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Ovsyanikova E, McGovern B, Hawkins E, Huijser L, Dunlop R, Noad M. Balance between stability and variability in bottlenose dolphin signature whistles offers potential for additional information. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2025; 157:2982-2993. [PMID: 40249179 DOI: 10.1121/10.0036433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2024] [Accepted: 03/26/2025] [Indexed: 04/19/2025]
Abstract
Bottlenose dolphins produce individually distinctive signature whistles (SWs) to broadcast identity. Stability of the SW frequency contour is essential to preserve identity information; however, SWs could carry additional information which requires variability. We used acoustic recordings from provisioned free-swimming Indo-Pacific bottlenose dolphins at Moreton Island (Mulgumpin), Australia, collected in 2002 and 2017-2018, to assess the long-term (15-year) stability in SWs, and if variability of acoustic parameters increases with whistle complexity. Stability was assessed by analyzing basic contour parameters (minimum and maximum frequency, duration, etc.) and visually. We quantified SW variability using two developed variability metrics. Complexity was defined using four developed metrics, and its effect on variability was tested. Our results demonstrated that SW contours remain highly stable over time, but minimum frequency decreased by 8.8%. SWs also showed different degrees of variability between individuals. Variability appeared to be higher in males than in females, possibly indicating differences in SW use in different social contexts. Furthermore, SWs with a greater level of frequency modulation varied more than less modulated whistles. We propose that SWs possess sufficient variation in their frequency contour to contain additional information, possibly related to social and behavioral context, while still maintaining their identity function.
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Affiliation(s)
- Ekaterina Ovsyanikova
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
- School of the Environment, The University of Queensland, Brisbane, Queensland 4167, Australia
| | - Barry McGovern
- Pacific Whale Foundation, Urangan, Queensland 4655, Australia
| | - Elizabeth Hawkins
- Dolphin Research Australia, Byron Bay, New South Wales 2481, Australia
| | - Léonie Huijser
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
| | - Rebecca Dunlop
- School of the Environment, The University of Queensland, Brisbane, Queensland 4167, Australia
| | - Michael Noad
- School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia
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2
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Chereskin E, Allen SJ, Connor RC, Krützen M, King SL. In pop pursuit: social bond strength predicts vocal synchrony during cooperative mate guarding in bottlenose dolphins. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230194. [PMID: 38768196 PMCID: PMC11391284 DOI: 10.1098/rstb.2023.0194] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 02/09/2024] [Accepted: 02/27/2024] [Indexed: 05/22/2024] Open
Abstract
Vocal communication is an emblematic feature of group-living animals, used to share information and strengthen social bonds. Vocalizations are also used to coordinate group-level behaviours in many taxa, but little is known of the factors that may influence vocal behaviour during cooperative acts. Allied male Indo-Pacific bottlenose dolphins (Tursiops aduncus) use the 'pop' vocalization as a coercive signal when working together to herd single oestrous females. Using long-term association and acoustic data, we examined the influence of social and non-social factors on pop use by allied male dolphins in this context. Neither pop rate nor pop bout duration were influenced by any of the factors examined. However, allied males with stronger social bonds engaged in higher rates of vocal synchrony; whereby they actively matched the timing of their pop production. Hence, social bond strength influenced pop use in a cooperative context, suggesting dual functions of pop use: to induce the female to remain close, and to promote social bond maintenance and cooperation among males. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
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Affiliation(s)
- Emma Chereskin
- School of Biological Sciences, University of Bristol , Bristol BS8 1TQ, UK
| | - Simon J Allen
- School of Biological Sciences, University of Bristol , Bristol BS8 1TQ, UK
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich , Zurich CH-8057, Switzerland
- School of Biological Sciences, University of Western Australia , Crawley WA 6009, Australia
| | - 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
| | - Michael Krützen
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich , Zurich CH-8057, Switzerland
- School of Biological Sciences, University of Western Australia , Crawley WA 6009, Australia
| | - 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
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3
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Briefer EF, Xie B, Engesser S, Sueur C, Freeberg TM, Brask JB. The power of sound: unravelling how acoustic communication shapes group dynamics. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230182. [PMID: 38768200 PMCID: PMC11391312 DOI: 10.1098/rstb.2023.0182] [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: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 05/22/2024] Open
Abstract
Acoustic signalling is a key mode of communication owing to its instantaneousness and rapid turnover, its saliency and flexibility and its ability to function strategically in both short- and long-range contexts. Acoustic communication is closely intertwined with both collective behaviour and social network structure, as it can facilitate the coordination of collective decisions and behaviour, and play an important role in establishing, maintaining and modifying social relationships. These research topics have each been studied separately and represent three well-established research areas. Yet, despite the close connection of acoustic communication with collective behaviour and social networks in natural systems, only few studies have focused on their interaction. The aim of this theme issue is therefore to build a foundation for understanding how acoustic communication is linked to collective behaviour, on the one hand, and social network structure on the other, in non-human animals. Through the building of such a foundation, our hope is that new questions in new avenues of research will arise. Understanding the links between acoustic communication and social behaviour seems crucial for gaining a comprehensive understanding of sociality and social evolution. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
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Affiliation(s)
- Elodie F Briefer
- Behavioural Ecology Group, Section for Ecology & Evolution, Department of Biology, University of Copenhagen , Copenhagen 2100, Denmark
| | - Bing Xie
- Behavioural Ecology Group, Section for Ecology & Evolution, Department of Biology, University of Copenhagen , Copenhagen 2100, Denmark
| | - Sabrina Engesser
- Behavioural Ecology Group, Section for Ecology & Evolution, Department of Biology, University of Copenhagen , Copenhagen 2100, Denmark
| | - Cedric Sueur
- Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, CNRS, UMR 7178 , Strasbourg 67087, France
| | - Todd M Freeberg
- Department of Psychology and Department of Ecology and Evolutionary Biology, University of Tennessee , Knoxville, TN 37996, USA
| | - Josefine Bohr Brask
- Behavioural Ecology Group, Section for Ecology & Evolution, Department of Biology, University of Copenhagen , Copenhagen 2100, Denmark
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4
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Iacopini I, Foote JR, Fefferman NH, Derryberry EP, Silk MJ. Not your private tête-à-tête: leveraging the power of higher-order networks to study animal communication. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230190. [PMID: 38768202 PMCID: PMC11391305 DOI: 10.1098/rstb.2023.0190] [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: 08/31/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 05/22/2024] Open
Abstract
Animal communication is frequently studied with conventional network representations that link pairs of individuals who interact, for example, through vocalization. However, acoustic signals often have multiple simultaneous receivers, or receivers integrate information from multiple signallers, meaning these interactions are not dyadic. Additionally, non-dyadic social structures often shape an individual's behavioural response to vocal communication. Recently, major advances have been made in the study of these non-dyadic, higher-order networks (e.g. hypergraphs and simplicial complexes). Here, we show how these approaches can provide new insights into vocal communication through three case studies that illustrate how higher-order network models can: (i) alter predictions made about the outcome of vocally coordinated group departures; (ii) generate different patterns of song synchronization from models that only include dyadic interactions; and (iii) inform models of cultural evolution of vocal communication. Together, our examples highlight the potential power of higher-order networks to study animal vocal communication. We then build on our case studies to identify key challenges in applying higher-order network approaches in this context and outline important research questions that these techniques could help answer. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
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Affiliation(s)
- Iacopo Iacopini
- Network Science Institute, Northeastern University London , London, E1W 1LP, UK
- Department of Physics, Northeastern University , Boston, MA 02115, USA
| | | | - Nina H Fefferman
- Department of Ecology and Evolutionary Biology, University of Tennessee , Knoxville, TN, USA
- Department of Mathematics, University of Tennessee , Knoxville, TN, USA
- NIMBioS, University of Tennessee , Knoxville, TN, USA
| | - Elizabeth P Derryberry
- Department of Ecology and Evolutionary Biology, University of Tennessee , Knoxville, TN, USA
| | - Matthew J Silk
- CEFE, Univ Montpellier, CNRS, EPHE, IRD , Montpellier, France
- Institute of Ecology and Evolution, University of Edinburgh , Edinburgh, UK
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5
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Xie B, Brask JB, Dabelsteen T, Briefer EF. Exploring the role of vocalizations in regulating group dynamics. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230183. [PMID: 38768197 PMCID: PMC11391291 DOI: 10.1098/rstb.2023.0183] [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: 08/31/2023] [Revised: 12/15/2023] [Accepted: 02/14/2024] [Indexed: 05/22/2024] Open
Abstract
Because of the diverging needs of individuals, group life can lead to disputes and competition, but it also has many advantages, such as reduced predation risk, information sharing and increased hunting success. Social animals have to maintain group cohesion and need to synchronize activities, such as foraging, resting, social interactions and movements, in order to thrive in groups. Acoustic signals are highly relevant for social dynamics, some because they are long-ranging and others because they are short-ranging, which may serve important within-group functions. However, although there has been an increase in studies concentrating on acoustic communication within groups in the past decade, many aspects of how vocalizations relate to group dynamics are still poorly understood. The aim of this review is to present an overview of our current knowledge on the role of vocalizations in regulating social group dynamics, identify knowledge gaps and recommend potential future research directions. We review the role that vocalizations play in (i) collective movement, (ii) separation risk and cohesion maintenance, (iii) fission-fusion dynamics, and (iv) social networks. We recommend that future studies aim to increase the diversity of studied species and strengthen the integration of state-of-the-art tools to study social dynamics and acoustic signals. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
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Affiliation(s)
- Bing Xie
- Behavioural Ecology Group, Section for Ecology and Evolution, University of Copenhagen , Copenhagen, 2100, Denmark
| | - Josefine B Brask
- Behavioural Ecology Group, Section for Ecology and Evolution, University of Copenhagen , Copenhagen, 2100, Denmark
| | - Torben Dabelsteen
- Behavioural Ecology Group, Section for Ecology and Evolution, University of Copenhagen , Copenhagen, 2100, Denmark
| | - Elodie F Briefer
- Behavioural Ecology Group, Section for Ecology and Evolution, University of Copenhagen , Copenhagen, 2100, Denmark
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6
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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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7
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Gallo A, De Moura Lima A, Böye M, Hausberger M, Lemasson A. Study of repertoire use reveals unexpected context-dependent vocalizations in bottlenose dolphins (Tursiops truncatus). THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 2023; 110:56. [PMID: 38060031 DOI: 10.1007/s00114-023-01884-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 12/08/2023]
Abstract
Dolphins are known for their complex vocal communication, not least because of their capacity for acoustic plasticity. Paradoxically, we know little about their capacity for flexible vocal use. The difficulty in describing the behaviours performed underwater while vocalizing makes it difficult to analyse the contexts of emissions. Dolphins' main vocal categories are typically considered to be used for scanning the environment (clicks), agonistic encounters (burst pulses) and socio-affiliative interactions (whistles). Dolphins can also combine these categories in mixed vocal emissions, whose use remains unclear. To better understand how vocalizations are used, we simultaneously recorded vocal production and the associated behaviours by conducting underwater observations (N = 479 events) on a group of 7 bottlenose dolphins under human care. Our results showed a non-random association between vocal categories and behavioural contexts. Precisely, clicks were preferentially emitted during affiliative interactions and not during other social/solitary contexts, supporting a possible complementary communicative function. Burst pulses were associated to high arousal contexts (agonistic and social play), pinpointing on their use as an "emotively charged" signal. Whistles were related to solitary swimming and not preferentially produced in any social context. This questions whistles' functions and supports their potential role as a distant contact call. Finally, mixed vocalizations were especially found associated with sexual (bust pulse-whistle-click), solitary play (burst pulse-whistle) and affiliative (click-whistle) behaviours. Depending on the case, their emission seems to confirm, modify or refine the functions of their simple counterparts. These results open up new avenues of research into the contextual use of dolphin acoustic signals.
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Affiliation(s)
- Alessandro Gallo
- Laboratoire d'Ethologie Animale Et Humaine, Université de Rennes, Université de Caen-Normandie, UMR 6552, Rennes, France.
- UMR 8002, Integrative Center for Neuroscience and Cognition, Université de Paris Cité, Paris, France.
- Centre de Recherche Et d'Études Pour L'Animal Sauvage (CREAS), Port Saint Père, France.
| | - Alice De Moura Lima
- Laboratoire d'Ethologie Animale Et Humaine, Université de Rennes, Université de Caen-Normandie, UMR 6552, Rennes, France
- Centre de Recherche Et d'Études Pour L'Animal Sauvage (CREAS), Port Saint Père, France
| | - Martin Böye
- Centre de Recherche Et d'Études Pour L'Animal Sauvage (CREAS), Port Saint Père, France
| | - Martine Hausberger
- UMR 8002, Integrative Center for Neuroscience and Cognition, Université de Paris Cité, Paris, France
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Alban Lemasson
- Laboratoire d'Ethologie Animale Et Humaine, Université de Rennes, Université de Caen-Normandie, UMR 6552, Rennes, France
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8
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Anderson KL, Colón L, Doolittle V, Rosario Martinez R, Uraga J, Whitney O. Context-dependent activation of a social behavior brain network during learned vocal production. Brain Struct Funct 2023; 228:1785-1797. [PMID: 37615758 DOI: 10.1007/s00429-023-02693-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 08/01/2023] [Indexed: 08/25/2023]
Abstract
Neural activation in brain regions for vocal control is social context dependent. This context-dependent brain activation reflects social context-appropriate vocal behavior but has unresolved mechanisms. Studies of non-vocal social behaviors in multiple organisms suggest a functional role for several evolutionarily conserved and highly interconnected brain regions. Here, we use neural activity-dependent gene expression to evaluate the functional connectivity of this social behavior network within zebra finches in non-social and social singing contexts. We found that activity in one social behavior network region, the medial preoptic area (POM), was strongly associated with the amount of non-social undirected singing in zebra finches. In addition, in all regions of the social behavior network and the paraventricular nucleus (PVN), a higher percentage of EGR1 expression was observed during a social female-directed singing context compared to a non-social undirected singing context. Furthermore, we observed distinct patterns of significantly correlated activity between regions of the social behavior network during non-social undirected and social female-directed singing. Our results suggest that non-social vs. social contexts differentially activate this social behavior network and PVN. Moreover, neuronal activity within this social behavior network, PVN, and POM may alter context-appropriate vocal production.
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Affiliation(s)
- Katherine L Anderson
- Biology Department, City College, City University of New York, New York, NY, USA
- Graduate Center, Molecular, Cellular, and Developmental Biology Program, City University of New York, New York, NY, USA
| | - Lionel Colón
- Biology Department, City College, City University of New York, New York, NY, USA
| | - Violet Doolittle
- Biology Department, City College, City University of New York, New York, NY, USA
| | | | - Joseph Uraga
- Biology Department, City College, City University of New York, New York, NY, USA
| | - Osceola Whitney
- Biology Department, City College, City University of New York, New York, NY, USA.
- Graduate Center, Molecular, Cellular, and Developmental Biology Program, City University of New York, New York, NY, USA.
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9
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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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10
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Rege-Colt M, Oswald JN, De Weerdt J, Palacios-Alfaro JD, Austin M, Gagne E, Morán Villatoro JM, Sahley CT, Alvarado-Guerra G, May-Collado LJ. Whistle repertoire and structure reflect ecotype distinction of pantropical spotted dolphins in the Eastern Tropical Pacific. Sci Rep 2023; 13:13449. [PMID: 37596372 PMCID: PMC10439233 DOI: 10.1038/s41598-023-40691-8] [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: 03/13/2023] [Accepted: 08/16/2023] [Indexed: 08/20/2023] Open
Abstract
The pantropical spotted dolphin in the Eastern Tropical Pacific (ETP) is found in two genetically and phenotypically diverged ecotypes, coastal and offshore. These habitats have distinct acoustic characteristics, which can lead to the evolution of distinct acoustic communication. Whistles are sounds widely used by dolphins to mediate species and individual recognition and social interactions. Here, we study the whistle acoustic structure and repertoire diversity of offshore and coastal pantropical spotted dolphins. Our results show that there is significantly more within- and across-group variation in whistle fundamental frequency between ecotypes than between offshore groups and between coastal groups. A Random Forest classification analysis performed with an accuracy of 83.99% and identified duration, peak and minimum frequency as the most informative variables for distinguishing between ecotypes. Overall, coastal spotted dolphins produced significantly shorter whistles that were significantly lower in frequency (peak, minimum and maximum, and start and end) than offshore dolphins. Ecotypes produced whistle repertoires that were similar in diversity, but different in contour composition, with the coastal ecotype producing more upsweep whistles than offshore dolphins. The results of this study suggest that acoustic adaptations to coastal and offshore environments could be important contributors to intraspecific variation of dolphin whistle repertoires.
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Affiliation(s)
| | - Julie N Oswald
- Scottish Oceans Institute, Sea Mammal Research Unit, University of St. Andrews, St. Andrews, KY168LB, UK
| | - Joelle De Weerdt
- Association ELI-S, Education, Liberté, Indépendance - Scientifique, Allée de Verdalle 39, 33470, Gujan-Mestras, France
- Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium
| | | | - Maia Austin
- Biology Department, University of Vermont, Burlington, VT, USA
| | - Emma Gagne
- Biology Department, University of Vermont, Burlington, VT, USA
| | | | | | - Gilma Alvarado-Guerra
- Instituto para el Crecimiento Sostenible de la Empresa (ICSEM), C/Hogar Padre Vito Guarato, B1, San Salvador, El Salvador
| | - Laura J May-Collado
- Biology Department, University of Vermont, Burlington, VT, USA.
- Smithsonian Tropical Research Institute, Panama, Panama.
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11
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Davies JR, Garcia-Pelegrin E. Bottlenose dolphins are sensitive to human attentional features, including eye functionality. Sci Rep 2023; 13:12565. [PMID: 37532744 PMCID: PMC10397197 DOI: 10.1038/s41598-023-39031-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/19/2023] [Indexed: 08/04/2023] Open
Abstract
The ability to attribute attentional states to other individuals is a highly adaptive socio-cognitive skill and thus may have evolved in many social species. However, whilst humans excel in this ability, even chimpanzees appear to not accurately understand how visual attention works, particularly in regard to the function of eyes. The complex socio-ecological background and socio-cognitive skill-set of bottlenose dolphins (Tursiops sp.), alongside the specialised training that captive dolphins typically undergo, make them an especially relevant candidate for an investigation into their sensitivity to human attentional states. Therefore, we tested 8 bottlenose dolphins on an object retrieval task. The dolphins were instructed to fetch an object by a trainer under various attentional state conditions involving the trainer's eyes and face orientation: 'not looking', 'half looking', 'eyes open', and 'eyes closed'. As the dolphins showed an increased latency to retrieve the object in conditions where the trainer's head and eyes cued a lack of attention to the dolphin, particularly when comparing 'eyes open' vs 'eyes closed' conditions, we demonstrate that dolphins can be sensitive to human attentional features, namely the functionality of eyes. This study supports growing evidence that dolphins possess highly complex cognitive abilities, particularly those in the social domain.
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Affiliation(s)
- James R Davies
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK.
| | - Elias Garcia-Pelegrin
- Department of Psychology, National University of Singapore, Singapore, 117572, Singapore.
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12
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Sayigh LS, El Haddad N, Tyack PL, Janik VM, Wells RS, Jensen FH. Bottlenose dolphin mothers modify signature whistles in the presence of their own calves. Proc Natl Acad Sci U S A 2023; 120:e2300262120. [PMID: 37364108 PMCID: PMC10318978 DOI: 10.1073/pnas.2300262120] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/09/2023] [Indexed: 06/28/2023] Open
Abstract
Human caregivers interacting with children typically modify their speech in ways that promote attention, bonding, and language acquisition. Although this "motherese," or child-directed communication (CDC), occurs in a variety of human cultures, evidence among nonhuman species is very rare. We looked for its occurrence in a nonhuman mammalian species with long-term mother-offspring bonds that is capable of vocal production learning, the bottlenose dolphin (Tursiops truncatus). Dolphin signature whistles provide a unique opportunity to test for CDC in nonhuman animals, because we are able to quantify changes in the same vocalizations produced in the presence or absence of calves. We analyzed recordings made during brief catch-and-release events of wild bottlenose dolphins in waters near Sarasota Bay, Florida, United States, and found that females produced signature whistles with significantly higher maximum frequencies and wider frequency ranges when they were recorded with their own dependent calves vs. not with them. These differences align with the higher fundamental frequencies and wider pitch ranges seen in human CDC. Our results provide evidence in a nonhuman mammal for changes in the same vocalizations when produced in the presence vs. absence of offspring, and thus strongly support convergent evolution of motherese, or CDC, in bottlenose dolphins. CDC may function to enhance attention, bonding, and vocal learning in dolphin calves, as it does in human children. Our data add to the growing body of evidence that dolphins provide a powerful animal model for studying the evolution of vocal learning and language.
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Affiliation(s)
- Laela S. Sayigh
- Biology Department, Woods Hole Oceanographic Institution, Falmouth, MA02543
- Hampshire College, Amherst, MA01002
| | - Nicole El Haddad
- Biology Department, Woods Hole Oceanographic Institution, Falmouth, MA02543
- Earth and Environmental Sciences Department, University of Milano Bicocca, Milano20126, Italy
| | - Peter L. Tyack
- Biology Department, Woods Hole Oceanographic Institution, Falmouth, MA02543
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, KY16 8LB, United Kingdom
| | - Vincent M. Janik
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, KY16 8LB, United Kingdom
| | - Randall S. Wells
- Chicago Zoological Society’s Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, Sarasota, FL34236
| | - Frants H. Jensen
- Biology Department, Woods Hole Oceanographic Institution, Falmouth, MA02543
- Marine Mammal Research, Department of Ecoscience, Aarhus University, Roskilde4000, Denmark
- Biology Department, Syracuse University, Syracuse, NY13244
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13
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Madsen PT, Siebert U, Elemans CPH. Toothed whales use distinct vocal registers for echolocation and communication. Science 2023; 379:928-933. [PMID: 36862790 DOI: 10.1126/science.adc9570] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Echolocating toothed whales (odontocetes) capture fast-moving prey in dark marine environments, which critically depends on their ability to generate powerful, ultrasonic clicks. How their supposedly air-driven sound source can produce biosonar clicks at depths of >1000 meters, while also producing rich vocal repertoires to mediate complex social communication, remains unknown. We show that odontocetes possess a sound production system based on air driven through nasal passages that is functionally analogous to laryngeal and syringeal sound production. Tissue vibration in different registers produces distinct echolocation and communication signals across all major odontocete clades, and thus provides a physiological basis for classifying their vocal repertoires. The vocal fry register is used by species from porpoises to sperm whales for generating powerful, highly air-efficient echolocation clicks.
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Affiliation(s)
- Peter T Madsen
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus, Denmark
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, 25761 Büsum, Germany
| | - Coen P H Elemans
- Sound Communication and Behavior Group, Department of Biology, University of Southern Denmark, 5230 Odense M, Denmark
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14
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Anderson KL, Colón L, Doolittle V, Martinez RR, Uraga J, Whitney O. Context-dependent activation of a social behavior brain network associates with learned vocal production. RESEARCH SQUARE 2023:rs.3.rs-2587773. [PMID: 36824963 PMCID: PMC9949236 DOI: 10.21203/rs.3.rs-2587773/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
In zebra finches, an avian brain network for vocal control undergoes context-dependent patterning of song-dependent activation. Previous studies in zebra finches also implicate the importance of dopaminergic input in producing context-appropriate singing behavior. In mice, it has been shown that oxytocinergic neurons originated in the paraventricular nucleus of the hypothalamus (PVN) synapse directly onto dopamine neurons in the ventral tegmental area (VTA), implicating the necessity of oxytocin signaling from the PVN for producing a context-appropriate song. Both avian and non-avian axonal tract-tracing studies indicate high levels of PVN innervation by the social behavior network. Here, we hypothesize that the motivation for PVN oxytocin neurons to trigger dopamine release originates in the social behavior network, a highly conserved and interconnected collection of six regions implicated in various social and homeostatic behaviors. We found that expression of the neuronal activity marker EGR1 was not strongly correlated with song production in any of the regions of the social behavior network. However, when EGR1 expression levels were normalized to the singing rate, we found significantly higher levels of expression in the social behavior network regions except the medial preoptic area during a social female-directed singing context compared to a non-social undirected singing context. Our results suggest neuronal activity within the male zebra finch social behavior network influences the synaptic release of oxytocin from PVN onto dopaminergic projection neurons in the VTA, which in turn signals to the vocal control network to allow for context-appropriate song production.
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15
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Zamorano-Abramson J, Michon M, Hernández-Lloreda MV, Aboitiz F. Multimodal imitative learning and synchrony in cetaceans: A model for speech and singing evolution. Front Psychol 2023; 14:1061381. [PMID: 37138983 PMCID: PMC10150787 DOI: 10.3389/fpsyg.2023.1061381] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 02/13/2023] [Indexed: 05/05/2023] Open
Abstract
Multimodal imitation of actions, gestures and vocal production is a hallmark of the evolution of human communication, as both, vocal learning and visual-gestural imitation, were crucial factors that facilitated the evolution of speech and singing. Comparative evidence has revealed that humans are an odd case in this respect, as the case for multimodal imitation is barely documented in non-human animals. While there is evidence of vocal learning in birds and in mammals like bats, elephants and marine mammals, evidence in both domains, vocal and gestural, exists for two Psittacine birds (budgerigars and grey parrots) and cetaceans only. Moreover, it draws attention to the apparent absence of vocal imitation (with just a few cases reported for vocal fold control in an orangutan and a gorilla and a prolonged development of vocal plasticity in marmosets) and even for imitation of intransitive actions (not object related) in monkeys and apes in the wild. Even after training, the evidence for productive or "true imitation" (copy of a novel behavior, i.e., not pre-existent in the observer's behavioral repertoire) in both domains is scarce. Here we review the evidence of multimodal imitation in cetaceans, one of the few living mammalian species that have been reported to display multimodal imitative learning besides humans, and their role in sociality, communication and group cultures. We propose that cetacean multimodal imitation was acquired in parallel with the evolution and development of behavioral synchrony and multimodal organization of sensorimotor information, supporting volitional motor control of their vocal system and audio-echoic-visual voices, body posture and movement integration.
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Affiliation(s)
- José Zamorano-Abramson
- Centro de Investigación en Complejidad Social, Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
- Grupo UCM de Psicobiología Social, Evolutiva y Comparada, Universidad Complutense de Madrid, Madrid, Spain
- *Correspondence: José Zamorano-Abramson,
| | - Maëva Michon
- Centro de Estudios en Neurociencia Humana y Neuropsicología, Facultad de Psicología, Universidad Diego Portales, Santiago, Chile
- Laboratory for Cognitive and Evolutionary Neuroscience, Department of Psychiatry, Faculty of Medicine, Interdisciplinary Center for Neuroscience, Pontificia Universidad Católica de, Santiago, Chile
- Maëva Michon,
| | - Ma Victoria Hernández-Lloreda
- Grupo UCM de Psicobiología Social, Evolutiva y Comparada, Universidad Complutense de Madrid, Madrid, Spain
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Facultad de Psicología, Campus de Somosaguas, Universidad Complutense de Madrid, Madrid, Spain
| | - Francisco Aboitiz
- Laboratory for Cognitive and Evolutionary Neuroscience, Department of Psychiatry, Faculty of Medicine, Interdisciplinary Center for Neuroscience, Pontificia Universidad Católica de, Santiago, Chile
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16
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Social and vocal complexity in bottlenose dolphins. Trends Neurosci 2022; 45:881-883. [PMID: 36404454 DOI: 10.1016/j.tins.2022.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
Bottlenose dolphins are highly social, renowned for their vocal flexibility, and possess highly enlarged brains relative to their body size. Here, we discuss some of the defining features of bottlenose dolphin social and vocal complexity and place this in the context of their cognitive evolution.
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17
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Abreu F, Pika S. Turn-taking skills in mammals: A systematic review into development and acquisition. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.987253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
How human language evolved remains one of the most intriguing questions in science, and different approaches have been used to tackle this question. A recent hypothesis, the Interaction Engine Hypothesis, postulates that language was made possible through the special capacity for social interaction involving different social cognitive skills (e.g., joint attention, common ground) and specific characteristics such as face-to-face interaction, mutual gaze and turn-taking, the exchange of rapid communicative turns. Recently, it has been argued that this turn-taking infrastructure may be a foundational and ancient mechanism of the layered system of language because communicative turn-taking has been found in human infants and across several non-human primate species. Moreover, there is some evidence for turn-taking in different mammalian taxa, especially those capable of vocal learning. Surprisingly, however, the existing studies have mainly focused on turn-taking production of adult individuals, while little is known about its emergence and development in young individuals. Hence, the aim of the current paper was 2-fold: First, we carried out a systematic review of turn-taking development and acquisition in mammals to evaluate possible research bias and existing gaps. Second, we highlight research avenues to spur more research into this domain and investigate if distinct turn-taking elements can be found in other non-human animal species. Since mammals exhibit an extended development period, including learning and strong parental care, they represent an excellent model group in which to investigate the acquisition and development of turn-taking abilities. We performed a systematic review including a wide range of terms and found 21 studies presenting findings on turn-taking abilities in infants and juveniles. Most of these studies were from the last decade, showing an increased interest in this field over the years. Overall, we found a considerable variation in the terminologies and methodological approaches used. In addition, studies investigating turn-taking abilities across different development periods and in relation to different social partners were very rare, thereby hampering direct, systematic comparisons within and across species. Nonetheless, the results of some studies suggested that specific turn-taking elements are innate, while others are acquired during development (e.g., flexibility). Finally, we pinpoint fruitful research avenues and hypotheses to move the field of turn-taking development forward and improve our understanding of the impact of turn-taking on language evolution.
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18
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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: 13] [Impact Index Per Article: 4.3] [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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19
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Mine JG, Slocombe KE, Willems EP, Gilby IC, Yu M, Thompson ME, Muller MN, Wrangham RW, Townsend SW, Machanda ZP. Vocal signals facilitate cooperative hunting in wild chimpanzees. SCIENCE ADVANCES 2022; 8:eabo5553. [PMID: 35905190 PMCID: PMC9337754 DOI: 10.1126/sciadv.abo5553] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 06/15/2022] [Indexed: 05/22/2023]
Abstract
Cooperation and communication likely coevolved in humans. However, the evolutionary roots of this interdependence remain unclear. We address this issue by investigating the role of vocal signals in facilitating a group cooperative behavior in an ape species: hunting in wild chimpanzees. First, we show that bark vocalizations produced before hunt initiation are reliable signals of behavioral motivation, with barkers being most likely to participate in the hunt. Next, we find that barks are associated with greater hunter recruitment and more effective hunting, with shorter latencies to hunting initiation and prey capture. Our results indicate that the coevolutionary relationship between vocal communication and group-level cooperation is not unique to humans in the ape lineage and is likely to have been present in our last common ancestor with chimpanzees.
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Affiliation(s)
- Joseph G. Mine
- Department of Comparative Language Science, University of Zürich, Zürich, Switzerland
- Center for the Interdisciplinary Study of Language Evolution, University of Zürich, Zürich, Switzerland
| | | | - Erik P. Willems
- Department of Anthropology, University of Zürich, Zürich, Switzerland
| | - Ian C. Gilby
- School of Human Evolution and Social Change, and Institute of Human Origins, Arizona State University, Tempe, AZ, USA
| | - Miranda Yu
- Departments of Anthropology and Biology, Tufts University, Medford, MA, USA
| | | | - Martin N. Muller
- Department of Anthropology, University of New Mexico, Albuquerque, NM, USA
| | - Richard W. Wrangham
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Simon W. Townsend
- Department of Comparative Language Science, University of Zürich, Zürich, Switzerland
- Center for the Interdisciplinary Study of Language Evolution, University of Zürich, Zürich, Switzerland
- Department of Psychology, University of Warwick, Warwick, UK
| | - Zarin P. Machanda
- Departments of Anthropology and Biology, Tufts University, Medford, MA, USA
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20
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Demartsev V, Gersick AS, Jensen FH, Thomas M, Roch MA, Strandburg‐Peshkin A. Signalling in groups: New tools for the integration of animal communication and collective movement. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Vlad Demartsev
- Department for the Ecology of Animal Societies Max Planck Institute of Animal Behavior Konstanz Germany
- Department of Biology University of Konstanz Konstanz Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Konstanz Germany
| | - Andrew S. Gersick
- Department of Ecology and Evolutionary Biology Princeton University Princeton NJ USA
| | | | - Mara Thomas
- Department for the Ecology of Animal Societies Max Planck Institute of Animal Behavior Konstanz Germany
- Department of Biology University of Konstanz Konstanz Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Konstanz Germany
| | - Marie A. Roch
- Department of Computer Science San Diego State University San Diego CA USA
| | - Ariana Strandburg‐Peshkin
- Department for the Ecology of Animal Societies Max Planck Institute of Animal Behavior Konstanz Germany
- Department of Biology University of Konstanz Konstanz Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Konstanz Germany
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21
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Davies JR, Garcia-Pelegrin E, Baciadonna L, Pilenga C, Favaro L, Clayton NS. Episodic-like memory in common bottlenose dolphins. Curr Biol 2022; 32:3436-3442.e2. [PMID: 35882234 DOI: 10.1016/j.cub.2022.06.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/27/2022] [Accepted: 06/10/2022] [Indexed: 11/18/2022]
Abstract
Episodic memory involves the conscious recollection of personally experienced events, which has often been argued to be a uniquely human ability.1-5 However, evidence for conscious episodic recall in humans is centered around language-based reports. With no agreed upon non-linguistic behavioral makers of consciousness,6 episodic-like memory7 therefore represents the behavioral characteristics of human episodic memory, in the absence of evidence for subjective experience during recall. Here, we provide compelling evidence for episodic-like memory in common bottlenose dolphins (Tursiops truncatus), based on the incidental encoding and unexpected question paradigm.8 This methodology aims to capture the incidental encoding characteristic of human episodic memory, in that when we recall an experience, we remember information that was trivial at the time of encoding, but was encoded automatically.9 We show that dolphins are able to use incidentally encoded spatial ("where") and social ("who") information to solve an unexpected memory task, using only a single test trial per test type, which ensured that the dolphins did not have the opportunity to semantically learn "rules" to pass the test. All participating dolphins made correct choices in both the "where" and "who" tests. These results suggest that dolphins are capable of encoding, recalling, and accessing incidental information within remembered events, which is an ability indicative of episodic memory in humans. We argue that the complex socio-ecological background of dolphins may have selected for the ability to recall both spatial and social information in an episodic-like manner.
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Affiliation(s)
- James R Davies
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK.
| | - Elias Garcia-Pelegrin
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK; Department of Psychology, National University of Singapore, Singapore 117572, Singapore
| | - Luigi Baciadonna
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK; Department of Life Sciences and Systems Biology, University of Turin, Turin 10123, Italy
| | | | - Livio Favaro
- Department of Life Sciences and Systems Biology, University of Turin, Turin 10123, Italy
| | - Nicola S Clayton
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
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Danaher-Garcia N, Connor R, Fay G, Melillo-Sweeting K, Dudzinski KM. Using Social Network Analysis to Confirm the ‘Gambit of the Group’ Hypothesis for a Small Cetacean. Behav Processes 2022; 200:104694. [DOI: 10.1016/j.beproc.2022.104694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 06/14/2022] [Accepted: 06/26/2022] [Indexed: 11/02/2022]
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