1
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Laeta M, Oliveira JA, Siciliano S, Lambert O, Jensen FH, Galatius A. Cranial asymmetry in odontocetes: a facilitator of sonic exploration? ZOOLOGY 2023; 160:126108. [PMID: 37633185 DOI: 10.1016/j.zool.2023.126108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 08/28/2023]
Abstract
Directional cranial asymmetry is an intriguing condition that has evolved in all odontocetes which has mostly been associated with sound production for echolocation. In this study, we investigated how cranial asymmetry varies across odontocete species both in terms of quality (i.e., shape), and quantity (magnitude of deviation from symmetry). We investigated 72 species across all ten families of Odontoceti using two-dimensional geometric morphometrics. The average asymmetric shape was largely consistent across odontocetes - the rostral tip, maxillae, antorbital notches and braincase, as well as the suture crest between the frontal and interparietal bones were displaced to the right, whereas the nasal septum and premaxillae showed leftward shifts, in concert with an enlargement of the right premaxilla and maxilla. A clear phylogenetic signal related to asymmetric shape variation was identified across odontocetes using squared-change parsimony. The magnitude of asymmetry was widely variable across Odontoceti, with greatest asymmetry in Kogiidae, Monodontidae and Globicephalinae, followed by Physeteridae, Platanistidae and Lipotidae, while the asymmetry was lowest in Lissodelphininae, Phocoenidae, Iniidae and Pontoporiidae. Ziphiidae presented a wide spectrum of asymmetry. Generalized linear models explaining magnitude of asymmetry found associations with click source level while accounting for cranial size. Using phylogenetic generalized least squares, we reconfirm that source level and centroid size significantly predict the level of cranial asymmetry, with more asymmetric marine taxa generally consisting of bigger species emitting higher output sonar signal, i.e. louder sounds. Both characteristics theoretically support foraging at depth, the former by allowing extended diving and the latter being adaptive for prey detection at longer distances. Thus, cranial asymmetry seems to be an evolutionary pathway that allows odontocetes to devote more space for sound-generating structures associated with echolocation and thus increases biosonar search range and foraging efficiency beyond simple phylogenetic scaling predictions.
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Affiliation(s)
- Maíra Laeta
- Setor de Mastozoologia, Departamento de Vertebrados, Museu Nacional/Universidade Federal do Rio de Janeiro, 20941-160 Rio de Janeiro, RJ, Brazil.
| | - João A Oliveira
- Setor de Mastozoologia, Departamento de Vertebrados, Museu Nacional/Universidade Federal do Rio de Janeiro, 20941-160 Rio de Janeiro, RJ, Brazil
| | - Salvatore Siciliano
- Departamento de Ciências Biológicas, Escola Nacional de Saúde Pública Sergio Arouca/Fiocruz, 21040-360 Rio de Janeiro, RJ, Brazil; Grupo de Estudos de Mamíferos Marinhos da Região dos Lagos (GEMM-Lagos), Rua São José, 1.260, Praia Seca, 28970-000 Araruama, RJ, Brazil
| | - Olivier Lambert
- D.O. Terre et Histoire de la Vie, Institut royal des Sciences naturelles de Belgique, 1000 Brussels, Belgium
| | - Frants H Jensen
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Biology Department, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, MA 02543, USA; Biology Department, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | - Anders Galatius
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
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2
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Wei C, Houser D, Erbe C, Mátrai E, Ketten DR, Finneran JJ. Does rotation increase the acoustic field of view? Comparative models based on CT data of a live dolphin versus a dead dolphin. BIOINSPIRATION & BIOMIMETICS 2023; 18:035006. [PMID: 36917857 DOI: 10.1088/1748-3190/acc43d] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 03/14/2023] [Indexed: 06/18/2023]
Abstract
Rotational behaviour has been observed when dolphins track or detect targets, however, its role in echolocation is unknown. We used computed tomography data of one live and one recently deceased bottlenose dolphin, together with measurements of the acoustic properties of head tissues, to perform acoustic property reconstruction. The anatomical configuration and acoustic properties of the main forehead structures between the live and deceased dolphins were compared. Finite element analysis (FEA) was applied to simulate the generation and propagation of echolocation clicks, to compute their waveforms and spectra in both near- and far-fields, and to derive echolocation beam patterns. Modelling results from both the live and deceased dolphins were in good agreement with click recordings from other, live, echolocating individuals. FEA was also used to estimate the acoustic scene experienced by a dolphin rotating 180° about its longitudinal axis to detect fish in the far-field at elevation angles of -20° to 20°. The results suggest that the rotational behaviour provides a wider insonification area and a wider receiving area. Thus, it may provide compensation for the dolphin's relatively narrow biosonar beam, asymmetries in sound reception, and constraints on the pointing direction that are limited by head movement. The results also have implications for examining the accuracy of FEA in acoustic simulations using recently deceased specimens.
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Affiliation(s)
- Chong Wei
- Centre for Marine Science and Technology, Curtin University, Perth, WA 6102, Australia
| | - Dorian Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, CA 92106, United States of America
| | - Christine Erbe
- Centre for Marine Science and Technology, Curtin University, Perth, WA 6102, Australia
| | - Eszter Mátrai
- Research Department, Ocean Park, Hong Kong, People's Republic of China
| | - Darlene R Ketten
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, United States of America
| | - James J Finneran
- United States Navy Marine Mammal Program, Naval Information Warfare Center Pacific Code 56710, 53560 Hull Street, San Diego, CA 92152, United States of America
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3
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Rio R. Acoustic recording of false killer whale (Pseudorca crassidens) from Mexico (L). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:2019. [PMID: 37092938 DOI: 10.1121/10.0017726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 03/14/2023] [Indexed: 05/03/2023]
Abstract
This study collected acoustic information on false killer whales (Pseudorca crassidens) in Mexican waters, close to Roca Partida Island, Revillagigedo Archipelago. In total, 321 whistles were collected after we found a group with at least ten individuals. The high prevalence of ascending contour types [upsweep (type I): 42.99%] contradicted the idea that false killer whales mostly produce constant whistles. Lack of well-established reproducibility criteria for whistle type categorization among studies may have generated results different from those expected for signal modulation. Future acoustic and ecological studies should be conducted to help clarify these findings and expand the limited knowledge about this species.
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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
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4
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Madsen PT, Siebert U, Elemans CPH. Toothed whales use distinct vocal registers for echolocation and communication. Science 2023; 379:928-933. [PMID: 36862790 DOI: 10.1126/science.adc9570] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Echolocating toothed whales (odontocetes) capture fast-moving prey in dark marine environments, which critically depends on their ability to generate powerful, ultrasonic clicks. How their supposedly air-driven sound source can produce biosonar clicks at depths of >1000 meters, while also producing rich vocal repertoires to mediate complex social communication, remains unknown. We show that odontocetes possess a sound production system based on air driven through nasal passages that is functionally analogous to laryngeal and syringeal sound production. Tissue vibration in different registers produces distinct echolocation and communication signals across all major odontocete clades, and thus provides a physiological basis for classifying their vocal repertoires. The vocal fry register is used by species from porpoises to sperm whales for generating powerful, highly air-efficient echolocation clicks.
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Affiliation(s)
- Peter T Madsen
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus, Denmark
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, 25761 Büsum, Germany
| | - Coen P H Elemans
- Sound Communication and Behavior Group, Department of Biology, University of Southern Denmark, 5230 Odense M, Denmark
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5
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Maiditsch IP, Ladich F. Different sound characteristics produced by the left and right pectoral fins constitute a new form of lateralization in a vocal fish. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:112-119. [PMID: 36214323 PMCID: PMC10092869 DOI: 10.1002/jez.2660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/14/2022] [Accepted: 09/19/2022] [Indexed: 11/05/2022]
Abstract
Songbirds and toothed whales are able to produce different sounds with the left and right part of their sonic organs, a phenomenon termed lateralized sound production. In fishes this phenomenon is poorly known, with lateralization having been observed solely in the channel catfish (Ictalurus punctatus). They produce more sounds with their right pectoral fins. Croaking gouramis Trichopsis vittata beat their pectoral fins alternately, resulting in a series of two-pulsed sound bursts termed croaking sounds. This study investigates lateralized sound production by comparing temporal and amplitude characteristics of sound bursts generated by pectoral fins in T. vittata. Croaking sounds, produced during dyadic contests, were analyzed in 19 females. We investigated the following characteristics of sound bursts: burst period, pulse period within bursts, the relative peak-to-peak amplitudes of bursts, and the ratio of peak-to-peak amplitudes of the first and second pulse within bursts. Sound bursts produced by the right and left sonic organ differed in 17 out of 19 females in at least one to four measured sound characteristics. The number of females whose temporal characteristics differed between pectoral fins was significantly higher than the number of females lacking such differences (16 out of 19). This was not the case for amplitude characteristics. Our data demonstrated that the sound characteristics produced by the left and right sonic organ in T. vittata differed significantly in most specimens. These differences in sound properties may constitute a new form of lateralized sound production in vocal fishes.
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Affiliation(s)
- Isabelle P Maiditsch
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria.,Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - Friedrich Ladich
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
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6
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The Distinctive Forehead Cleft of the Risso's Dolphin ( Grampus griseus) Hardly Affects Biosonar Beam Formation. Animals (Basel) 2022; 12:ani12243472. [PMID: 36552392 PMCID: PMC9774579 DOI: 10.3390/ani12243472] [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: 11/04/2022] [Revised: 12/03/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
The Risso's dolphin (Grampus griseus) has a distinctive vertical crease (or cleft) along the anterior surface of the forehead. Previous studies have speculated that the cleft may contribute to biosonar beam formation. To explore this, we constructed 2D finite element models based on computer tomography data of the head of a naturally deceased Risso's dolphin. The simulated acoustic near-field signals, far-field signals, and transmission beam patterns were compared to corresponding measurements from a live, echolocating Risso's dolphin. To investigate the effect of the cleft, we filled the cleft with neighboring soft tissues in our model, creating a hypothetical "cleftless" forehead, as found in other odontocetes. We compared the acoustic pressure field and the beam pattern between the clefted and cleftless cases. Our results suggest that the cleft plays an insignificant role in forehead biosonar sound propagation and far-field beam formation. Furthermore, the cleft was not responsible for the bimodal click spectrum recorded and reported from this species.
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7
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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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8
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Johnson CM, Ruiz-Mendoza C, Schoenbeck C. Conspecific "gaze following" in bottlenose dolphins. Anim Cogn 2022; 25:1219-1229. [PMID: 36063306 PMCID: PMC9617818 DOI: 10.1007/s10071-022-01665-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/23/2022] [Accepted: 08/06/2022] [Indexed: 11/29/2022]
Abstract
"Gaze following"—when one individual witnesses another shift its orientation, and then re-orients in the same direction—has been observed in a wide range of species. Related work with dolphins has to date focused on human–dolphin interactions. In this conspecific study, we examined a group of dolphins orienting, in passing, to gateways between their pools, as opportunities for witnesses to demonstrate "gaze following". Seven bottlenose dolphins were synchronously videotaped on six underwater cameras, for 21 h over three days, and the recordings analyzed by trained observers. The identities of all animals present, their partner state, and whether and to what degree they had altered their access to the gate (e.g., from Monocular to Binocular, or Binocular to Visio-Echoic) was recorded. Compared to animals that did not witness such a change, witnesses of an increase in access by another dolphin were significantly more likely to also act to increase their own access. We observed 460 such cases of "gaze following" in these animals. Dolphins who were partnered (showed sustained swimming within 1 body length) were significantly more likely, than non-partnered animals, to "gaze follow". Dolphins also showed a significant tendency toward matching the kind of access they observed. No significant difference was found in the presence of animals in the back pools, during changes in orientation that were followed, versus in those that were not. These findings support adding bottlenose dolphins to the growing list of species that display conspecific "gaze following".
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Affiliation(s)
- Christine M Johnson
- Department of Cognitive Science, University of California, Gilman Drive, La Jolla, San Diego, 9500, USA.
| | - Christina Ruiz-Mendoza
- Department of Cognitive Science, University of California, Gilman Drive, La Jolla, San Diego, 9500, USA
| | - Clara Schoenbeck
- Marine Science Program, Scripps Institution of Oceanography, UCSD, Kennel Way, La Jolla, San Diego, CA, 8622, USA
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9
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Cosentino M, Nairn D, Coscarella M, Jackson JC, Windmill JFC. I beg your pardon? Acoustic behaviour of a wild solitary common dolphin who interacts with harbour porpoises. BIOACOUSTICS 2022. [DOI: 10.1080/09524622.2021.1982005] [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)
- Mel Cosentino
- Bioacoustics Group, Centre for Ultrasonic Engineering, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, UK
| | | | - Mariano Coscarella
- Cesimar – Cct Cenpat -conicet, Puerto Madryn, Argentina
- Universidad Nacional de la Patagonia San Juan Bosco, Puerto Madryn, Argentina
| | - Joseph C. Jackson
- Bioacoustics Group, Centre for Ultrasonic Engineering, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - James F. C. Windmill
- Bioacoustics Group, Centre for Ultrasonic Engineering, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, UK
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10
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Ravignani A, Garcia M. A cross-species framework to identify vocal learning abilities in mammals. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200394. [PMID: 34775824 PMCID: PMC8591379 DOI: 10.1098/rstb.2020.0394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Vocal production learning (VPL) is the experience-driven ability to produce novel vocal signals through imitation or modification of existing vocalizations. A parallel strand of research investigates acoustic allometry, namely how information about body size is conveyed by acoustic signals. Recently, we proposed that deviation from acoustic allometry principles as a result of sexual selection may have been an intermediate step towards the evolution of vocal learning abilities in mammals. Adopting a more hypothesis-neutral stance, here we perform phylogenetic regressions and other analyses further testing a potential link between VPL and being an allometric outlier. We find that multiple species belonging to VPL clades deviate from allometric scaling but in the opposite direction to that expected from size exaggeration mechanisms. In other words, our correlational approach finds an association between VPL and being an allometric outlier. However, the direction of this association, contra our original hypothesis, may indicate that VPL did not necessarily emerge via sexual selection for size exaggeration: VPL clades show higher vocalization frequencies than expected. In addition, our approach allows us to identify species with potential for VPL abilities: we hypothesize that those outliers from acoustic allometry lying above the regression line may be VPL species. Our results may help better understand the cross-species diversity, variability and aetiology of VPL, which among other things is a key underpinning of speech in our species. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part II)'.
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Affiliation(s)
- Andrea Ravignani
- Comparative Bioacoustics Group, Max Planck Institute for Psycholinguistics, Wundtlaan 1, 6525 XD Nijmegen, The Netherlands
| | - Maxime Garcia
- Animal Behaviour, Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich 8051, Switzerland.,Center for the Interdisciplinary Study of Language Evolution, University of Zurich, Zurich 8032, Switzerland
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11
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Amano M, Kawano Y, Kubo T, Kuwahara T, Kobayashi H. Population-level laterality in foraging finless porpoises. Sci Rep 2021; 11:21164. [PMID: 34707173 PMCID: PMC8551196 DOI: 10.1038/s41598-021-00635-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 10/15/2021] [Indexed: 11/23/2022] Open
Abstract
Laterality has been reported in many vertebrates, and asymmetrical cerebral hemisphere function has been hypothesized to cause a left-bias in social behavior and a right-bias in feeding behavior. In this paper, we provide the first report of behavioral laterality in free-ranging finless porpoises, which seems to support the aforementioned hypothesis. We observed the turning behavior of finless porpoises in Omura Bay, Japan, using land-based and unmanned aerial system observations. We found a strong tendency in finless porpoises to turn counterclockwise with their right side down when pursuing and catching fish at the surface of the water. Our results suggest that this population of finless porpoises shows consistent right-biased laterality. Right-biased laterality has been observed in various foraging cetaceans and is usually explained by the dominance of the right eye-left cerebral hemisphere in prey recognition; however, right-biased laterality in foraging cetaceans may have multiple causes.
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Affiliation(s)
- Masao Amano
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
| | - Yudai Kawano
- Faculty of Fisheries, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan
| | - Taketo Kubo
- Faculty of Fisheries, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan
| | - Tsuyoshi Kuwahara
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan
| | - Hayao Kobayashi
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.,Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido, 099-2493, Japan
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12
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Frainer G, Huggenberger S, Moreno IB, Plön S, Galatius A. Head adaptation for sound production and feeding strategy in dolphins (Odontoceti: Delphinida). J Anat 2021; 238:1070-1081. [PMID: 33319356 PMCID: PMC8053589 DOI: 10.1111/joa.13364] [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: 09/17/2020] [Revised: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 01/01/2023] Open
Abstract
Head morphology in toothed whales evolved under selective pressures on feeding strategy and sound production. The postnatal development of the skull (n = 207) and mandible (n = 219) of six Delphinida species which differ in feeding strategy but exhibit similar sound emission patterns, including two narrow-band high-frequency species, were investigated through 3D morphometrics. Morphological changes throughout ontogeny were demonstrated based on the main source of variation (i.e., prediction lines) and the common allometric component. Multivariate trajectory analysis with pairwise comparisons between all species was performed to evaluate specific differences on the postnatal development of skulls and mandibles. Changes in the rostrum formation contributed to the variation (skull: 49%; mandible: 90%) of the entire data set and might not only reflect the feeding strategy adopted by each lineage but also represents an adaptation for sound production and reception. As an important structure for directionality of sound emissions, this may increase directionality in raptorial feeders. Phylogenetic generalized least squares analyses indicated that shape of the anterior portion of the skull is strongly dependent on phylogeny and might not only reflect feeding mode, but also morphological adaptations for sound production, particularly in raptorial species. Thus, postnatal development seems to represent a crucial stage for biosonar maturation in some raptorial species such as Pontoporia blainvillei and Sousa plumbea. The ontogeny of their main tool for navigation and hunting might reflect their natural history peculiarities and thus potentially define their main vulnerabilities to anthropogenic changes in the environment.
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Affiliation(s)
- Guilherme Frainer
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Ignacio B Moreno
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centro de Estudos Costeiros, Limnológicos e Marinhos (CECLIMAR/CLN/UFRGS), Universidade Federal do Rio Grande do Sul, Imbé, Brazil
| | - Stephanie Plön
- Bayworld Centre for Research and Education (BCRE), Port Elizabeth, South Africa
| | - Anders Galatius
- Marine Mammal Research, Department of Bioscience, Aarhus University, Roskilde, Denmark
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13
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Wei C, Hoffmann-Kuhnt M, Au WWL, Ho AZH, Matrai E, Feng W, Ketten DR, Zhang Y. Possible limitations of dolphin echolocation: a simulation study based on a cross-modal matching experiment. Sci Rep 2021; 11:6689. [PMID: 33758216 PMCID: PMC7988039 DOI: 10.1038/s41598-021-85063-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 02/22/2021] [Indexed: 12/02/2022] Open
Abstract
Dolphins use their biosonar to discriminate objects with different features through the returning echoes. Cross-modal matching experiments were conducted with a resident bottlenose dolphin (Tursiops aduncus). Four types of objects composed of different materials (water-filled PVC pipes, air-filled PVC pipes, foam ball arrays, and PVC pipes wrapped in closed-cell foam) were used in the experiments, respectively. The size and position of the objects remained the same in each case. The data collected in the experiment showed that the dolphin’s matching accuracy was significantly different across the cases. To gain insight into the underlying mechanism in the experiments, we used finite element methods to construct two-dimensional target detection models of an echolocating dolphin in the vertical plane, based on computed tomography scan data. The acoustic processes of the click’s interaction with the objects and the surrounding media in the four cases were simulated and compared. The simulation results provide some possible explanations for why the dolphin performed differently when discriminating the objects that only differed in material composition in the previous matching experiments.
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Affiliation(s)
- Chong Wei
- Centre for Marine Science and Technology, Curtin University, Kent Street, Bentley, WA, 6102, Australia.
| | - Matthias Hoffmann-Kuhnt
- Acoustic Research Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore, 119227, Singapore.
| | - Whitlow W L Au
- Hawaii Institute of Marine Biology, University of Hawaii, 46-007 Lilipuna Road, Kaneohe, HI, 96744, USA
| | - Abel Zhong Hao Ho
- Acoustic Research Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore, 119227, Singapore
| | - Eszter Matrai
- Research Department, Ocean Park Hong Kong, Hong Kong (SAR), China
| | - Wen Feng
- School of Information Engineering, Jimei University, Xiamen, 361021, People's Republic of China
| | - Darlene R Ketten
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA.,Department of Otology and Laryngology, Harvard Medical School, Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Yu Zhang
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiangan South Road, Xiamen, 361100, People's Republic of China.,College of Oceanography and Environmental Science, Xiamen University, Xiangan South Road, Xiamen, 361100, People's Republic of China
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14
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Beedholm K, Malinka C, Ladegaard M, Madsen PT. Do echolocating toothed whales direct their acoustic gaze on- or off-target in a static detection task? THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2021; 149:581. [PMID: 33514151 DOI: 10.1121/10.0003357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/28/2020] [Indexed: 06/12/2023]
Abstract
Echolocating mammals produce directional sound beams with high source levels to improve echo-to-noise ratios and reduce clutter. Recent studies have suggested that the differential spectral gradients of such narrow beams are exploited to facilitate target localization by pointing the beam slightly off targets to maximize the precision of angular position estimates [maximizing bearing Fisher information (FI)]. Here, we test the hypothesis that echolocating toothed whales focus their acoustic gaze askew during target detection to maximize spectral cues by investigating the acoustic gaze direction of two trained delphinids (Tursiops truncatus and Pseudorca crassidens) echolocating to detect an aluminum cylinder behind a hydrophone array in a go/no-go paradigm. The animals rarely placed their beam axis directly on the target, nor within the narrow range around the off-axis angle that maximizes FI. However, the target was, for each trial, ensonified within the swath of the half-power beam width, and hence we conclude that the animals solved the detection task using a strategy that seeks to render high echo-to-noise ratios rather than maximizing bearing FI. We posit that biosonar beam adjustment and acoustic gaze strategies are likely task-dependent and that maximizing bearing FI by pointing off-axis does not improve target detection performance.
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Affiliation(s)
- Kristian Beedholm
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Chloe Malinka
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Michael Ladegaard
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
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15
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Laeta M, Ruenes GF, Siciliano S, Oliveira JA, Galatius A. Variation in cranial asymmetry among the Delphinoidea. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
The remarkable directional cranial asymmetry of odontocete skulls has been proposed to be related to sound production. We investigated the variation in quality and quantity of cranial asymmetry in the superfamily Delphinoidea using geometric morphometrics and then investigated the relationship between asymmetry and aspects of sound production. In the average asymmetric shape, the dorsal aspect of the skull outline and interparietal suture crest were displaced to the right, while the nasal septum, nasal bones and right premaxilla were displaced to the left. The nasal bone, premaxilla and maxilla were all larger on the right side. Three delphinoid families presented similar expressions of asymmetry; however, the magnitude of the asymmetry varied. The Monodontidae showed the greatest magnitude of asymmetry, whereas the Phocoenidae were much less asymmetric. The most speciose family, the Delphinidae, presented a wide spectrum of asymmetry, with globicephalines and lissodelphinines among the most and least asymmetric species, respectively. Generalized linear models explaining the magnitude of asymmetry with characteristics of echolocation clicks, habitat use and size revealed associations with source level, dive depth and centroid size. This supports a relationship between asymmetry and sound production, with more asymmetric species emitting louder sounds. For example, louder clicks would be beneficial for prey detection at longer ranges in deeper waters.
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Affiliation(s)
- Maíra Laeta
- Programa de Pós-graduação em Biodiversidade e Biologia Evolutiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Setor de Mastozoologia, Departamento de Vertebrados, Museu Nacional/Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Grupo de Estudos de Mamíferos Marinhos da Região dos Lagos, Praia Seca, Araruama, RJ, Brazil
| | - Greicy F Ruenes
- Programa de Pós-graduação em Ecologia e Recursos Naturais, Universidade Estadual do Norte Fluminense “Darcy Ribeiro”, Campos dos Goytacazes, RJ, Brazil
- Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil
| | - Salvatore Siciliano
- Laboratório de Biodiversidade, Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, Rio de Janeiro, Brazil
- Grupo de Estudos de Mamíferos Marinhos da Região dos Lagos, Praia Seca, Araruama, RJ, Brazil
| | - João A Oliveira
- Setor de Mastozoologia, Departamento de Vertebrados, Museu Nacional/Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Anders Galatius
- Marine Mammal Research, Department of Bioscience, Aarhus University, Roskilde, Denmark
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16
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Ames AE, Beedholm K, Madsen PT. Lateralized sound production in the beluga whale ( Delphinapterus leucas). J Exp Biol 2020; 223:jeb226316. [PMID: 32665444 DOI: 10.1242/jeb.226316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 07/09/2020] [Indexed: 11/20/2022]
Abstract
Like other toothed whales, belugas produce sound through pneumatic actuation of two phonic lip pairs, but it is unclear whether both pairs are actuated concurrently to generate a single sound (the dual actuation hypothesis) or laterally in the production of their rich vocal repertoires. Here, using suction cup hydrophones on the head of a trained beluga whale, we measured seven different communication signal types and echolocation clicks in order to test the hypothesis that belugas produce distinct sounds unilaterally. We show that, like other delphinoids, belugas produce echolocation clicks with the right phonic lips and tonal sounds from the left. We also demonstrate for the first time that the left phonic lips are responsible for generating communication signals other than tonal sounds. Thus, our findings provide empirical support for functionalized laterality in delphinoid sound production, in keeping with the functional laterality hypothesis of vocal-motor control in toothed whales.
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Affiliation(s)
- Audra E Ames
- Fundación Oceanogràfic de la Comunitat Valenciana, 46013 Valencia, Spain
| | - Kristian Beedholm
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus, Denmark
| | - Peter T Madsen
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus, Denmark
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17
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Macaulay JDJ, Malinka CE, Gillespie D, Madsen PT. High resolution three-dimensional beam radiation pattern of harbour porpoise clicks with implications for passive acoustic monitoring. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:4175. [PMID: 32611133 DOI: 10.1121/10.0001376] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
The source properties and radiation patterns of animal vocalisations define, along with propagation and noise conditions, the active space in which these vocalisations can be detected by conspecifics, predators, prey, and by passive acoustic monitoring (PAM). This study reports the 4π (360° horizontal and vertical) beam profile of a free-swimming, trained harbour porpoise measured using a 27-element hydrophone array. The forward echolocation beam is highly directional, as predicted by a piston model, and is consistent with previous measurements. However, at off-axis angles greater than ±30°, the beam attenuates more rapidly than the piston model and no side lobes are present. A diffuse back beam is also present with levels about -30 dB relative to the source level. In PAM, up to 50% of detections can be from portions of the beam profile with distorted click spectra, although this drops substantially for higher detection thresholds. Simulations of the probability of acoustically detecting a harbour porpoise show that a traditional piston model can underestimate the probability of detection compared to the actual three-dimensional radiation pattern documented here. This highlights the importance of empirical 4π measurements of beam profiles of toothed whales, both to improve understanding of toothed whale biology and to inform PAM.
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Affiliation(s)
- Jamie D J Macaulay
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of Saint Andrews, East Sands, Saint Andrews, Fife, KY16 9LB, United Kingdom
| | - Chloe E Malinka
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Douglas Gillespie
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of Saint Andrews, East Sands, Saint Andrews, Fife, KY16 9LB, United Kingdom
| | - Peter T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
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18
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Wei C, Au WWL, Ketten DR. Modeling of the near to far acoustic fields of an echolocating bottlenose dolphin and harbor porpoise. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:1790. [PMID: 32237856 DOI: 10.1121/10.0000918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 02/27/2020] [Indexed: 06/11/2023]
Abstract
Echolocation signals emitted by odontocetes can be roughly classified into three broad categories: broadband echolocation signals, narrowband high-frequency echolocation signals, and frequency modulated clicks. Previous measurements of broadband echolocation signal propagation in the bottlenose dolphin (Tursiops truncatus) did not find any evidence of focusing as the signals travel from the near-field to far-field. Finite element analysis (FEA) of high-resolution computed tomography scan data was used to examine signal propagation of broadband echolocation signals of dolphins and narrowband echolocation signals of porpoises. The FEA results were used to simulate the propagation of clicks from phonic lips, traveling through the forehead, and finally transmission into the water. Biosonar beam formation in the near-field and far-field, including the amplitude contours for the two species, was determined. The finite element model result for the simulated amplitude contour in the horizontal plane was consistent with prior direct measurement results for Tursiops, validating the model. Furthermore, the simulated far-field transmission beam patterns in both the vertical and horizontal planes were also qualitatively consistent with results measured from live animals. This study indicates that there is no evidence of convergence for either Tursiops or Phocoena as the sound propagates from the near-field to the far-field.
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Affiliation(s)
- Chong Wei
- Centre for Marine Science and Technology, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - Whitlow W L Au
- Hawaii Institute of Marine Biology, University of Hawaii, 46-007 Lilipuna Road, Kaneohe, Hawaii 96744, USA
| | - Darlene R Ketten
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
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19
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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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20
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Kaplan JD, Goodrich SY, Melillo-Sweeting K, Reiss D. Behavioural laterality in foraging bottlenose dolphins ( Tursiops truncatus). ROYAL SOCIETY OPEN SCIENCE 2019; 6:190929. [PMID: 31827837 PMCID: PMC6894562 DOI: 10.1098/rsos.190929] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Lateralized behaviour is found in humans and a wide variety of other species. At a population level, lateralization of behaviour suggests hemispheric specialization may underlie this behaviour. As in other cetaceans, dolphins exhibit a strong right-side bias in foraging behaviour. Common bottlenose dolphins in The Bahamas use a foraging technique termed 'crater feeding', in which they swim slowly along the ocean floor, scanning the substrate using echolocation, and then bury their rostrums into the sand to obtain prey. The bottlenose dolphins off Bimini, The Bahamas, frequently execute a sharp turn before burying their rostrums in the sand. Based on data collected from 2012 to 2018, we report a significant right-side (left turn) bias in these dolphins. Out of 709 turns recorded from at least 27 different individuals, 99.44% (n = 705) were to the left (right side and right eye down) [z = 3.275, p = 0.001]. Only one individual turned right (left side and left eye down, 4/4 turns). We hypothesize that this right-side bias may be due in part to the possible laterization of echolocation production mechanisms, the dolphins' use of the right set of phonic lips to produce echolocation clicks, and a right eye (left hemisphere) advantage in visual discrimination and visuospatial processing.
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Affiliation(s)
| | - Samantha Y. Goodrich
- Department of Psychology, St Mary's College of Maryland, St Mary's City, MD, USA
| | | | - Diana Reiss
- Department of Psychology, Hunter College, CUNY, New York, NY, 10065, USA
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21
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Deep-diving pilot whales make cheap, but powerful, echolocation clicks with 50 µL of air. Sci Rep 2019; 9:15720. [PMID: 31673021 PMCID: PMC6823382 DOI: 10.1038/s41598-019-51619-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 09/02/2019] [Indexed: 11/10/2022] Open
Abstract
Echolocating toothed whales produce powerful clicks pneumatically to detect prey in the deep sea where this long-range sensory channel makes them formidable top predators. However, air supplies for sound production compress with depth following Boyle’s law suggesting that deep-diving whales must use very small air volumes per echolocation click to facilitate continuous sensory flow in foraging dives. Here we test this hypothesis by analysing click-induced acoustic resonances in the nasal air sacs, recorded by biologging tags. Using 27000 clicks from 102 dives of 23 tagged pilot whales (Globicephala macrorhynchus), we show that click production requires only 50 µL of air/click at 500 m depth increasing gradually to 100 µL at 1000 m. With such small air volumes, the metabolic cost of sound production is on the order of 40 J per dive which is a negligible fraction of the field metabolic rate. Nonetheless, whales must make frequent pauses in echolocation to recycle air between nasal sacs. Thus, frugal use of air and periodic recycling of very limited air volumes enable pilot whales, and likely other toothed whales, to echolocate cheaply and almost continuously throughout foraging dives, providing them with a strong sensory advantage in diverse aquatic habitats.
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22
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Frainer G, Moreno IB, Serpa N, Galatius A, Wiedermann D, Huggenberger S. Ontogeny and evolution of the sound-generating structures in the infraorder Delphinida (Odontoceti: Delphinida). Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz118] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AbstractThe ontogeny of the structures involved in sound generation and modulation in dolphins was investigated through a comparison of the soft nasal structures of foetal, perinatal, neonatal and adult specimens of Pontoporiidae, Phocoenidae and Delphinidae. Foetal samples were sectioned at 10 µm in the saggital and coronal planes, and stained for histological examination. Computed tomography and magentic resonance imaging scan series were combined with new data to represent the ontogenetic stages of the three groups. The images were analysed in 3D-Slicer to characterize the general head topography. The origins of the melon and the vestibular air sac were detected between Carnegie stages C16 and F22. The three groups analysed showed distinct formation of the nasal plug and nasal plug muscles, mainly with regard to the loss of fat pathways (or their maintenance in Pontoporiidae) and the development of the nasal plug muscles on both sides (during perinatal development of Phocoenidae) or just on the left side (during postnatal development in Delphinidae). Broadband vocalizing delphinidans might have evolved under heterochronic events acting on the formation of sound-generating structures such as the rostrum and vestibular air sacs, and on the transformation of the branches of the melon, probably leading to a reduced directionality of the sonar beam.
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Affiliation(s)
- Guilherme Frainer
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Centro de Estudos Costeiros, Limnológicos e Marinhos (CECLIMAR/UFRGS), Campus Litoral Norte, Universidade Federal do Rio Grande do Sul, Imbé, Brazil
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Ignacio B Moreno
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Centro de Estudos Costeiros, Limnológicos e Marinhos (CECLIMAR/UFRGS), Campus Litoral Norte, Universidade Federal do Rio Grande do Sul, Imbé, Brazil
| | - Nathalia Serpa
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Centro de Estudos Costeiros, Limnológicos e Marinhos (CECLIMAR/UFRGS), Campus Litoral Norte, Universidade Federal do Rio Grande do Sul, Imbé, Brazil
| | - Anders Galatius
- Department of Bioscience, Aarhus University, Roskilde, Denmark
| | - Dirk Wiedermann
- Max Planck Institute for Metabolism Research, Cologne, Germany
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23
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Jones B, Zapetis M, Samuelson MM, Ridgway S. Sounds produced by bottlenose dolphins (Tursiops): a review of the defining characteristics and acoustic criteria of the dolphin vocal repertoire. BIOACOUSTICS 2019. [DOI: 10.1080/09524622.2019.1613265] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Brittany Jones
- Sound and Health Department, National Marine Mammal Foundation, San Diego, CA, USA
| | - Maria Zapetis
- Sound and Health Department, National Marine Mammal Foundation, San Diego, CA, USA
| | - Mystera M. Samuelson
- Research and Stranding Department, The Institute for Marine Mammal Studies, Gulfport, MS, USA
| | - Sam Ridgway
- Sound and Health Department, National Marine Mammal Foundation, San Diego, CA, USA
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24
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Starkhammar J, Reinhold I, Moore PW, Houser DS, Sandsten M. Detailed analysis of two detected overlaying transient components within the echolocation beam of a bottlenose dolphin (Tursiops truncatus). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:2138. [PMID: 31046343 DOI: 10.1121/1.5096640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 03/13/2019] [Indexed: 06/09/2023]
Abstract
Dolphin echolocation clicks measured far off-axis contain two time-separated components. Whether these components overlap and appear as a single signal on axis has received little attention. Here, the scaled reassigned spectrogram analysis was used to examine if bottlenose dolphin (Tursiops truncatus) clicks measured near- or on-axis of the echolocation beam contained overlapping components. Across click trains, the number of overlapping components spatially varied within the echolocation beam. Two overlapping components were found to predominantly occur in the upper portion of the beam, whereas the lower portion of the beam predominantly contained a single component. When components overlapped, the trailing component generally had a higher center frequency and arrived less than 5 μs after the leading component. The spatial relationship of components was consistent with previous findings of two vertically distinct beam lobes with separated frequency content. The two components in the upper portion of the beam possibly result from a single transient click propagating through a geometrically dispersive media; specifically, the slower sound speed of the dolphin melon's core slightly delays the more directional, high frequency energy of the click, whereas the less directional, lower frequency energy propagates through more peripheral but higher sound speed portions of the melon.
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Affiliation(s)
| | - Isabella Reinhold
- Mathematical Statistics, Centre for Mathematical Sciences, Lund University, Lund, Sweden
| | - Patrick W Moore
- National Marine Mammal Foundation, San Diego, California 92106, USA
| | - Dorian S Houser
- National Marine Mammal Foundation, San Diego, California 92106, USA
| | - Maria Sandsten
- Mathematical Statistics, Centre for Mathematical Sciences, Lund University, Lund, Sweden
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25
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Girola E, Noad MJ, Dunlop RA, Cato DH. Source levels of humpback whales decrease with frequency suggesting an air-filled resonator is used in sound production. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:869. [PMID: 30823805 DOI: 10.1121/1.5090492] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 01/25/2019] [Indexed: 05/26/2023]
Abstract
Source level and frequency are important in determining how far an acoustic signal can travel. However, in some species these sound characteristics have been found to be biomechanically linked, and therefore cannot be modified independently to achieve optimal transmission. This study investigates the variability in source levels and their relationship with frequency in the songs of humpback whales (Megaptera novaeangliae). Songs were recorded off eastern Australia using a fixed hydrophone array deployed on the whales' migratory corridor. Singing whales were acoustically tracked. An empirical, frequency-dependent model was used to estimate transmission loss. Source levels and frequency were measured for 2408 song units from 19 singers. Source levels varied from 138 to 187 dB re 1 μPa at 1 m (root mean squared), while peak frequency ranged between 52 and 3877 Hz. Much of the variability in source levels was accounted for by differences between the unit types, with mean source levels for each unit type varying by up to 17 dB. Source levels were negatively correlated with peak frequency and decreased by 2.3 dB per octave. The negative correlation between source levels and frequency is consistent with the presence of an air-filled resonator in the whales' sound production system.
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Affiliation(s)
- Elisa Girola
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, University of Queensland, Gatton, Queensland 4343, Australia
| | - Michael J Noad
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, University of Queensland, Gatton, Queensland 4343, Australia
| | - Rebecca A Dunlop
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, University of Queensland, Gatton, Queensland 4343, Australia
| | - Douglas H Cato
- School of Geosciences, University of Sydney, Sydney, New South Wales 2006, Australia
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26
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Jensen FH, Johnson M, Ladegaard M, Wisniewska DM, Madsen PT. Narrow Acoustic Field of View Drives Frequency Scaling in Toothed Whale Biosonar. Curr Biol 2018; 28:3878-3885.e3. [DOI: 10.1016/j.cub.2018.10.037] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/12/2018] [Accepted: 10/12/2018] [Indexed: 11/27/2022]
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27
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Frainer G, Plön S, Serpa NB, Moreno IB, Huggenberger S. Sound Generating Structures of the Humpback DolphinSousa plumbea(Cuvier, 1829) and the Directionality in Dolphin Sounds. Anat Rec (Hoboken) 2018; 302:849-860. [DOI: 10.1002/ar.23981] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/01/2018] [Accepted: 07/14/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Guilherme Frainer
- Programa de Pós‐Graduação em Biologia Animal, Departamento de ZoologiaUniversidade Federal do Rio Grande do Sul 91540‐000 Porto Alegre Brazil
- Centro de Estudos CosteirosLimnológicos e Marinhos (CECLIMAR/UFRGS), Campus Litoral Norte, Universidade Federal do Rio Grande do Sul 95625‐000 Imbé Brazil
- Department II of AnatomyUniversity of Cologne 50924 Cologne Germany
| | - Stephanie Plön
- African Earth Observation Network (AEON) ‐Earth Stewardship Science Research Institute (ESSRI)Nelson Mandela University 6031 Port Elizabeth South Africa
| | - Nathalia B. Serpa
- Programa de Pós‐Graduação em Biologia Animal, Departamento de ZoologiaUniversidade Federal do Rio Grande do Sul 91540‐000 Porto Alegre Brazil
- Centro de Estudos CosteirosLimnológicos e Marinhos (CECLIMAR/UFRGS), Campus Litoral Norte, Universidade Federal do Rio Grande do Sul 95625‐000 Imbé Brazil
| | - Ignacio B. Moreno
- Programa de Pós‐Graduação em Biologia Animal, Departamento de ZoologiaUniversidade Federal do Rio Grande do Sul 91540‐000 Porto Alegre Brazil
- Centro de Estudos CosteirosLimnológicos e Marinhos (CECLIMAR/UFRGS), Campus Litoral Norte, Universidade Federal do Rio Grande do Sul 95625‐000 Imbé Brazil
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28
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Volodin IA, Panyutina AA, Abramov AV, Ilchenko OG, Volodina EV. Ultrasonic bouts of a blind climbing rodent (Typhlomys chapensis): acoustic analysis. BIOACOUSTICS 2018. [DOI: 10.1080/09524622.2018.1509374] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Ilya A. Volodin
- Department of Vertebrate Zoology, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
- Scientific Research Department, Moscow Zoo, Moscow, Russia
| | | | - Alexei V. Abramov
- Zoological Institute, Russian Academy of Sciences, Saint Petersburg, Russia
- Joint Vietnam–Russian Tropical Research and Technological Centre, Nguyen Van Huyen, Hanoi, Vietnam
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29
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Wei C, Au WWL, Ketten DR, Zhang Y. Finite element simulation of broadband biosonar signal propagation in the near- and far-field of an echolocating Atlantic bottlenose dolphin (Tursiops truncatus). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:2611. [PMID: 29857761 DOI: 10.1121/1.5034464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bottlenose dolphins project broadband echolocation signals for detecting and locating prey and predators, and for spatial orientation. There are many unknowns concerning the specifics of biosonar signal production and propagation in the head of dolphins and this manuscript represents an effort to address this topic. A two-dimensional finite element model was constructed using high resolution CT scan data. The model simulated the acoustic processes in the vertical plane of the biosonar signal emitted from the phonic lips and propagated into the water through the animal's head. The acoustic field on the animal's forehead and the farfield transmission beam pattern of the echolocating dolphin were determined. The simulation results and prior acoustic measurements were qualitatively extremely consistent. The role of the main structures on the sound propagation pathway such as the air sacs, melon, and connective tissue was investigated. Furthermore, an investigation of the driving force at the phonic lips for dolphins that emit broadband echolocation signals and porpoises that emit narrowband echolocation signals suggested that the driving force is different for the two types of biosonar. Finally, the results provide a visual understanding of the sound transmission in dolphin's biosonar.
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Affiliation(s)
- Chong Wei
- Hawaii Institute of Marine Biology, University of Hawaii, 46-007 Lilipuna Road, Kaneohe, Hawaii 96744, USA
| | - Whitlow W L Au
- Hawaii Institute of Marine Biology, University of Hawaii, 46-007 Lilipuna Road, Kaneohe, Hawaii 96744, USA
| | - Darlene R Ketten
- Department of Otology and Laryngology, Harvard Medical School, Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - Yu Zhang
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Zengcuoan West Road, Xiamen, 361005, People's Republic of China
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30
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Kaplan JD, Melillo-Sweeting K, Reiss D. Biphonal calls in Atlantic spotted dolphins ( Stenella frontalis): bitonal and burst-pulse whistles. BIOACOUSTICS 2018. [DOI: 10.1080/09524622.2017.1300105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- J. Daisy Kaplan
- The Graduate Center, City University of New York, New York, NY, USA
- Department of Psychology, St. Mary’s College of Maryland, St. Mary's City, MD, USA
| | | | - Diana Reiss
- The Graduate Center, City University of New York, New York, NY, USA
- Department of Psychology, Hunter College, City University of New York, New York, NY, USA
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31
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Reinhold I, Sandsten M, Starkhammar J. Objective detection and time-frequency localization of components within transient signals. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:2368. [PMID: 29716299 DOI: 10.1121/1.5032215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
An automatic component detection method for overlapping transient pulses in multi-component signals is presented and evaluated. The recently proposed scaled reassignment technique is shown to have the best achievable resolution for closely located Gaussian shaped transient pulses, even in heavy disruptive noise. As a result, the method automatically detects and counts the number of transients, giving the center times and center frequencies of all components with considerable accuracy. The presented method shows great potential for applications in several acoustic research fields, where coinciding Gaussian shaped transients are analyzed. The performance is tested on measured data from a laboratory pulse-echo setup and from a dolphin echolocation signal measured simultaneously at two different locations in the echolocation beam. Since the method requires little user input, it should be easily employed in a variety of research projects.
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Affiliation(s)
- Isabella Reinhold
- Mathematical Statistics, Centre for Mathematical Sciences, Lund University, Lund, Sweden
| | - Maria Sandsten
- Mathematical Statistics, Centre for Mathematical Sciences, Lund University, Lund, Sweden
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32
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Finneran JJ, Mulsow J, Jones R, Houser DS, Accomando AW, Ridgway SH. Non-auditory, electrophysiological potentials preceding dolphin biosonar click production. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:271-283. [PMID: 29222726 PMCID: PMC5816092 DOI: 10.1007/s00359-017-1234-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/16/2017] [Accepted: 11/20/2017] [Indexed: 12/03/2022]
Abstract
The auditory brainstem response to a dolphin’s own emitted biosonar click can be measured by averaging epochs of the instantaneous electroencephalogram (EEG) that are time-locked to the emitted click. In this study, averaged EEGs were measured using surface electrodes placed on the head in six different configurations while dolphins performed an echolocation task. Simultaneously, biosonar click emissions were measured using contact hydrophones on the melon and a hydrophone in the farfield. The averaged EEGs revealed an electrophysiological potential (the pre-auditory wave, PAW) that preceded the production of each biosonar click. The largest PAW amplitudes occurred with the non-inverting electrode just right of the midline—the apparent side of biosonar click generation—and posterior of the blowhole. Although the source of the PAW is unknown, the temporal and spatial properties rule out an auditory source. The PAW may be a neural or myogenic potential associated with click production; however, it is not known if muscles within the dolphin nasal system can be actuated at the high rates reported for dolphin click production, or if sufficiently coordinated and fast motor endplates of nasal muscles exist to produce a PAW detectable with surface electrodes.
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33
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Arribart M, Ognard J, Tavernier C, Richaudeau Y, Guintard C, Dabin W, Ben Salem D, Jung JL. Comparative anatomical study of sound production and reception systems in the common dolphin (Delphinus delphis) and the harbour porpoise (Phocoena phocoena) heads. Anat Histol Embryol 2018; 47:3-10. [PMID: 29052248 DOI: 10.1111/ahe.12305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 08/11/2017] [Indexed: 11/29/2022]
Abstract
Magnetic resonance imaging (MRI) and computed tomography (CT) scans were used to analyse, respectively, the soft tissues and the bones of the heads of four common dolphins and three harbour porpoises. This imaging study was completed by an examination of anatomical sections performed on two odontocete heads (a subadult common dolphin and a subadult harbour porpoise). The three complementary approaches allowed to illustrate anatomical differences in the echolocation systems of the common dolphin and the harbour porpoise. We captured images confirming strong differences of symmetry of the melon and of its connexions to the MLDB (Monkeys Lips/Dorsal Bursae) between the common dolphin and the harbour porpoise. The melon of the common dolphin is asymmetrically directly connected to the right bursae cantantes at its right side, whereas the melon of the harbour porpoise is symmetrical, and separated from the two bursae cantantes by a set of connective tissues. Another striking difference comes from the bursae cantantes themselves, less deeply located in the head of the common dolphin than in the harbour porpoise.
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Affiliation(s)
- M Arribart
- Service d'anatomie comparée, École Nationale Vétérinaire ONIRIS, Nantes, France
| | - J Ognard
- Service d'Imagerie Forensique, CHRU Brest, LaTIM, INSERM U 1101, Université de Bretagne Occidentale, Brest, France
| | | | | | - C Guintard
- Service d'anatomie comparée, École Nationale Vétérinaire ONIRIS, Nantes, France
| | - W Dabin
- Observatoire PELAGIS, UMS 3462, CNRS, Université de La Rochelle, La Rochelle, France
| | - D Ben Salem
- Service d'Imagerie Forensique, CHRU Brest, LaTIM, INSERM U 1101, Université de Bretagne Occidentale, Brest, France
| | - J-L Jung
- Laboratoire BioGeMME, Université de Bretagne Occidentale et Université Bretagne Loire, UFR Sciences et Techniques, Brest, France
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34
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Wright AK, Theilmann RJ, Ridgway SH, Scadeng M. Diffusion tractography reveals pervasive asymmetry of cerebral white matter tracts in the bottlenose dolphin (Tursiops truncatus). Brain Struct Funct 2017; 223:1697-1711. [PMID: 29189908 PMCID: PMC5884918 DOI: 10.1007/s00429-017-1525-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 07/06/2017] [Indexed: 12/18/2022]
Abstract
Brain enlargement is associated with concomitant growth of interneuronal distance, increased conduction time, and reduced neuronal interconnectivity. Recognition of these functional constraints led to the hypothesis that large-brained mammals should exhibit greater structural and functional brain lateralization. As a taxon with the largest brains in the animal kingdom, Cetacea provides a unique opportunity to examine asymmetries of brain structure and function. In the present study, diffusion tensor imaging and tractography were used to investigate cerebral white matter asymmetry in the bottlenose dolphin (Tursiops truncatus). Widespread white matter asymmetries were observed with the preponderance of tracts exhibiting leftward structural asymmetries. Leftward lateralization may reflect differential processing and execution of behaviorally variant sensory and motor functions by the cerebral hemispheres. The arcuate fasciculus, an association tract linked to human language evolution, was isolated and exhibited rightward asymmetry suggesting a right hemisphere bias for conspecific communication unlike that of most mammals. This study represents the first examination of cetacean white matter asymmetry and constitutes an important step toward understanding potential drivers of structural asymmetry and its role in underpinning functional and behavioral lateralization in cetaceans.
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Affiliation(s)
- Alexandra K Wright
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California-San Diego, La Jolla, CA, 92093, USA.
| | - Rebecca J Theilmann
- Department of Radiology, University of California-San Diego, La Jolla, CA, 92093, USA
| | - Sam H Ridgway
- National Marine Mammal Foundation, San Diego, CA, 92106, USA
| | - Miriam Scadeng
- Center for Functional MRI, Department of Radiology, University of California-San Diego, La Jolla, CA, 92093, USA
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35
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Thometz NM, Dearolf JL, Dunkin RC, Noren DP, Holt MM, Sims OC, Cathey BC, Williams TM. Comparative physiology of vocal musculature in two odontocetes, the bottlenose dolphin (Tursiops truncatus) and the harbor porpoise (Phocoena phocoena). J Comp Physiol B 2017; 188:177-193. [PMID: 28569355 DOI: 10.1007/s00360-017-1106-5] [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: 01/31/2017] [Accepted: 05/11/2017] [Indexed: 10/19/2022]
Abstract
The mechanism by which odontocetes produce sound is unique among mammals. To gain insight into the physiological properties that support sound production in toothed whales, we examined myoglobin content ([Mb]), non-bicarbonate buffering capacity (β), fiber-type profiles, and myosin heavy chain expression of vocal musculature in two odontocetes: the bottlenose dolphin (Tursiops truncatus; n = 4) and the harbor porpoise (Phocoena phocoena; n = 5). Both species use the same anatomical structures to produce sound, but differ markedly in their vocal repertoires. Tursiops produce both broadband clicks and tonal whistles, while Phocoena only produce higher frequency clicks. Specific muscles examined in this study included: (1) the nasal musculature around the phonic lips on the right (RNM) and left (LNM) sides of the head, (2) the palatopharyngeal sphincter (PPS), which surrounds the larynx and aids in pressurizing cranial air spaces, and (3) the genioglossus complex (GGC), a group of muscles positioned ventrally within the head. Overall, vocal muscles had significantly lower [Mb] and β than locomotor muscles from the same species. The PPS was predominately composed of small diameter slow-twitch fibers. Fiber-type and myosin heavy chain analyses revealed that the GGC was comprised largely of fast-twitch fibers (Tursiops: 88.6%, Phocoena: 79.7%) and had the highest β of all vocal muscles. Notably, there was a significant difference in [Mb] between the RNM and LNM in Tursiops, but not Phocoena. Our results reveal shared physiological characteristics of individual vocal muscles across species that enhance our understanding of key functional roles, as well as species-specific differences which appear to reflect differences in vocal capacities.
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Affiliation(s)
- Nicole M Thometz
- Department of Biology, University of San Francisco, 2130 Fulton St, San Francisco, CA, 94117, USA. .,Department of Ecology and Evolutionary Biology, Long Marine Laboratory, University of California at Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA.
| | - Jennifer L Dearolf
- Biology Department, Hendrix College, 1600 Washington Ave., Conway, AR, 72032, USA
| | - Robin C Dunkin
- Department of Ecology and Evolutionary Biology, Long Marine Laboratory, University of California at Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Dawn P Noren
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA, 98112, USA
| | - Marla M Holt
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA, 98112, USA
| | - Olivia C Sims
- Biology Department, Hendrix College, 1600 Washington Ave., Conway, AR, 72032, USA
| | - Brandon C Cathey
- Biology Department, Hendrix College, 1600 Washington Ave., Conway, AR, 72032, USA
| | - Terrie M Williams
- Department of Ecology and Evolutionary Biology, Long Marine Laboratory, University of California at Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
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36
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Huggenberger S, Leidenberger S, Oelschläger HHA. Asymmetry of the nasofacial skull in toothed whales (Odontoceti). J Zool (1987) 2016. [DOI: 10.1111/jzo.12425] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Huggenberger
- Department II of Anatomy University of Cologne Cologne Germany
| | - S. Leidenberger
- Swedish Species Information Centre/ArtDatabanken Swedish University of Agricultural Sciences Uppsala Sweden
| | - H. H. A. Oelschläger
- Department of Anatomy III (Dr. Senckenbergische Anatomie) Johann Wolfgang Goethe University Frankfurt am Main Frankfurt am Main Germany
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37
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Ladegaard M, Jensen FH, de Freitas M, Ferreira da Silva VM, Madsen PT. Amazon river dolphins (Inia geoffrensis) use a high-frequency short-range biosonar. ACTA ACUST UNITED AC 2016; 218:3091-101. [PMID: 26447198 DOI: 10.1242/jeb.120501] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Toothed whales produce echolocation clicks with source parameters related to body size; however, it may be equally important to consider the influence of habitat, as suggested by studies on echolocating bats. A few toothed whale species have fully adapted to river systems, where sonar operation is likely to result in higher clutter and reverberation levels than those experienced by most toothed whales at sea because of the shallow water and dense vegetation. To test the hypothesis that habitat shapes the evolution of toothed whale biosonar parameters by promoting simpler auditory scenes to interpret in acoustically complex habitats, echolocation clicks of wild Amazon river dolphins were recorded using a vertical seven-hydrophone array. We identified 404 on-axis biosonar clicks having a mean SLpp of 190.3 ± 6.1 dB re. 1 µPa, mean SLEFD of 132.1 ± 6.0 dB re. 1 µPa(2)s, mean Fc of 101.2 ± 10.5 kHz, mean BWRMS of 29.3 ± 4.3 kHz and mean ICI of 35.1 ± 17.9 ms. Piston fit modelling resulted in an estimated half-power beamwidth of 10.2 deg (95% CI: 9.6-10.5 deg) and directivity index of 25.2 dB (95% CI: 24.9-25.7 dB). These results support the hypothesis that river-dwelling toothed whales operate their biosonars at lower amplitude and higher sampling rates than similar-sized marine species without sacrificing high directivity, in order to provide high update rates in acoustically complex habitats and simplify auditory scenes through reduced clutter and reverberation levels. We conclude that habitat, along with body size, is an important evolutionary driver of source parameters in toothed whale biosonars.
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Affiliation(s)
- Michael Ladegaard
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus 8000, Denmark
| | - Frants Havmand Jensen
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Mafalda de Freitas
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus 8000, Denmark
| | | | - Peter Teglberg Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus 8000, Denmark Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
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38
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Filatova OA, Samarra FIP, Barrett-Lennard LG, Miller PJO, Ford JKB, Yurk H, Matkin CO, Hoyt E. Physical constraints of cultural evolution of dialects in killer whales. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:3755. [PMID: 27908070 DOI: 10.1121/1.4967369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Odontocete sounds are produced by two pairs of phonic lips situated in soft nares below the blowhole; the right pair is larger and is more likely to produce clicks, while the left pair is more likely to produce whistles. This has important implications for the cultural evolution of delphinid sounds: the greater the physical constraints, the greater the probability of random convergence. In this paper the authors examine the call structure of eight killer whale populations to identify structural constraints and to determine if they are consistent among all populations. Constraints were especially pronounced in two-voiced calls. In the calls of all eight populations, the lower component of two-voiced (biphonic) calls was typically centered below 4 kHz, while the upper component was typically above that value. The lower component of two-voiced calls had a narrower frequency range than single-voiced calls in all populations. This may be because some single-voiced calls are homologous to the lower component, while others are homologous to the higher component of two-voiced calls. Physical constraints on the call structure reduce the possible variation and increase the probability of random convergence, producing similar calls in different populations.
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Affiliation(s)
- Olga A Filatova
- Department of Vertebrate Zoology, Faculty of Biology, Moscow State University, Moscow 119991, Russia
| | - Filipa I P Samarra
- Marine and Freshwater Research Institute, Skúlagata 4, 101 Reykjavík, Iceland
| | | | - Patrick J O Miller
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, Fife KY168LB, Scotland
| | - John K B Ford
- Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, British Columbia V9T1K6, Canada
| | - Harald Yurk
- JASCO Research Ltd., 2305-4464 Markham Street, Victoria, British Columbia V8Z7X8, Canada
| | | | - Erich Hoyt
- Whale and Dolphin Conservation, Park House, Allington Park, Bridport, Dorset DT65DD, United Kingdom
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39
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Finneran JJ, Mulsow J, Branstetter B, Moore P, Houser DS. Nearfield and farfield measurements of dolphin echolocation beam patterns: No evidence of focusing. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:1346. [PMID: 27586761 DOI: 10.1121/1.4961015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The potential for bottlenose dolphins to actively focus their biosonar transmissions was examined by measuring emitted clicks in four dolphins using horizontal, planar hydrophone arrays. Two hydrophone configurations were used: a rectangular array with hydrophones 0.2 to 2 m from the dolphins and a polar array with hydrophones 0.5 to 5 m from the dolphins. The biosonar task was a target change detection utilizing physical targets at ranges from 1.3 to 6.3 m with all subjects and "phantom" targets at simulated ranges from 2.5 to 20 m with two subjects. To provide a basis for evaluating the experimental data, sound fields radiated from flat and focused circular pistons were mathematically simulated using transient excitation functions similar to dolphin clicks. The array measurements showed no evidence that the dolphins adaptively focused their click emissions; axial amplitudes and iso-amplitude contours matched the pattern of the simulation results for flat transducers and showed a single region of maximum amplitude, beyond which spherical spreading loss was approximated.
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Affiliation(s)
- James J Finneran
- U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific, Code 71510, 53560 Hull Street, San Diego, California 92152, USA
| | - Jason Mulsow
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Brian Branstetter
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Patrick Moore
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Dorian S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
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40
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Neuroanatomy of the killer whale (Orcinus orca): a magnetic resonance imaging investigation of structure with insights on function and evolution. Brain Struct Funct 2016; 222:417-436. [PMID: 27119362 DOI: 10.1007/s00429-016-1225-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 04/07/2016] [Indexed: 12/18/2022]
Abstract
The evolutionary process of adaptation to an obligatory aquatic existence dramatically modified cetacean brain structure and function. The brain of the killer whale (Orcinus orca) may be the largest of all taxa supporting a panoply of cognitive, sensory, and sensorimotor abilities. Despite this, examination of the O. orca brain has been limited in scope resulting in significant deficits in knowledge concerning its structure and function. The present study aims to describe the neural organization and potential function of the O. orca brain while linking these traits to potential evolutionary drivers. Magnetic resonance imaging was used for volumetric analysis and three-dimensional reconstruction of an in situ postmortem O. orca brain. Measurements were determined for cortical gray and cerebral white matter, subcortical nuclei, cerebellar gray and white matter, corpus callosum, hippocampi, superior and inferior colliculi, and neuroendocrine structures. With cerebral volume comprising 81.51 % of the total brain volume, this O. orca brain is one of the most corticalized mammalian brains studied to date. O. orca and other delphinoid cetaceans exhibit isometric scaling of cerebral white matter with increasing brain size, a trait that violates an otherwise evolutionarily conserved cerebral scaling law. Using comparative neurobiology, it is argued that the divergent cerebral morphology of delphinoid cetaceans compared to other mammalian taxa may have evolved in response to the sensorimotor demands of the aquatic environment. Furthermore, selective pressures associated with the evolution of echolocation and unihemispheric sleep are implicated in substructure morphology and function. This neuroanatomical dataset, heretofore absent from the literature, provides important quantitative data to test hypotheses regarding brain structure, function, and evolution within Cetacea and across Mammalia.
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41
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Galatius A, Goodall RNP. Skull shapes of the Lissodelphininae: radiation, adaptation and asymmetry. J Morphol 2016; 277:776-85. [DOI: 10.1002/jmor.20535] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 02/01/2016] [Accepted: 02/27/2016] [Indexed: 11/05/2022]
Affiliation(s)
| | - R. Natalie P. Goodall
- Museo Acatushún de Aves y Mamiferos Marines Australes (AMMA); Tierra del Fuego Argentina
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42
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Baumann-Pickering S, Simonis AE, Oleson EM, Baird RW, Roch MA, Wiggins SM. False killer whale and short-finned pilot whale acoustic identification. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00685] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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43
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de Freitas M, Jensen FH, Tyne J, Bejder L, Madsen PT. Echolocation parameters of Australian humpback dolphins (Sousa sahulensis) and Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the wild. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:3033-41. [PMID: 26093395 DOI: 10.1121/1.4921277] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Echolocation is a key sensory modality for toothed whale orientation, navigation, and foraging. However, a more comparative understanding of the biosonar properties of toothed whales is necessary to understand behavioral and evolutionary adaptions. To address this, two free-ranging sympatric delphinid species, Australian humpback dolphins (Sousa sahulensis) and Indo-Pacific bottlenose dolphins (Tursiops aduncus), were studied. Biosonar clicks from both species were recorded within the same stretch of coastal habitat in Exmouth Gulf, Western Australia, using a vertical seven element hydrophone array. S. sahulensis used biosonar clicks with a mean source level of 199 ± 3 dB re 1 μPa peak-peak (pp), mean centroid frequency of 106 ± 11 kHz, and emitted at interclick intervals (ICIs) of 79 ± 33 ms. These parameters were similar to click parameters of sympatric T. aduncus, characterized by mean source levels of 204 ± 4 dB re 1 μPa pp, centroid frequency of 112 ± 9 kHz, and ICIs of 73 ± 29 ms. These properties are comparable to those of other similar sized delphinids and suggest that biosonar parameters are independent of sympatric delphinids and possibly driven by body size. The dynamic biosonar behavior of these delphinids may have, consequently, allowed for adaptations to local environments through high levels of control over sonar beam properties.
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Affiliation(s)
- Mafalda de Freitas
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, C.F. Moellers Alle 3, DK-8000 Aarhus C, Denmark
| | - Frants H Jensen
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Julian Tyne
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
| | - Lars Bejder
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
| | - Peter T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, C.F. Moellers Alle 3, DK-8000 Aarhus C, Denmark
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44
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45
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Holt MM, Noren DP, Dunkin RC, Williams TM. Vocal performance affects metabolic rate in dolphins: implications for animals communicating in noisy environments. ACTA ACUST UNITED AC 2015; 218:1647-54. [PMID: 25852069 DOI: 10.1242/jeb.122424] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 03/30/2015] [Indexed: 11/20/2022]
Abstract
Many animals produce louder, longer or more repetitious vocalizations to compensate for increases in environmental noise. Biological costs of increased vocal effort in response to noise, including energetic costs, remain empirically undefined in many taxa, particularly in marine mammals that rely on sound for fundamental biological functions in increasingly noisy habitats. For this investigation, we tested the hypothesis that an increase in vocal effort would result in an energetic cost to the signaler by experimentally measuring oxygen consumption during rest and a 2 min vocal period in dolphins that were trained to vary vocal loudness across trials. Vocal effort was quantified as the total acoustic energy of sounds produced. Metabolic rates during the vocal period were, on average, 1.2 and 1.5 times resting metabolic rate (RMR) in dolphin A and B, respectively. As vocal effort increased, we found that there was a significant increase in metabolic rate over RMR during the 2 min following sound production in both dolphins, and in total oxygen consumption (metabolic cost of sound production plus recovery costs) in the dolphin that showed a wider range of vocal effort across trials. Increases in vocal effort, as a consequence of increases in vocal amplitude, repetition rate and/or duration, are consistent with behavioral responses to noise in free-ranging animals. Here, we empirically demonstrate for the first time in a marine mammal, that these vocal modifications can have an energetic impact at the individual level and, importantly, these data provide a mechanistic foundation for evaluating biological consequences of vocal modification in noise-polluted habitats.
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Affiliation(s)
- Marla M Holt
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd. East, Seattle, WA 98112, USA
| | - Dawn P Noren
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd. East, Seattle, WA 98112, USA
| | - Robin C Dunkin
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Long Marine Laboratory, 100 Shaffer Road, Santa Cruz, CA 95060, USA
| | - Terrie M Williams
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Long Marine Laboratory, 100 Shaffer Road, Santa Cruz, CA 95060, USA
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Wisniewska DM, Ratcliffe JM, Beedholm K, Christensen CB, Johnson M, Koblitz JC, Wahlberg M, Madsen PT. Range-dependent flexibility in the acoustic field of view of echolocating porpoises (Phocoena phocoena). eLife 2015; 4:e05651. [PMID: 25793440 PMCID: PMC4413254 DOI: 10.7554/elife.05651] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 03/19/2015] [Indexed: 12/03/2022] Open
Abstract
Toothed whales use sonar to detect, locate, and track prey. They adjust emitted sound intensity, auditory sensitivity and click rate to target range, and terminate prey pursuits with high-repetition-rate, low-intensity buzzes. However, their narrow acoustic field of view (FOV) is considered stable throughout target approach, which could facilitate prey escape at close-range. Here, we show that, like some bats, harbour porpoises can broaden their biosonar beam during the terminal phase of attack but, unlike bats, maintain the ability to change beamwidth within this phase. Based on video, MRI, and acoustic-tag recordings, we propose this flexibility is modulated by the melon and implemented to accommodate dynamic spatial relationships with prey and acoustic complexity of surroundings. Despite independent evolution and different means of sound generation and transmission, whales and bats adaptively change their FOV, suggesting that beamwidth flexibility has been an important driver in the evolution of echolocation for prey tracking. DOI:http://dx.doi.org/10.7554/eLife.05651.001 Bats and toothed whales such as porpoises have independently evolved the same solution for hunting prey when it is hard to see. Bats hunt in the dark with little light to allow them to see the insects they chase. Porpoises hunt in murky water where different ocean environments can quickly obscure fish from view. So, both bats and porpoises evolved to emit a beam of sound and then track their prey based on the echoes of that sound bouncing off the prey and other objects. This process is called echolocation. A narrow beam of sound can help a porpoise or bat track distant prey. But as either animal closes in on its prey such a narrow sound beam can be a disadvantage because prey can easily escape to one side. Scientists recently found that bats can widen their sound beam as they close in on prey by changing the frequency—or pitch—of the signal they emit or by adjusting how they open their mouth. Porpoises, by contrast, create their echolocation clicks by forcing air through a structure in their blowhole called the phonic lips. The sound is transmitted through a fatty structure on the front of their head known as the melon, which gives these animals their characteristic round-headed look, before being transmitted into the sea. Porpoises would also likely benefit from widening their echolocation beam as they approach prey, but it was not clear if and how they could do this. Wisniewska et al. used 48 tightly spaced underwater microphones to record the clicks emitted by three captive porpoises as they approached a target or a fish. This revealed that in the last stage of their approach, the porpoises could triple the area their sound beam covered, giving them a ‘wide angle view’ as they closed in. This widening of the sound beam occurred during a very rapid series of echolocation signals called a buzz, which porpoises and bats perform at the end of a pursuit. Unlike bats, porpoises are able to continue to change the width of their sound beam throughout the buzz. Wisniewska et al. also present a video that shows that the shape of the porpoise's melon changes rapidly during a buzz, which may explain the widening beam. Furthermore, images obtained using a technique called magnetic resonance imaging (MRI) revealed that a porpoise has a network of facial muscles that are capable of producing these beam-widening melon distortions. As both bats and porpoises have evolved the capability to adjust the width of their sound beam, this ability is likely to be crucial for hunting effectively using echolocation. DOI:http://dx.doi.org/10.7554/eLife.05651.002
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Affiliation(s)
| | - John M Ratcliffe
- Sound and Behaviour Group, Institute of Biology, University of Southern Denmark, Odense, Denmark
| | - Kristian Beedholm
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | | | - Mark Johnson
- Scottish Oceans Institute, University of St Andrews, St Andrews, Scotland
| | - Jens C Koblitz
- Animal Physiology, Institute for Neurobiology, University of Tübingen, Tübingen, Germany
| | - Magnus Wahlberg
- Sound and Behaviour Group, Institute of Biology, University of Southern Denmark, Odense, Denmark
| | - Peter T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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Jensen FH, Wahlberg M, Beedholm K, Johnson M, Soto NA, Madsen PT. Single-click beam patterns suggest dynamic changes to the field of view of echolocating Atlantic spotted dolphins (Stenella frontalis) in the wild. J Exp Biol 2015; 218:1314-24. [DOI: 10.1242/jeb.116285] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 02/23/2015] [Indexed: 11/20/2022]
Abstract
Echolocating animals exercise an extensive control over the spectral and temporal properties of their biosonar signals to facilitate perception of their actively generated auditory scene when homing in on prey. The intensity and directionality of the biosonar beam defines the field of view of echolocating animals by affecting the acoustic detection range and angular coverage. However, the spatial relationship between an echolocating predator and its prey changes rapidly, resulting in different biosonar requirements throughout prey pursuit and capture. Here we measured single click beam patterns using a parametric fit procedure to test whether free-ranging Atlantic spotted dolphins (Stenella frontalis) modify their biosonar beamwidth. We recorded echolocation clicks using a linear array of receivers and estimated the beamwidth of individual clicks using a parametric spectral fit, cross-validated with well-established composite beam pattern estimates. The dolphins apparently increased the biosonar beamwidth, to a large degree without changing the signal frequency, when they approached the recording array. This is comparable to bats that also expand their field of view during prey capture, but achieve this by decreasing biosonar frequency. This behaviour may serve to decrease the risk that rapid escape movements of prey take them outside the biosonar beam of the predator. It is likely that shared sensory requirements have resulted in bats and toothed whales expanding their acoustic field of view at close range to increase the likelihood of successfully acquiring prey using echolocation, representing a case of convergent evolution of echolocation behaviour between these two taxa.
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Affiliation(s)
- Frants H. Jensen
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08540, USA
- Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Magnus Wahlberg
- Fjord&Bælt, Margrethes Plads 1, 5300 Kerteminde, Denmark
- Marine Biological Research Center, University of Southern Denmark, Hindsholmsvej 11, 5300 Kerteminde, Denmark
| | - Kristian Beedholm
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
| | - Mark Johnson
- Scottish Oceans Institute, University of St. Andrews, Fife, KY16 8LB, United Kingdom
| | - Natacha Aguilar Soto
- Scottish Oceans Institute, University of St. Andrews, Fife, KY16 8LB, United Kingdom
- BIOECOMAC, Dept. Animal Biology, International Campus of Excellence, La Laguna University, La Laguna 38206, Tenerife, Spain
| | - Peter T. Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
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Ridgway S, Samuelson D, Van Alstyne K, Price D. On doing two things at once: dolphin brain and nose coordinate sonar clicks, buzzes, and emotional squeals with social sounds during fish capture. J Exp Biol 2015; 218:3987-95. [DOI: 10.1242/jeb.130559] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 10/13/2015] [Indexed: 11/20/2022]
Abstract
Dolphins fishing alone in open waters may whistle without interrupting their sonar clicks as they find and eat or reject fish. Our study is the first to match sound and video from the dolphin with sound and video from near the fish. During search and capture of fish, free-swimming dolphins carried cameras to record video and sound. A hydrophone in the far field near the fish also recorded sound. From these two perspectives, we studied the time course of dolphin sound production during fish capture. Our observations identify the instant of fish capture. There are three consistent acoustic phases: sonar clicks locate the fish; bout 0.4 sec before capture, the dolphin clicks become more rapid to form a second phase, the terminal buzz; at or just before capture, the buzz turns to an emotional squeal-the victory squeal, which may last 0.2 to 20 sec after capture. The squeals are pulse bursts that vary in duration, peak frequency, and amplitude. The victory squeal may be a reflection of emotion triggered by brain dopamine release. It may also affect prey to ease capture and or it may be a way to communicate the presence of food to other dolphins.
Dolphins also use whistles as communication or social sounds. Whistling during sonar clicking suggests that dolphins may be adept at doing two things at once. We know that dolphin brain hemispheres may sleep independently. Our results suggest that the two dolphin brain hemispheres may also act independently in communication.
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Affiliation(s)
- Sam Ridgway
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Ste 200, San Diego, CA 92106, USA
| | - Dianna Samuelson
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Ste 200, San Diego, CA 92106, USA
| | - Kaitlin Van Alstyne
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Ste 200, San Diego, CA 92106, USA
| | - DruAnn Price
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Ste 200, San Diego, CA 92106, USA
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Berta A, Ekdale EG, Cranford TW. Review of the Cetacean Nose: Form, Function, and Evolution. Anat Rec (Hoboken) 2014; 297:2205-15. [DOI: 10.1002/ar.23034] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 06/25/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Annalisa Berta
- Department of Biology; San Diego State University; San Diego California USA
| | - Eric G. Ekdale
- Department of Biology; San Diego State University; San Diego California USA
| | - Ted W. Cranford
- Department of Biology; San Diego State University; San Diego California USA
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50
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Kriesell HJ, Elwen SH, Nastasi A, Gridley T. Identification and characteristics of signature whistles in wild bottlenose dolphins (Tursiops truncatus) from Namibia. PLoS One 2014; 9:e106317. [PMID: 25203814 PMCID: PMC4159226 DOI: 10.1371/journal.pone.0106317] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 08/05/2014] [Indexed: 11/19/2022] Open
Abstract
A signature whistle type is a learned, individually distinctive whistle type in a dolphin's acoustic repertoire that broadcasts the identity of the whistle owner. The acquisition and use of signature whistles indicates complex cognitive functioning that requires wider investigation in wild dolphin populations. Here we identify signature whistle types from a population of approximately 100 wild common bottlenose dolphins (Tursiops truncatus) inhabiting Walvis Bay, and describe signature whistle occurrence, acoustic parameters and temporal production. A catalogue of 43 repeatedly emitted whistle types (REWTs) was generated by analysing 79 hrs of acoustic recordings. From this, 28 signature whistle types were identified using a method based on the temporal patterns in whistle sequences. A visual classification task conducted by 5 naïve judges showed high levels of agreement in classification of whistles (Fleiss-Kappa statistic, κ = 0.848, Z = 55.3, P<0.001) and supported our categorisation. Signature whistle structure remained stable over time and location, with most types (82%) recorded in 2 or more years, and 4 identified at Walvis Bay and a second field site approximately 450 km away. Whistle acoustic parameters were consistent with those of signature whistles documented in Sarasota Bay (Florida, USA). We provide evidence of possible two-voice signature whistle production by a common bottlenose dolphin. Although signature whistle types have potential use as a marker for studying individual habitat use, we only identified approximately 28% of those from the Walvis Bay population, despite considerable recording effort. We found that signature whistle type diversity was higher in larger dolphin groups and groups with calves present. This is the first study describing signature whistles in a wild free-ranging T. truncatus population inhabiting African waters and it provides a baseline on which more in depth behavioural studies can be based.
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Affiliation(s)
- Hannah Joy Kriesell
- Department of Conservation Biology, Georg-August University Göttingen, Göttingen, Germany
- Namibian Dolphin Project, Walvis Bay, Namibia
| | - Simon Harvey Elwen
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield, Gauteng, South Africa
- Namibian Dolphin Project, Walvis Bay, Namibia
| | - Aurora Nastasi
- Namibian Dolphin Project, Walvis Bay, Namibia
- Sapienza Università di Roma, Dipartimento di Scienze della Terra, Rome, Italy
| | - Tess Gridley
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield, Gauteng, South Africa
- Namibian Dolphin Project, Walvis Bay, Namibia
- * E-mail:
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