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Huang X, Li G, Zhang G, Li Z, Zhao L, Zhu M, Xiang Q, Liu X, Tian M, Zhang H, Buesching CD, Liu D. Friend or foe? Using eye-tracking technology to investigate the visual discrimination ability of giant pandas. Curr Zool 2024; 70:430-439. [PMID: 39176058 PMCID: PMC11336681 DOI: 10.1093/cz/zoad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 04/27/2023] [Indexed: 08/24/2024] Open
Abstract
The role that visual discriminative ability plays among giant pandas in social communication and individual discrimination has received less attention than olfactory and auditory modalities. Here, we used an eye-tracker technology to investigate pupil fixation patterns for 8 captive male giant pandas Ailuropoda melanoleuca. We paired images (N = 26) of conspecifics against: 1) sympatric predators (gray wolves and tigers), and non-threatening sympatric species (golden pheasant, golden snub-nosed monkey, takin, and red panda), 2) conspecifics with atypical fur coloration (albino and brown), and 3) zookeepers/non-zookeepers wearing either work uniform or plain clothing. For each session, we tracked the panda's pupil movements and measured pupil first fixation point (FFP), fixation latency, total fixation count (TFC), and duration (TFD) of attention to each image. Overall, pandas exhibited similar attention (FFPs and TFCs) to images of predators and non-threatening sympatric species. Images of golden pheasant, snub-nosed monkey, and tiger received less attention (TFD) than images of conspecifics, whereas images of takin and red panda received more attention, suggesting a greater alertness to habitat or food competitors than to potential predators. Pandas' TFCs were greater for images of black-white conspecifics than for albino or brown phenotypes, implying that familiar color elicited more interest. Pandas reacted differently to images of men versus women. For images of women only, pandas gave more attention (TFC) to familiar combinations (uniformed zookeepers and plain-clothed non-zookeepers), consistent with the familiarity hypothesis. That pandas can use visual perception to discriminate intra-specifically and inter-specifically, including details of human appearance, has applications for panda conservation and captive husbandry.
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Affiliation(s)
- Xinrui Huang
- Ministry of Education, Key Laboratory of Biodiversity Science and Ecological Engineering, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Guo Li
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in the Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Sichuan 623004, China
| | - Guiquan Zhang
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in the Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Sichuan 623004, China
| | - Zixiang Li
- Ministry of Education, Key Laboratory of Biodiversity Science and Ecological Engineering, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Lin Zhao
- Ministry of Education, Key Laboratory of Biodiversity Science and Ecological Engineering, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Mengdie Zhu
- Ministry of Education, Key Laboratory of Biodiversity Science and Ecological Engineering, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Qinghua Xiang
- School of Computer and Information Technology, Beijing Jiaotong University, Beijing 100044, China
| | - Xuefeng Liu
- Beijing Key Laboratory of Captive Wildlife Technology, Beijing Zoo, Beijing 100044, China
| | - Mei Tian
- School of Computer and Information Technology, Beijing Jiaotong University, Beijing 100044, China
| | - Hemin Zhang
- Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in the Giant Panda National Park, China Conservation and Research Center for the Giant Panda, Sichuan 623004, China
| | - Christina D Buesching
- Department of Biology, Irving K. Barber Faculty of Science, The University of British Columbia, Okanagan Campus, Kelowna, BC, Canada
| | - Dingzhen Liu
- Ministry of Education, Key Laboratory of Biodiversity Science and Ecological Engineering, Department of Ecology, College of Life Sciences, Beijing Normal University, Beijing 100875, China
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2
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Oestreich WK, Oliver RY, Chapman MS, Go MC, McKenna MF. Listening to animal behavior to understand changing ecosystems. Trends Ecol Evol 2024:S0169-5347(24)00145-9. [PMID: 38972787 DOI: 10.1016/j.tree.2024.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 06/11/2024] [Accepted: 06/14/2024] [Indexed: 07/09/2024]
Abstract
Interpreting sound gives powerful insight into the health of ecosystems. Beyond detecting the presence of wildlife, bioacoustic signals can reveal their behavior. However, behavioral bioacoustic information is underused because identifying the function and context of animals' sounds remains challenging. A growing acoustic toolbox is allowing researchers to begin decoding bioacoustic signals by linking individual and population-level sensing. Yet, studies integrating acoustic tools for behavioral insight across levels of biological organization remain scarce. We aim to catalyze the emerging field of behavioral bioacoustics by synthesizing recent successes and rising analytical, logistical, and ethical challenges. Because behavior typically represents animals' first response to environmental change, we posit that behavioral bioacoustics will provide theoretical and applied insights into animals' adaptations to global change.
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Affiliation(s)
| | - Ruth Y Oliver
- Bren School of Environmental Science and Management, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Melissa S Chapman
- National Center for Ecological Analysis and Synthesis, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Madeline C Go
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Megan F McKenna
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
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3
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Zeng Y, Baciadonna L, Davies JR, Pilenga C, Favaro L, Garcia-Pelegrin E. Bottlenose dolphins ( Tursiops truncatus) display gaze alternation and referential communication in an impossible task. Heliyon 2024; 10:e33192. [PMID: 39005890 PMCID: PMC11239698 DOI: 10.1016/j.heliyon.2024.e33192] [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: 01/20/2024] [Revised: 06/13/2024] [Accepted: 06/16/2024] [Indexed: 07/16/2024] Open
Abstract
Gaze cues play a vital role in conveying critical information about objects and locations necessary for survival, such as food sources, predators, and the attentional states of conspecific and heterospecific individuals. During referential intentional communication, the continuous alternation of gaze between a communicative partner and a specific object or point of interest attracts the partner's attention towards the target. This behaviour is considered by many as essential for understanding intentions and is thought to involve mental planning. Here, we investigated the behavioural responses of seven bottlenose dolphins (Tursiops truncatus) that were given an impossible task in the presence of two experimenters (a 'commanding experimenter' and a 'non-commanding experimenter'), whose attentional state towards the dolphins varied. We found that the dolphins spontaneously displayed gaze alternation, specifically triadic referential pointing, only when the human commanding experimenter was facing them. However, they ceased to alternate their gaze between the impossible object and the commanding experimenter when the experimenter had their back turned. Notably, the dolphins' behaviour differed from general pointing and gaze, as their triadic sequence occurred within a narrow time window. These findings suggest that the dolphins were sensitive to human attentional cues and utilized their own gaze cue (pointing) as a salient signal to attract the attention of the commanding experimenter towards a specific location.
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Affiliation(s)
- Ying Zeng
- Department of Psychology, National University of Singapore, Singapore
| | - Luigi Baciadonna
- Institut de Biologie Paris-Seine, Sorbonne University, INSERM, CNRS, Paris, France
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - James R Davies
- Department of Psychology, University of Cambridge, Cambridge, UK
| | | | - Livio Favaro
- Institut de Biologie Paris-Seine, Sorbonne University, INSERM, CNRS, Paris, France
- CIRCE, Centro Interuniversitario per la Ricerca sui Cetacei, University of Siena, Siena, Italy
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4
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Brewer AM, Castellote M, Van Cise AM, Gage T, Berdahl AM. Communication in Cook Inlet beluga whales: Describing the vocal repertoire and masking of calls by commercial ship noise. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:3487-3505. [PMID: 38032263 DOI: 10.1121/10.0022516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023]
Abstract
Many species rely on acoustic communication to coordinate activities and communicate to conspecifics. Cataloging vocal behavior is a first step towards understanding how individuals communicate information and how communication may be degraded by anthropogenic noise. The Cook Inlet beluga population is endangered with an estimated 331 individuals. Anthropogenic noise is considered a threat for this population and can negatively impact communication. To characterize this population's vocal behavior, vocalizations were measured and classified into three categories: whistles (n = 1264, 77%), pulsed calls (n = 354, 22%), and combined calls (n = 15, 1%), resulting in 41 call types. Two quantitative analyses were conducted to compare with the manual classification. A classification and regression tree and Random Forest had a 95% and 85% agreement with the manual classification, respectively. The most common call types per category were then used to investigate masking by commercial ship noise. Results indicate that these call types were partially masked by distant ship noise and completely masked by close ship noise in the frequency range of 0-12 kHz. Understanding vocal behavior and the effects of masking in Cook Inlet belugas provides important information supporting the management of this endangered population.
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Affiliation(s)
- Arial M Brewer
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Manuel Castellote
- Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington, Seattle, Washington 98195, USA
| | - Amy M Van Cise
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Tom Gage
- Alaska Department of Fish and Game, Anchorage, Alaska 99518, USA
| | - Andrew M Berdahl
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
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5
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Rio R. First acoustic evidence of signature whistle production by spinner dolphins (Stenella longirostris). Anim Cogn 2023; 26:1915-1927. [PMID: 37676587 DOI: 10.1007/s10071-023-01824-8] [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: 03/03/2023] [Revised: 08/23/2023] [Accepted: 08/29/2023] [Indexed: 09/08/2023]
Abstract
A dolphin's signature whistle (SW) is a distinctive acoustic signal, issued in a bout pattern of unique frequency modulation contours; it allows individuals belonging to a given group to recognize each other and, consequently, to maintain contact and cohesion. The current study is the first scientific evidence that spinner dolphins (Stenella longirostris) produce SWs. Acoustic data were recorded at a shallow rest bay called "Biboca", in Fernando de Noronha Archipelago, Brazil. In total, 1902 whistles were analyzed; 40% (753/1,902) of them were classified as stereotyped whistles (STW). Based on the SIGID method, 63% (472/753) of all STWs were identified as SWs; subsequently, they were categorized into one of 18 SW types. SWs accounted for 25% (472/1,902) of the acoustic repertoire. External observers have shown near perfect agreement to classify whistles into the adopted SW categorization. Most acoustic and temporal variables measured for SWs showed mean values similar to those recorded in other studies with spinner dolphins, whose authors did not differentiate SWs from non-SWs. Principal component analysis has explained 78% of total SW variance, and it emphasized the relevance of shape/contour and frequency variables to SW variance. This scientific discovery helps improving bioacoustics knowledge about the investigated species. Future studies to be conducted in Fernando de Noronha Archipelago should focus on continuous investigations about SW development and use by S. longirostris, expanding individuals' identifications (Photo ID and SW Noronha Catalog), assessing long-term whistle stability and emission rates, and making mother-offspring comparisons with sex-based differences.
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Affiliation(s)
- Raul Rio
- Laboratory of Observational and Bioacoustics Technologies Applied to Biodiversity (TecBio), Department of Veterinary Medicine, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Minas Gerais, Brazil.
- Ocean Sound, Non-Governmental Organization (NGO), Santos, São Paulo, Brazil.
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6
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Smeele SQ, Senar JC, Aplin LM, McElreath MB. Evidence for vocal signatures and voice-prints in a wild parrot. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230835. [PMID: 37800160 PMCID: PMC10548090 DOI: 10.1098/rsos.230835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/04/2023] [Indexed: 10/07/2023]
Abstract
In humans, identity is partly encoded in a voice-print that is carried across multiple vocalizations. Other species also signal vocal identity in calls, such as shown in the contact call of parrots. However, it remains unclear to what extent other call types in parrots are individually distinct, and whether there is an analogous voice-print across calls. Here we test if an individual signature is present in other call types, how stable this signature is, and if parrots exhibit voice-prints across call types. We recorded 5599 vocalizations from 229 individually marked monk parakeets (Myiopsitta monachus) over a 2-year period in Barcelona, Spain. We examined five distinct call types, finding evidence for an individual signature in three. We further show that in the contact call, while birds are individually distinct, the calls are more variable than previously assumed, changing over short time scales (seconds to minutes). Finally, we provide evidence for voice-prints across multiple call types, with a discriminant function being able to predict caller identity across call types. This suggests that monk parakeets may be able to use vocal cues to recognize conspecifics, even across vocalization types and without necessarily needing active vocal signatures of identity.
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Affiliation(s)
- Simeon Q. Smeele
- Cognitive and Cultural Ecology Research Group, Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Lucy M. Aplin
- Cognitive and Cultural Ecology Research Group, Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Evolutionary Biology and Environmental Science, University of Zurich, Zurich, Switzerland
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australia
| | - Mary Brooke McElreath
- Cognitive and Cultural Ecology Research Group, Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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7
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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: 4.0] [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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8
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Smith-Vidaurre G, Pérez-Marrufo V, Hobson EA, Salinas-Melgoza A, Wright TF. Individual identity information persists in learned calls of introduced parrot populations. PLoS Comput Biol 2023; 19:e1011231. [PMID: 37498847 PMCID: PMC10374045 DOI: 10.1371/journal.pcbi.1011231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 06/01/2023] [Indexed: 07/29/2023] Open
Abstract
Animals can actively encode different types of identity information in learned communication signals, such as group membership or individual identity. The social environments in which animals interact may favor different types of information, but whether identity information conveyed in learned signals is robust or responsive to social disruption over short evolutionary timescales is not well understood. We inferred the type of identity information that was most salient in vocal signals by combining computational tools, including supervised machine learning, with a conceptual framework of "hierarchical mapping", or patterns of relative acoustic convergence across social scales. We used populations of a vocal learning species as a natural experiment to test whether the type of identity information emphasized in learned vocalizations changed in populations that experienced the social disruption of introduction into new parts of the world. We compared the social scales with the most salient identity information among native and introduced range monk parakeet (Myiopsitta monachus) calls recorded in Uruguay and the United States, respectively. We also evaluated whether the identity information emphasized in introduced range calls changed over time. To place our findings in an evolutionary context, we compared our results with another parrot species that exhibits well-established and distinctive regional vocal dialects that are consistent with signaling group identity. We found that both native and introduced range monk parakeet calls displayed the strongest convergence at the individual scale and minimal convergence within sites. We did not identify changes in the strength of acoustic convergence within sites over time in the introduced range calls. These results indicate that the individual identity information in learned vocalizations did not change over short evolutionary timescales in populations that experienced the social disruption of introduction. Our findings point to exciting new research directions about the robustness or responsiveness of communication systems over different evolutionary timescales.
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Affiliation(s)
- Grace Smith-Vidaurre
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
- Laboratory of Neurogenetics of Language, Rockefeller University, New York, New York, United States of America
- Rockefeller University Field Research Center, Millbrook, New York, United States of America
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Valeria Pérez-Marrufo
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
- Department of Biology, Syracuse University, Syracuse, New York, United States of America
| | - Elizabeth A. Hobson
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | | | - Timothy F. Wright
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
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Arnaud V, Pellegrino F, Keenan S, St-Gelais X, Mathevon N, Levréro F, Coupé C. Improving the workflow to crack Small, Unbalanced, Noisy, but Genuine (SUNG) datasets in bioacoustics: The case of bonobo calls. PLoS Comput Biol 2023; 19:e1010325. [PMID: 37053268 PMCID: PMC10129004 DOI: 10.1371/journal.pcbi.1010325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 04/25/2023] [Accepted: 03/01/2023] [Indexed: 04/15/2023] Open
Abstract
Despite the accumulation of data and studies, deciphering animal vocal communication remains challenging. In most cases, researchers must deal with the sparse recordings composing Small, Unbalanced, Noisy, but Genuine (SUNG) datasets. SUNG datasets are characterized by a limited number of recordings, most often noisy, and unbalanced in number between the individuals or categories of vocalizations. SUNG datasets therefore offer a valuable but inevitably distorted vision of communication systems. Adopting the best practices in their analysis is essential to effectively extract the available information and draw reliable conclusions. Here we show that the most recent advances in machine learning applied to a SUNG dataset succeed in unraveling the complex vocal repertoire of the bonobo, and we propose a workflow that can be effective with other animal species. We implement acoustic parameterization in three feature spaces and run a Supervised Uniform Manifold Approximation and Projection (S-UMAP) to evaluate how call types and individual signatures cluster in the bonobo acoustic space. We then implement three classification algorithms (Support Vector Machine, xgboost, neural networks) and their combination to explore the structure and variability of bonobo calls, as well as the robustness of the individual signature they encode. We underscore how classification performance is affected by the feature set and identify the most informative features. In addition, we highlight the need to address data leakage in the evaluation of classification performance to avoid misleading interpretations. Our results lead to identifying several practical approaches that are generalizable to any other animal communication system. To improve the reliability and replicability of vocal communication studies with SUNG datasets, we thus recommend: i) comparing several acoustic parameterizations; ii) visualizing the dataset with supervised UMAP to examine the species acoustic space; iii) adopting Support Vector Machines as the baseline classification approach; iv) explicitly evaluating data leakage and possibly implementing a mitigation strategy.
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Affiliation(s)
- Vincent Arnaud
- Département des arts, des lettres et du langage, Université du Québec à Chicoutimi, Chicoutimi, Canada
- Laboratoire Dynamique Du Langage, UMR 5596, Université de Lyon, CNRS, Lyon, France
| | - François Pellegrino
- Laboratoire Dynamique Du Langage, UMR 5596, Université de Lyon, CNRS, Lyon, France
| | - Sumir Keenan
- ENES Bioacoustics Research Laboratory, University of Saint Étienne, CRNL, CNRS UMR 5292, Inserm UMR_S 1028, Saint-Étienne, France
| | - Xavier St-Gelais
- Département des arts, des lettres et du langage, Université du Québec à Chicoutimi, Chicoutimi, Canada
| | - Nicolas Mathevon
- ENES Bioacoustics Research Laboratory, University of Saint Étienne, CRNL, CNRS UMR 5292, Inserm UMR_S 1028, Saint-Étienne, France
| | - Florence Levréro
- ENES Bioacoustics Research Laboratory, University of Saint Étienne, CRNL, CNRS UMR 5292, Inserm UMR_S 1028, Saint-Étienne, France
| | - Christophe Coupé
- Laboratoire Dynamique Du Langage, UMR 5596, Université de Lyon, CNRS, Lyon, France
- Department of Linguistics, The University of Hong Kong, Hong Kong, China
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10
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Anthropogenic noise impairs cooperation in bottlenose dolphins. Curr Biol 2023; 33:749-754.e4. [PMID: 36638798 DOI: 10.1016/j.cub.2022.12.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/16/2022] [Accepted: 12/22/2022] [Indexed: 01/15/2023]
Abstract
Understanding the impact of human disturbance on wildlife populations is of societal importance,1 with anthropogenic noise known to impact a range of taxa, including mammals,2 birds,3 fish,4 and invertebrates.5 While animals are known to use acoustic and other behavioral mechanisms to compensate for increasing noise at the individual level, our understanding of how noise impacts social animals working together remains limited. Here, we investigated the effect of noise on coordination between two bottlenose dolphins performing a cooperative task. We previously demonstrated that the dolphin dyad can use whistles to coordinate their behavior, working together with extreme precision.6 By equipping each dolphin with a sound-and-movement recording tag (DTAG-37) and exposing them to increasing levels of anthropogenic noise, we show that both dolphins nearly doubled their whistle durations and increased whistle amplitude in response to increasing noise. While these acoustic compensatory mechanisms are the same as those frequently used by wild cetaceans,8,9,10,11,12,13 they were insufficient to overcome the effect of noise on behavioral coordination. Indeed, cooperative task success decreased in the presence of noise, dropping from 85% during ambient noise control trials to 62.5% during the highest noise exposure. This is the first study to demonstrate in any non-human species that noise impairs communication between conspecifics performing a cooperative task. Cooperation facilitates vital functions across many taxa and our findings highlight the need to account for the impact of disturbance on functionally important group tasks in wild animal populations.
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11
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Panova E, Agafonov A. Possible occurrence of contact calls in all‐male groups of free‐ranging beluga whales. J Zool (1987) 2023. [DOI: 10.1111/jzo.13054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- E. Panova
- Shirshov Institute of Oceanology Russian Academy of Sciences Moscow Russia
| | - A. Agafonov
- Shirshov Institute of Oceanology Russian Academy of Sciences Moscow Russia
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12
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Berthet M, Coye C, Dezecache G, Kuhn J. Animal linguistics: a primer. Biol Rev Camb Philos Soc 2023; 98:81-98. [PMID: 36189714 PMCID: PMC10091714 DOI: 10.1111/brv.12897] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 01/12/2023]
Abstract
The evolution of language has been investigated by several research communities, including biologists and linguists, striving to highlight similar linguistic capacities across species. To date, however, no consensus exists on the linguistic capacities of non-human species. Major controversies remain on the use of linguistic terminology, analysis methods and behavioural data collection. The field of 'animal linguistics' has emerged to overcome these difficulties and attempt to reach uniform methods and terminology. This primer is a tutorial review of 'animal linguistics'. It describes the linguistic concepts of semantics, pragmatics and syntax, and proposes minimal criteria to be fulfilled to claim that a given species displays a particular linguistic capacity. Second, it reviews relevant methods successfully applied to the study of communication in animals and proposes a list of useful references to detect and overcome major pitfalls commonly observed in the collection of animal behaviour data. This primer represents a step towards mutual understanding and fruitful collaborations between linguists and biologists.
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Affiliation(s)
- Mélissa Berthet
- Institut Jean Nicod, Département d'études cognitives, ENS, EHESS, CNRS, PSL University, 75005, Paris, France.,Center for the Interdisciplinary Study of Language Evolution, University of Zürich, Affolternstrasse 56, 8050, Zurich, Switzerland.,Department of Comparative Language Science, University of Zürich, Affolternstrasse 56, 8050, Zurich, Switzerland
| | - Camille Coye
- Institut Jean Nicod, Département d'études cognitives, ENS, EHESS, CNRS, PSL University, 75005, Paris, France.,Center for Ecology and Conservation, Bioscience Department, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | | | - Jeremy Kuhn
- Institut Jean Nicod, Département d'études cognitives, ENS, EHESS, CNRS, PSL University, 75005, Paris, France
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13
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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: 2.0] [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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14
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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: 1.5] [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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15
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Longden EG, Gillespie D, Mann DA, McHugh KA, Rycyk AM, Wells RS, Tyack PL. Comparison of the marine soundscape before and during the COVID-19 pandemic in dolphin habitat in Sarasota Bay, FL. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 152:3170. [PMID: 36586823 DOI: 10.1121/10.0015366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 11/06/2022] [Indexed: 06/17/2023]
Abstract
During the COVID-19 pandemic, changes in vessel activity and associated noise have been reported globally. Sarasota Bay is home to a large and increasing number of recreational vessels as well as a long-term resident community of bottlenose dolphins, Tursiops truncatus. Data were analyzed from two hydrophones to compare the soundscape during the COVID-19 pandemic to previous years (March-May 2020 and 2018/2019). Hourly metrics were calculated: vessel passes, 95th percentile sound levels [125 Hz and 16 kHz third octave bands (TOBs), and two broader bands: 88-1122 Hz and 1781-17 959 Hz], and dolphin whistle detection to understand changes in vessel activity and the effect on wildlife. Vessel activity increased during COVID-19 restrictions by almost 80% at one site and remained the same at the other site. Of the four sound level measures, only the 125 Hz TOB and 88-1122 Hz band increased with vessel activity at both sites, suggesting that these may be appropriate measures of noise from rapid pass-bys of small vessels in very shallow (<10 m) habitats. Dolphin whistle detection decreased during COVID-19 restrictions at one site but remained the same at the site that experienced increased vessel activity. The results suggest that pandemic effects on wildlife should not be viewed as homogeneous globally.
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Affiliation(s)
- E G Longden
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, KY16 8LB, United Kingdom
| | - D Gillespie
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, KY16 8LB, United Kingdom
| | - D A Mann
- Loggerhead Instruments, Inc., Sarasota, Florida 34238, USA
| | - K A McHugh
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, Sarasota, Florida 34236, USA
| | - A M Rycyk
- Division of Natural Sciences, New College of Florida, Sarasota, Florida 34243, USA
| | - R S Wells
- Chicago Zoological Society's Sarasota Dolphin Research Program, c/o Mote Marine Laboratory, Sarasota, Florida 34236, USA
| | - P L Tyack
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, KY16 8LB, United Kingdom
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16
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Sportelli JJ, Jones BL, Ridgway SH. Non-linear phenomena: a common acoustic feature of bottlenose dolphin ( Tursiops truncatus) signature whistles. BIOACOUSTICS 2022. [DOI: 10.1080/09524622.2022.2106306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Jessica J. Sportelli
- Conservation Biology, Sound and Health, National Marine Mammal Foundation, San Diego, CA, USA
| | - Brittany L. Jones
- Conservation Biology, Sound and Health, National Marine Mammal Foundation, San Diego, CA, USA
| | - Sam H. Ridgway
- Conservation Biology, Sound and Health, National Marine Mammal Foundation, San Diego, CA, USA
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17
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Bruck JN, Pack AA. Understanding across the senses: cross-modal studies of cognition in cetaceans. Anim Cogn 2022; 25:1059-1075. [PMID: 36074310 DOI: 10.1007/s10071-022-01684-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 08/15/2022] [Accepted: 08/18/2022] [Indexed: 11/29/2022]
Abstract
Cross-modal approaches to the study of sensory perception, social recognition, cognition, and mental representation have proved fruitful in humans as well as in a variety of other species including toothed whales in revealing equivalencies that suggest that different sensory stimuli associated with objects or individuals may effectively evoke mental representations that are, respectively, object based or individual based. Building on established findings of structural equivalence in the form of spontaneous recognition of complex shapes across the modalities of echolocation and vision and behavior favoring identity echoic-visual cross-modal relationships over associative echoic-visual cross-modal relationships, examinations of transitive inference equivalencies from initially learned associations of visual and acoustic stimuli, and recent work examining spontaneous cross-modal social recognition of individual identity across acoustic and gustatory chemical modalities (i.e., the equivalence relationships among an individual's characteristics), we examine the history, utility and implications for cross-modal research in cetacean cognition. Drawing from research findings on bottlenose dolphins and beluga whales as well as other species we suggest future directions for cetacean cross-modal research to further illuminate understanding how structural and individual sensory equivalencies lead to object-centered and individual-centered mental representations, as well as to explore the potential for practical applications related to cetacean conservation.
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Affiliation(s)
- Jason N Bruck
- Department of Biology, Stephen F. Austin State University, Miller Science Building 112 SFA Station, P.O. Box 13003, Nacogdoches, Texas, 75962, USA.
| | - Adam A Pack
- Department of Psychology, Department of Biology, University of Hawai'i at Hilo, 200 West Kawili Street, Hilo, Hawai'i, 96720, USA.,The Dolphin Institute, 1178 North Kumuwaina Place, Hilo, Hawai'i, 96720, USA
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18
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Selection levels on vocal individuality: strategic use or byproduct. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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19
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Girard-Buttoz C, Bortolato T, Laporte M, Grampp M, Zuberbühler K, Wittig RM, Crockford C. Population-specific call order in chimpanzee greeting vocal sequences. iScience 2022; 25:104851. [PMID: 36034222 PMCID: PMC9399282 DOI: 10.1016/j.isci.2022.104851] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/01/2022] [Accepted: 07/25/2022] [Indexed: 11/25/2022] Open
Abstract
Primates rarely learn new vocalizations, but they can learn to use their vocalizations in different contexts. Such “vocal usage learning,” particularly in vocal sequences, is a hallmark of human language, but remains understudied in non-human primates. We assess usage learning in four wild chimpanzee communities of Taï and Budongo Forests by investigating population differences in call ordering of a greeting vocal sequence. Whilst in all groups, these sequences consisted of pant-hoots (long-distance contact call) and pant-grunts (short-distance submissive call), the order of the two calls differed across populations. Taï chimpanzees consistently commenced greetings with pant-hoots, whereas Budongo chimpanzees started with pant-grunts. We discuss different hypotheses to explain this pattern and conclude that higher intra-group aggression in Budongo may have led to a local pattern of individuals signaling submission first. This highlights how within-species variation in social dynamics may lead to flexibility in call order production, possibly acquired via usage learning. Chimpanzees combine pant-grunt and pant-hoot calls into a greeting hoot sequence Call-order of these greeting and contact calls is population specific Pant-grunt is uttered first in the population with higher in-group aggressions Vocal usage learning may lead to these population differences in sequence structure
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20
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King SL, Jensen FH. Rise of the machines: Integrating technology with playback experiments to study cetacean social cognition in the wild. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13935] [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)
- Stephanie L. King
- School of Biological Sciences University of Bristol BS8 1TQ Bristol United Kingdom
| | - Frants H. Jensen
- Biology department, Syracuse University 107 College Place 13244 Syracuse NY USA
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21
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Hamilton RA, Gazda SK, King SL, Stakhammar J, Connor IC. Bottlenose dolphin communication during a role-specialized group foraging task. Behav Processes 2022; 200:104691. [PMID: 35750114 DOI: 10.1016/j.beproc.2022.104691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 05/16/2022] [Accepted: 06/18/2022] [Indexed: 11/02/2022]
Abstract
A division of labor with role specialization is defined as individuals specializing in a subtask during repetitions of a group task. While this behavior is ubiquitous among humans, there are only four candidates found among non-eusocial mammals: lions, mice, chimpanzees, and bottlenose dolphins. Bottlenose dolphins in the Cedar Keys, Florida, engage in role specialized "driver-barrier feeding", where a "driver" dolphin herds mullet towards "barrier" dolphins. Thus trapped, the mullet leap out of the water where the dolphins catch them in air. To investigate whether dolphins use acoustic cues or signals to coordinate this behavior, vocalizations were recorded before and during driver-barrier feeding. Results of fine-scale audio and video analysis during 81 events by 7 different driver individuals suggest that barrier animals coordinate movements during these events by cueing on the driver's echolocation. Analyses of dolphin whistle occurrence before driving events versus another foraging technique, which does not involve role specialization, revealed significantly higher whistle production immediately prior to driver-barrier events. Possible whistle functions include signaling motivation, recruiting individuals to participate, and/or behavioral coordination. While the use of cues and signals is common in humans completing role-specialized tasks, this is the first study to investigate the use of vocalizations in the coordination of a role-specialized behavior in a non-human mammal.
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Affiliation(s)
- Rebecca A Hamilton
- Biology Department, University of Massachusetts Dartmouth, North Dartmouth, MA, USA.
| | | | - Stephanie L King
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | | | - Ichard C Connor
- Biology Department, University of Massachusetts Dartmouth, North Dartmouth, MA, USA
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22
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Jones B, Tufano S, Ridgway S. Signature whistles exhibit a 'fade-in' and then 'fade-out' pattern of relative amplitude declination. Behav Processes 2022; 200:104690. [PMID: 35709885 DOI: 10.1016/j.beproc.2022.104690] [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: 11/19/2021] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/19/2022]
Abstract
Bottlenose dolphins have individually distinct signature whistles that are characterized by a stereotyped frequency-time contour. Signature whistles are commonly exchanged with short time delays between calls. Dolphin whistles are produced by pressurized nasal sacs that increase and then decrease in pressure over emission. This study found that the relative amplitude modulation pattern over time exhibited the same fade-in and then fade-out pattern in the signature whistles of eight bottlenose dolphins at the Navy in San Diego, CA. Both the initial and final five percent of the whistle's duration also had significantly lower mean relative amplitude than the center five percent. The current analyses of the amplitude-time relationship was then integrated to a previously reported model of the negative relationship between relative log amplitude and log peak frequency. This produced a more robust model for accounting for the predictable aspects of the more broadly non-stereotyped amplitude modulations of signature whistles. Whether dolphins can intentionally manipulate these amplitude features or they are simple by-products of the sound production system, and further whether they are perceived and utilized by receivers, is an exciting area for continued research.
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Affiliation(s)
- Brittany Jones
- National Marine Mammal Foundation: 3131, 2240 Shelter Island Dr, San Diego, CA 92106, USA.
| | - Samantha Tufano
- National Marine Mammal Foundation: 3131, 2240 Shelter Island Dr, San Diego, CA 92106, USA
| | - Sam Ridgway
- National Marine Mammal Foundation: 3131, 2240 Shelter Island Dr, San Diego, CA 92106, USA
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23
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Determinants of variability in signature whistles of the Mediterranean common bottlenose dolphin. Sci Rep 2022; 12:6980. [PMID: 35618794 PMCID: PMC9135725 DOI: 10.1038/s41598-022-10920-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/30/2022] [Indexed: 11/09/2022] Open
Abstract
One of the most studied aspects of animal communication is the acoustic repertoire difference between populations of the same species. While numerous studies have investigated the variability of bottlenose dolphin whistles between populations, very few studies have focused on the signature whistles alone and the factors underlying differentiation of signature whistles are still poorly understood. Here we describe the signature whistles produced by six distinct geographical units of the common bottlenose dolphin (Tursiops truncatus) in the Mediterranean Sea and identify the main determinants of their variability. Particularly, the influence of the region (proxy of genetic distance), the geographic site, and the environmental (sea bottom-related) and demographical (population-related) conditions on the acoustic structure of signature whistles was evaluated. The study provides the first evidence that the genetic structure, which distinguishes the eastern and western Mediterranean bottlenose dolphin populations has no strong influence on the acoustic structure of their signature whistles, and that the geographical isolation between populations only partially affected whistle variability. The environmental conditions of the areas where the whistles developed and the demographic characteristics of the belonging populations strongly influenced signature whistles, in accordance with the "acoustic adaptation hypothesis" and the theory of signature whistle determination mediated by learning.
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24
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Bruck JN, Walmsley SF, Janik VM. Cross-modal perception of identity by sound and taste in bottlenose dolphins. SCIENCE ADVANCES 2022; 8:eabm7684. [PMID: 35584227 PMCID: PMC9116882 DOI: 10.1126/sciadv.abm7684] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
While studies have demonstrated concept formation in animals, only humans are known to label concepts to use them in mental simulations or predictions. To investigate whether other animals use labels comparably, we studied cross-modal, individual recognition in bottlenose dolphins (Tursiops truncatus) that use signature whistles as labels for conspecifics in their own communication. First, we tested whether dolphins could use gustatory stimuli and found that they could distinguish between water and urine samples, as well as between urine from familiar and unfamiliar individuals. Then, we paired playbacks of signature whistles of known animals with urine samples from either the same dolphin or a different, familiar animal. Dolphins investigated the presentation area longer when the acoustic and gustatory sample matched than when they mismatched. This demonstrates that dolphins recognize other individuals by gustation alone and can integrate information from acoustic and taste inputs indicating a modality independent, labeled concept for known conspecifics.
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25
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Parameterizing animal sounds and motion with animal-attached tags to study acoustic communication. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03154-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Abstract
Stemming from the traditional use of field observers to score states and events, the study of animal behaviour often relies on analyses of discrete behavioural categories. Many studies of acoustic communication record sequences of animal sounds, classify vocalizations, and then examine how call categories are used relative to behavioural states and events. However, acoustic parameters can also convey information independent of call type, offering complementary study approaches to call classifications. Animal-attached tags can continuously sample high-resolution behavioural data on sounds and movements, which enables testing how acoustic parameters of signals relate to parameters of animal motion. Here, we present this approach through case studies on wild common bottlenose dolphins (Tursiops truncatus). Using data from sound-and-movement recording tags deployed in Sarasota (FL), we parameterized dolphin vocalizations and motion to investigate how senders and receivers modified movement parameters (including vectorial dynamic body acceleration, “VeDBA”, a proxy for activity intensity) as a function of signal parameters. We show that (1) VeDBA of one female during consortships had a negative relationship with centroid frequency of male calls, matching predictions about agonistic interactions based on motivation-structural rules; (2) VeDBA of four males had a positive relationship with modulation rate of their pulsed vocalizations, confirming predictions that click-repetition rate of these calls increases with agonism intensity. Tags offer opportunities to study animal behaviour through analyses of continuously sampled quantitative parameters, which can complement traditional methods and facilitate research replication. Our case studies illustrate the value of this approach to investigate communicative roles of acoustic parameter changes.
Significance statement
Studies of animal behaviour have traditionally relied on classification of behavioural patterns and analyses of discrete behavioural categories. Today, technologies such as animal-attached tags enable novel approaches, facilitating the use of quantitative metrics to characterize behaviour. In the field of acoustic communication, researchers typically classify vocalizations and examine usage of call categories. Through case studies of bottlenose dolphin social interactions, we present here a novel tag-based complementary approach. We used high-resolution tag data to parameterize dolphin sounds and motion, and we applied continuously sampled parameters to examine how individual dolphins responded to conspecifics’ signals and moved while producing sounds. Activity intensity of senders and receivers changed with specific call parameters, matching our predictions and illustrating the value of our approach to test communicative roles of acoustic parameter changes. Parametric approaches can complement traditional methods for animal behaviour and facilitate research replication.
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26
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Allied male dolphins use vocal exchanges to "bond at a distance". Curr Biol 2022; 32:1657-1663.e4. [PMID: 35334229 DOI: 10.1016/j.cub.2022.02.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/20/2022] [Accepted: 02/03/2022] [Indexed: 11/22/2022]
Abstract
Vocal interactions are intrinsic features of social groups and can play a pivotal role in social bonding.1,2 Dunbar's social bonding hypothesis posits that vocal exchanges evolved to "groom at a distance" when social groups became too large or complex for individuals to devote time to physical bonding activities.1,3 Tests of this hypothesis in non-human primates, however, suggest that vocal exchanges occur between more strongly bonded individuals that engage in higher grooming rates4-7 and thus do not provide evidence for replacement of physical bonding. Here, we combine data on social bond strength, whistle exchange frequency, and affiliative contact behavior rates to test this hypothesis in wild male Indo-Pacific bottlenose dolphins, who form multi-level alliances that cooperate over access to females.8-10 We show that, although whistle exchanges are more likely to occur within the core alliance, they occur more frequently between those males that share weaker social bonds, i.e., between core allies that spend less time together, while the opposite occurs for affiliative physical contact behavior. This suggests that vocal exchanges function as a low-cost mechanism for male dolphins that spend less time in close proximity and engage in fewer affiliative contact behaviors to reinforce and maintain their valuable alliance relationships. Our findings provide new evidence outside of the primate lineage that vocal exchanges serve a bonding function and reveal that, as the social bonding hypothesis originally suggested, vocal exchanges can function as a replacement of physical bonding activities for individuals to maintain their important social relationships.
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A Fish and Dolphin Biophony in the Boat Noise-Dominated Soundscape of the Cres-Lošinj Archipelago (Croatia). JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10020300] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Spatio-temporal variability of marine soundscapes reflects environmental dynamics and local habitat health. This study characterizes the coastal soundscape of the Cres-Lošinj Natura 2000 Site of Community Importance, encompassing the non-tourist (11–15 March 2020) and the tourist (26–30 July 2020) season. A total of 240 h of continuous recordings were manually analyzed and the abundance of animal vocalizations and boat noise was obtained; sound pressure levels were calculated for the low (63–2000 Hz) and high (2000–20,000 Hz) frequency range. Two fish sound types were drivers of both seasonal and diel variability of the low-frequency soundscape. The first is emitted by the cryptic Roche’s snake blenny (Ophidion rochei), while the second, whose emitter remains unknown, was previously only described in canyons and coralligenous habitats of the Western Mediterranean Sea. The high-frequency bands were characterized by bottlenose dolphin (Tursiops truncatus) vocalizations, indicating dolphins’ use of area for various purposes. Boat noise, however, dominated the local soundscape along the whole considered periods and higher sound pressure levels were found during the Tourist season. Human-generated noise pollution, which has been previously found 10 years ago, is still present in the area and this urges management actions.
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28
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Viana Y, Amorim TOS, de Castro FR, Wedekin L, Paro AD, Montoril MH, Rossi-Santos M, Andriolo A. Are dolphins modulating whistles in interspecific group contexts? BIOACOUSTICS 2022. [DOI: 10.1080/09524622.2021.2023047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Yasmin Viana
- Laboratório de Ecologia Comportamental e Bioacústica - LABEC, Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Thiago Orion Simões Amorim
- Laboratório de Ecologia Comportamental e Bioacústica - LABEC, Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
- Instituto Aqualie, Juiz de Fora, Brazil
| | - Franciele Rezende de Castro
- Laboratório de Ecologia Comportamental e Bioacústica - LABEC, Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
- Instituto Aqualie, Juiz de Fora, Brazil
| | - Leonardo Wedekin
- Socioambiental Consultores Associados Ltda, Florianópolis, Brazil
| | - Alexandre Douglas Paro
- Programa de Pós-Graduação em Biotecnologia Marinha (IEAPM/UFF), Departamento de Biotecnologia Marinha, Instituto de Estudos do Mar Almirante Paulo Moreira, Arraial do Cabo, Brazil
| | | | - Marcos Rossi-Santos
- Laboratório de Ecologia Acústica E Comportamento Animal - LEAC, Centro de Ciências Agrárias, Ambientais e Biológicas, Universidade Federal do Recôncavo da Bahia, Bahia, Brazil
| | - Artur Andriolo
- Laboratório de Ecologia Comportamental e Bioacústica - LABEC, Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
- Instituto Aqualie, Juiz de Fora, Brazil
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29
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Jones B, Tufano S, Daniels R, Mulsow J, Ridgway S. Non-stereotyped amplitude modulation across signature whistle contours. Behav Processes 2021; 194:104561. [PMID: 34838900 DOI: 10.1016/j.beproc.2021.104561] [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: 07/09/2021] [Revised: 11/16/2021] [Accepted: 11/23/2021] [Indexed: 11/25/2022]
Abstract
Bottlenose dolphin signature whistles are characterized by distinctive frequency modulation over time. The stable frequency contours of these whistles broadcast individual identity information. Little is known however, about whether or not the amplitude contour is also stereotyped. Here, we examined the relative amplitude-time contour of signature whistle emissions from eight bottlenose dolphins (Tursiops truncatus) in the U.S. Navy Marine Mammal Program (MMP) in San Diego, CA. The results suggested that unlike the stable frequency-time contour, the amplitude-time contour of signature whistles were largely non-stereotyped, characterized by large variability across multiple whistle emissions. Relative amplitude was negatively related to log peak frequency, with more energy focused in the lower frequency bands. This trend was consistent over all eight dolphins despite having quite different signature whistle contours. This relationship led to the amplitude contours being slightly more stereotyped within than between dolphins. We propose that amplitude across signature whistle emissions may serve as an avenue for encoding additional communicative information. We encourage future studies to incorporate analyses of amplitude contours in addition to frequency contours of signature whistles in order to begin to understand what role it may play in the dolphin communication system.
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Affiliation(s)
- Brittany Jones
- National Marine Mammal Foundation, 2240 Shelter Island Dr, Suite 200, San Diego, CA 92106, USA.
| | - Samantha Tufano
- National Marine Mammal Foundation, 2240 Shelter Island Dr, Suite 200, San Diego, CA 92106, USA
| | - Risa Daniels
- National Marine Mammal Foundation, 2240 Shelter Island Dr, Suite 200, San Diego, CA 92106, USA
| | - Jason Mulsow
- National Marine Mammal Foundation, 2240 Shelter Island Dr, Suite 200, San Diego, CA 92106, USA
| | - Sam Ridgway
- National Marine Mammal Foundation, 2240 Shelter Island Dr, Suite 200, San Diego, CA 92106, USA
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30
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Vernes SC, Janik VM, Fitch WT, Slater PJB. Vocal learning in animals and humans. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200234. [PMID: 34482718 PMCID: PMC8422595 DOI: 10.1098/rstb.2020.0234] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Sonja C Vernes
- School of Biology, The University of St Andrews, St Andrews, UK.,Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Vincent M Janik
- School of Biology, The University of St Andrews, St Andrews, UK
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Oswald JN, Walmsley SF, Casey C, Fregosi S, Southall B, Janik VM. Species information in whistle frequency modulation patterns of common dolphins. Philos Trans R Soc Lond B Biol Sci 2021; 376:20210046. [PMID: 34482716 PMCID: PMC8419585 DOI: 10.1098/rstb.2021.0046] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2021] [Indexed: 12/14/2022] Open
Abstract
The most flexible communication systems are those of open-ended vocal learners that can acquire new signals throughout their lifetimes. While acoustic signals carry information in general voice features that affect all of an individual's vocalizations, vocal learners can also introduce novel call types to their repertoires. Delphinids are known for using such learned call types in individual recognition, but their role in other contexts is less clear. We investigated the whistles of two closely related, sympatric common dolphin species, Delphinus delphis and Delphinus bairdii, to evaluate species differences in whistle contours. Acoustic recordings of single-species groups were obtained from the Southern California Bight. We used an unsupervised neural network to categorize whistles and compared the resulting whistle types between species. Of the whistle types recorded in more than one encounter, 169 were shared between species and 60 were species-specific (32 D. delphis types, 28 D. bairdii types). Delphinus delphis used 15 whistle types with an oscillatory frequency contour while only one such type was found in D. bairdii. Given the role of vocal learning in delphinid vocalizations, we argue that these differences in whistle production are probably culturally driven and could help facilitate species recognition between Delphinus species. This article is part of the theme issue 'Vocal learning in animals and humans'.
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Affiliation(s)
- Julie N. Oswald
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, UK
| | - Sam F. Walmsley
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, UK
| | - Caroline Casey
- Southall Environmental Associates, 9099 Soquel Drive, Suite 8, Aptos, CA 95003, USA
| | - Selene Fregosi
- Southall Environmental Associates, 9099 Soquel Drive, Suite 8, Aptos, CA 95003, USA
| | - Brandon Southall
- Southall Environmental Associates, 9099 Soquel Drive, Suite 8, Aptos, CA 95003, USA
- Long Marine Laboratory, Institute of Marine Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Vincent M. Janik
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Fife KY16 8LB, UK
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32
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Abstract
Vocal production learning, the ability to modify the structure of vocalizations as a result of hearing those of others, has been studied extensively in birds but less attention has been given to its occurrence in mammals. We summarize the available evidence for vocal learning in mammals from the last 25 years, updating earlier reviews on the subject. The clearest evidence comes from cetaceans, pinnipeds, elephants and bats where species have been found to copy artificial or human language sounds, or match acoustic models of different sound types. Vocal convergence, in which parameter adjustments within one sound type result in similarities between individuals, occurs in a wider range of mammalian orders with additional evidence from primates, mole-rats, goats and mice. Currently, the underlying mechanisms for convergence are unclear with vocal production learning but also usage learning or matching physiological states being possible explanations. For experimental studies, we highlight the importance of quantitative comparisons of seemingly learned sounds with vocal repertoires before learning started or with species repertoires to confirm novelty. Further studies on the mammalian orders presented here as well as others are needed to explore learning skills and limitations in greater detail. This article is part of the theme issue 'Vocal learning in animals and humans'.
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Affiliation(s)
- Vincent M Janik
- Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews KY16 8LB, UK
| | - Mirjam Knörnschild
- Museum für Naturkunde, Leibniz-Institute for Evolution and Biodiversity Science, Berlin, Germany.,Animal Behavior Lab, Freie Universität, Berlin, Germany.,Smithsonian Tropical Research Institute, Balboa, Ancón, Panama
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33
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Meyer J, Magnasco MO, Reiss D. The Relevance of Human Whistled Languages for the Analysis and Decoding of Dolphin Communication. Front Psychol 2021; 12:689501. [PMID: 34621209 PMCID: PMC8490682 DOI: 10.3389/fpsyg.2021.689501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/30/2021] [Indexed: 11/26/2022] Open
Abstract
Humans use whistled communications, the most elaborate of which are commonly called "whistled languages" or "whistled speech" because they consist of a natural type of speech. The principle of whistled speech is straightforward: people articulate words while whistling and thereby transform spoken utterances by simplifying them, syllable by syllable, into whistled melodies. One of the most striking aspects of this whistled transformation of words is that it remains intelligible to trained speakers, despite a reduced acoustic channel to convey meaning. It constitutes a natural traditional means of telecommunication that permits spoken communication at long distances in a large diversity of languages of the world. Historically, birdsong has been used as a model for vocal learning and language. But conversely, human whistled languages can serve as a model for elucidating how information may be encoded in dolphin whistle communication. In this paper, we elucidate the reasons why human whistled speech and dolphin whistles are interesting to compare. Both are characterized by similar acoustic parameters and serve a common purpose of long distance communication in natural surroundings in two large brained social species. Moreover, their differences - e.g., how they are produced, the dynamics of the whistles, and the types of information they convey - are not barriers to such a comparison. On the contrary, by exploring the structure and attributes found across human whistle languages, we highlight that they can provide an important model as to how complex information is and can be encoded in what appears at first sight to be simple whistled modulated signals. Observing details, such as processes of segmentation and coarticulation, in whistled speech can serve to advance and inform the development of new approaches for the analysis of whistle repertoires of dolphins, and eventually other species. Human whistled languages and dolphin whistles could serve as complementary test benches for the development of new methodologies and algorithms for decoding whistled communication signals by providing new perspectives on how information may be encoded structurally and organizationally.
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Affiliation(s)
- Julien Meyer
- CNRS, GIPSA-Lab, Université Grenoble Alpes, Grenoble, France
| | - Marcelo O. Magnasco
- Laboratory of Integrative Neuroscience, Rockefeller University, New York, NY, United States
| | - Diana Reiss
- Department of Psychology, Hunter College, New York, NY, United States
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34
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Smith-Vidaurre G, Perez-Marrufo V, Wright TF. Individual vocal signatures show reduced complexity following invasion. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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35
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Ames AE, Blackwell SB, Tervo OM, Heide-Jørgensen MP. Evidence of stereotyped contact call use in narwhal (Monodon monoceros) mother-calf communication. PLoS One 2021; 16:e0254393. [PMID: 34449769 PMCID: PMC8396719 DOI: 10.1371/journal.pone.0254393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 06/28/2021] [Indexed: 11/25/2022] Open
Abstract
Narwhals (Monodon monoceros) are gregarious toothed whales that strictly reside in the high Arctic. They produce a broad range of signal types; however, studies of narwhal vocalizations have been mostly descriptive of the sounds available in the species’ overall repertoire. Little is known regarding the functions of highly stereotyped mixed calls (i.e., biphonations with both sound elements produced simultaneously), although preliminary evidence has suggested that such vocalizations are individually distinctive and function as contact calls. Here we provide evidence that supports this notion in narwhal mother-calf communication. A female narwhal was tagged as part of larger studies on the life history and acoustic behavior of narwhals. At the time of tagging, it became apparent that the female had a calf, which remained close by during the tagging event. We found that the narwhal mother produced a distinct, highly stereotyped mixed call when separated from her calf and immediately after release from capture, which we interpret as preliminary evidence for contact call use between the mother and her calf. The mother’s mixed call production occurred continually over the 4.2 day recording period in addition to a second prominent but different stereotyped mixed call which we believe belonged to the narwhal calf. Thus, narwhal mothers produce highly stereotyped contact calls when separated from their calves, and it appears that narwhal calves similarly produce distinct, stereotyped mixed calls which we hypothesize also contribute to maintaining mother-calf contact. We compared this behavior to the acoustic behavior of two other adult females without calves, but also each with a unique, stereotyped call type. While we provide additional support for individual distinctiveness across narwhal contact calls, more research is necessary to determine whether these calls are vocal signatures which broadcast identity.
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Affiliation(s)
- Audra E. Ames
- Fundación Oceanogràfic de la Comunitat Valenciana, Valencia, Spain
- * E-mail:
| | | | - Outi M. Tervo
- Department of Birds and Mammals, Greenland Institute of Natural Resources, Copenhagen, Denmark
- Department of Birds and Mammals, Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Mads Peter Heide-Jørgensen
- Department of Birds and Mammals, Greenland Institute of Natural Resources, Copenhagen, Denmark
- Department of Birds and Mammals, Greenland Institute of Natural Resources, Nuuk, Greenland
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36
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Bailey H, Fandel AD, Silva K, Gryzb E, McDonald E, Hoover AL, Ogburn MB, Rice AN. Identifying and predicting occurrence and abundance of a vocal animal species based on individually specific calls. Ecosphere 2021. [DOI: 10.1002/ecs2.3685] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- H. Bailey
- Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Solomons Maryland 20688 USA
| | - A. D. Fandel
- Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Solomons Maryland 20688 USA
| | - K. Silva
- Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Solomons Maryland 20688 USA
| | - E. Gryzb
- Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Solomons Maryland 20688 USA
| | - E. McDonald
- Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Solomons Maryland 20688 USA
| | - A. L. Hoover
- Chesapeake Biological Laboratory University of Maryland Center for Environmental Science Solomons Maryland 20688 USA
| | - M. B. Ogburn
- Smithsonian Environmental Research Center 647 Contees Wharf Road Edgewater Maryland 21037 USA
| | - A. N. Rice
- Center for Conservation Bioacoustics Cornell Lab of Ornithology Cornell University Ithaca New York 14850 USA
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37
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Zhao L, Santos JC, Wang J, Ran J, Tang Y, Cui J. Noise constrains the evolution of call frequency contours in flowing water frogs: a comparative analysis in two clades. Front Zool 2021; 18:37. [PMID: 34348772 PMCID: PMC8336270 DOI: 10.1186/s12983-021-00423-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 07/20/2021] [Indexed: 11/26/2022] Open
Abstract
Background The acoustic adaptation hypothesis (AAH) states that signals should evolve towards an optimal transmission of the intended information from senders to intended receivers given the environmental constraints of the medium that they traverse. To date, most AAH studies have focused on the effect of stratified vegetation on signal propagation. These studies, based on the AAH, predict that acoustic signals should experience less attenuation and degradation where habitats are less acoustically complex. Here, we explored this effect by including an environmental noise dimension to test some AAH predictions in two clades of widespread amphibians (Bufonidae and Ranidae) that actively use acoustic signals for communication. By using data from 106 species in these clades, we focused on the characterization of the differences in dominant frequency (DF) and frequency contour (i.e., frequency modulation [FM] and harmonic performances) of mating calls and compared them between species that inhabit flowing-water or still-water environments. Results After including temperature, body size, habitat type and phylogenetic relationships, we found that DF differences among species were explained mostly by body size and habitat structure. We also showed that species living in lentic habitats tend to have advertisement calls characterized by well-defined FM and harmonics. Likewise, our results suggest that flowing-water habitats can constrain the evolutionary trajectories of the frequency-contour traits of advertisement calls in these anurans. Conclusions Our results may support AAH predictions in frogs that vocalize in noisy habitats because flowing-water environments often produce persistent ambient noise. For instance, these anurans tend to generate vocalizations with less well-defined FM and harmonic traits. These findings may help us understand how noise in the environment can influence natural selection as it shapes acoustic signals in affected species. Supplementary Information The online version contains supplementary material available at 10.1186/s12983-021-00423-y.
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Affiliation(s)
- Longhui Zhao
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, China.,Ministry of Education Key Laboratory for Tropical Plant and Animal Ecology, College of Life Sciences, Hainan Normal University, Haikou, 571158, Hainan, China.,Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, China
| | - Juan C Santos
- Department of Biological Sciences, St. John's University, Queens, NY, 11439, USA
| | - Jichao Wang
- Ministry of Education Key Laboratory for Tropical Plant and Animal Ecology, College of Life Sciences, Hainan Normal University, Haikou, 571158, Hainan, China
| | - Jianghong Ran
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, China
| | - Yezhong Tang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, China
| | - Jianguo Cui
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, China.
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38
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Lieck R, Rohrmeier M. Discretisation and continuity: The emergence of symbols in communication. Cognition 2021; 215:104787. [PMID: 34303183 PMCID: PMC8381766 DOI: 10.1016/j.cognition.2021.104787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/11/2021] [Accepted: 05/19/2021] [Indexed: 11/30/2022]
Abstract
Vocal signalling systems, as used by humans and various non-human animals, exhibit discrete and continuous properties that can naturally be used to express discrete and continuous information, such as distinct words to denote objects in the world and prosodic features to convey the emotions of the speaker. However, continuous aspects are not always expressed with the continuous properties of an utterance but are frequently categorised into discrete symbols. While the existence of symbols in communication is self-evident, the emergence of discretisation from a continuous space is not well understood. In this paper, we investigate the emergence of discrete symbols in regions with a continuous semantics by simulating the learning process of two agents that acquire a shared signalling system. The task is formalised as a reinforcement learning problem with a continuous form and meaning space. We identify two causes for the emergence of discretisation that do not originate in discrete semantics: 1) premature convergence to sub-optimal signalling conventions and 2) topological mismatch between the continuous form space and the continuous semantic space. The insights presented in this paper shed light on the origins of discrete symbols, whose existence is assumed by a large body of research concerned with the emergence of syntactic structures and meaning in language.
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Affiliation(s)
- Robert Lieck
- Digital and Cognitive Musicology Lab, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| | - Martin Rohrmeier
- Digital and Cognitive Musicology Lab, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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Cooperation-based concept formation in male bottlenose dolphins. Nat Commun 2021; 12:2373. [PMID: 33888703 PMCID: PMC8062458 DOI: 10.1038/s41467-021-22668-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/18/2021] [Indexed: 02/02/2023] Open
Abstract
In Shark Bay, Western Australia, male bottlenose dolphins form a complex nested alliance hierarchy. At the first level, pairs or trios of unrelated males cooperate to herd individual females. Multiple first-order alliances cooperate in teams (second-order alliances) in the pursuit and defence of females, and multiple teams also work together (third-order alliances). Yet it remains unknown how dolphins classify these nested alliance relationships. We use 30 years of behavioural data combined with 40 contemporary sound playback experiments to 14 allied males, recording responses with drone-mounted video and a hydrophone array. We show that males form a first-person social concept of cooperative team membership at the second-order alliance level, independently of first-order alliance history and current relationship strength across all three alliance levels. Such associative concepts develop through experience and likely played an important role in the cooperative behaviour of early humans. These results provide evidence that cooperation-based concepts are not unique to humans, occurring in other animal societies with extensive cooperation between non-kin.
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40
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Yuan J, Wang Z, Duan P, Xiao Y, Zhang H, Huang Z, Zhou R, Wen H, Wang K, Wang D. Whistle signal variations among three Indo-Pacific humpback dolphin populations in the South China Sea: a combined effect of the Qiongzhou Strait's geographical barrier function and local ambient noise? Integr Zool 2021; 16:499-511. [PMID: 33725414 DOI: 10.1111/1749-4877.12531] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Geographic variations in the dolphin whistles could be useful in assessing association and isolation among populations. Whistle of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) among the Pearl River Estuary (PRE), Leizhou Bei (LZB) and Sanniang Bay (SNB) populations were investigated. A total of 2850 whistles with legible fundamental contour were extracted and 15 acoustic parameters were measured. Contrary to SNB, PRE and LZB had the same relative proportion of tonal type compositions with flat and sine representing the most frequent types. The generalized linear model analysis showed significant acoustic difference among populations and tonal types. All frequency parameters in SNB were significantly higher than those in PRE and LZB, where no significant variation was observed in most of the parameters either at the population level or within each tonal type. Canonical discriminant functions analysis showed a smaller difference between PRE and LZB than between PRE and SNB and between LZB and SNB. Compared with previous recordings, recent recordings demonstrated a consistent pattern of becoming higher in whistle frequency parameters in both LZB and SNB populations, suggesting that noise pollution in LZB and SNB increasing with time according to the acoustic niche hypothesis. Dolphin whistle's geographic variations could be shaped by the combined function of the geographical barrier function of the Qiongzhou strait and local ambient noise. Considering the isolated condition and the relatively smaller population size of the humpback dolphin in the SNB, more effective and proactive conservation actions should be taken to prevent the extinction of small populations.
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Affiliation(s)
- Jing Yuan
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhitao Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences, Wuhan, China
| | - Pengxiang Duan
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences, Wuhan, China
| | - Yousheng Xiao
- Pearl River Estuary Chinese White Dolphin National Nature Reserve, Zhuhai, China
| | - Hongke Zhang
- National Hepu Dugong Nature Reserve Administration Station, Beihai, China
| | | | - Ruichun Zhou
- Pearl River Estuary Chinese White Dolphin National Nature Reserve, Zhuhai, China
| | - Hua Wen
- Hong Kong-Zhuhai-Macao Bridge Authority, Zhuhai, China
| | - Kexiong Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences, Wuhan, China
| | - Ding Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences, Wuhan, China
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41
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King SL, Guarino E, Donegan K, McMullen C, Jaakkola K. Evidence that bottlenose dolphins can communicate with vocal signals to solve a cooperative task. ROYAL SOCIETY OPEN SCIENCE 2021; 8:202073. [PMID: 33959360 PMCID: PMC8074934 DOI: 10.1098/rsos.202073] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/19/2021] [Indexed: 05/04/2023]
Abstract
Cooperation experiments have long been used to explore the cognition underlying animals' coordination towards a shared goal. While the ability to understand the need for a partner in a cooperative task has been demonstrated in a number of species, there has been far less focus on cooperation experiments that address the role of communication. In humans, cooperative efforts can be enhanced by physical synchrony, and coordination problems can be solved using spoken language. Indeed, human children adapt to complex coordination problems by communicating with vocal signals. Here, we investigate whether bottlenose dolphins can use vocal signals to coordinate their behaviour in a cooperative button-pressing task. The two dolphin dyads used in this study were significantly more likely to cooperate successfully when they used whistles prior to pressing their buttons, with whistling leading to shorter button press intervals and more successful trials. Whistle timing was important as the dolphins were significantly more likely to succeed if they pushed their buttons together after the last whistle, rather than pushing independently of whistle production. Bottlenose dolphins are well known for cooperating extensively in the wild, and while it remains to be seen how wild dolphins use communication to coordinate cooperation, our results reveal that at least some dolphins are capable of using vocal signals to facilitate the successful execution of coordinated, cooperative actions.
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Affiliation(s)
- Stephanie L. King
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Emily Guarino
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL 33050, USA
| | - Katy Donegan
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL 33050, USA
| | - Christina McMullen
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL 33050, USA
| | - Kelly Jaakkola
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL 33050, USA
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42
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Panova E, Agafonov A, Logominova I. First description of whistles of Black Sea short-beaked common dolphins, Delphinus delphis ponticus. BIOACOUSTICS 2020. [DOI: 10.1080/09524622.2020.1842245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Elena Panova
- Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia
| | - Alexandr Agafonov
- Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia
- T.I. Vyazemsky Karadag Scientific Station – Nature Reserve of the Russian Academy of Sciences, Feodosia, Russia
| | - Irina Logominova
- T.I. Vyazemsky Karadag Scientific Station – Nature Reserve of the Russian Academy of Sciences, Feodosia, Russia
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43
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Bauer GB, Cook PF, Harley HE. The Relevance of Ecological Transitions to Intelligence in Marine Mammals. Front Psychol 2020; 11:2053. [PMID: 33013519 PMCID: PMC7505747 DOI: 10.3389/fpsyg.2020.02053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/24/2020] [Indexed: 12/26/2022] Open
Abstract
Macphail's comparative approach to intelligence focused on associative processes, an orientation inconsistent with more multifaceted lay and scientific understandings of the term. His ultimate emphasis on associative processes indicated few differences in intelligence among vertebrates. We explore options more attuned to common definitions by considering intelligence in terms of richness of representations of the world, the interconnectivity of those representations, the ability to flexibly change those connections, and knowledge. We focus on marine mammals, represented by the amphibious pinnipeds and the aquatic cetaceans and sirenians, as animals that transitioned from a terrestrial existence to an aquatic one, experiencing major changes in ecological pressures. They adapted with morphological transformations related to streamlining the body, physiological changes in respiration and thermoregulation, and sensory/perceptual changes, including echolocation capabilities and diminished olfaction in many cetaceans, both in-air and underwater visual focus, and enhanced senses of touch in pinnipeds and sirenians. Having a terrestrial foundation on which aquatic capacities were overlaid likely affected their cognitive abilities, especially as a new reliance on sound and touch, and the need to surface to breath changed their interactions with the world. Vocal and behavioral observational learning capabilities in the wild and in laboratory experiments suggest versatility in group coordination. Empirical reports on aspects of intelligent behavior like problem-solving, spatial learning, and concept learning by various species of cetaceans and pinnipeds suggest rich cognitive abilities. The high energy demands of the brain suggest that brain-intelligence relationships might be fruitful areas for study when specific hypotheses are considered, e.g., brain mapping indicates hypertrophy of specific sensory areas in marine mammals. Modern neuroimaging techniques provide ways to study neural connectivity, and the patterns of connections between sensory, motor, and other cortical regions provide a biological framework for exploring how animals represent and flexibly use information in navigating and learning about their environment. At this stage of marine mammal research, it would still be prudent to follow Macphail's caution that it is premature to make strong comparative statements without more empirical evidence, but an approach that includes learning more about how animals flexibly link information across multiple representations could be a productive way of comparing species by allowing them to use their specific strengths within comparative tasks.
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Affiliation(s)
- Gordon B. Bauer
- Division of Social Sciences, New College of Florida, Sarasota, FL, United States
- Mote Marine Laboratory, Sarasota, FL, United States
| | - Peter F. Cook
- Division of Social Sciences, New College of Florida, Sarasota, FL, United States
- Mote Marine Laboratory, Sarasota, FL, United States
| | - Heidi E. Harley
- Division of Social Sciences, New College of Florida, Sarasota, FL, United States
- Mote Marine Laboratory, Sarasota, FL, United States
- The Seas, Epcot, Walt Disney World Resorts, Lake Buena Vista, FL, United States
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44
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Webster MM, Laland KN. No evidence for individual recognition in threespine or ninespine sticklebacks ( Gasterosteus aculeatus or Pungitius pungitius). ROYAL SOCIETY OPEN SCIENCE 2020; 7:191703. [PMID: 32874600 PMCID: PMC7428269 DOI: 10.1098/rsos.191703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Recognition plays an important role in the formation and organization of animal groups. Many animals are capable of class-level recognition, discriminating, for example, on the basis of species, kinship or familiarity. Individual recognition requires that animals recognize distinct cues, and learn to associate these with the specific individual from which they are derived. In this study, we asked whether sticklebacks (Gasterosteus aculeatus and Pungitius pungitius) were capable of learning to recognize individual conspecifics. We have used these fish as model organisms for studying selective social learning, and demonstrating a capacity for individual recognition in these species would provide an exciting opportunity for studying how biases for copying specific individuals shape the dynamics of information transmission. To test for individual recognition, we trained subjects to associate green illumination with the provision of a food reward close to one of two conspecifics, and, for comparison, one of two physical landmarks. Both species were capable of recognizing the rewarded landmark, but neither showed a preference for associating with the rewarded conspecific. Our study provides no evidence for individual recognition in either species. We speculate that the fission-fusion structure of their social groups may not favour a capacity for individual recognition.
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Affiliation(s)
- Mike M. Webster
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, Fife KY16 9TF, UK
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Morrison EL, DeLong CM, Wilcox KT. How humans discriminate acoustically among bottlenose dolphin signature whistles with and without masking by boat noise. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:4162. [PMID: 32611182 DOI: 10.1121/10.0001450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 05/31/2020] [Indexed: 06/11/2023]
Abstract
Anthropogenic noise in the world's oceans is known to impede many species' ability to perceive acoustic signals, but little research has addressed how this noise affects the perception of bioacoustic signals used for communication in marine mammals. Bottlenose dolphins (Tursiops truncatus) use signature whistles containing identification information. Past studies have used human participants to gain insight into dolphin perception, but most previous research investigated echolocation. In Experiment 1, human participants were tested on their ability to discriminate among signature whistles from three dolphins. Participants' performance was nearly errorless. In Experiment 2, participants identified signature whistles masked by five different samples of boat noise utilizing different signal-to-noise ratios. Lower signal-to-noise ratio and proximity in frequency between the whistle and noise both significantly decreased performance. Like dolphins, human participants primarily identified whistles using frequency contour. Participants reported greater use of amplitude in noise-present vs noise-absent trials, but otherwise did not vary cue usage. These findings can be used to generate hypotheses about dolphins' performance and auditory cue use for future research. This study may provide insight into how specific characteristics of boat noise affect dolphin whistle perception and may have implications for conservation and regulations.
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Affiliation(s)
- Evan L Morrison
- Department of Psychology, College of Liberal Arts, Rochester Institute of Technology, 18 Lomb Memorial Drive, Rochester, New York 14623, USA
| | - Caroline M DeLong
- Department of Psychology, College of Liberal Arts, Rochester Institute of Technology, 18 Lomb Memorial Drive, Rochester, New York 14623, USA
| | - Kenneth Tyler Wilcox
- Department of Psychology, College of Arts and Letters, University of Notre Dame, 390 Corbett Family Hall, Notre Dame, Indiana 46556, USA
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Indeck KL, Girola E, Torterotot M, Noad MJ, Dunlop RA. Adult female-calf acoustic communication signals in migrating east Australian humpback whales. BIOACOUSTICS 2020. [DOI: 10.1080/09524622.2020.1742204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Katherine L. Indeck
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, University of Queensland, Gatton, Australia
| | - Elisa Girola
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, University of Queensland, Gatton, Australia
| | - Maëlle Torterotot
- University of Brest and CNRS, Laboratoire Géosciences Océan, Institut Universitaire Européen de la Mer, Plouzané, France
| | - Michael J. Noad
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, University of Queensland, Gatton, Australia
| | - Rebecca A. Dunlop
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, University of Queensland, Gatton, Australia
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Melo-Santos G, Walmsley SF, Marmontel M, Oliveira-da-Costa M, Janik VM. Repeated downsweep vocalizations of the Araguaian river dolphin, Inia araguaiaensis. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:748. [PMID: 32113279 DOI: 10.1121/10.0000624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 01/09/2020] [Indexed: 06/10/2023]
Abstract
Araguaian botos (Inia araguaiaensis) are known to produce pulsed as well as tonal sounds. This study documents the first evidence for repetitive sequences of downsweep whistles in botos that appear to be shared between individuals, and the context of their occurrence is investigated. Boat surveys were conducted along the Tocantins River located in the Eastern Amazon over a period of 42 days between 2012 and 2018. Eighty-two groups of Araguaian botos were observed, and 43 h of sound recordings were acquired. 632 downsweep whistles were recorded in 10 encounters. Four of these encounters contained downsweep bouts (21 bouts with ≥2 whistles) with short inter-call intervals (bout criterion 50 s) and up to 161 whistles. A statistical relationship was not found between downsweep occurrence and any of the contextual parameters that were investigated, including socializing, travelling, feeding, group size, presence of calves, and socio-sexual displays. The rarity of these signals makes them unlikely candidates for individual or group identification. It is more likely that they are associated with very specific contexts, such as nursing or mating, both of which were rarely observed in this study. Further studies are required to investigate context specificity and elucidate the function of these signals.
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Affiliation(s)
- Gabriel Melo-Santos
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, East Sands, KY16 8LB, St Andrews, Scotland, United Kingdom
| | - Sam F Walmsley
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, East Sands, KY16 8LB, St Andrews, Scotland, United Kingdom
| | - Miriam Marmontel
- Research Group on Amazonian Aquatic Mammals, Mamirauá Sustainable, Development Institute, Estrada do Bexiga No. 2584, Tefé, Brazil
| | | | - Vincent M Janik
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, East Sands, KY16 8LB, St Andrews, Scotland, United Kingdom
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Pedersen MB, Fahlman A, Borque-Espinosa A, Madsen PT, Jensen FH. Whistling is metabolically cheap for communicating bottlenose dolphins ( Tursiops truncatus). ACTA ACUST UNITED AC 2020; 223:jeb.212498. [PMID: 31796610 DOI: 10.1242/jeb.212498] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/26/2019] [Indexed: 11/20/2022]
Abstract
Toothed whales depend on sound for communication and foraging, making them potentially vulnerable to acoustic masking from increasing anthropogenic noise. Masking effects may be ameliorated by higher amplitudes or rates of calling, but such acoustic compensation mechanisms may incur energetic costs if sound production is expensive. The costs of whistling in bottlenose dolphins (Tursiops truncatus) have been reported to be much higher (20% of resting metabolic rate, RMR) than theoretical predictions (0.5-1% of RMR). Here, we address this dichotomy by measuring the change in the resting O2 consumption rate (V̇ O2 ), a proxy for RMR, in three post-absorptive bottlenose dolphins during whistling and silent trials, concurrent with simultaneous measurement of acoustic output using a calibrated hydrophone array. The experimental protocol consisted of a 2-min baseline period to establish RMR, followed by a 2-min voluntary resting surface apnea, with or without whistling as cued by the trainers, and then a 5-min resting period to measure recovery costs. Daily fluctuations in V̇ O2 were accounted for by subtracting the baseline RMR from the recovery costs to estimate the cost of apnea with and without whistles relative to RMR. Analysis of 52 sessions containing 1162 whistles showed that whistling did not increase metabolic cost (P>0.1, +4.2±6.9%) as compared with control trials (-0.5±5.9%; means±s.e.m.). Thus, we reject the hypothesis that whistling is costly for bottlenose dolphins, and conclude that vocal adjustments such as the Lombard response to noise do not represent large direct energetic costs for communicating toothed whales.
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Affiliation(s)
- Michael B Pedersen
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
| | - Andreas Fahlman
- Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain.,Global Diving Research, Ottawa, ON, K2J 5E8
| | - Alicia Borque-Espinosa
- Fundación Oceanogràfic de la Comunitat Valenciana, Gran Vía Marqués del Turia 19, 46005 Valencia, Spain.,University of Valencia, Av. de Blasco Ibáñez, 13, 46010 Valencia, Spain
| | - Peter T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark.,Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C, Denmark
| | - Frants H Jensen
- Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C, Denmark.,Scottish Oceans Institute, University of St Andrews, East Sands, St Andrews KY16 8LB, UK.,Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
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La Manna G, Rako-Gòspic N, Manghi M, Ceccherelli G. Influence of environmental, social and behavioural variables on the whistling of the common bottlenose dolphin (Tursiops truncatus). Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2736-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Vyshedskiy A. Language evolution to revolution: the leap from rich-vocabulary non-recursive communication system to recursive language 70,000 years ago was associated with acquisition of a novel component of imagination, called Prefrontal Synthesis, enabled by a mutation that slowed down the prefrontal cortex maturation simultaneously in two or more children – the Romulus and Remus hypothesis. RESEARCH IDEAS AND OUTCOMES 2019. [DOI: 10.3897/rio.5.e38546] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
There is an overwhelming archeological and genetic evidence that modern speech apparatus was acquired by hominins by 600,000 years ago. On the other hand, artifacts signifying modern imagination, such as (1) composite figurative arts, (2) bone needles with an eye, (3) construction of dwellings, and (4) elaborate burials arose not earlier than 70,000 years ago. It remains unclear (1) why there was a long gap between acquisition of modern speech apparatus and modern imagination, (2) what triggered the acquisition of modern imagination 70,000 years ago, and (3) what role language might have played in this process. Our research into evolutionary origin of modern imagination has been driven by the observation of a temporal limit for the development of a particular component of imagination. Modern children not exposed to recursive language in early childhood never acquire the type of active constructive imagination called Prefrontal Synthesis (PFS). Unlike vocabulary and grammar acquisition, which can be learned throughout one’s lifetime, there is a strong critical period for the development of PFS and individuals not exposed to recursive language in early childhood can never acquire PFS as adults. Their language will always lack understanding of spatial prepositions and recursion that depend on the PFS ability. In a similar manner, early hominins would not have been able to learn recursive language as adults and, therefore, would not be able to teach recursive language to their children. Thus, the existence of a strong critical period for PFS acquisition creates an evolutionary barrier for behavioral modernity. An evolutionary mathematical model suggests that a synergistic confluence of three events (1) a genetic mutation that extended the critical period by slowing down the prefrontal cortex development simultaneously in two or more children, (2) invention of recursive elements of language, such as spatial prepositions, by these children and (3) their dialogic communications using these recursive elements, resulted in concurrent conversion of a non-recursive communication system of their parents to recursive language and acquisition of PFS around 70,000 years ago.
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