelligence hypothesis holds that complex social relationships are the major selective force underlying the evolution of large brain size and intelligence. Complex social relationships are exemplified by coalitions and alliances that are mediated by affiliative behavior, resulting in differentiated but shifting relationships. Male Indo-Pacific bottlenose dolphins in Shark Bay, Australia, form three alliance levels or 'orders', primarily among non-relatives. Strategic alliance formation has been documented within both first- and second-order alliances and between second-order alliances ('third-order alliances'), revealing that the formation of strategic inter-group alliances is not limited to humans. Here we conducted a fine-scale study on 22 adult males over a 6-year period to determine if third-order alliance relationships are differentiated, and mediated by affiliative interactions. We found third-order alliance relationships were strongly differentiated, with key individuals playing a disproportionate role in maintaining alliances. Nonetheless, affiliative interactions occurred broadly between third-order allies, indicating males maintain bonds with third-order allies of varying strength. We also documented a shift in relationships and formation of a new third-order alliance. These findings further our understanding of dolphin alliance dynamics and provide evidence that strategic alliance formation is found in all three alliance levels, a phenomenon with no peer among non-human animals.
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Affiliation(s)
- Whitney R Friedman
- Department of Environmental Studies, University of California Santa Cruz, Santa Cruz, 95064, USA.
- Department of Cognitive Science, University of California San Diego, San Diego, 92093, USA.
| | - Michael Krützen
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich, Switzerland
| | - Stephanie L King
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
- School of Biological Sciences, University of Western Australia, Crawley, WA, 6009, Australia
| | - Simon J Allen
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich, Switzerland
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
- School of Biological Sciences, University of Western Australia, Crawley, WA, 6009, Australia
| | - Livia Gerber
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich, Switzerland
- Australian National Wildlife Collection, National Research Collections Australia, CSIRO, Canberra, ACT, 2601, Australia
| | - Samuel Wittwer
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich, Switzerland
| | - Richard C Connor
- Biology Department, University of Massachusetts Dartmouth, North Dartmouth, MA, 02747, USA.
- Institute of Environment and Department of Biological Sciences, Florida International University, North Miami, FL, 33181, USA.
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5
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Bigiani S, Pilenga C. Cooperation increases bottlenose dolphins' (Tursiops truncatus) social affiliation. Anim Cogn 2023:10.1007/s10071-023-01781-2. [PMID: 37140723 DOI: 10.1007/s10071-023-01781-2] [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: 09/08/2022] [Revised: 04/20/2023] [Accepted: 04/26/2023] [Indexed: 05/05/2023]
Abstract
Dolphins live in a fission-fusion society, where strong social bonds and alliances can last for decades. However, the mechanism that allows dolphins to form such strong social bonds is still unclear. Here, we hypothesized the existence of a positive feedback mechanism in which social affiliation promotes dolphins' cooperation, which in turn promotes their social affiliation. To test it, we stimulated the cooperation of the 11 dolphins studied by providing a cooperative enrichment tool based on a rope-pulling task to access a resource. Then we measured the social affiliation [simple ratio index (SRI)] of each possible pair of dolphins and evaluated whether it increased after cooperation. We also evaluated whether, before cooperation, pairs that cooperated had a higher SRI than those that did not cooperate. Our findings showed that the 11 cooperating pairs had significantly stronger social affiliation before cooperation than the 15 non-cooperating pairs. Furthermore, cooperating pairs significantly increased their social affiliation after cooperation, while non-cooperating pairs did not. As a result, our findings provide support to our hypothesis, and suggest that the previous social affiliation between dolphins facilitates cooperation, which in turn promotes their social affiliation.
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6
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Fox SA, Muller MN, González NT, Enigk DK, Machanda ZP, Otali E, Wrangham R, Thompson ME. Weak, but not strong, ties support coalition formation among wild female chimpanzees. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210427. [PMID: 36440557 PMCID: PMC9703227 DOI: 10.1098/rstb.2021.0427] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/23/2022] [Indexed: 11/29/2022] Open
Abstract
In social species, individuals may be able to overcome competitive constraints on cooperation by leveraging relationships with familiar, tolerant partners. While strong social ties have been linked to cooperation in several social mammals, it is unclear the extent to which weak social ties can support cooperation, particularly among non-kin. We tested the hypothesis that weakly affiliative social relationships support cooperative coalition formation using 10 years of behavioural data on wild female chimpanzees. Female chimpanzees typically disperse and reside with non-kin as adults. Their social relationships are differentiated but often relatively weak, with few dyads sharing strong bonds. Females occasionally form aggressive coalitions together. Three measures of relationship quality-party association, five-metre proximity and whether a dyad groomed-positively predicted coalitions, indicating that relationship quality influenced coalition partnerships. However, dyads that groomed frequently did not form more coalitions than dyads that groomed occasionally, and kin did not cooperate more than expected given their relationship quality. Thus, strong bonds and kinship did not bolster cooperation. We conclude that cooperative coalitions among female chimpanzees depend on social tolerance but do not require strong bonds. Our findings highlight social tolerance as a distinct pathway through which females can cultivate cooperative relationships. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- Stephanie A. Fox
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Martin N. Muller
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Nicole Thompson González
- Department of Anthropology, University of California Santa Barbara, Santa Barbara, CA 93106-3210, USA
| | - Drew K. Enigk
- Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Zarin P. Machanda
- Department of Anthropology, Tufts University, Medford, MA 02155, USA
| | - Emily Otali
- Kibale Chimpanzee Project, Fort Portal, Uganda
| | - Richard Wrangham
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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7
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Connor RC, Krützen M, Allen SJ, Sherwin WB, King SL. Strategic intergroup alliances increase access to a contested resource in male bottlenose dolphins. Proc Natl Acad Sci U S A 2022; 119:e2121723119. [PMID: 36037370 PMCID: PMC9457541 DOI: 10.1073/pnas.2121723119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 07/24/2022] [Indexed: 11/18/2022] Open
Abstract
Efforts to understand human social evolution rely largely on comparisons with nonhuman primates. However, a population of bottlenose dolphins in Shark Bay, Western Australia, combines a chimpanzee-like fission-fusion grouping pattern, mating system, and life history with the only nonhuman example of strategic multilevel male alliances. Unrelated male dolphins form three alliance levels, or "orders", in competition over females: both within-group alliances (i.e., first- and second-order) and between-group alliances (third-order), based on cooperation between two or more second-order alliances against other groups. Both sexes navigate an open society with a continuous mosaic of overlapping home ranges. Here, we use comprehensive association and consortship data to examine fine-scale alliance relationships among 121 adult males. This analysis reveals the largest nonhuman alliance network known, with highly differentiated relationships among individuals. Each male is connected, directly or indirectly, to every other male, including direct connections with adult males outside of their three-level alliance network. We further show that the duration with which males consort females is dependent upon being well connected with third-order allies, independently of the effect of their second-order alliance connections, i.e., alliances between groups increase access to a contested resource, thereby increasing reproductive success. Models of human social evolution traditionally link intergroup alliances to other divergent human traits, such as pair bonds, but our study reveals that intergroup male alliances can arise directly from a chimpanzee-like, promiscuous mating system without one-male units, pair bonds, or male parental care.
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Affiliation(s)
- Richard C. Connor
- Biology Department, University of Massachusetts Dartmouth, North Dartmouth, MA 02747
- Department of Biological Sciences, Marine Sciences Program, Florida International University, North Miami, FL 33181
| | - Michael Krützen
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, CH-8057 Zurich, Switzerland
| | - Simon J. Allen
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, CH-8057 Zurich, Switzerland
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, United Kingdom
- School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - William B. Sherwin
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephanie L. King
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, United Kingdom
- School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
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8
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Reproductive timing as an explanation for skewed parentage assignment ratio in a bisexually philopatric population. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03233-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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9
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Tai YM, Chen MM, Zhang YH, Ma AX, Wang H, Wang X. Social Rank or Social Bonds: Which one Facilitates Coalition Formation in Male Tibetan Macaques? BIOLOGY 2022; 11:1269. [PMID: 36138747 PMCID: PMC9495305 DOI: 10.3390/biology11091269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/21/2022] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Previous studies have shown that fierce competition could promote male coalitions. There are two ways for males to choose their allies in the conflict. The first is that supporters choose high-ranking individuals, and the second is that supporters choose affiliated individuals. It is necessary to clarify the factors for forming a coalition and the process of cooperation in primates with complex relationships and strict hierarchies. Thus, we conducted a study on a group of free-ranging Tibetan macaques (Macaca thibetana) in Anhui, China, and recorded the whole process of male macaques forming coalitions once agonistic support occurred. The results showed that a higher intensity of the social bond between males was associated with more frequent coalitions. Dominance rank also significantly influenced male coalitions, showing that high-ranking individuals allied more frequently. Moreover, males with longer residence times formed more stable coalitions. We suggest that male Tibetan macaques form a stable social relationship, where social bond and social rank both promote the formation of a coalition. This study provided some insights into the mechanism by which social cooperation develops in multi-male and multi-female groups.
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Affiliation(s)
- Yi-Mei Tai
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral Ecology, Hefei 230601, China
| | - Meng-Meng Chen
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral Ecology, Hefei 230601, China
| | - Yu-Heng Zhang
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral Ecology, Hefei 230601, China
| | - An-Xiang Ma
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Huan Wang
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Xi Wang
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral Ecology, Hefei 230601, China
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10
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Lee VE, Arnott G, Turner SP. Social behavior in farm animals: Applying fundamental theory to improve animal welfare. Front Vet Sci 2022; 9:932217. [PMID: 36032304 PMCID: PMC9411962 DOI: 10.3389/fvets.2022.932217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
A fundamental understanding of behavior is essential to improving the welfare of billions of farm animals around the world. Despite living in an environment managed by humans, farm animals are still capable of making important behavioral decisions that influence welfare. In this review, we focus on social interactions as perhaps the most dynamic and challenging aspects of the lives of farm animals. Social stress is a leading welfare concern in livestock, and substantial variation in social behavior is seen at the individual and group level. Here, we consider how a fundamental understanding of social behavior can be used to: (i) understand agonistic and affiliative interactions in farm animals; (ii) identify how artificial environments influence social behavior and impact welfare; and (iii) provide insights into the mechanisms and development of social behavior. We conclude by highlighting opportunities to build on previous work and suggest potential fundamental hypotheses of applied relevance. Key areas for further research could include identifying the welfare benefits of socio–positive interactions, the potential impacts of disrupting important social bonds, and the role of skill in allowing farm animals to navigate competitive and positive social interactions. Such studies should provide insights to improve the welfare of farm animals, while also being applicable to other contexts, such as zoos and laboratories.
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Affiliation(s)
- Victoria E. Lee
- Animal Behaviour and Welfare, Animal and Veterinary Sciences Department, Scotland's Rural College (SRUC), Edinburgh, United Kingdom
- *Correspondence: Victoria E. Lee
| | - Gareth Arnott
- Institute for Global Food Security, School of Biological Sciences, Queen's University, Belfast, United Kingdom
| | - Simon P. Turner
- Animal Behaviour and Welfare, Animal and Veterinary Sciences Department, Scotland's Rural College (SRUC), Edinburgh, United Kingdom
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11
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Danaher-Garcia N, Connor R, Fay G, Melillo-Sweeting K, Dudzinski KM. The partial merger of two dolphin societies. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211963. [PMID: 35950199 PMCID: PMC9346368 DOI: 10.1098/rsos.211963] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 07/11/2022] [Indexed: 05/17/2023]
Abstract
Interactions between mammalian social groups are generally antagonistic as individuals in groups cooperate to defend resources from non-members. Members of the family Delphinidae inhabit a three-dimensional habitat where resource defence is usually impractical. Here, we describe a long-term partial fusion of two communities of Atlantic spotted dolphins (Stenella frontalis). The northern community, studied for 30 years, immigrated 160 km to the range of the southern community, observed for 20 years. Both communities featured fission-fusion grouping patterns, strongest associations between adult males, and frequent affiliative contact between individuals. For the 5-year period following the immigration, we found members of all age classes and both sexes in mixed groups, but there was a strong bias toward finding immigrant males in mixed groups. Some association levels between males, and males and females, from different communities were as high as the highest within-community associations. Affiliative contacts indicate that these individuals were forming social relationships. The mixing of two separate social groups with new bond formation is rare in terrestrial mammal groups. Such mixing between spotted dolphin groups suggests that adaptations to respond aggressively to 'outsiders' are diminished in this species and possibly other ecologically similar dolphins.
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Affiliation(s)
- Nicole Danaher-Garcia
- Department of Biological Sciences, Institute of the Environment, Florida International University, 3000 NE 151st Street, North Miami, FL 33181, USA
- Dolphin Communication Project, PO Box 7485, Port Saint Lucie, FL 34984, USA
- University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, MA, USA
| | - Richard Connor
- Dolphin Alliance Project, PO Box 6449, New Bedford, MA 02742, USA
| | - Gavin Fay
- School for Marine Science and Technology, University of Massachusetts Dartmouth, 836 S Rodney French Boulevard, New Bedford, MA 02744, USA
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12
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Crespi BJ, Flinn MV, Summers K. Runaway Social Selection in Human Evolution. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.894506] [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
Darwin posited that social competition among conspecifics could be a powerful selective pressure. Alexander proposed a model of human evolution involving a runaway process of social competition based on Darwin’s insight. Here we briefly review Alexander’s logic, and then expand upon his model by elucidating six core arenas of social selection that involve runaway, positive-feedback processes, and that were likely involved in the evolution of the remarkable combination of adaptations in humans. We discuss how these ideas fit with the hypothesis that a key life history innovation that opened the door to runaway social selection, and cumulative culture, during hominin evolution was increased cooperation among individuals in small fission-fusion groups.
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13
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Gerber L, Connor RC, Allen SJ, Horlacher K, King SL, Sherwin WB, Willems EP, Wittwer S, Krützen M. Social integration influences fitness in allied male dolphins. Curr Biol 2022; 32:1664-1669.e3. [PMID: 35334228 DOI: 10.1016/j.cub.2022.03.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/10/2022] [Accepted: 03/09/2022] [Indexed: 12/26/2022]
Abstract
Understanding determinants of differential reproductive success is at the core of evolutionary biology because of its connection to fitness. Early work has linked variation in reproductive success to differences in age,1 rank,2 or size,3,4 as well as habitat characteristics.5 More recently, studies in group-living taxa have revealed that social relationships also have measurable effects on fitness.6-8 The influence of social bonds on fitness is particularly interesting in males who compete over reproductive opportunities. In Shark Bay, Western Australia, groups of 4-14 unrelated male bottlenose dolphins cooperate in second-order alliances to compete with rival alliances over access to females.9-12 Nested within second-order alliances, pairs or trios of males, which can vary in composition, form first-order alliances to herd estrus females. Using 30 years of behavioral data, we examined how individual social factors, such as first-order alliance stability, social connectivity, and variation in social bond strength within second-order alliances, affect male fitness. Analyzing the reproductive careers of 85 males belonging to 10 second-order alliances, we found that the number of paternities a male achieved was positively correlated with his cumulative social bond strength but negatively correlated with his variation in bond strength. Thus, well-integrated males with more homogeneous social bonds to second-order allies obtained most paternities. Our findings provide novel insights into the fitness benefits of polyadic cooperation among unrelated males and highlight the adaptive value of social bonds in this context.
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Affiliation(s)
- Livia Gerber
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW, Sydney, NSW 2052, Australia.
| | - Richard C Connor
- Biology Department, UMASS Dartmouth, North Dartmouth, MA 02747, USA; Department of Biological Sciences, Marine Sciences Program, Florida International University, North Miami, FL 33181, USA
| | - Simon J Allen
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland; School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK; School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Kay Horlacher
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland
| | - Stephanie L King
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK; School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - William B Sherwin
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW, Sydney, NSW 2052, Australia
| | - Erik P Willems
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland
| | - Samuel Wittwer
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland
| | - Michael Krützen
- Evolutionary Genetics Group, Department of Anthropology, University of Zurich, 8057 Zurich, Switzerland
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Allied male dolphins use vocal exchanges to "bond at a distance". Curr Biol 2022; 32:1657-1663.e4. [PMID: 35334229 DOI: 10.1016/j.cub.2022.02.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/20/2022] [Accepted: 02/03/2022] [Indexed: 11/22/2022]
Abstract
Vocal interactions are intrinsic features of social groups and can play a pivotal role in social bonding.1,2 Dunbar's social bonding hypothesis posits that vocal exchanges evolved to "groom at a distance" when social groups became too large or complex for individuals to devote time to physical bonding activities.1,3 Tests of this hypothesis in non-human primates, however, suggest that vocal exchanges occur between more strongly bonded individuals that engage in higher grooming rates4-7 and thus do not provide evidence for replacement of physical bonding. Here, we combine data on social bond strength, whistle exchange frequency, and affiliative contact behavior rates to test this hypothesis in wild male Indo-Pacific bottlenose dolphins, who form multi-level alliances that cooperate over access to females.8-10 We show that, although whistle exchanges are more likely to occur within the core alliance, they occur more frequently between those males that share weaker social bonds, i.e., between core allies that spend less time together, while the opposite occurs for affiliative physical contact behavior. This suggests that vocal exchanges function as a low-cost mechanism for male dolphins that spend less time in close proximity and engage in fewer affiliative contact behaviors to reinforce and maintain their valuable alliance relationships. Our findings provide new evidence outside of the primate lineage that vocal exchanges serve a bonding function and reveal that, as the social bonding hypothesis originally suggested, vocal exchanges can function as a replacement of physical bonding activities for individuals to maintain their important social relationships.
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Toyoda A, Maruhashi T, Kawamoto Y, Matsudaira K, Matsuda I, Malaivijitnond S. Mating and Reproductive Success in Free-Ranging Stump-Tailed Macaques: Effectiveness of Male–Male Coalition Formation as a Reproductive Strategy. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.802012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Male coalition-like formation, recently found in stump-tailed macaques (Macaca arctoides), occurs when several top-ranking males collaboratively guard females to prevent mating with other rival males and actively share secured mating opportunities with their allies. We lack a comprehensive understanding of the proximate mechanisms underlying such male coalitions, e.g., the effect of genetic relatedness. Such cooperative partner choice among males is particularly interesting in animals, such as M. arctoides, that live in matrilineal (female philopatry/male dispersal) society. Theoretically, in such a social system, females, and not males, are often related to each other by kinship. Thus, the occurrence of cooperative behavior between related females are generally common, but it would be rare between unrelated/non-kin males in such matrilineal society. Herein, for the first time, we report detailed copulatory behaviors, including mating and reproductive success, in relation to male coalition-like formation in free-ranging M. arctoides following direct behavioral observation and genetic analysis. We found that coalition-forming male–male alliances often occur among both individuals that are highly related and those that are less related. We identified two groups with different mating strategies, i.e., single-male monopoly and coalition-male monopoly groups. In both groups, nearly 80% of copulations were monopolized by a single male or by coalition males. However, the single-male monopoly strategy allows opportunistic/sneaky copulations by other males with a relatively high probability. Thus, the degree of reproductive success did not reflect mating success. In contrast, the males employing a coalition strategy successfully shared their mating and reproductive success, particularly in the largest group. Compared with single-male monopolized groups, the coalition-male monopoly groups copulated with a considerably more number of females, suggesting that coalition males can effectively guard against opportunistic/sneaky copulation by rival males. We also found that coalition-forming male–male alliances often occur regardless of the degree of kinship/relatedness, indicating the complexity and flexibility inherent in the male social bond of M. arctoides.
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Matrai E, Kwok ST, Boos M, Pogány Á. Testing use of the first multi-partner cognitive enrichment devices by a group of male bottlenose dolphins. Anim Cogn 2022; 25:961-973. [PMID: 35146593 DOI: 10.1007/s10071-022-01605-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 01/27/2022] [Accepted: 02/02/2022] [Indexed: 11/26/2022]
Abstract
Alliance formation plays a crucial part in male dolphins' lives. These partnerships may last for decades or even for a lifetime; thus, partner choice and the maintenance of these relationships are both considered key components of alliance formation. In our previous investigations, pairs of adult male dolphins showed a high success rate in cooperative manipulation of a cognitive enrichment device. Here, we introduced two novel cognitive enrichment devices to the group of five dolphins, facilitating simultaneous actions for not only pairs, but for three or even four dolphins. The devices were made of PVC tubes, fittings and caps equipped with rope handles, creating a three-way (T-shape) and a four-way (TT-shape) device. The devices were filled with fish and ice and were designed to be opened by simultaneous pull of the handles. Both devices were tested in 12 trials (each lasted for 15 min), separately. Only one of the caps could be opened, the others were affixed with the position of the openable cap counter-balanced over the trials. Although the dolphins received no training regarding the manipulation of the devices, they were successful in cooperatively opening the three-way devices in 10/12 of trials (70% by two and 30% by three dolphins) and the four-way devices also in 10/12 trials (50% by two, 40% by three and 10% by four dolphins). The dolphins interacted with the devices during the entire testing time, and this was mostly spent in cooperative play (77% and 56% of the test duration with the three-way and four-way device, respectively). The majority of the cooperative play was observed between one particular pair of dolphins that was temporarily associated with a third or sometimes even with a fourth dolphin. These findings demonstrate the first successful use of multi-partner cooperative enrichment devices, providing information on the social organization of a male dolphin group.
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Affiliation(s)
- Eszter Matrai
- Research Department, Ocean Park, Hong Kong, 180 Wong Chuk Hang Road, Aberdeen, Hong Kong.
- Department of Ethology, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary.
| | - Shaw Ting Kwok
- Research Department, Ocean Park, Hong Kong, 180 Wong Chuk Hang Road, Aberdeen, Hong Kong
| | - Michael Boos
- Research Department, Ocean Park, Hong Kong, 180 Wong Chuk Hang Road, Aberdeen, Hong Kong
| | - Ákos Pogány
- Department of Ethology, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest, 1117, Hungary
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