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Jacobs ER, Gero S, Malinka CE, Tønnesen PH, Beedholm K, DeRuiter SL, Madsen PT. The active space of sperm whale codas: inter-click information for intra-unit communication. J Exp Biol 2024; 227:jeb246442. [PMID: 38264868 DOI: 10.1242/jeb.246442] [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: 07/19/2023] [Accepted: 01/16/2024] [Indexed: 01/25/2024]
Abstract
Sperm whales (Physeter macrocephalus) are social mega-predators who form stable matrilineal units that often associate within a larger vocal clan. Clan membership is defined by sharing a repertoire of coda types consisting of specific temporal spacings of multi-pulsed clicks. It has been hypothesized that codas communicate membership across socially segregated sympatric clans, but others propose that codas are primarily used for behavioral coordination and social cohesion within a closely spaced social unit. Here, we test these hypotheses by combining measures of ambient noise levels and coda click source levels with models of sound propagation to estimate the active space of coda communication. Coda clicks were localized off the island of Dominica with a four- or five-element 80 m vertical hydrophone array, allowing us to calculate the median RMS source levels of 1598 clicks from 444 codas to be 161 dB re. 1 μPa (IQR 153-167), placing codas among the most powerful communication sounds in toothed whales. However, together with measured ambient noise levels, these source levels lead to a median active space of coda communication of ∼4 km, reflecting the maximum footprint of a single foraging sperm whale unit. We conclude that while sperm whale codas may contain information about clan affiliation, their moderate active space shows that codas are not used for long range acoustic communication between units and clans, but likely serve to mediate social cohesion and behavioral transitions in intra-unit communication.
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Affiliation(s)
- Ellen R Jacobs
- Zoophysiology, Department of Biology, Aarhus University, C. F. Møllers Allé 3, DK-8000 Aarhus C, Denmark
- Department of Biology, Georgetown University, 3700 O St NW, Washington, DC 20057, USA
| | - Shane Gero
- Zoophysiology, Department of Biology, Aarhus University, C. F. Møllers Allé 3, DK-8000 Aarhus C, Denmark
- Department of Biology, Carleton University, 1125 Colonel By Dr, Ottawa, ON, Canada K1S 5B6
| | - Chloe E Malinka
- Zoophysiology, Department of Biology, Aarhus University, C. F. Møllers Allé 3, DK-8000 Aarhus C, Denmark
- SMRU Consulting, Scottish Oceans Institute, East Sands, University of St Andrews, KY16 8LB, UK
| | - Pernille H Tønnesen
- Zoophysiology, Department of Biology, Aarhus University, C. F. Møllers Allé 3, DK-8000 Aarhus C, Denmark
| | - Kristian Beedholm
- Zoophysiology, Department of Biology, Aarhus University, C. F. Møllers Allé 3, DK-8000 Aarhus C, Denmark
| | - Stacy L DeRuiter
- Department of Mathematics and Statistics, Calvin University, 3201 Burton St SE, Grand Rapids, MI 49546, USA
| | - Peter T Madsen
- Zoophysiology, Department of Biology, Aarhus University, C. F. Møllers Allé 3, DK-8000 Aarhus C, Denmark
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2
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He P, Klarevas‐Irby JA, Papageorgiou D, Christensen C, Strauss ED, Farine DR. A guide to sampling design for
GPS
‐based studies of animal societies. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peng He
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Constance Germany
- Department of Biology University of Konstanz Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
| | - James A. Klarevas‐Irby
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Constance Germany
- Department of Biology University of Konstanz Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
- Department of Migration Max Planck Institute of Animal Behavior Radolfzell Germany
- Mpala Research Centre Nanyuki Kenya
| | - Danai Papageorgiou
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
| | - Charlotte Christensen
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
- Mpala Research Centre Nanyuki Kenya
| | - Eli D. Strauss
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Centre for the Advanced Study of Collective Behaviour University of Konstanz Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
| | - Damien R. Farine
- Department of Collective Behaviour Max Planck Institute of Animal Behavior Constance Germany
- Department of Evolutionary Biology and Environmental Science University of Zurich Zurich Switzerland
- Division of Ecology and Evolution, Research School of Biology Australian National University Canberra Australia
- Department of Ornithology National Museums of Kenya Nairobi Kenya
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3
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Wiśniewska A, Janczarek I, Tkaczyk E, Wilk I, Janicka W, Próchniak T, Kaczmarek B, Pokora E, Łuszczyński J. Minimizing the Effects of Social Isolation of Horses by Contact with Animals of a Different Species: The Domestic Goat as an Example. Animals (Basel) 2022; 12:ani12172271. [PMID: 36077991 PMCID: PMC9454851 DOI: 10.3390/ani12172271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
This study aimed to perform a comparative analysis of the horses’ heart rate parameters and locomotor activity in a herd or isolation, with or without the company of goats. Twenty horses were tested in a paddock, accompanied (or not) by three goats. The experiment comprised four tests (a control test of a herd of horses without goats, a horse isolation test without goats, a test of a herd of horses with goats and a test of an isolated horse with goats). The horse’s locomotor behavior, and the HR, RR, rMSSD, LF, HF, and LF/HF were recorded. The data analysis included a 15-min rest, procedural and recovery HR/HRV periods, and a 5-min period at the beginning of the test. The duration of the horses standing in the company of goats increased significantly. The rMSSD parameter was the significantly lowest in the test of a herd of horses with goats. The company of goats in a paddock does not eliminate the emotional effects of the phenomenon. However, the locomotor behavior decreases. Goats in a paddock can provide a positive distraction for horses in a herd as a decrease in emotional excitability can be regarded as having a relaxing impact on a different animal species.
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Affiliation(s)
- Anna Wiśniewska
- Department of Horse Breeding and Use, Faculty of Animal Breeding and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
| | - Iwona Janczarek
- Department of Horse Breeding and Use, Faculty of Animal Breeding and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
- Correspondence:
| | - Ewelina Tkaczyk
- Department of Horse Breeding and Use, Faculty of Animal Breeding and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
| | - Izabela Wilk
- Department of Horse Breeding and Use, Faculty of Animal Breeding and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
| | - Wiktoria Janicka
- Department of Horse Breeding and Use, Faculty of Animal Breeding and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
| | - Tomasz Próchniak
- Institute of Biological Basis of Animal Production, Faculty of Animal Breeding and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
| | - Beata Kaczmarek
- Department and Clinic of Animal Internal Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
| | - Elżbieta Pokora
- Department of Horse Breeding and Use, Faculty of Animal Breeding and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13 Str, 20-950 Lublin, Poland
| | - Jarosław Łuszczyński
- Department of Genetics, Animal Breeding and Ethology, Faculty of Animal Science, University of Agriculture in Cracow, 30-059 Cracow, Poland
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4
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Andreas J, Beguš G, Bronstein MM, Diamant R, Delaney D, Gero S, Goldwasser S, Gruber DF, de Haas S, Malkin P, Pavlov N, Payne R, Petri G, Rus D, Sharma P, Tchernov D, Tønnesen P, Torralba A, Vogt D, Wood RJ. Toward understanding the communication in sperm whales. iScience 2022; 25:104393. [PMID: 35663036 PMCID: PMC9160774 DOI: 10.1016/j.isci.2022.104393] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Machine learning has been advancing dramatically over the past decade. Most strides are human-based applications due to the availability of large-scale datasets; however, opportunities are ripe to apply this technology to more deeply understand non-human communication. We detail a scientific roadmap for advancing the understanding of communication of whales that can be built further upon as a template to decipher other forms of animal and non-human communication. Sperm whales, with their highly developed neuroanatomical features, cognitive abilities, social structures, and discrete click-based encoding make for an excellent model for advanced tools that can be applied to other animals in the future. We outline the key elements required for the collection and processing of massive datasets, detecting basic communication units and language-like higher-level structures, and validating models through interactive playback experiments. The technological capabilities developed by such an undertaking hold potential for cross-applications in broader communities investigating non-human communication and behavioral research.
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Affiliation(s)
- Jacob Andreas
- MIT CSAIL, Cambridge, MA, USA
- Project CETI, New York, NY, USA
| | - Gašper Beguš
- Department of Linguistics, University of California, Berkeley, CA, USA
- Project CETI, New York, NY, USA
| | - Michael M. Bronstein
- Department of Computer Science, University of Oxford, Oxford, UK
- IDSIA, University of Lugano, Lugano, Switzerland
- Twitter, London, UK
- Project CETI, New York, NY, USA
| | - Roee Diamant
- Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
- Project CETI, New York, NY, USA
| | - Denley Delaney
- Exploration Technology Lab, National Geographic Society, Washington DC, USA
- Project CETI, New York, NY, USA
| | - Shane Gero
- Dominica Sperm Whale Project, Roseau, Commonwealth of Dominica
- Department of Biology, Carleton University, Ottawa, ON, Canada
- Project CETI, New York, NY, USA
| | - Shafi Goldwasser
- Simons Institute for the Theory of Computing, University of California, Berkeley, CA, USA
| | - David F. Gruber
- Department of Natural Sciences, Baruch College and The Graduate Center, PhD Program in Biology, City University of New York, New York, NY, USA
- Project CETI, New York, NY, USA
| | - Sarah de Haas
- Google Research, Mountain View, CA USA
- Project CETI, New York, NY, USA
| | - Peter Malkin
- Google Research, Mountain View, CA USA
- Project CETI, New York, NY, USA
| | | | | | - Giovanni Petri
- ISI Foundation, Turin, Italy
- Project CETI, New York, NY, USA
| | - Daniela Rus
- MIT CSAIL, Cambridge, MA, USA
- Project CETI, New York, NY, USA
| | | | - Dan Tchernov
- Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
- Project CETI, New York, NY, USA
| | - Pernille Tønnesen
- Marine Bioacoustics Lab, Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
- Project CETI, New York, NY, USA
| | | | - Daniel Vogt
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- Project CETI, New York, NY, USA
| | - Robert J. Wood
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- Project CETI, New York, NY, USA
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5
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Vachon F, Hersh TA, Rendell L, Gero S, Whitehead H. Ocean nomads or island specialists? Culturally driven habitat partitioning contrasts in scale between geographically isolated sperm whale populations. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211737. [PMID: 35619996 PMCID: PMC9114939 DOI: 10.1098/rsos.211737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/14/2022] [Indexed: 05/03/2023]
Abstract
The sperm whale (Physeter macrocephalus) is a deep-diving cetacean with a global distribution and a multi-leveled, culturally segregated, social structure. While sperm whales have previously been described as 'ocean nomads', this might not be universal. We conducted surveys of sperm whales along the Lesser Antilles to document the acoustic repertoires, movements and distributions of Eastern Caribbean (EC) sperm whale cultural groups (called vocal clans). In addition to documenting a potential third vocal clan in the EC, we found strong evidence of fine-scale habitat partitioning between vocal clans with scales of horizontal movements an order of magnitude smaller than from comparable studies on Eastern Tropical Pacific sperm whales. These results suggest that sperm whales can display cultural ecological specialization and habitat partitioning on flexible spatial scales according to local conditions and broadens our perception of the ecological flexibility of the species. This study highlights the importance of incorporating multiple temporal and spatial scales to understand the impact of culture on ecological adaptability, as well as the dangers of extrapolating results across geographical areas and cultural groups.
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Affiliation(s)
- Felicia Vachon
- Department of Biology, Dalhousie University, Halifax, Canada
| | - Taylor A. Hersh
- Department of Biology, Dalhousie University, Halifax, Canada
- Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Luke Rendell
- Sea Mammal Research Unit, University of St Andrews, School of Biology, St Andrews, UK
| | - Shane Gero
- Department of Biology, Dalhousie University, Halifax, Canada
- Sea Mammal Research Unit, University of St Andrews, School of Biology, St Andrews, UK
- Department of Biology, Carleton University, Ottawa, Canada
- Department of Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Hal Whitehead
- Department of Biology, Dalhousie University, Halifax, Canada
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6
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Assessing social structure: a data-driven approach to define associations between individuals. Mamm Biol 2022; 102:551-566. [PMID: 36721404 PMCID: PMC9883313 DOI: 10.1007/s42991-022-00231-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/16/2022] [Indexed: 02/06/2023]
Abstract
Our interpretation of animal social structures is inherently dependent on our ability to define association criteria that are biologically meaningful. However, association thresholds are often based upon generalized preconceptions of a species' social behaviour, and the impact of using these arbitrary definitions has been largely overlooked. In this study we suggest a probability-based method for defining association thresholds using lagged identification rates on photographic records of identifiable individuals. This technique uses a simple model of emigration/immigration from photographable clusters to identify the time-dependent lag value between identifications of two individuals that corresponds to approximately 75% probability of being in close spatial proximity and likely associating. This lag value is then used as the threshold to define associations for social analyses. We applied the technique to a dataset of northern resident killer whales (Orcinus orca) in the Northeast Pacific and tested its performance against two arbitrary thresholds. The probabilistic association maximized the variation in association strengths at different levels of the social structure, in line with known social patterns in this population. Furthermore, variability in inferred social structure metrics generated by different association criteria highlighted the consequential effect of choosing arbitrary thresholds. Data-driven association thresholds are a promising approach to study populations without the need to subjectively define associations in the field, especially in societies with prominent fission-fusion dynamics. This method is applicable to any dataset of sequential identifications where it can be assumed that associated individuals will tend to be identified in close proximity. Supplementary Information The online version contains supplementary material available at 10.1007/s42991-022-00231-9.
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7
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Riley JL, Noble DWA, Stow AJ, Bolton PE, While GM, Dennison S, Byrne RW, Whiting MJ. Socioecology of the Australian Tree Skink (Egernia striolata). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.722455] [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
There is great diversity in social behavior across the animal kingdom. Understanding the factors responsible for this diversity can help inform theory about how sociality evolves and is maintained. The Australian Tree Skink (Egernia striolata) exhibits inter- and intra-population variability in sociality and is therefore a good system for informing models of social evolution. Here, we conducted a multi-year study of a Tree Skink population to describe intra-population variation in the social organization and mating system of this species. Skinks aggregated in small groups of 2–5 individuals, and these aggregations were typically associated with shared shelter sites (crevices and hollows within rocks and trees). Aggregations were typically made up of one or more adult females and, often, one male and/or juvenile(s). Social network and spatial overlap analyses showed that social associations were strongly biased toward kin. Tree skinks also exhibited high site fidelity regardless of age or sex. There were high levels of genetic monogamy observed with most females (87%) and males (68%) only breeding with a single partner. Our results indicate that Tree Skinks reside in small family groups and are monogamous, which corresponds with existing research across populations. Similar to previous work, our study area consisted of discrete habitat patches (i.e., rock outcrops, trees, or both), which likely limits offspring dispersal and promotes social tolerance between parents and their offspring. Our study clearly demonstrates that there is intra-population variability in Tree Skink social behavior, but it also provides evidence that there is a high degree of inter-population consistency in sociality across their geographic range. We also highlight promising possible avenues for future research, specifically discussing the importance of studying the nature and extent of Tree Skink parental care and quantifying the fitness outcomes of kin-based sociality in this species, which are topics that will further our understanding of the mechanisms underlying variation in vertebrate social behavior.
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8
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Kalbitzer U, Chapman CA. Patterns of female social relationships in a primate with female-biased dispersal. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.04.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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Bertulli CG, Rasmussen MH, Rosso M. Fission-fusion dynamics of a pelagic delphinid in the arctic: the white-beaked dolphin (Lagenorhynchus albirostris). Integr Zool 2021; 16:512-526. [PMID: 33559948 DOI: 10.1111/1749-4877.12524] [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] [Indexed: 01/07/2023]
Abstract
Delphinids exhibit great variability in their social structures. It is therefore important to document lesser known species, in extreme changing habitats, to compare and contrast mechanisms driving sociality. Here, we describe the first long-term assessment of social structure of white-beaked dolphins (Lagenorhynchus albirostris) using a compiled version of SOCPROG 2.8 and an 11-year photo-identification dataset (2002-2013) collected from whale-watching vessels at 2 sites (Faxaflói and Skjálfandi bays) off Iceland. We identified a total of 487 dolphins which are suggested to be part of an open population as shown by the discovery curve obtained analyzing photo-id data. The social analyses were restricted to 35 adults which were sighted on ≥5 different days. The mean residency time of white-beaked dolphins in our 2 study areas was of 95 days (SE = 35.63; 95% CI: 23-171), with the "migration-full interchange" model best describing movements of dolphins in and out of our 2 study sites. Social differentiation in this population was high (Likelihood: S = 0.87, SE = 0.04; r = 0.31, SE = 0.03) indicating diverse, non-random social relationships. Temporal associations best fit the model of "casual acquaintances" against the standardized lagged association rates with the majority of white-beaked dolphin associations being short-term, but with a few long-term across years. Testing for preferred companionship, long-term associations are favored over short-term. In this study, associations among white-beaked dolphins are short-term but with desirably long-term associations fitting into a society with fission-fusion dynamics. This information expands the latitudinal range for which social structure has been described for oceanic dolphin species.
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Affiliation(s)
- Chiara G Bertulli
- Department of Life and Environmental Sciences, University of Iceland, Reykjavik, Iceland.,Sea Watch Foundation, New Quay, UK
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10
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Sarano F, Girardet J, Sarano V, Vitry H, Preud'homme A, Heuzey R, Garcia-Cegarra AM, Madon B, Delfour F, Glotin H, Adam O, Jung JL. Kin relationships in cultural species of the marine realm: case study of a matrilineal social group of sperm whales off Mauritius island, Indian Ocean. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201794. [PMID: 33972866 PMCID: PMC8074673 DOI: 10.1098/rsos.201794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/11/2021] [Indexed: 05/14/2023]
Abstract
Understanding the organization and dynamics of social groups of marine mammals through the study of kin relationships is particularly challenging. Here, we studied a stable social group of sperm whales off Mauritius, using underwater observations, individual-specific identification, non-invasive sampling and genetic analyses based on mitochondrial sequencing and microsatellite profiling. Twenty-four sperm whales were sampled between 2017 and 2019. All individuals except one adult female shared the same mitochondrial DNA (mtDNA) haplotype-one that is rare in the western Indian Ocean-thus confirming with near certainty the matrilineality of the group. All probable first- and second-degree kin relationships were depicted in the sperm whale social group: 13 first-degree and 27 second-degree relationships were identified. Notably, we highlight the likely case of an unrelated female having been integrated into a social unit, in that she presented a distinct mtDNA haplotype and no close relationships with any members of the group. Investigating the possible matrilineality of sperm whale cultural units (i.e. vocal clans) is the next step in our research programme to elucidate and better apprehend the complex organization of sperm whale social groups.
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Affiliation(s)
| | - Justine Girardet
- Université de Brest, Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, ISYEB, Brest, France
| | | | - Hugues Vitry
- Marine Megafauna Conservation Organisation, Mauritius
| | | | | | - Ana M. Garcia-Cegarra
- Centro de Investigación de Fauna Marina y Avistamiento de Cetáceos, CIFAMAC, Mejillones, Chile
- Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Antofagasta, Chile
| | - Bénédicte Madon
- Université de Brest, AMURE - Aménagement des Usages des Ressources et des Espaces marins et littoraux - Centre de droit et d'économie de la mer, Plouzané, France
| | - Fabienne Delfour
- Laboratoire d'Ethologie Expérimentale et Comparée EA 4443, Université Paris 13, Sorbonne Paris Cité, Villetaneuse, France
| | - Hervé Glotin
- Toulon University, Aix Marseille Université, CNRS, LIS, DYNI Team, Marseille, France
| | - Olivier Adam
- Sorbonne Université, CNRS, Institut Jean Le Rond d'Alembert, UMR 7190, Paris, France
- Institute of Neurosciences Paris-Saclay, Bioacoustics Team, CNRS UMR 9197, Université Paris Sud, Orsay, France
| | - Jean-Luc Jung
- Université de Brest, Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, ISYEB, Brest, France
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11
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Fisher DN, Pinter-Wollman N. Using multilayer network analysis to explore the temporal dynamics of collective behavior. Curr Zool 2021; 67:71-80. [PMID: 33654492 PMCID: PMC7901757 DOI: 10.1093/cz/zoaa050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/27/2020] [Indexed: 01/12/2023] Open
Abstract
Social organisms often show collective behaviors such as group foraging or movement. Collective behaviors can emerge from interactions between group members and may depend on the behavior of key individuals. When social interactions change over time, collective behaviors may change because these behaviors emerge from interactions among individuals. Despite the importance of, and growing interest in, the temporal dynamics of social interactions, it is not clear how to quantify changes in interactions over time or measure their stability. Furthermore, the temporal scale at which we should observe changes in social networks to detect biologically meaningful changes is not always apparent. Here we use multilayer network analysis to quantify temporal dynamics of social networks of the social spider Stegodyphus dumicola and determine how these dynamics relate to individual and group behaviors. We found that social interactions changed over time at a constant rate. Variation in both network structure and the identity of a keystone individual was not related to the mean or variance of the collective prey attack speed. Individuals that maintained a large and stable number of connections, despite changes in network structure, were the boldest individuals in the group. Therefore, social interactions and boldness are linked across time, but group collective behavior is not influenced by the stability of the social network. Our work demonstrates that dynamic social networks can be modeled in a multilayer framework. This approach may reveal biologically important temporal changes to social structure in other systems.
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Affiliation(s)
- David N Fisher
- Department of Psychology, Neuroscience, & Behaviour, McMaster University, Hamilton, ON L8S 4K1, Canada
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3FX, UK
| | - Noa Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
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12
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Kobayashi H, Whitehead H, Amano M. Long-term associations among male sperm whales (Physeter macrocephalus). PLoS One 2020; 15:e0244204. [PMID: 33362216 PMCID: PMC7757888 DOI: 10.1371/journal.pone.0244204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 12/04/2020] [Indexed: 12/02/2022] Open
Abstract
Little is known about the social structure of male sperm whales (Physeter macrocephalus) after they leave their natal units. While previous studies found no evidence for preferred associations among males, the observation of mass-strandings consisting exclusively of males, suggest that they have strong social bonds. To investigate the social associations among male sperm whales, we used half weight index of association, permutation tests and standardized lagged association rate models on a large photo-identification database collected between 2006 and 2017 in Nemuro Strait, Japan. Our results suggest that while male sperm whales are not as social as females, they do form long term associations, have preferred companionship, and forage in social proximity to each other. The best-fitting model to the standardized lagged association rate showed that associations among males last for at least 2.7 years and as most males leave the area after 2 years, associations may last for longer. Twenty dyads were observed associating over more than 2 years, for a maximum 5 years. One dyad was observed associating on 19 different days and clustered on 7 different days. Male associations may function to enhance foraging or to fend off predators. Such relationships seem to be adapted to a pelagic habitat with uncertain resource availability and predation pressure.
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Affiliation(s)
- Hayao Kobayashi
- Graduate School of Fisheries and Environmental Science, Nagasaki University, Nagasaki, Japan
- * E-mail:
| | - Hal Whitehead
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Masao Amano
- Graduate School of Fisheries and Environmental Science, Nagasaki University, Nagasaki, Japan
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13
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Genetic relatedness cannot explain social preferences in black-and-white ruffed lemurs, Varecia variegata. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Deep Machine Learning Techniques for the Detection and Classification of Sperm Whale Bioacoustics. Sci Rep 2019; 9:12588. [PMID: 31467331 PMCID: PMC6715799 DOI: 10.1038/s41598-019-48909-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 08/15/2019] [Indexed: 11/08/2022] Open
Abstract
We implemented Machine Learning (ML) techniques to advance the study of sperm whale (Physeter macrocephalus) bioacoustics. This entailed employing Convolutional Neural Networks (CNNs) to construct an echolocation click detector designed to classify spectrograms generated from sperm whale acoustic data according to the presence or absence of a click. The click detector achieved 99.5% accuracy in classifying 650 spectrograms. The successful application of CNNs to clicks reveals the potential of future studies to train CNN-based architectures to extract finer-scale details from cetacean spectrograms. Long short-term memory and gated recurrent unit recurrent neural networks were trained to perform classification tasks, including (1) “coda type classification” where we obtained 97.5% accuracy in categorizing 23 coda types from a Dominica dataset containing 8,719 codas and 93.6% accuracy in categorizing 43 coda types from an Eastern Tropical Pacific (ETP) dataset with 16,995 codas; (2) “vocal clan classification” where we obtained 95.3% accuracy for two clan classes from Dominica and 93.1% for four ETP clan types; and (3) “individual whale identification” where we obtained 99.4% accuracy using two Dominica sperm whales. These results demonstrate the feasibility of applying ML to sperm whale bioacoustics and establish the validity of constructing neural networks to learn meaningful representations of whale vocalizations.
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Rendell L, Cantor M, Gero S, Whitehead H, Mann J. Causes and consequences of female centrality in cetacean societies. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180066. [PMID: 31303160 DOI: 10.1098/rstb.2018.0066] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cetaceans are fully aquatic predatory mammals that have successfully colonized virtually all marine habitats. Their adaptation to these habitats, so radically different from those of their terrestrial ancestors, can give us comparative insights into the evolution of female roles and kinship in mammalian societies. We provide a review of the diversity of such roles across the Cetacea, which are unified by some key and apparently invariable life-history features. Mothers are uniparous, while paternal care is completely absent as far as we currently know. Maternal input is extensive, lasting months to many years. Hence, female reproductive rates are low, every cetacean calf is a significant investment, and offspring care is central to female fitness. Here strategies diverge, especially between toothed and baleen whales, in terms of mother-calf association and related social structures, which range from ephemeral grouping patterns to stable, multi-level, societies in which social groups are strongly organized around female kinship. Some species exhibit social and/or spatial philopatry in both sexes, a rare phenomenon in vertebrates. Communal care can be vital, especially among deep-diving species, and can be supported by female kinship. Female-based sociality, in its diverse forms, is therefore a prevailing feature of cetacean societies. Beyond the key role in offspring survival, it provides the substrate for significant vertical and horizontal cultural transmission, as well as the only definitive non-human examples of menopause. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.
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Affiliation(s)
- Luke Rendell
- 1 Sea Mammal Research Unit, School of Biology, University of St Andrews , St Andrews KY16 9TH , UK
| | - Mauricio Cantor
- 2 Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina , Florianópolis 88040-970 , Brazil.,3 Centro de Estudos do Mar, Universidade Federal do Paraná , Pontal do Paraná 83255-000 , Brazil.,4 School of Animal, Plant and Environmental Sciences, University of the Witwatersrand , Johannesburg-Braamfontein , South Africa
| | - Shane Gero
- 5 Department of Zoophysiology, Institute for Bioscience, Aarhus University , Aarhus 8000 , Denmark
| | - Hal Whitehead
- 6 Department of Biology, Dalhousie University , Halifax , Canada B3H 4J1
| | - Janet Mann
- 7 Department of Biology, Georgetown University , Washington, DC 20057 , USA
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Konrad CM, Frasier TR, Rendell L, Whitehead H, Gero S. Kinship and association do not explain vocal repertoire variation among individual sperm whales or social units. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.09.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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17
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Konrad CM, Frasier TR, Whitehead H, Gero S. Kin selection and allocare in sperm whales. Behav Ecol 2018. [DOI: 10.1093/beheco/ary143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Christine M Konrad
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Timothy R Frasier
- Department of Biology, St Mary’s University, Halifax, Nova Scotia, Canada
| | - Hal Whitehead
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Shane Gero
- Department of Zoophysiology, Institute for Bioscience, Aarhus University, Aarhus C, Denmark
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Tønnesen P, Gero S, Ladegaard M, Johnson M, Madsen PT. First-year sperm whale calves echolocate and perform long, deep dives. Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2570-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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19
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Konrad CM, Gero S, Frasier T, Whitehead H. Kinship influences sperm whale social organization within, but generally not among, social units. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180914. [PMID: 30225081 PMCID: PMC6124104 DOI: 10.1098/rsos.180914] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/06/2018] [Indexed: 05/14/2023]
Abstract
Sperm whales have a multi-level social structure based upon long-term, cooperative social units. What role kinship plays in structuring this society is poorly understood. We combined extensive association data (518 days, during 2005-2016) and genetic data (18 microsatellites and 346 bp mitochondrial DNA (mtDNA) control region sequences) for 65 individuals from 12 social units from the Eastern Caribbean to examine patterns of kinship and social behaviour. Social units were clearly matrilineally based, evidenced by greater relatedness within social units (mean r = 0.14) than between them (mean r = 0.00) and uniform mtDNA haplotypes within social units. Additionally, most individuals (82.5%) had a first-degree relative in their social unit, while we found no first-degree relatives between social units. Generally and within social units, individuals associated more with their closer relatives (matrix correlations: 0.18-0.25). However, excepting a highly related pair of social units that merged over the study period, associations between social units were not correlated with kinship (p > 0.1). These results are the first to robustly demonstrate kinship's contribution to social unit composition and association preferences, though they also reveal variability in association preferences that is unexplained by kinship. Comparisons with other matrilineal species highlight the range of possible matrilineal societies and how they can vary between and even within species.
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Affiliation(s)
- Christine M. Konrad
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, CanadaB3H 4J1
| | - Shane Gero
- Department of Zoophysiology, Institute for Bioscience, Aarhus University, C.F. Møllers Allé 3, Aarhus 8000, Denmark
| | - Timothy Frasier
- Department of Biology, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia, CanadaB3H 3C3
| | - Hal Whitehead
- Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, CanadaB3H 4J1
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20
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Autenrieth M, Ernst A, Deaville R, Demaret F, IJsseldijk LL, Siebert U, Tiedemann R. Putative origin and maternal relatedness of male sperm whales (Physeter macrocephalus) recently stranded in the North Sea. Mamm Biol 2018. [DOI: 10.1016/j.mambio.2017.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Herzing DL, Augliere BN, Elliser CR, Green ML, Pack AA. Exodus! Large-scale displacement and social adjustments of resident Atlantic spotted dolphins (Stenella frontalis) in the Bahamas. PLoS One 2017; 12:e0180304. [PMID: 28792947 PMCID: PMC5549894 DOI: 10.1371/journal.pone.0180304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 06/13/2017] [Indexed: 11/18/2022] Open
Abstract
Over the last 20 years, significant habitat shifts have been documented in some populations of cetaceans. On Little Bahama Bank (LBB) there are sympatric communities of resident Atlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus), monitored since 1985. The size and social structure (three clusters: Northern, Central, Southern) have been stable among the spotted dolphin community with little immigration/emigration, even after large demographic losses (36%) following two major hurricanes in 2004. In 2013 an unprecedented exodus of over 50% (52 individuals) of the spotted dolphin community was documented. The entire Central cluster and a few Northern and Southern individuals relocated 161 km south to Great Bahama Bank (GBB), also home to two sympatric resident communities of spotted dolphins and bottlenose dolphins. During the late summer of 2013 and the summers of 2014 and 2015 both sites were regularly monitored but no former LBB dolphins returned to LBB. Uncharacteristic matriline splits were observed. Social analyses revealed random associations for those spotted dolphins and very little integration between spotted dolphins that moved to GBB (MGBB) and those dolphin resident to GBB (RGBB). Male alliances among spotted dolphins were present, with some altered patterns. On LBB, the operational sex ratio (OSR) was reduced (.40 to .25). OSR for MGBB and RGBB dolphins were similar (.45 and .43). A significant steady decrease in sea surface temperature and chlorophyll a (a proxy for plankton production) occurred on LBB leading up to this exodus. Similar trends were not present over the same period on GBB. The sudden large-scale shift of spotted dolphins from LBB to GBB in association with the gradual decline in certain environmental factors suggests that a possible "tipping point" was reached in prey availability. This study provides a unique view into social and genetic implications of large-scale displacement of stable dolphin communities.
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Affiliation(s)
- Denise L. Herzing
- Wild Dolphin Project, Jupiter, Florida, United States of America
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, United States of America
| | | | - Cindy R. Elliser
- Wild Dolphin Project, Jupiter, Florida, United States of America
- Pacific Mammal Research, Anacortes, Washington, United States of America
| | - Michelle L. Green
- Wild Dolphin Project, Jupiter, Florida, United States of America
- Department of Animal Science and Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Adam A. Pack
- Departments of Psychology and Biology, University of Hawaii at Hilo, Hilo, Hawaii, United States of America
- The Dolphin Institute, Hilo, Hawaii, United States of America
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22
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Mann J, Karniski C. Diving beneath the surface: long-term studies of dolphins and whales. J Mammal 2017. [DOI: 10.1093/jmammal/gyx036] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Janet Mann
- Department of Biology, Georgetown University, NW, Washington, DC, USA
| | - Caitlin Karniski
- Department of Biology, Georgetown University, NW, Washington, DC, USA
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23
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Scheiber IBR, Weiß BM, Kingma SA, Komdeur J. The importance of the altricial - precocial spectrum for social complexity in mammals and birds - a review. Front Zool 2017; 14:3. [PMID: 28115975 PMCID: PMC5242088 DOI: 10.1186/s12983-016-0185-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 12/08/2016] [Indexed: 12/31/2022] Open
Abstract
Various types of long-term stable relationships that individuals uphold, including cooperation and competition between group members, define social complexity in vertebrates. Numerous life history, physiological and cognitive traits have been shown to affect, or to be affected by, such social relationships. As such, differences in developmental modes, i.e. the ‘altricial-precocial’ spectrum, may play an important role in understanding the interspecific variation in occurrence of social interactions, but to what extent this is the case is unclear because the role of the developmental mode has not been studied directly in across-species studies of sociality. In other words, although there are studies on the effects of developmental mode on brain size, on the effects of brain size on cognition, and on the effects of cognition on social complexity, there are no studies directly investigating the link between developmental mode and social complexity. This is surprising because developmental differences play a significant role in the evolution of, for example, brain size, which is in turn considered an essential building block with respect to social complexity. Here, we compiled an overview of studies on various aspects of the complexity of social systems in altricial and precocial mammals and birds. Although systematic studies are scarce and do not allow for a quantitative comparison, we show that several forms of social relationships and cognitive abilities occur in species along the entire developmental spectrum. Based on the existing evidence it seems that differences in developmental modes play a minor role in whether or not individuals or species are able to meet the cognitive capabilities and requirements for maintaining complex social relationships. Given the scarcity of comparative studies and potential subtle differences, however, we suggest that future studies should consider developmental differences to determine whether our finding is general or whether some of the vast variation in social complexity across species can be explained by developmental mode. This would allow a more detailed assessment of the relative importance of developmental mode in the evolution of vertebrate social systems.
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Affiliation(s)
- Isabella B R Scheiber
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Brigitte M Weiß
- Behavioural Ecology Research Group, University of Leipzig, Faculty of Bioscience, Pharmacy and Psychology, Institute of Biology, Talstraße 33, 04103 Leipzig, Germany.,Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Sjouke A Kingma
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jan Komdeur
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
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24
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Augusto J, Frasier T, Whitehead H. Social structure of long-finned pilot whales (Globicephala melas) off northern Cape Breton Island, Nova Scotia. BEHAVIOUR 2017. [DOI: 10.1163/1568539x-00003432] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cetacean social structures include fluid and stable elements. Long-finned pilot whales (Globicephala melas) live in units that interact forming labile groups. In this study conducted off Cape Breton Island, between 1998–2011, we confirm unit membership predicts associations between individuals. We determine how units are structured and interact. We delineated 21 nearly-stable social units, with an average 7 members. For units where multiple individuals are sexed, both sexes are present. Most units showed long-term stability, while one showed evidence of splitting. Three units shared individuals with the largest unit (K, average size = 29). Splitting is likely triggered by size and difficulties maintaining associations between all individuals. Pilot whales face many pressures driving sociality at a range of temporal and social scales producing a multilevel society. While we have produced a more detailed model of long-finned pilot whale social structure, there are still unanswered questions, particularly whether units are strict matrilines.
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Affiliation(s)
- J.F. Augusto
- Department of Biology, Dalhousie University, Halifax, NS, Canada B3H 4R2
| | - T.R. Frasier
- Department of Biology & Forensic Sciences Programme, Saint Mary’s University, Halifax, NS, Canada B3H 3C3
| | - H. Whitehead
- Department of Biology, Dalhousie University, Halifax, NS, Canada B3H 4R2
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25
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Gero S, Whitehead H. Critical Decline of the Eastern Caribbean Sperm Whale Population. PLoS One 2016; 11:e0162019. [PMID: 27706153 PMCID: PMC5051958 DOI: 10.1371/journal.pone.0162019] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 08/16/2016] [Indexed: 11/19/2022] Open
Abstract
Sperm whale (Physeter macrocephalus) populations were expected to rebuild following the end of commercial whaling. We document the decline of the population in the eastern Caribbean by tracing demographic changes of well-studied social units. We address hypotheses that, over a ten-year period of dedicated effort (2005–2015), unit size, numbers of calves and/or calving rates have each declined. Across 16 units, the number of adults decreased in 12 units, increased in two, and showed no change in two. The number of adults per unit decreased at -0.195 individuals/yr (95% CI: -0.080 to -0.310; P = 0.001). The number of calves also declined, but the decline was not significant. This negative trend of -4.5% per year in unit size started in about 2010, with numbers being fairly stable until then. There are several natural and anthropogenic threats, but no well-substantiated cause for the decline.
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Affiliation(s)
- Shane Gero
- Zoophysiology, Institute for Bioscience, Aarhus University, Aarhus, Denmark
- * E-mail:
| | - Hal Whitehead
- Dept. of Biology, Dalhousie University, Halifax, Canada
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26
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Rendell L, Frantzis A. Mediterranean Sperm Whales, Physeter macrocephalus: The Precarious State of a Lost Tribe. ADVANCES IN MARINE BIOLOGY 2016; 75:37-74. [PMID: 27770991 DOI: 10.1016/bs.amb.2016.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
First observed in the classical era, a population of sperm whales (Physeter macrocephalus) persists to this day in the deep waters of the Mediterranean Sea. Genetic and observational evidence support the notion that this is an isolated population, separated from its Atlantic neighbours. These whales depend on mesopelagic squid for food, and appear to occupy a very similar ecological niche to sperm whales in the open oceans. Recent evidence proving that individuals can pass between the eastern and western deep water basins confirms that this is a single population, not isolated into western and eastern stocks. We lack robust information on their population status, but they could number in the hundreds rather than thousands, and current densities appear to be much lower than those reported in the 1950s, suggesting that we should be very concerned about the conservation status of this population. This makes it vitally important to address the serious threats posed by ship strikes and entanglement in fishing nets, especially driftnets, and to carefully monitor other potential sources of anthropogenic impact. A step change in funding to collect better data and a clear shift in policy priorities are needed if we are to be serious about conserving this population.
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Affiliation(s)
- L Rendell
- Sea Mammal Research Unit, University of St Andrews, St Andrews, Fife, United Kingdom.
| | - A Frantzis
- Pelagos Cetacean Research Institute, Vouliagmeni, Greece
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27
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Guiana dolphins form social modules in a large population with high ranging overlap and small demographic changes. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2188-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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28
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Gero S, Bøttcher A, Whitehead H, Madsen PT. Socially segregated, sympatric sperm whale clans in the Atlantic Ocean. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160061. [PMID: 27429766 PMCID: PMC4929901 DOI: 10.1098/rsos.160061] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 05/10/2016] [Indexed: 05/14/2023]
Abstract
Sperm whales (Physeter macrocephalus) are unusual in that there is good evidence for sympatric populations with distinct culturally determined behaviour, including potential acoustic markers of the population division. In the Pacific, socially segregated, vocal clans with distinct dialects coexist; by contrast, geographical variation in vocal repertoire in the Atlantic has been attributed to drift. We examine networks of acoustic repertoire similarity and social interactions for 11 social units in the Eastern Caribbean. We find the presence of two socially segregated, sympatric vocal clans whose dialects differ significantly both in terms of categorical coda types produced by each clan (Mantel test between clans: matrix correlation = 0.256; p ≤ 0.001) and when using classification-free similarity which ignores defined types (Mantel test between clans: matrix correlation = 0.180; p ≤ 0.001). The more common of the two clans makes a characteristic 1 + 1 + 3 coda, while the other less often sighted clan makes predominantly regular codas. Units were only observed associating with other units within their vocal clan. This study demonstrates that sympatric vocal clans do exist in the Atlantic, that they define a higher order level of social organization as they do in the Pacific, and suggests that cultural identity at the clan level is probably important in this species worldwide.
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Affiliation(s)
- Shane Gero
- Department of Zoophysiology, Institute of Bioscience, Aarhus University, Aarhus, Denmark
- Author for correspondence: Shane Gero e-mail:
| | - Anne Bøttcher
- Department of Zoophysiology, Institute of Bioscience, Aarhus University, Aarhus, Denmark
| | - Hal Whitehead
- Department of Biology, Dalhousie University, Halifax, Canada
| | - Peter Teglberg Madsen
- Department of Zoophysiology, Institute of Bioscience, Aarhus University, Aarhus, Denmark
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29
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Alexander A, Steel D, Hoekzema K, Mesnick SL, Engelhaupt D, Kerr I, Payne R, Baker CS. What influences the worldwide genetic structure of sperm whales (Physeter macrocephalus)? Mol Ecol 2016; 25:2754-72. [DOI: 10.1111/mec.13638] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 03/06/2016] [Accepted: 03/22/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Alana Alexander
- Marine Mammal Institute; Hatfield Marine Science Center; Oregon State University; 2030 SE Marine Science Drive Newport OR 97365 USA
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis OR 97330 USA
- Biodiversity Institute; University of Kansas; 1345 Jayhawk Blvd Lawrence KS 66045 USA
| | - Debbie Steel
- Marine Mammal Institute; Hatfield Marine Science Center; Oregon State University; 2030 SE Marine Science Drive Newport OR 97365 USA
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis OR 97330 USA
| | - Kendra Hoekzema
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis OR 97330 USA
| | - Sarah L. Mesnick
- Southwest Fisheries Science Center; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; 8901 La Jolla Shores Drive La Jolla CA 92037 USA
| | | | - Iain Kerr
- Ocean Alliance; 32 Horton Street Gloucester MA 01930 USA
| | - Roger Payne
- Ocean Alliance; 32 Horton Street Gloucester MA 01930 USA
| | - C. Scott Baker
- Marine Mammal Institute; Hatfield Marine Science Center; Oregon State University; 2030 SE Marine Science Drive Newport OR 97365 USA
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis OR 97330 USA
- School of Biological Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
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30
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Fais A, Lewis TP, Zitterbart DP, Álvarez O, Tejedor A, Aguilar Soto N. Abundance and Distribution of Sperm Whales in the Canary Islands: Can Sperm Whales in the Archipelago Sustain the Current Level of Ship-Strike Mortalities? PLoS One 2016; 11:e0150660. [PMID: 26999791 PMCID: PMC4801403 DOI: 10.1371/journal.pone.0150660] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 02/16/2016] [Indexed: 12/02/2022] Open
Abstract
Sperm whales are present in the Canary Islands year-round, suggesting that the archipelago is an important area for this species in the North Atlantic. However, the area experiences one of the highest reported rates of sperm whale ship-strike in the world. Here we investigate if the number of sperm whales found in the archipelago can sustain the current rate of ship-strike mortality. The results of this study may also have implications for offshore areas where concentrations of sperm whales may coincide with high densities of ship traffic, but where ship-strikes may be undocumented. The absolute abundance of sperm whales in an area of 52933 km2, covering the territorial waters of the Canary Islands, was estimated from 2668 km of acoustic line-transect survey using Distance sampling analysis. Data on sperm whale diving and acoustic behaviour, obtained from bio-logging, were used to calculate g(0) = 0.92, this is less than one because of occasional extended periods when whales do not echolocate. This resulted in an absolute abundance estimate of 224 sperm whales (95% log-normal CI 120–418) within the survey area. The recruitment capability of this number of whales, some 2.5 whales per year, is likely to be exceeded by the current ship-strike mortality rate. Furthermore, we found areas of higher whale density within the archipelago, many coincident with those previously described, suggesting that these are important habitats for females and immature animals inhabiting the archipelago. Some of these areas are crossed by active shipping lanes increasing the risk of ship-strikes. Given the philopatry in female sperm whales, replacement of impacted whales might be limited. Therefore, the application of mitigation measures to reduce the ship-strike mortality rate seems essential for the conservation of sperm whales in the Canary Islands.
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Affiliation(s)
- Andrea Fais
- Biodiversidad, Ecología Marina y Conservación (BIOECOMAC), Dept. Animal Biology, Geology and Edaphology, La Laguna University, Tenerife, Canary Islands, Spain
- * E-mail:
| | - Tim P. Lewis
- Biodiversidad, Ecología Marina y Conservación (BIOECOMAC), Dept. Animal Biology, Geology and Edaphology, La Laguna University, Tenerife, Canary Islands, Spain
| | - Daniel P. Zitterbart
- Ocean Acoustics Lab, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung, Bremerhaven, Germany
- Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Omar Álvarez
- Biodiversidad, Ecología Marina y Conservación (BIOECOMAC), Dept. Animal Biology, Geology and Edaphology, La Laguna University, Tenerife, Canary Islands, Spain
- CIMA Canarias, Avda. Los Majuelos 115, 38107 Santa Cruz de Tenerife, Tenerife, Canary Islands, Spain
| | - Ana Tejedor
- KAI Marine Services, Nalon 16, 28240, Hoyo de Manzanares, Madrid, Spain
| | - Natacha Aguilar Soto
- Biodiversidad, Ecología Marina y Conservación (BIOECOMAC), Dept. Animal Biology, Geology and Edaphology, La Laguna University, Tenerife, Canary Islands, Spain
- CREEM, Centre for Research into Ecological and Environmental Modelling, Scottish Oceans Institute, University of St. Andrews, St Andrews, Scotland
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Gero S, Whitehead H, Rendell L. Individual, unit and vocal clan level identity cues in sperm whale codas. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150372. [PMID: 26909165 PMCID: PMC4736920 DOI: 10.1098/rsos.150372] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/03/2015] [Indexed: 05/09/2023]
Abstract
The 'social complexity hypothesis' suggests that complex social structure is a driver of diversity in animal communication systems. Sperm whales have a hierarchically structured society in which the largest affiliative structures, the vocal clans, are marked on ocean-basin scales by culturally transmitted dialects of acoustic signals known as 'codas'. We examined variation in coda repertoires among both individual whales and social units-the basic element of sperm whale society-using data from nine Caribbean social units across six years. Codas were assigned to individuals using photo-identification and acoustic size measurement, and we calculated similarity between repertoires using both continuous and categorical methods. We identified 21 coda types. Two of those ('1+1+3' and '5R1') made up 65% of the codas recorded, were shared across all units and have dominated repertoires in this population for at least 30 years. Individuals appear to differ in the way they produce '5R1' but not '1+1+3' coda. Units use distinct 4-click coda types which contribute to making unit repertoires distinctive. Our results support the social complexity hypothesis in a marine species as different patterns of variation between coda types suggest divergent functions, perhaps representing selection for identity signals at several levels of social structure.
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Affiliation(s)
- Shane Gero
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Jutland, Denmark
- Department of Biology, Dalhousie University, Halifax, Canada B3H 4J1
- Centre for Social Learning and Cognitive Evolution, and Sea Mammal Research Unit, School of Biology, University of St Andrews, St Andrews KY16 9TH, UK
- Author for correspondence: Shane Gero e-mail:
| | - Hal Whitehead
- Department of Biology, Dalhousie University, Halifax, Canada B3H 4J1
| | - Luke Rendell
- Centre for Social Learning and Cognitive Evolution, and Sea Mammal Research Unit, School of Biology, University of St Andrews, St Andrews KY16 9TH, UK
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Carter G, Leffer L. Social Grooming in Bats: Are Vampire Bats Exceptional? PLoS One 2015; 10:e0138430. [PMID: 26445502 PMCID: PMC4596566 DOI: 10.1371/journal.pone.0138430] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 08/30/2015] [Indexed: 11/18/2022] Open
Abstract
Evidence for long-term cooperative relationships comes from several social birds and mammals. Vampire bats demonstrate cooperative social bonds, and like primates, they maintain these bonds through social grooming. It is unclear, however, to what extent vampires are special among bats in this regard. We compared social grooming rates of common vampire bats Desmodus rotundus and four other group-living bats, Artibeus jamaicensis, Carollia perspicillata, Eidolon helvum and Rousettus aegyptiacus, under the same captive conditions of fixed association and no ectoparasites. We conducted 13 focal sampling sessions for each combination of sex and species, for a total of 1560 presence/absence observations per species. We observed evidence for social grooming in all species, but social grooming rates were on average 14 times higher in vampire bats than in other species. Self-grooming rates did not differ. Vampire bats spent 3.7% of their awake time social grooming (95% CI = 1.5-6.3%), whereas bats of the other species spent 0.1-0.5% of their awake time social grooming. Together with past data, this result supports the hypothesis that the elevated social grooming rate in the vampire bat is an adaptive trait, linked to their social bonding and unique regurgitated food sharing behavior.
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Affiliation(s)
- Gerald Carter
- Department of Biology, University of Maryland, College Park, Maryland, United States of America
| | - Lauren Leffer
- Department of Biology, University of Maryland, College Park, Maryland, United States of America
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