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Syme J, Kiszka JJ, Parra GJ. How to define a dolphin "group"? Need for consistency and justification based on objective criteria. Ecol Evol 2022; 12:e9513. [PMID: 36415876 PMCID: PMC9674468 DOI: 10.1002/ece3.9513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/21/2022] Open
Abstract
Group living is a critical component of the ecology of social animals such as delphinids. In many studies on these animals, groups represent sampling units that form the basis of the collection and analysis of data on their abundance, behavior, and social structure. Nevertheless, defining what constitutes a group has proven problematic. There is inconsistency in the terms and criteria used and many definitions lack biological justification. We conducted a literature review and an online expert survey to assess various terms (group, school, party, and pod), and their definitions as applied to delphinids to identify issues to ultimately make recommendations. Of 707 studies analyzed, 325 explicitly defined one or more terms, providing 344 definitions. Additionally, 192 definitions were obtained from the survey. Among these definitions, group was the most common term used (review: 286 definitions, 83.1%; survey: 69 definitions, 35.9%) and the most familiar to the survey respondents (73 respondents, 100.0%). In definitions of group, spatial proximity was the most used criterion (review: 200 definitions, 71.2%; survey: 53 definitions, 81.5%) followed by behavior (review: 176 definitions, 62.6%; survey: 38 definitions, 58.5%). The terms and criteria used to define delphinid groups vary considerably. Rather than proposing a single formal definition, we instead recommend that the term group and spatial proximity criteria be used to define sampling units of individuals observed in the field. Furthermore, we propose a process for formulating definitions that involves analyzing interindividual distances to determine naturally occurring patterns that are indicative of group membership. Although this process is based principally on the spatial proximity of individuals, it could also incorporate the behavior of group members by evaluating the influence of behavior on interindividual distances. Such a process produces definitions that are biologically meaningful and compatible across studies and populations, thus increasing our ability to draw strong conclusions about group living in delphinids.
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Affiliation(s)
- Jonathan Syme
- Cetacean Ecology, Behaviour and Evolution Lab, College of Science and EngineeringFlinders UniversityAdelaideSouth AustraliaAustralia
| | - Jeremy J. Kiszka
- Institute of Environment, Department of Biological SciencesFlorida International UniversityNorth MiamiFloridaUSA
| | - Guido J. Parra
- Cetacean Ecology, Behaviour and Evolution Lab, College of Science and EngineeringFlinders UniversityAdelaideSouth AustraliaAustralia
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King SL, Jensen FH. Rise of the machines: Integrating technology with playback experiments to study cetacean social cognition in the wild. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stephanie L. King
- School of Biological Sciences University of Bristol BS8 1TQ Bristol United Kingdom
| | - Frants H. Jensen
- Biology department, Syracuse University 107 College Place 13244 Syracuse NY USA
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Behavioral Pattern of Risso’s Dolphin (Grampus griseus) in the Gulf of Taranto (Northern Ionian Sea, Central-Eastern Mediterranean Sea). JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10020175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Relatively scant information is available on the Risso’s dolphin in comparison to the other species regularly present in the Mediterranean Sea. Recently, its conservation status has been updated to Endangered by the International Union for Conservation of Nature (IUCN) in this Sea. Therefore, the need to increase information on its biology and ecology is even more urgent. This study reports the first preliminary information on the behavioral traits of the species occurring in the Gulf of Taranto (Northern Ionian Sea). Data on predominant behavioral activity states and on a set of group composition variables (group formation, cruising speed, dive duration and interaction between individuals) were collected from April 2019 to September 2021, applying the focal-group protocol with instantaneous scan sampling. Group size, depth and group composition variables were compared between activity states. Results highlight that both the group size and the several variables considered varied significantly depending on activity state. The group size was significantly smaller during feeding than resting and traveling and a characterization in terms of group formation, cruise speed, dive duration and interaction between animals is provided for the different activity states. Moreover, a list of behavioral events which occurred, as well as their relative frequency of distribution among activity states, is reported. Finally, details on the sympatric occurrences between Risso’s and striped dolphins, as well as the repetitive interaction observed between adult individuals and plastic bags floating on the sea surface, are reported and discussed.
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Zhang C, Sun C, Wang Z, Lin P, Xiao Y, Metzner W, Feng J, Jiang T. Minor modification of frequency modulated call parameters underlies a shift in behavioral response in the Great Himalayan leaf-nosed bats, Hipposideros armiger. J Mammal 2021. [DOI: 10.1093/jmammal/gyab019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Different categories of social calls may be used in a variety of behavioral contexts and may have different functions. Here, we show that Great Himalayan leaf-nosed bats emit two types of calls: bent upward frequency modulated (bUFM) calls emitted during agonistic interactions between two bats that have perched close to each other and stepped upward frequency modulated (sUFM) calls emitted by a roosting individual when a free-flying bat approached. There were significant differences in acoustic parameters between bUFM calls and sUFM calls. Moreover, we tested different choices of Hipposideros armiger to playback of bUFM calls and sUFM calls. The bats avoided the location of bUFM call playbacks independent of the simultaneous playback of echolocation pulses, silence, or sUFM calls. The bats also avoided approaching the side of the flight room where sUFM calls were broadcast when also presented with playbacks of echolocation pulses, but not when simultaneously presented with silence. The results suggest that bUFM calls may serve the function of territorial defense, while sUFM calls may convey warning information. Our results, therefore, imply that the two types of calls have different functions depending on behavioral context. These differences in function suggest that bats can detect context-dependent modifications of acoustic cues across the two types of social calls.
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Affiliation(s)
- Chunmian Zhang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Congnan Sun
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Zhiqiang Wang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Peichen Lin
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Yanhong Xiao
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Walter Metzner
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Jiang Feng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
- College of Life Science, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, China
| | - Tinglei Jiang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
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Mamzer HM. Ritual Slaughter: The Tradition of Pilot Whale Hunting on the Faroe Islands. Front Vet Sci 2021; 8:552465. [PMID: 33898540 PMCID: PMC8062700 DOI: 10.3389/fvets.2021.552465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 01/29/2021] [Indexed: 11/14/2022] Open
Abstract
Faroese people consider grindadráp, the hunting of pilot whales, as a part of their cultural heritage, but from the point of view of veterinary sciences and biology, the method of killing pilot whales is a form of a ritual slaughter performed on fully conscious animals that are aware of their circumstances. Pilot whales are social, intelligent, and communicative animals that demonstrate complex social behaviors. Therefore, this traditional whaling method should be considered as a procedure in which animals are exposed to high levels of distress. In the context of contemporary civilizational development and material welfare, the practice of whaling may appear to be an inadequate and cruel relic of the past. This text explores social and cultural issues caused by pilot whale hunts and presents an understanding of the term tradition and some perspectives of how traditions change. The specificity of pilot whales as a species is presented, setting a foundation for a discussion about hunting itself. The conclusion of the text discusses different social perceptions of grindadráp by presenting arguments for and against the hunting. This analysis includes a presentation of actions undertaken bywhale hunting opponents.
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Courts R, Erbe C, Wellard R, Boisseau O, Jenner KC, Jenner MN. Australian long-finned pilot whales (Globicephala melas) emit stereotypical, variable, biphonic, multi-component, and sequenced vocalisations, similar to those recorded in the northern hemisphere. Sci Rep 2020; 10:20609. [PMID: 33244014 PMCID: PMC7693278 DOI: 10.1038/s41598-020-74111-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/08/2020] [Indexed: 11/09/2022] Open
Abstract
While in the northern hemisphere, many studies have been conducted on the vocal repertoire of long-finned pilot whales (Globicephala melas), no such study has been conducted in the southern hemisphere. Presented here, is the first study on the vocalisations of long-finned pilot whales along the southern coast of mainland Australia. Multiple measures were taken of 2028 vocalisations recorded over five years in several locations. These vocalisations included tonal sounds with and without overtones, sounds of burst-pulse character, graded sounds, biphonations, and calls of multiple components. Vocalisations were further categorised based on spectrographic features into 18 contour classes. Altogether, vocalisations ranged from approximately 200 Hz to 25 kHz in fundamental frequency and from 0.03 s to 2.07 s in duration. These measures compared well with those from northern hemisphere pilot whales. Some call types were almost identical to northern hemisphere vocalisations, even though the geographic ranges of the two populations are far apart. Other call types were unique to Australia. Striking similarities with calls of short-finned pilot whales (Globicephala macrorhynchus) and sometimes sympatric killer whales (Orcinus orca) were also found. Theories for call convergence and divergence are discussed.
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Affiliation(s)
- Rachael Courts
- Centre for Marine Science and Technology, Curtin University, Perth, WA, 6102, Australia.
| | - Christine Erbe
- Centre for Marine Science and Technology, Curtin University, Perth, WA, 6102, Australia
| | - Rebecca Wellard
- Centre for Marine Science and Technology, Curtin University, Perth, WA, 6102, Australia
- Project ORCA, Perth, WA, 6026, Australia
| | - Oliver Boisseau
- Song of the Whale Research Team, Marine Conservation Research, 94 High Street, Kelvedon Essex, CO5 9AA, UK
| | - K Curt Jenner
- Centre for Whale Research (WA) Inc., PO Box 1622, Fremantle, WA, 6959, Australia
| | - Micheline-N Jenner
- Centre for Whale Research (WA) Inc., PO Box 1622, Fremantle, WA, 6959, Australia
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Kok ACM, van Kolfshoten L, Campbell JA, von Benda-Beckmann AM, Miller PJO, Slabbekoorn H, Visser F. Diving apart together: call propagation in diving long-finned pilot whales. J Exp Biol 2020; 223:jeb207878. [PMID: 32321748 DOI: 10.1242/jeb.207878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 04/09/2020] [Indexed: 11/20/2022]
Abstract
Group-living animals must communicate to stay in contact. In long-finned pilot whales, there is a trade-off between the benefits of foraging individually at depth and the formation of tight social groups at the surface. Using theoretical modelling and empirical data of tagged pairs within a group, we examined the potential of pilot whale social calls to reach dispersed group members during foraging periods. Both theoretical predictions and empirical data of tag pairs showed a potential for communication between diving and non-diving group members over separation distances up to 385 m (empirical) and 1800 m (theoretical). These distances match or exceed pilot whale dive depths recorded across populations. Call characteristics and environmental characteristics were analysed to investigate determinants of call detectability. Longer calls with a higher sound pressure level (SPL) that were received in a quieter environment were more often detected than their shorter, lower SPL counterparts within a noisier environment. In a noisier environment, calls were louder and had a lower peak frequency, indicating mechanisms for coping with varying conditions. However, the vulnerability of pilot whales to anthropogenic noise is still of concern as the ability to cope with increasing background noise may be limited. Our study shows that combining propagation modelling and actual tag recordings provides new insights into the communicative potential for social calls in orientation and reunion with group members for deep-diving pilot whales.
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Affiliation(s)
- Annebelle C M Kok
- Institute of Biology, Leiden University, P.O. Box 9505, 2300 RA Leiden, The Netherlands
| | - Lisette van Kolfshoten
- Institute of Biology, Leiden University, P.O. Box 9505, 2300 RA Leiden, The Netherlands
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands
| | - James A Campbell
- Institute of Biology, Leiden University, P.O. Box 9505, 2300 RA Leiden, The Netherlands
| | | | - Patrick J O Miller
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, KY16 8LB, UK
| | - Hans Slabbekoorn
- Institute of Biology, Leiden University, P.O. Box 9505, 2300 RA Leiden, The Netherlands
| | - Fleur Visser
- Department of Freshwater and Marine Ecology, IBED, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, The Netherlands
- Department of Coastal Systems, NIOZ and Utrecht University, P.O. Box 59, 1790 AB Den Burg, The Netherlands
- Kelp Marine Research, 1624 CJ Hoorn, The Netherlands
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Fear of Killer Whales Drives Extreme Synchrony in Deep Diving Beaked Whales. Sci Rep 2020; 10:13. [PMID: 32029750 PMCID: PMC7005263 DOI: 10.1038/s41598-019-55911-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/13/2019] [Indexed: 11/21/2022] Open
Abstract
Fear of predation can induce profound changes in the behaviour and physiology of prey species even if predator encounters are infrequent. For echolocating toothed whales, the use of sound to forage exposes them to detection by eavesdropping predators, but while some species exploit social defences or produce cryptic acoustic signals, deep-diving beaked whales, well known for mass-strandings induced by navy sonar, seem enigmatically defenceless against their main predator, killer whales. Here we test the hypothesis that the stereotyped group diving and vocal behaviour of beaked whales has benefits for abatement of predation risk and thus could have been driven by fear of predation over evolutionary time. Biologging data from 14 Blainville’s and 12 Cuvier’s beaked whales show that group members have an extreme synchronicity, overlapping vocal foraging time by 98% despite hunting individually, thereby reducing group temporal availability for acoustic detection by killer whales to <25%. Groups also perform a coordinated silent ascent in an unpredictable direction, covering a mean of 1 km horizontal distance from their last vocal position. This tactic sacrifices 35% of foraging time but reduces by an order of magnitude the risk of interception by killer whales. These predator abatement behaviours have likely served beaked whales over millions of years, but may become maladaptive by playing a role in mass strandings induced by man-made predator-like sonar sounds.
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Krüger A, Fabrizius A, Mikkelsen B, Siebert U, Folkow LP, Burmester T. Transcriptome analysis reveals a high aerobic capacity in the whale brain. Comp Biochem Physiol A Mol Integr Physiol 2019; 240:110593. [PMID: 31676411 DOI: 10.1016/j.cbpa.2019.110593] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/30/2019] [Accepted: 10/22/2019] [Indexed: 01/04/2023]
Abstract
The brain of diving mammals is repeatedly exposed to low oxygen conditions (hypoxia) that would have caused severe damage to most terrestrial mammals. Some whales may dive for >2 h with their brain remaining active. Many of the physiological adaptations of whales to diving have been investigated, but little is known about the molecular mechanisms that enable their brain to survive sometimes prolonged periods of hypoxia. Here, we have used an RNA-Seq approach to compare the mRNA levels in the brains of whales with those of cattle, which serves as a terrestrial relative. We sequenced the transcriptomes of the brains from cattle (Bos taurus), killer whale (Orcinus orca), and long-finned pilot whale (Globicephala melas). Further, the brain transcriptomes of cattle, minke whale (Balaenoptera acutorostrata) and bowhead whale (Balaena mysticetus), which were available in the databases, were included. We found a high expression of genes related to oxidative phosphorylation and the respiratory electron chain in the whale brains. In the visual cortex of whales, transcripts related to the detoxification of reactive oxygen species were more highly expressed than in the visual cortex of cattle. These findings indicate a high oxidative capacity in the whale brain that might help to maintain aerobic metabolism in periods of reduced oxygen availability during dives.
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Affiliation(s)
- Alena Krüger
- Institute of Zoology, University of Hamburg, Germany.
| | | | | | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, D-25761 Büsum, Germany.
| | - Lars P Folkow
- University of Tromsø - The Arctic University of Norway, NO-9037 Tromsø, Norway.
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Beasley I, Cherel Y, Robinson S, Betty E, Hagihara R, Gales R. Stomach contents of long-finned pilot whales, Globicephala melas mass-stranded in Tasmania. PLoS One 2019; 14:e0206747. [PMID: 30640963 PMCID: PMC6331100 DOI: 10.1371/journal.pone.0206747] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 10/18/2018] [Indexed: 11/30/2022] Open
Abstract
New data are reported from analyses of stomach contents from 114 long-finned pilot whales mass-stranded at four locations around Tasmania, Australia from 1992–2006. Identifiable prey remains were recovered from 84 (74%) individuals, with 30 (26%) individuals (17 females and 13 males) having empty stomachs. Prey remains comprised 966 identifiable lower beaks and 1244 upper beaks, belonging to 17 families (26 species) of cephalopods. Ommastrephidae spp. were the most important cephalopod prey accounting for 16.9% by number and 45.6% by reconstructed mass. Lycoteuthis lorigera was the next most important, followed by Ancistrocheirus lesueurii. Multivariate statistics identified significant differences in diet among the four stranding locations. Long-finned pilot whales foraging off Southern Australia appear to be targeting a diverse assemblage of prey (≥10 species dominated by cephalopods). This is compared to other similar studies from New Zealand and some locations in the Northern Hemisphere, where the diet has been reported to be primarily restricted to ≤3 species dominated by cephalopods. This study emphasises the importance of cephalopods as primary prey for Southern long-finned pilot whales and other marine vertebrates, and has increased our understanding of long-finned pilot whale diet in Southern Ocean waters.
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Affiliation(s)
- Isabel Beasley
- Snubfin Dolphin Project, Colebrook, Tasmania, Australia
- College of Science and Engineering, James Cook University, Townsville, Australia
- * E-mail:
| | - Yves Cherel
- Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-Université de La Rochelle, Villiers-en-Bois, France
| | - Sue Robinson
- Invasive Species Branch, Biosecurity Tasmania, Department of Primary Industries, Parks, Water and Environment, Tasmania, Australia
| | - Emma Betty
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
- Institute of Natural and Mathematical Sciences, College of Sciences, Massey University, Palmerston North, New Zealand
| | - Rie Hagihara
- College of Science and Engineering, James Cook University, Townsville, Australia
| | - Rosemary Gales
- Natural Values Conservation Branch, Department of Primary Industries, Parks, Water and Environment, Tasmania, Australia
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