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Favaro L, Zanoli A, Ludynia K, Snyman A, Carugati F, Friard O, Scaglione FE, Manassero L, Valazza A, Mathevon N, Gamba M, Reby D. Vocal tract shape variation contributes to individual vocal identity in African penguins. Proc Biol Sci 2023; 290:20231029. [PMID: 37817600 PMCID: PMC10565386 DOI: 10.1098/rspb.2023.1029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/18/2023] [Indexed: 10/12/2023] Open
Abstract
Variation in formant frequencies has been shown to affect social interactions and sexual competition in a range of avian species. Yet, the anatomical bases of this variation are poorly understood. Here, we investigated the morphological correlates of formants production in the vocal apparatus of African penguins. We modelled the geometry of the supra-syringeal vocal tract of 20 specimens to generate a population of virtual vocal tracts with varying dimensions. We then estimated the acoustic response of these virtual vocal tracts and extracted the centre frequency of the first four predicted formants. We demonstrate that: (i) variation in length and cross-sectional area of vocal tracts strongly affects the formant pattern, (ii) the tracheal region determines most of this variation, and (iii) the skeletal size of penguins does not correlate with the trachea length and consequently has relatively little effect on formants. We conclude that in African penguins, while the variation in vocal tract geometry generates variation in resonant frequencies supporting the discrimination of conspecifics, such variation does not provide information on the emitter's body size. Overall, our findings advance our understanding of the role of formant frequencies in bird vocal communication.
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Affiliation(s)
- Livio Favaro
- ENES Bioacoustics Research Laboratory, CRNL, University of Saint-Etienne, CNRS, Inserm, Saint-Etienne, France
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Anna Zanoli
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Katrin Ludynia
- Southern African Foundation for the Conservation of Coastal Birds (SANCCOB), Cape Town, South Africa
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Bellville, South Africa
| | - Albert Snyman
- Southern African Foundation for the Conservation of Coastal Birds (SANCCOB), Cape Town, South Africa
| | - Filippo Carugati
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Olivier Friard
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | | | - Luca Manassero
- Department of Veterinary Science, University of Turin, Turin, Italy
| | - Alberto Valazza
- Department of Veterinary Science, University of Turin, Turin, Italy
| | - Nicolas Mathevon
- ENES Bioacoustics Research Laboratory, CRNL, University of Saint-Etienne, CNRS, Inserm, Saint-Etienne, France
- Institut Universitaire de France, Ministry of Higher Education, Research and Innovation, 1 rue Descartes, 75231 Paris Cedex 05, France
| | - Marco Gamba
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - David Reby
- ENES Bioacoustics Research Laboratory, CRNL, University of Saint-Etienne, CNRS, Inserm, Saint-Etienne, France
- Institut Universitaire de France, Ministry of Higher Education, Research and Innovation, 1 rue Descartes, 75231 Paris Cedex 05, France
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2
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Terranova F, Baciadonna L, Maccarone C, Isaja V, Gamba M, Favaro L. Penguins perceive variations of source- and filter-related vocal parameters of species-specific vocalisations. Anim Cogn 2023; 26:1613-1622. [PMID: 37401990 PMCID: PMC10442253 DOI: 10.1007/s10071-023-01806-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 05/22/2023] [Accepted: 06/27/2023] [Indexed: 07/05/2023]
Abstract
Animal vocalisations encode a wide range of biological information about the age, sex, body size, and social status of the emitter. Moreover, vocalisations play a significant role in signalling the identity of the emitter to conspecifics. Recent studies have shown that, in the African penguin (Spheniscus demersus), acoustic cues to individual identity are encoded in the fundamental frequency (F0) and resonance frequencies (formants) of the vocal tract. However, although penguins are known to produce vocalisations where F0 and formants vary among individuals, it remains to be tested whether the receivers can perceive and use such information in the individual recognition process. In this study, using the Habituation-Dishabituation (HD) paradigm, we tested the hypothesis that penguins perceive and respond to a shift of ± 20% (corresponding to the natural inter-individual variation observed in ex-situ colonies) of F0 and formant dispersion (ΔF) of species-specific calls. We found that penguins were more likely to look rapidly and for longer at the source of the sound when F0 and formants of the calls were manipulated, indicating that they could perceive variations of these parameters in the vocal signals. Our findings provide the first experimental evidence that, in the African penguin, listeners can perceive changes in F0 and formants, which can be used by the receiver as potential cues for the individual discrimination of the emitter.
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Affiliation(s)
- Francesca Terranova
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Luigi Baciadonna
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy.
| | - Chiara Maccarone
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | | | - Marco Gamba
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Livio Favaro
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy.
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3
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Manatee calf call contour and acoustic structure varies by species and body size. Sci Rep 2022; 12:19597. [PMID: 36379989 PMCID: PMC9666457 DOI: 10.1038/s41598-022-23321-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 10/29/2022] [Indexed: 11/16/2022] Open
Abstract
Vocal activity and signal characteristics of mammals are driven by several factors that result in both stability and plasticity over multiple time scales. All three extant species of manatee communicate with several calls that are especially important for maintaining contact between cows and calves. Determining if calf calls differ across manatee species will provide insights into the evolution of species-specific acoustic communication traits. We investigated the interspecific differences in the vocalizations of calves of Amazonian manatees (Trichechus inunguis) and the two subspecies of the West Indian manatee (T. manatus). Vocalizations of individual calves were recorded in rehabilitation centers in Brazil, Puerto Rico, the United States, and Mexico. The acoustic structure of calls produced by manatee calves varied between species and with body size. Amazonian manatee calves produced shorter calls with multiple notes at higher frequency while West Indian calves produced modulated calls that were lower in frequency and longer in duration. Smaller West Indian calves produced frequency modulated, hill-shaped calls that flattened with an increase in body length. Our results provide evidence for divergence in the ontogeny of vocalizations across T. manatus and T. inunguis and suggest variation in body size contributed to the evolution of differences in the characteristics of their calls.
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4
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de Reus K, Carlson D, Lowry A, Gross S, Garcia M, Rubio-Garcia A, Salazar-Casals A, Ravignani A. Vocal tract allometry in a mammalian vocal learner. J Exp Biol 2022; 225:275049. [PMID: 35483405 PMCID: PMC9124484 DOI: 10.1242/jeb.243766] [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: 11/05/2021] [Accepted: 03/14/2022] [Indexed: 11/20/2022]
Abstract
Acoustic allometry occurs when features of animal vocalisations can be predicted from body size measurements. Despite this being considered the norm, allometry sometimes breaks, resulting in species sounding smaller or larger than expected for their size. A recent hypothesis suggests that allometry-breaking mammals cluster into two groups: those with anatomical adaptations to their vocal tracts and those capable of learning new sounds (vocal learners). Here, we tested which mechanism is used to escape from acoustic allometry by probing vocal tract allometry in a proven mammalian vocal learner, the harbour seal (Phoca vitulina). We tested whether vocal tract structures and body size scale allometrically in 68 young individuals. We found that both body length and body mass accurately predict vocal tract length and one tracheal dimension. Independently, body length predicts vocal fold length while body mass predicts a second tracheal dimension. All vocal tract measures are larger in weaners than in pups and some structures are sexually dimorphic within age classes. We conclude that harbour seals do comply with anatomical allometric constraints. However, allometry between body size and vocal fold length seems to emerge after puppyhood, suggesting that ontogeny may modulate the anatomy–learning distinction previously hypothesised as clear cut. We suggest that seals, and perhaps other species producing signals that deviate from those expected from their vocal tract dimensions, may break allometry without morphological adaptations. In seals, and potentially other vocal learning mammals, advanced neural control over vocal organs may be the main mechanism for breaking acoustic allometry. Summary: Harbour seals are vocal learners that can escape acoustic allometry despite complying with anatomical allometric constraints. Advanced neural control over their vocal organs may allow them to break acoustic allometry.
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Affiliation(s)
- Koen de Reus
- Comparative Bioacoustics Group, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands.,Artificial Intelligence Lab, Vrije Universiteit Brussel, 1050 Brussels, Belgium.,Research Department, Sealcentre Pieterburen, 9968 AG Pieterburen, The Netherlands
| | - Daryll Carlson
- Research Department, Sealcentre Pieterburen, 9968 AG Pieterburen, The Netherlands.,Department of Earth System Science, Stanford University, Stanford, CA 94305-4216, USA
| | - Alice Lowry
- Research Department, Sealcentre Pieterburen, 9968 AG Pieterburen, The Netherlands.,School of Environmental Sciences, University of Liverpool, Liverpool, L3 5DA, UK
| | - Stephanie Gross
- Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Foundation, 25761 Büsum, Germany
| | - Maxime Garcia
- Animal Behaviour, Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zürich, Switzerland.,Center for the Interdisciplinary Study of Language Evolution, University of Zurich, CH-8050 Zürich, Switzerland
| | - Ana Rubio-Garcia
- Research Department, Sealcentre Pieterburen, 9968 AG Pieterburen, The Netherlands
| | - Anna Salazar-Casals
- Research Department, Sealcentre Pieterburen, 9968 AG Pieterburen, The Netherlands
| | - Andrea Ravignani
- Comparative Bioacoustics Group, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands.,Research Department, Sealcentre Pieterburen, 9968 AG Pieterburen, The Netherlands.,Center for Music in the Brain, Department of Clinical Medicine, Aarhus University & The Royal Academy of Music Aarhus/Aalborg, 8000 Aarhus C, Denmark
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Jiang AZ, Murray P, Phillips C, Tribe A, Ellis W. Movement of Free-Ranging Koalas in Response to Male Vocalisation Playbacks. Animals (Basel) 2022; 12:ani12030287. [PMID: 35158611 PMCID: PMC8833420 DOI: 10.3390/ani12030287] [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: 12/02/2021] [Revised: 01/13/2022] [Accepted: 01/21/2022] [Indexed: 11/23/2022] Open
Abstract
Simple Summary Conservation management is critical for threatened wildlife species and an effective conservation approach relies on good understanding of animal behaviour in natural habitat. Currently, koalas are listed as vulnerable to extinction in Australia with declining populations, but their social and breeding system remains unclear. Male koala vocalisations, known as bellows, are believed to be closely related to their breeding behaviour. Bellows incorporate callers’ body size information which can be perceived by other koalas. In this study, we tested the behavioural responses of 20 GPS-collared free ranging koalas to bellow recordings collected from small (<6 kg) and large (>8.5 kg) adult male koalas. We report evidence of intra-male competition, with adult males approaching bellow playbacks, particularly those from small-sized males. In contrast, juvenile males under three years of age showed avoidance of the playbacks. No patterns in the response of females were detected. Our results provide the strongest evidence yet that bellows are primarily a means by which males occupy and control habitat space during the breeding season. Future studies are required to see if female response to bellows depends on their reproductive status. Abstract Effective conservation strategies rely on knowledge of seasonal and social drivers of animal behaviour. Koalas are generally solitary and their social arrangement appears to rely on vocal and chemical signalling. Male koala vocalisations, known as bellows, are believed to be closely related to their breeding behaviour. Previous research suggests that oestrous female koalas use bellows to locate unique males to mate with, and that males can similarly use bellows to evaluate the physical attributes of their peers. We tested the behavioural responses of 20 free ranging koalas to bellow recordings collected from small (<6 kg) and large (>8.5 kg) adult male koalas. Individual koala movement was reported by hourly-uploaded GPS coordinates. We report evidence of intra-male competition, with adult males approaching bellow playbacks, particularly those from small-sized males. In contrast, males under three years of age were averse to the playbacks. No patterns in the response of females were detected. Our results provide the strongest evidence yet that bellows are primarily a means by which males occupy and control space during the breeding season. Future studies are required to see if female response to bellows depends on their reproductive status.
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Affiliation(s)
- Alex Zijian Jiang
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (A.Z.J.); (P.M.)
| | - Peter Murray
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (A.Z.J.); (P.M.)
- School of Agriculture and Environmental Sciences, University of Southern Queensland, Toowoomba 4350, Australia
| | - Clive Phillips
- Sustainability Policy Institute, Curtin University, Bentley 6102, Australia;
- Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51014 Tartu, Estonia
| | - Andrew Tribe
- Turner Family Foundation, Hidden Vale Wildlife Centre, 617 Grandchester Mount Mort Rd., Grandchester 4340, Australia;
| | - William Ellis
- School of Agriculture and Food Sciences, The University of Queensland, St Lucia 4072, Australia
- Correspondence:
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6
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Chest beats as an honest signal of body size in male mountain gorillas (Gorilla beringei beringei). Sci Rep 2021; 11:6879. [PMID: 33833252 PMCID: PMC8032651 DOI: 10.1038/s41598-021-86261-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/04/2021] [Indexed: 11/29/2022] Open
Abstract
Acoustic signals that reliably indicate body size, which usually determines competitive ability, are of particular interest for understanding how animals assess rivals and choose mates. Whereas body size tends to be negatively associated with formant dispersion in animal vocalizations, non-vocal signals have received little attention. Among the most emblematic sounds in the animal kingdom is the chest beat of gorillas, a non-vocal signal that is thought to be important in intra and inter-sexual competition, yet it is unclear whether it reliably indicates body size. We examined the relationship among body size (back breadth), peak frequency, and three temporal characteristics of the chest beat: duration, number of beats and beat rate from sound recordings of wild adult male mountain gorillas. Using linear mixed models, we found that larger males had significantly lower peak frequencies than smaller ones, but we found no consistent relationship between body size and the temporal characteristics measured. Taken together with earlier findings of positive correlations among male body size, dominance rank and reproductive success, we conclude that the gorilla chest beat is an honest signal of competitive ability. These results emphasize the potential of non-vocal signals to convey important information in mammal communication.
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7
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Verzola-Olivio P, Ferreira BL, Frei F, Monticelli PF. Guinea pig's courtship call: cues for identity and male dominance status? Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.01.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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8
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Linn SN, Schmidt S, Scheumann M. Individual distinctiveness across call types of the southern white rhinoceros ( Ceratotherium simum simum). J Mammal 2021; 102:440-456. [PMID: 34121952 PMCID: PMC8189687 DOI: 10.1093/jmammal/gyab007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 01/21/2021] [Indexed: 01/04/2023] Open
Abstract
Individual distinctiveness in the acoustic structure of vocalizations provides a basis for individual recognition in mammals and plays an important role in social behavior. Within a species, call types can differ in individual distinctiveness, which can be explained by three factors, namely differences in the social function, the distance of the caller to the receiver, and the acoustic structure of the call. We explored the variation in individual distinctiveness across three call types (Grunt, Hiss, Snort) of the southern white rhinoceros (Ceratotherium simum simum) and investigated to what extent the abovementioned factors account for individual distinctiveness. Calls were recorded from 25 adult southern white rhinoceroses in six different zoos. We used three methods to compare the level of individual distinctiveness across call types, namely discriminant function analysis (DFA), potential for individual identity coding (PIC), and the information criterion (Hs). The three call types possessed an acoustic structure capable of showing individual variation to different extents. Individual distinctiveness was lowest for Snorts, intermediate for Hisses, and highest for Grunts. The level of individual distinctiveness of all three call types was lower than that previously reported for Pant calls of this species. Calls functioning to mediate intragroup social interactions had the highest individual distinctiveness. This highlights that a given communicative function and the need for individual discrimination during a social interaction have a major influence on the degree of individual distinctiveness.
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Affiliation(s)
| | - Sabine Schmidt
- Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559 Hannover, Germany
| | - Marina Scheumann
- Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559 Hannover, Germany
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9
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Pisanski K, Reby D. Efficacy in deceptive vocal exaggeration of human body size. Nat Commun 2021; 12:968. [PMID: 33579910 PMCID: PMC7881139 DOI: 10.1038/s41467-021-21008-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/05/2021] [Indexed: 11/10/2022] Open
Abstract
How can deceptive communication signals exist in an evolutionarily stable signalling system? To resolve this age-old honest signalling paradox, researchers must first establish whether deception benefits deceivers. However, while vocal exaggeration is widespread in the animal kingdom and assumably adaptive, its effectiveness in biasing listeners has not been established. Here, we show that human listeners can detect deceptive vocal signals produced by vocalisers who volitionally shift their voice frequencies to exaggerate or attenuate their perceived size. Listeners can also judge the relative heights of cheaters, whose deceptive signals retain reliable acoustic cues to interindividual height. Importantly, although vocal deception biases listeners' absolute height judgments, listeners recalibrate their height assessments for vocalisers they correctly and concurrently identify as deceptive, particularly men judging men. Thus, while size exaggeration can fool listeners, benefiting the deceiver, its detection can reduce bias and mitigate costs for listeners, underscoring an unremitting arms-race between signallers and receivers in animal communication.
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Affiliation(s)
- Katarzyna Pisanski
- Equipe de Neuro-Ethologie Sensorielle (ENES), Centre de Recherche en Neurosciences de Lyon (CRNL), CNRS, INSERM, University of Lyon/Saint-Étienne, Saint-Étienne, France. .,Institute of Psychology, University of Wrocław, Wrocław, Poland.
| | - David Reby
- Equipe de Neuro-Ethologie Sensorielle (ENES), Centre de Recherche en Neurosciences de Lyon (CRNL), CNRS, INSERM, University of Lyon/Saint-Étienne, Saint-Étienne, France
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10
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Pawelec ŁP, Graja K, Lipowicz A. Vocal Indicators of Size, Shape and Body Composition in Polish Men. J Voice 2020; 36:878.e9-878.e22. [PMID: 33069508 DOI: 10.1016/j.jvoice.2020.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 11/25/2022]
Abstract
OBJECTIVES From a human evolution perspective, identifying a link between physique and vocal quality could demonstrate dual signaling in terms of the health and biological condition of an individual. In this regard, this study investigates the relationship between men's body size, shape, and composition, and their vocal characteristics. MATERIALS AND METHODS Eleven anthropometric measurements, using seven indices, were carried out with 80 adult Polish male participants, while the speech analysis adopted a voice recording procedure that involved phonetically recording vowels /ɑː/, /ɛː/, /iː/, /ɔː/, /uː/ to define the voice acoustic components used in Praat software. RESULTS The relationship between voice parameters and body size/shape/composition was found. The analysis indicated that the formants and their derivatives were useful parameters for prediction of height, weight, neck, shoulder, waist, and hip circumferences. Fundamental frequency (F0) was negatively correlated with neck circumference at Adam's apple level and body height. Moreover neck circumference and F0 association was observed for the first time in this paper. The association between waist circumference and formant component showed a net effect. In addition, the formant parameters showed significant correlations with body shape, indicating a lower vocal timbre in men with a larger relative waist circumference. DISCUSSION Men with lower vocal pitch had wider necks, probably a result of larynx size. Furthermore, a greater waist circumference, presumably resulting from abdominal fat distribution in men, correlated with a lower vocal timbre. While these results are inconclusive, they highlight new directions for further research.
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Affiliation(s)
- Łukasz Piotr Pawelec
- Department of Anthropology, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
| | - Katarzyna Graja
- Department of Anthropology, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Anna Lipowicz
- Department of Anthropology, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland; Institute of Physiotherapy and Health Sciences, Academy of Physical Education, Katowice, Poland
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Filippi P. Emotional Voice Intonation: A Communication Code at the Origins of Speech Processing and Word-Meaning Associations? JOURNAL OF NONVERBAL BEHAVIOR 2020. [DOI: 10.1007/s10919-020-00337-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
The aim of the present work is to investigate the facilitating effect of vocal emotional intonation on the evolution of the following processes involved in language: (a) identifying and producing phonemes, (b) processing compositional rules underlying vocal utterances, and (c) associating vocal utterances with meanings. To this end, firstly, I examine research on the presence of these abilities in animals, and the biologically ancient nature of emotional vocalizations. Secondly, I review research attesting to the facilitating effect of emotional voice intonation on these abilities in humans. Thirdly, building on these studies in animals and humans, and through taking an evolutionary perspective, I provide insights for future empirical work on the facilitating effect of emotional intonation on these three processes in animals and preverbal humans. In this work, I highlight the importance of a comparative approach to investigate language evolution empirically. This review supports Darwin’s hypothesis, according to which the ability to express emotions through voice modulation was a key step in the evolution of spoken language.
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12
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Garcia M, Ravignani A. Acoustic allometry and vocal learning in mammals. Biol Lett 2020; 16:20200081. [PMID: 32634374 PMCID: PMC7423041 DOI: 10.1098/rsbl.2020.0081] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 06/11/2020] [Indexed: 12/15/2022] Open
Abstract
Acoustic allometry is the study of how animal vocalizations reflect their body size. A key aim of this research is to identify outliers to acoustic allometry principles and pinpoint the evolutionary origins of such outliers. A parallel strand of research investigates species capable of vocal learning, the experience-driven ability to produce novel vocal signals through imitation or modification of existing vocalizations. Modification of vocalizations is a common feature found when studying both acoustic allometry and vocal learning. Yet, these two fields have only been investigated separately to date. Here, we review and connect acoustic allometry and vocal learning across mammalian clades, combining perspectives from bioacoustics, anatomy and evolutionary biology. Based on this, we hypothesize that, as a precursor to vocal learning, some species might have evolved the capacity for volitional vocal modulation via sexual selection for 'dishonest' signalling. We provide preliminary support for our hypothesis by showing significant associations between allometric deviation and vocal learning in a dataset of 164 mammals. Our work offers a testable framework for future empirical research linking allometric principles with the evolution of vocal learning.
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Affiliation(s)
- Maxime Garcia
- Animal Behaviour, Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8051 Zurich, Switzerland
- Center for the Interdisciplinary Study of Language Evolution, University of Zurich, 8032 Zurich, Switzerland
| | - Andrea Ravignani
- Comparative Bioacoustics Group, Max Planck Institute for Psycholinguistics, Wundtlaan 1, 6525 XD Nijmegen, The Netherlands
- Research Department, Sealcentre Pieterburen, Hoofdstraat 94a, 9968 AG Pieterburen, The Netherlands
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13
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Watchorn DJ, Whisson DA. Quantifying the interactions between koalas in a high-density population during the breeding period. AUSTRALIAN MAMMALOGY 2020. [DOI: 10.1071/am18027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A species’ social structure influences its patterns of gene flow and disease transmission. Knowledge of social structure therefore is critical for understanding conservation challenges and informing management strategies. We examined the social structure of 33 free-ranging koalas (Phascolarctos cinereus) in a high-density population (6.7 koalas per hectare) during the early and peak phase of the breeding period (August–December) at Cape Otway, Victoria. We used GPS and proximity loggers to quantify koala space use and interactions, and direct observations to determine behaviours associated with interactions. Our proximity loggers recorded 661 interactions (64% male–female, 28% male–male and 8% female–female). A peak in male–male interactions at the onset of the breeding period suggested that males may physically compete for mates at this time. Male–female interactions increased from the onset of the breeding period, and were mostly of short duration (median duration 5.5 min). From field observations of interactions, and the absence of pouch young in December, many of these interactions may have been unsuccessful copulation attempts. Space use and social network analyses revealed that most males had strong links (total interaction duration >30 min) with only one or two females, despite their spatial overlap and interactions with multiple females. Body mass did not influence a male’s mating success in terms of number of female mates. Our results contrast with those of a lower-density population in central eastern Queensland, suggesting that some aspects of koala social structure may be plastic relative to population density.
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14
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Frey R, Volodin IA, Volodina EV, Efremova KO, Menges V, Portas R, Melzheimer J, Fritsch G, Gerlach C, von Dörnberg K. Savannah roars: The vocal anatomy and the impressive rutting calls of male impala (Aepyceros melampus) - highlighting the acoustic correlates of a mobile larynx. J Anat 2019; 236:398-424. [PMID: 31777085 PMCID: PMC7018640 DOI: 10.1111/joa.13114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2019] [Indexed: 11/29/2022] Open
Abstract
A retractable larynx and adaptations of the vocal folds in the males of several polygynous ruminants serve for the production of rutting calls that acoustically announce larger than actual body size to both rival males and potential female mates. Here, such features of the vocal tract and of the sound source are documented in another species. We investigated the vocal anatomy and laryngeal mobility including its acoustical effects during the rutting vocal display of free‐ranging male impala (Aepyceros melampus melampus) in Namibia. Male impala produced bouts of rutting calls (consisting of oral roars and interspersed explosive nasal snorts) in a low‐stretch posture while guarding a rutting territory or harem. For the duration of the roars, male impala retracted the larynx from its high resting position to a low mid‐neck position involving an extensible pharynx and a resilient connection between the hyoid apparatus and the larynx. Maximal larynx retraction was 108 mm based on estimates in video single frames. This was in good concordance with 91‐mm vocal tract elongation calculated on the basis of differences in formant dispersion between roar portions produced with the larynx still ascended and those produced with maximally retracted larynx. Judged by their morphological traits, the larynx‐retracting muscles of male impala are homologous to those of other larynx‐retracting ruminants. In contrast, the large and massive vocal keels are evolutionary novelties arising by fusion and linear arrangement of the arytenoid cartilage and the canonical vocal fold. These bulky and histologically complex vocal keels produced a low fundamental frequency of 50 Hz. Impala is another ruminant species in which the males are capable of larynx retraction. In addition, male impala vocal folds are spectacularly specialized compared with domestic bovids, allowing the production of impressive, low‐frequency roaring vocalizations as a significant part of their rutting behaviour. Our study expands knowledge on the evolutionary variation of vocal fold morphology in mammals, suggesting that the structure of the mammalian sound source is not always human‐like and should be considered in acoustic analysis and modelling.
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Affiliation(s)
- Roland Frey
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Ilya A Volodin
- Faculty of Biology, Department of Vertebrate Zoology, Lomonosov Moscow State University, Moscow, Russia.,Scientific Research Department, Moscow Zoo, Moscow, Russia
| | | | | | - Vera Menges
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Ruben Portas
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Jörg Melzheimer
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Guido Fritsch
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
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15
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Charlton BD, Owen MA, Zhou X, Zhang H, Swaisgood RR. Influence of season and social context on male giant panda (Ailuropoda melanoleuca) vocal behaviour. PLoS One 2019; 14:e0225772. [PMID: 31770420 PMCID: PMC6879133 DOI: 10.1371/journal.pone.0225772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 11/12/2019] [Indexed: 11/29/2022] Open
Abstract
Documenting the different social and behavioural contexts that vocalisations are produced in remains an important step towards understanding the functional relevance of specific call types in a given species’ vocal repertoire. In this study we investigated whether seasonal differences and the presence or absence of male and female conspecifics influence the production of male giant panda vocal signals. To this end, captive male giant pandas were observed during and outside of the breeding season in three social contexts: only male conspecific neighbours, only female conspecific neighbours, and a context with no neighbours. We found that males were more likely to bleat, chirp, honk and moan during the breeding season, and showed a tendency to growl more outside of the reproductive period. The contextual analysis revealed that bleats were more likely to be produced by males when opposite-sexed conspecifics are in close attendance during the breeding season. Conversely, males were more likely to chirp when neighboured by males than females or no neighbours. In addition, males were more likely to honk in the absence of neighbouring conspecifics during the breeding season, raising the possibility that these calls function to signal location and gain the attention of potential mates. Moans were produced more often when male giant pandas had male than female neighbours during the breeding season, which may reflect mild aggression towards these same-sexed rivals, whereas the production of barks and growls did not vary according to season or the sex of conspecific neighbours. Our findings underscore the importance of male giant panda bleats for coordinating reproduction and promoting contact with potential mating partners in this non-gregarious species, and yield fresh insights into the function of male honks that warrant further investigation. They also provide a basis for comparison with free-ranging giant panda vocal behaviour that could potentially inform conservation efforts.
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Affiliation(s)
- Benjamin D. Charlton
- Institute for Conservation Research, San Diego Zoo Global, San Diego, California, United States of America
- * E-mail:
| | - Megan A. Owen
- Institute for Conservation Research, San Diego Zoo Global, San Diego, California, United States of America
| | - Xiaoping Zhou
- China Conservation and Research Center for the Giant Panda, Wolong, Sichuan, China
| | - Hemin Zhang
- China Conservation and Research Center for the Giant Panda, Wolong, Sichuan, China
| | - Ronald R. Swaisgood
- Institute for Conservation Research, San Diego Zoo Global, San Diego, California, United States of America
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16
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Charlton BD, Owen MA, Swaisgood RR. Coevolution of vocal signal characteristics and hearing sensitivity in forest mammals. Nat Commun 2019; 10:2778. [PMID: 31239439 PMCID: PMC6592901 DOI: 10.1038/s41467-019-10768-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/28/2019] [Indexed: 11/09/2022] Open
Abstract
Although signal characteristics and sensory systems are predicted to co-evolve according to environmental constraints, this hypothesis has not been tested for acoustic signalling across a wide range of species, or any mammal sensory modality. Here we use phylogenetic comparative techniques to show that mammal vocal characteristics and hearing sensitivity have co-evolved to utilise higher frequencies in forest environments - opposite to the general prediction that lower frequencies should be favoured in acoustically cluttered habitats. We also reveal an evolutionary trade-off between high frequency hearing sensitivity and the production of calls with high frequency acoustic energy that suggests forest mammals further optimise vocal communication according to their high frequency hearing sensitivity. Our results provide clear evidence of adaptive signal and sensory system coevolution. They also emphasize how constraints imposed by the signalling environment can jointly shape vocal signal structure and auditory systems, potentially driving acoustic diversity and reproductive isolation.
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Affiliation(s)
- Benjamin D Charlton
- Institute for Conservation Research, San Diego Zoo Global, California, CA, 92027-7000, USA.
| | - Megan A Owen
- Institute for Conservation Research, San Diego Zoo Global, California, CA, 92027-7000, USA
| | - Ronald R Swaisgood
- Institute for Conservation Research, San Diego Zoo Global, California, CA, 92027-7000, USA
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17
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Contiguity-based sound iconicity: The meaning of words resonates with phonetic properties of their immediate verbal contexts. PLoS One 2019; 14:e0216930. [PMID: 31095612 PMCID: PMC6522027 DOI: 10.1371/journal.pone.0216930] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 05/01/2019] [Indexed: 11/18/2022] Open
Abstract
We tested the hypothesis that phonosemantic iconicity--i.e., a motivated resonance of sound and meaning--might not only be found on the level of individual words or entire texts, but also in word combinations such that the meaning of a target word is iconically expressed, or highlighted, in the phonetic properties of its immediate verbal context. To this end, we extracted single lines from German poems that all include a word designating high or low dominance, such as large or small, strong or weak, etc. Based on insights from previous studies, we expected to find more vowels with a relatively short distance between the first two formants (low formant dispersion) in the immediate context of words expressing high physical or social dominance than in the context of words expressing low dominance. Our findings support this hypothesis, suggesting that neighboring words can form iconic dyads in which the meaning of one word is sound-iconically reflected in the phonetic properties of adjacent words. The construct of a contiguity-based phono-semantic iconicity opens many venues for future research well beyond lines extracted from poems.
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18
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Raine J, Pisanski K, Bond R, Simner J, Reby D. Human roars communicate upper-body strength more effectively than do screams or aggressive and distressed speech. PLoS One 2019; 14:e0213034. [PMID: 30830931 PMCID: PMC6398857 DOI: 10.1371/journal.pone.0213034] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 02/13/2019] [Indexed: 11/27/2022] Open
Abstract
Despite widespread evidence that nonverbal components of human speech (e.g., voice pitch) communicate information about physical attributes of vocalizers and that listeners can judge traits such as strength and body size from speech, few studies have examined the communicative functions of human nonverbal vocalizations (such as roars, screams, grunts and laughs). Critically, no previous study has yet to examine the acoustic correlates of strength in nonverbal vocalisations, including roars, nor identified reliable vocal cues to strength in human speech. In addition to being less acoustically constrained than articulated speech, agonistic nonverbal vocalizations function primarily to express motivation and emotion, such as threat, and may therefore communicate strength and body size more effectively than speech. Here, we investigated acoustic cues to strength and size in roars compared to screams and speech sentences produced in both aggressive and distress contexts. Using playback experiments, we then tested whether listeners can reliably infer a vocalizer's actual strength and height from roars, screams, and valenced speech equivalents, and which acoustic features predicted listeners' judgments. While there were no consistent acoustic cues to strength in any vocal stimuli, listeners accurately judged inter-individual differences in strength, and did so most effectively from aggressive voice stimuli (roars and aggressive speech). In addition, listeners more accurately judged strength from roars than from aggressive speech. In contrast, listeners' judgments of height were most accurate for speech stimuli. These results support the prediction that vocalizers maximize impressions of physical strength in aggressive compared to distress contexts, and that inter-individual variation in strength may only be honestly communicated in vocalizations that function to communicate threat, particularly roars. Thus, in continuity with nonhuman mammals, the acoustic structure of human aggressive roars may have been selected to communicate, and to some extent exaggerate, functional cues to physical formidability.
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Affiliation(s)
- Jordan Raine
- Mammal Vocal Communication and Cognition Research Group, University of Sussex, Brighton, United Kingdom
| | - Katarzyna Pisanski
- Mammal Vocal Communication and Cognition Research Group, University of Sussex, Brighton, United Kingdom
- Equipe Neuro-Ethologie Sensorielle, ENES/Neuro-PSI CNRS UMR 9197, Bioacoustics Team, University of Lyon/Saint-Etienne, Saint-Etienne, France
| | - Rod Bond
- Mammal Vocal Communication and Cognition Research Group, University of Sussex, Brighton, United Kingdom
| | - Julia Simner
- MULTISENSE Research Lab, University of Sussex, Brighton, United Kingdom
| | - David Reby
- Mammal Vocal Communication and Cognition Research Group, University of Sussex, Brighton, United Kingdom
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19
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Reby D, Wyman MT, Frey R, Charlton BD, Dalmont JP, Gilbert J. Vocal tract modelling in fallow deer: are male groans nasalized? ACTA ACUST UNITED AC 2018; 221:jeb.179416. [PMID: 29941611 DOI: 10.1242/jeb.179416] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/21/2018] [Indexed: 11/20/2022]
Abstract
Males of several species of deer have a descended and mobile larynx, resulting in an unusually long vocal tract, which can be further extended by lowering the larynx during call production. Formant frequencies are lowered as the vocal tract is extended, as predicted when approximating the vocal tract as a uniform quarter wavelength resonator. However, formant frequencies in polygynous deer follow uneven distribution patterns, indicating that the vocal tract configuration may in fact be rather complex. We CT-scanned the head and neck region of two adult male fallow deer specimens with artificially extended vocal tracts and measured the cross-sectional areas of the supra-laryngeal vocal tract along the oral and nasal tracts. The CT data were then used to predict the resonances produced by three possible configurations, including the oral vocal tract only, the nasal vocal tract only, or combining the two. We found that the area functions from the combined oral and nasal vocal tracts produced resonances more closely matching the formant pattern and scaling observed in fallow deer groans than those predicted by the area functions of the oral vocal tract only or of the nasal vocal tract only. This indicates that the nasal and oral vocal tracts are both simultaneously involved in the production of a non-human mammal vocalization, and suggests that the potential for nasalization in putative oral loud calls should be carefully considered.
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Affiliation(s)
- D Reby
- School of Psychology, University of Sussex, Falmer, Brighton BN1 9QH, UK
| | - M T Wyman
- School of Psychology, University of Sussex, Falmer, Brighton BN1 9QH, UK.,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - R Frey
- Department of Reproduction Management, Leibniz Institute for Zoo and Wildlife Research (IZW), 10315 Berlin, Germany
| | - B D Charlton
- San Diego Zoo's Institute for Conservation Research, Escondido 92027, CA, USA
| | - J P Dalmont
- Laboratoire d'Acoustique de l'Université du Mans, CNRS, 72085 le Mans, France
| | - J Gilbert
- Laboratoire d'Acoustique de l'Université du Mans, CNRS, 72085 le Mans, France
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20
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Raine J, Pisanski K, Oleszkiewicz A, Simner J, Reby D. Human Listeners Can Accurately Judge Strength and Height Relative to Self from Aggressive Roars and Speech. iScience 2018; 4:273-280. [PMID: 30240746 PMCID: PMC6146593 DOI: 10.1016/j.isci.2018.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/02/2018] [Accepted: 04/06/2018] [Indexed: 11/29/2022] Open
Abstract
Although animal vocalizations and human speech are known to communicate physical formidability, no previous study has examined whether human listeners can assess the strength or body size of vocalizers relative to their own, either from speech or from nonverbal vocalizations. Here, although men tended to underestimate women's formidability, and women to overestimate men's, listeners judged relative strength and height from aggressive roars and aggressive speech accurately. For example, when judging roars, male listeners accurately identified vocalizers who were substantially stronger than themselves in 88% of trials, and never as weaker. For male vocalizers only, roars functioned to exaggerate the expression of threat compared to aggressive speech, as men were rated as relatively stronger when producing roars. These results indicate that, like other mammals, the acoustic structure of human aggressive vocal signals (and in particular roars) may have been selected to communicate functional information relevant to listeners' survival.
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Affiliation(s)
- Jordan Raine
- School of Psychology, University of Sussex, Brighton, UK.
| | - Katarzyna Pisanski
- School of Psychology, University of Sussex, Brighton, UK; Institute of Psychology, University of Wrocław, Wrocław, Poland
| | - Anna Oleszkiewicz
- Institute of Psychology, University of Wrocław, Wrocław, Poland; Taste and Smell Center, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | - Julia Simner
- School of Psychology, University of Sussex, Brighton, UK
| | - David Reby
- School of Psychology, University of Sussex, Brighton, UK
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21
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Frey R, Reby D, Fritsch G, Charlton BD. The remarkable vocal anatomy of the koala (Phascolarctos cinereus): insights into low-frequency sound production in a marsupial species. J Anat 2018; 232:575-595. [PMID: 29460389 DOI: 10.1111/joa.12770] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2017] [Indexed: 11/27/2022] Open
Abstract
Koalas are characterised by a highly unusual vocal anatomy, with a descended larynx and velar vocal folds, allowing them to produce calls at disproportionately low frequencies. Here we use advanced imaging techniques, histological data, classical macroscopic dissection and behavioural observations to provide the first detailed description and interpretation of male and female koala vocal anatomy. We show that both males and females have an elongated pharynx and soft palate, resulting in a permanently descended larynx. In addition, the hyoid apparatus has a human-like configuration in which paired dorsal, resilient ligaments suspend the hyoid apparatus from the skull, while the ventral parts tightly connect to the descended larynx. We also show that koalas can retract the larynx down into the thoracic inlet, facilitated by a dramatic evolutionary transformation of the ventral neck muscles. First, the usual retractors of the larynx and the hyoid have their origins deep in the thorax. Secondly, three hyoid muscles have lost their connection to the hyoid skeleton. Thirdly, the genioglossus and geniohyoid muscles are greatly increased in length. Finally, the digastric, omohyoid and sternohyoid muscles, connected by a common tendinous intersection, form a guiding channel for the dynamic down-and-up movements of the ventral hyoid parts and the larynx. We suggest that these features evolved to accommodate the low resting position of the larynx and assist in its retraction during call production. We also confirm that the edges of the intra-pharyngeal ostium have specialised to form the novel, extra-laryngeal velar vocal folds, which are much larger than the true intra-laryngeal vocal folds in both sexes, but more developed and specialised for low frequency sound production in males than in females. Our findings illustrate that strong selection pressures on acoustic signalling not only lead to the specialisation of existing vocal organs but can also result in the evolution of novel vocal structures in both sexes.
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Affiliation(s)
- Roland Frey
- Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
| | - David Reby
- School of Psychology, University of Sussex, Brighton, UK
| | - Guido Fritsch
- Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
| | - Benjamin D Charlton
- Behavioural Ecology Research Group, Department of Biology, Anglia Ruskin University, Cambridge, UK
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22
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Garcia M, Herbst CT, Bowling DL, Dunn JC, Fitch WT. Acoustic allometry revisited: morphological determinants of fundamental frequency in primate vocal production. Sci Rep 2017; 7:10450. [PMID: 28874852 PMCID: PMC5585385 DOI: 10.1038/s41598-017-11000-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/15/2017] [Indexed: 11/08/2022] Open
Abstract
A fundamental issue in the evolution of communication is the degree to which signals convey accurate ("honest") information about the signaler. In bioacoustics, the assumption that fundamental frequency (f o) should correlate with the body size of the caller is widespread, but this belief has been challenged by various studies, possibly because larynx size and body size can vary independently. In the present comparative study, we conducted excised larynx experiments to investigate this hypothesis rigorously and explore the determinants of f o. Using specimens from eleven primate species, we carried out an inter-specific investigation, examining correlations between the minimum f o produced by the sound source, body size and vocal fold length (VFL). We found that, across species, VFL predicted minimum f o much better than body size, clearly demonstrating the potential for decoupling between larynx size and body size in primates. These findings shed new light on the diversity of primate vocalizations and vocal morphology, highlighting the importance of vocal physiology in understanding the evolution of mammal vocal communication.
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Affiliation(s)
- Maxime Garcia
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
- ENES Lab, Université Lyon/Saint-Etienne, NEURO-PSI, CNRS UMR 9197, Saint-Etienne, France.
| | - Christian T Herbst
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Daniel L Bowling
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Jacob C Dunn
- Division of Biological Anthropology, University of Cambridge, Pembroke Street, Cambridge, CB2 3QG, UK
- Animal and Environment Research Group, Anglia Ruskin University, East Road, Cambridge, CB1 1PT, UK
| | - W Tecumseh Fitch
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
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23
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Ravignani A, Gross S, Garcia M, Rubio-Garcia A, de Boer B. How small could a pup sound? The physical bases of signaling body size in harbor seals. Curr Zool 2017; 63:457-465. [PMID: 29492005 PMCID: PMC5804196 DOI: 10.1093/cz/zox026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 04/08/2017] [Indexed: 11/24/2022] Open
Abstract
Vocal communication is a crucial aspect of animal behavior. The mechanism which most mammals use to vocalize relies on three anatomical components. First, air overpressure is generated inside the lower vocal tract. Second, as the airstream goes through the glottis, sound is produced via vocal fold vibration. Third, this sound is further filtered by the geometry and length of the upper vocal tract. Evidence from mammalian anatomy and bioacoustics suggests that some of these three components may covary with an animal's body size. The framework provided by acoustic allometry suggests that, because vocal tract length (VTL) is more strongly constrained by the growth of the body than vocal fold length (VFL), VTL generates more reliable acoustic cues to an animal's size. This hypothesis is often tested acoustically but rarely anatomically, especially in pinnipeds. Here, we test the anatomical bases of the acoustic allometry hypothesis in harbor seal pups Phoca vitulina. We dissected and measured vocal tract, vocal folds, and other anatomical features of 15 harbor seals post-mortem. We found that, while VTL correlates with body size, VFL does not. This suggests that, while body growth puts anatomical constraints on how vocalizations are filtered by harbor seals' vocal tract, no such constraints appear to exist on vocal folds, at least during puppyhood. It is particularly interesting to find anatomical constraints on harbor seals' vocal tracts, the same anatomical region partially enabling pups to produce individually distinctive vocalizations.
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Affiliation(s)
- Andrea Ravignani
- Veterinary & Research Department, Sealcentre Pieterburen, Hoofdstraat 94a, Pieterburen, AG 9968, The Netherlands
- Artificial Intelligence Laboratory, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium
- Language and Cognition Department, Max Planck Institute for Psycholinguistics, Wundtlaan 1, Nijmegen, XD 6525, The Netherlands
| | - Stephanie Gross
- Veterinary & Research Department, Sealcentre Pieterburen, Hoofdstraat 94a, Pieterburen, AG 9968, The Netherlands
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstrasse 6, Buesum 25761, Germany
| | - Maxime Garcia
- ENES Lab/Neuro-PSI, CNRS UMR9197, University of Lyon/Saint Etienne, 23 rue Paul Michelon, 42023 Saint-Etienne cedex 2, France
| | - Ana Rubio-Garcia
- Veterinary & Research Department, Sealcentre Pieterburen, Hoofdstraat 94a, Pieterburen, AG 9968, The Netherlands
| | - Bart de Boer
- Artificial Intelligence Laboratory, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium
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24
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Charlton BD, Watchorn DJ, Whisson DA. Subharmonics increase the auditory impact of female koala rejection calls. Ethology 2017. [DOI: 10.1111/eth.12628] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Benjamin D. Charlton
- School of Biology and Environmental Science; University College Dublin (UCD); Dublin Ireland
| | - Darcy J. Watchorn
- School of Life and Environmental Sciences, Centre for Integrative Ecology; Deakin University; Geelong VIC Australia
| | - Desley A. Whisson
- School of Life and Environmental Sciences, Centre for Integrative Ecology; Deakin University; Geelong VIC Australia
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25
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Favaro L, Gamba M, Gili C, Pessani D. Acoustic correlates of body size and individual identity in banded penguins. PLoS One 2017; 12:e0170001. [PMID: 28199318 PMCID: PMC5310857 DOI: 10.1371/journal.pone.0170001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 12/27/2016] [Indexed: 11/18/2022] Open
Abstract
Animal vocalisations play a role in individual recognition and mate choice. In nesting penguins, acoustic variation in vocalisations originates from distinctiveness in the morphology of the vocal apparatus. Using the source-filter theory approach, we investigated vocal individuality cues and correlates of body size and mass in the ecstatic display songs the Humboldt and Magellanic penguins. We demonstrate that both fundamental frequency (f0) and formants (F1-F4) are essential vocal features to discriminate among individuals. However, we show that only duration and f0 are honest indicators of the body size and mass, respectively. We did not find any effect of body dimension on formants, formant dispersion nor estimated vocal tract length of the emitters. Overall, our findings provide the first evidence that the resonant frequencies of the vocal tract do not correlate with body size in penguins. Our results add important information to a growing body of literature on the role of the different vocal parameters in conveying biologically meaningful information in bird vocalisations.
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Affiliation(s)
- Livio Favaro
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Marco Gamba
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Claudia Gili
- Acquario di Genova, Costa Edutainment SpA, Genoa, Italy
| | - Daniela Pessani
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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Abstract
For both humans and other animals, the ability to combine information obtained through different senses is fundamental to the perception of the environment. It is well established that humans form systematic cross-modal correspondences between stimulus features that can facilitate the accurate combination of sensory percepts. However, the evolutionary origins of the perceptual and cognitive mechanisms involved in these cross-modal associations remain surprisingly underexplored. In this review we outline recent comparative studies investigating how non-human mammals naturally combine information encoded in different sensory modalities during communication. The results of these behavioural studies demonstrate that various mammalian species are able to combine signals from different sensory channels when they are perceived to share the same basic features, either because they can be redundantly sensed and/or because they are processed in the same way. Moreover, evidence that a wide range of mammals form complex cognitive representations about signallers, both within and across species, suggests that animals also learn to associate different sensory features which regularly co-occur. Further research is now necessary to determine how multisensory representations are formed in individual animals, including the relative importance of low level feature-related correspondences. Such investigations will generate important insights into how animals perceive and categorise their environment, as well as provide an essential basis for understanding the evolution of multisensory perception in humans.
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27
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28
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Volitional exaggeration of body size through fundamental and formant frequency modulation in humans. Sci Rep 2016; 6:34389. [PMID: 27687571 PMCID: PMC5043380 DOI: 10.1038/srep34389] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 09/09/2016] [Indexed: 11/09/2022] Open
Abstract
Several mammalian species scale their voice fundamental frequency (F0) and formant frequencies in competitive and mating contexts, reducing vocal tract and laryngeal allometry thereby exaggerating apparent body size. Although humans’ rare capacity to volitionally modulate these same frequencies is thought to subserve articulated speech, the potential function of voice frequency modulation in human nonverbal communication remains largely unexplored. Here, the voices of 167 men and women from Canada, Cuba, and Poland were recorded in a baseline condition and while volitionally imitating a physically small and large body size. Modulation of F0, formant spacing (∆F), and apparent vocal tract length (VTL) were measured using Praat. Our results indicate that men and women spontaneously and systemically increased VTL and decreased F0 to imitate a large body size, and reduced VTL and increased F0 to imitate small size. These voice modulations did not differ substantially across cultures, indicating potentially universal sound-size correspondences or anatomical and biomechanical constraints on voice modulation. In each culture, men generally modulated their voices (particularly formants) more than did women. This latter finding could help to explain sexual dimorphism in F0 and formants that is currently unaccounted for by sexual dimorphism in human vocal anatomy and body size.
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Charlton BD, Reby D. The evolution of acoustic size exaggeration in terrestrial mammals. Nat Commun 2016; 7:12739. [PMID: 27598835 PMCID: PMC5025854 DOI: 10.1038/ncomms12739] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/28/2016] [Indexed: 11/20/2022] Open
Abstract
Recent studies have revealed that some mammals possess adaptations that enable them to produce vocal signals with much lower fundamental frequency (F0) and formant frequency spacing (ΔF) than expected for their size. Although these adaptations are assumed to reflect selection pressures for males to lower frequency components and exaggerate body size in reproductive contexts, this hypothesis has not been tested across a broad range of species. Here we show that male terrestrial mammals produce vocal signals with lower ΔF (but not F0) than expected for their size in mating systems with greater sexual size dimorphism. We also reveal that males produce calls with higher than expected F0 and ΔF in species with increased sperm competition. This investigation confirms that sexual selection favours the use of ΔF as an acoustic size exaggerator and supports the notion of an evolutionary trade-off between pre-copulatory signalling displays and sperm production.
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Affiliation(s)
- Benjamin D. Charlton
- School of Biology and Environmental Science, Science Centre West, University College Dublin (UCD), Belfield, Dublin 4, Ireland
| | - David Reby
- Mammal Vocal Communication and Cognition Research Group, School of Psychology, University of Sussex, Sussex BN1 9QH, UK
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Bálint A, Faragó T, Miklósi Á, Pongrácz P. Threat-level-dependent manipulation of signaled body size: dog growls’ indexical cues depend on the different levels of potential danger. Anim Cogn 2016; 19:1115-1131. [DOI: 10.1007/s10071-016-1019-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 07/19/2016] [Accepted: 07/26/2016] [Indexed: 11/30/2022]
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Reber SA, Nishimura T, Janisch J, Robertson M, Fitch WT. A Chinese alligator in heliox: formant frequencies in a crocodilian. ACTA ACUST UNITED AC 2016; 218:2442-7. [PMID: 26246611 PMCID: PMC4528706 DOI: 10.1242/jeb.119552] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Crocodilians are among the most vocal non-avian reptiles. Adults of both sexes produce loud vocalizations known as ‘bellows’ year round, with the highest rate during the mating season. Although the specific function of these vocalizations remains unclear, they may advertise the caller's body size, because relative size differences strongly affect courtship and territorial behaviour in crocodilians. In mammals and birds, a common mechanism for producing honest acoustic signals of body size is via formant frequencies (vocal tract resonances). To our knowledge, formants have to date never been documented in any non-avian reptile, and formants do not seem to play a role in the vocalizations of anurans. We tested for formants in crocodilian vocalizations by using playbacks to induce a female Chinese alligator (Alligator sinensis) to bellow in an airtight chamber. During vocalizations, the animal inhaled either normal air or a helium/oxygen mixture (heliox) in which the velocity of sound is increased. Although heliox allows normal respiration, it alters the formant distribution of the sound spectrum. An acoustic analysis of the calls showed that the source signal components remained constant under both conditions, but an upward shift of high-energy frequency bands was observed in heliox. We conclude that these frequency bands represent formants. We suggest that crocodilian vocalizations could thus provide an acoustic indication of body size via formants. Because birds and crocodilians share a common ancestor with all dinosaurs, a better understanding of their vocal production systems may also provide insight into the communication of extinct Archosaurians. Highlighted Article: Frequency peaks in bellows of a Chinese alligator breathing a helium–oxygen mixture instead of air shift to significantly higher frequencies, showing that crocodilian vocalizations contain vocal resonance frequencies or ‘formants’.
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Affiliation(s)
- Stephan A Reber
- Department of Cognitive Biology, University of Vienna, Vienna 1150, Austria
| | - Takeshi Nishimura
- Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan
| | - Judith Janisch
- Department of Cognitive Biology, University of Vienna, Vienna 1150, Austria
| | - Mark Robertson
- St Augustine Alligator Farm Zoological Park, St Augustine, FL 32080, USA
| | - W Tecumseh Fitch
- Department of Cognitive Biology, University of Vienna, Vienna 1150, Austria
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Garcia M, Wondrak M, Huber L, Fitch WT. Honest signaling in domestic piglets (Sus scrofa domesticus): vocal allometry and the information content of grunt calls. J Exp Biol 2016; 219:1913-21. [PMID: 27059064 PMCID: PMC4920241 DOI: 10.1242/jeb.138255] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/29/2016] [Indexed: 11/20/2022]
Abstract
The information conveyed in acoustic signals is a central topic in mammal vocal communication research. Body size is one form of information that can be encoded in calls. Acoustic allometry aims to identify the specific acoustic correlates of body size within the vocalizations of a given species, and formants are often a useful acoustic cue in this context. We conducted a longitudinal investigation of acoustic allometry in domestic piglets (Sus scrofa domesticus), asking whether formants of grunt vocalizations provide information concerning the caller's body size over time. On four occasions, we recorded grunts from 20 kunekune piglets, measured their vocal tract length by means of radiographs (X-rays) and weighed them. Controlling for effects of age and sex, we found that body weight strongly predicts vocal tract length, which in turn determines formant frequencies. We conclude that grunt formant frequencies could allow domestic pigs to assess a signaler's body size as it grows. Further research using playback experiments is needed to determine the perceptual role of formants in domestic pig communication.
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Affiliation(s)
- Maxime Garcia
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, Vienna 1090, Austria
| | - Marianne Wondrak
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of Vienna, Veterinaerplatz 1, Vienna 1210, Austria Haidlhof Research Station, 2540 Bad Vöslau, Austria
| | - Ludwig Huber
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of Vienna, Veterinaerplatz 1, Vienna 1210, Austria Haidlhof Research Station, 2540 Bad Vöslau, Austria
| | - W Tecumseh Fitch
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, Vienna 1090, Austria
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Stoeger AS, Baotic A. Information content and acoustic structure of male African elephant social rumbles. Sci Rep 2016; 6:27585. [PMID: 27273586 PMCID: PMC4897791 DOI: 10.1038/srep27585] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 05/17/2016] [Indexed: 11/14/2022] Open
Abstract
Until recently, the prevailing theory about male African elephants (Loxodonta africana) was that, once adult and sexually mature, males are solitary and targeted only at finding estrous females. While this is true during the state of 'musth' (a condition characterized by aggressive behavior and elevated androgen levels), 'non-musth' males exhibit a social system seemingly based on companionship, dominance and established hierarchies. Research on elephant vocal communication has so far focused on females, and very little is known about the acoustic structure and the information content of male vocalizations. Using the source and filter theory approach, we analyzed social rumbles of 10 male African elephants. Our results reveal that male rumbles encode information about individuality and maturity (age and size), with formant frequencies and absolute fundamental frequency values having the most informative power. This first comprehensive study on male elephant vocalizations gives important indications on their potential functional relevance for male-male and male-female communication. Our results suggest that, similar to the highly social females, future research on male elephant vocal behavior will reveal a complex communication system in which social knowledge, companionship, hierarchy, reproductive competition and the need to communicate over long distances play key roles.
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Affiliation(s)
- Angela S. Stoeger
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna, 1090, Austria
| | - Anton Baotic
- Mammal Communication Lab, Department of Cognitive Biology, University of Vienna, Vienna, 1090, Austria
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Reby D, Wyman MT, Frey R, Passilongo D, Gilbert J, Locatelli Y, Charlton BD. Evidence of biphonation and source–filter interactions in the bugles of male North American wapiti (Cervus canadensis). J Exp Biol 2016; 219:1224-36. [DOI: 10.1242/jeb.131219] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 02/12/2016] [Indexed: 11/20/2022]
Abstract
ABSTRACT
With an average male body mass of 320 kg, the wapiti, Cervus canadensis, is the largest extant species of Old World deer (Cervinae). Despite this large body size, male wapiti produce whistle-like sexual calls called bugles characterised by an extremely high fundamental frequency. Investigations of the biometry and physiology of the male wapiti's relatively large larynx have so far failed to account for the production of such a high fundamental frequency. Our examination of spectrograms of male bugles suggested that the complex harmonic structure is best explained by a dual-source model (biphonation), with one source oscillating at a mean of 145 Hz (F0) and the other oscillating independently at an average of 1426 Hz (G0). A combination of anatomical investigations and acoustical modelling indicated that the F0 of male bugles is consistent with the vocal fold dimensions reported in this species, whereas the secondary, much higher source at G0 is more consistent with an aerodynamic whistle produced as air flows rapidly through a narrow supraglottic constriction. We also report a possible interaction between the higher frequency G0 and vocal tract resonances, as G0 transiently locks onto individual formants as the vocal tract is extended. We speculate that male wapiti have evolved such a dual-source phonation to advertise body size at close range (with a relatively low-frequency F0 providing a dense spectrum to highlight size-related information contained in formants) while simultaneously advertising their presence over greater distances using the very high-amplitude G0 whistle component.
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Affiliation(s)
- D. Reby
- Mammal Vocal Communication and Cognition Research Group, School of Psychology, University of Sussex, Brighton BN1 9QH, UK
| | - M. T. Wyman
- Mammal Vocal Communication and Cognition Research Group, School of Psychology, University of Sussex, Brighton BN1 9QH, UK
| | - R. Frey
- Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin 10315, Germany
| | - D. Passilongo
- Department of Science for Nature and Environmental Resources, University of Sassari, Sassari 07100, Italy
| | - J. Gilbert
- Laboratoire d'Acoustique de l'Université du Maine – UMR CNRS, le Mans 72085, France
| | - Y. Locatelli
- Réserve de la Haute Touche, Muséum National d'Histoire Naturelle, Obterre 36290, France
| | - B. D. Charlton
- School of Biology and Environmental Science, Science Centre West, University College Dublin (UCD), Belfield, Dublin 4, Ireland
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Leuchtenberger C, Sousa-Lima R, Ribas C, Magnusson WE, Mourão G. Giant otter alarm calls as potential mechanisms for individual discrimination and sexual selection. BIOACOUSTICS 2016. [DOI: 10.1080/09524622.2016.1157704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Caroline Leuchtenberger
- Graduate Program in Ecology, National Institute of Amazon Research – INPA, Manaus, Brazil
- Wildlife Laboratory, Embrapa Pantanal, Corumbá, Brazil
- Laboratory of Bioacoustics, Department of Physiology, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Renata Sousa-Lima
- Laboratory of Bioacoustics, Department of Physiology, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Carolina Ribas
- Graduate Program in Ecology, National Institute of Amazon Research – INPA, Manaus, Brazil
- Wildlife Laboratory, Embrapa Pantanal, Corumbá, Brazil
| | - William E. Magnusson
- Graduate Program in Ecology, National Institute of Amazon Research – INPA, Manaus, Brazil
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Garcia M, Gingras B, Bowling DL, Herbst CT, Boeckle M, Locatelli Y, Fitch WT. Structural Classification of Wild Boar ( Sus scrofa) Vocalizations. Ethology 2016; 122:329-342. [PMID: 27065507 PMCID: PMC4793927 DOI: 10.1111/eth.12472] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 07/20/2015] [Accepted: 12/28/2015] [Indexed: 11/28/2022]
Abstract
Determining whether a species' vocal communication system is graded or discrete requires definition of its vocal repertoire. In this context, research on domestic pig (Sus scrofa domesticus) vocalizations, for example, has led to significant advances in our understanding of communicative functions. Despite their close relation to domestic pigs, little is known about wild boar (Sus scrofa) vocalizations. The few existing studies, conducted in the 1970s, relied on visual inspections of spectrograms to quantify acoustic parameters and lacked statistical analysis. Here, we use objective signal processing techniques and advanced statistical approaches to classify 616 calls recorded from semi‐free ranging animals. Based on four spectral and temporal acoustic parameters—quartile Q25, duration, spectral flux, and spectral flatness—extracted from a multivariate analysis, we refine and extend the conclusions drawn from previous work and present a statistically validated classification of the wild boar vocal repertoire into four call types: grunts, grunt‐squeals, squeals, and trumpets. While the majority of calls could be sorted into these categories using objective criteria, we also found evidence supporting a graded interpretation of some wild boar vocalizations as acoustically continuous, with the extremes representing discrete call types. The use of objective criteria based on modern techniques and statistics in respect to acoustic continuity advances our understanding of vocal variation. Integrating our findings with recent studies on domestic pig vocal behavior and emotions, we emphasize the importance of grunt‐squeals for acoustic approaches to animal welfare and underline the need of further research investigating the role of domestication on animal vocal communication.
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Affiliation(s)
- Maxime Garcia
- Department of Cognitive Biology University of Vienna Vienna Austria
| | - Bruno Gingras
- Department of Cognitive Biology University of Vienna Vienna Austria
| | - Daniel L Bowling
- Department of Cognitive Biology University of Vienna Vienna Austria
| | - Christian T Herbst
- Voice Research Lab Department of Biophysics Faculty of Science Palacký University Olomouc Czech Republic
| | - Markus Boeckle
- Department of Cognitive Biology University of Vienna Vienna Austria; Department of Psychotherapy and Biopsychosocial Health Danube University Krems Krems Austria
| | - Yann Locatelli
- Réserve de la Haute Touche Muséum National d'Histoire Naturelle Obterre France; Equipe Interactions Cellulaires et Fertilité UMR0085 Physiologie de la Reproduction et des Comportements Institut National de la Recherche Agronomique Nouzilly France
| | - W Tecumseh Fitch
- Department of Cognitive Biology University of Vienna Vienna Austria
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Vocal Production by Terrestrial Mammals: Source, Filter, and Function. VERTEBRATE SOUND PRODUCTION AND ACOUSTIC COMMUNICATION 2016. [DOI: 10.1007/978-3-319-27721-9_8] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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McCurry MR, Quayle MR, Cally J, Adams JW. Velar vocal folds are present in female and immature male koalas (Phascolarctos cinereus). AUSTRALIAN MAMMALOGY 2016. [DOI: 10.1071/am15038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It was recently shown that adult male koalas (Phascolarctos cinereus) possess a novel vocal organ, the velar vocal folds, that underlie their mating bellows. Here we demonstrate through dissection of the infrahyoid region that this novel structure is also present in female and immature male koalas.
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Vertebrate Bioacoustics: Prospects and Open Problems. VERTEBRATE SOUND PRODUCTION AND ACOUSTIC COMMUNICATION 2016. [DOI: 10.1007/978-3-319-27721-9_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Mitchell RLC, Xu Y. What is the Value of Embedding Artificial Emotional Prosody in Human-Computer Interactions? Implications for Theory and Design in Psychological Science. Front Psychol 2015; 6:1750. [PMID: 26617563 PMCID: PMC4641894 DOI: 10.3389/fpsyg.2015.01750] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/31/2015] [Indexed: 11/18/2022] Open
Abstract
In computerized technology, artificial speech is becoming increasingly important, and is already used in ATMs, online gaming and healthcare contexts. However, today’s artificial speech typically sounds monotonous, a main reason for this being the lack of meaningful prosody. One particularly important function of prosody is to convey different emotions. This is because successful encoding and decoding of emotions is vital for effective social cognition, which is increasingly recognized in human–computer interaction contexts. Current attempts to artificially synthesize emotional prosody are much improved relative to early attempts, but there remains much work to be done due to methodological problems, lack of agreed acoustic correlates, and lack of theoretical grounding. If the addition of synthetic emotional prosody is not of sufficient quality, it may risk alienating users instead of enhancing their experience. So the value of embedding emotion cues in artificial speech may ultimately depend on the quality of the synthetic emotional prosody. However, early evidence on reactions to synthesized non-verbal cues in the facial modality bodes well. Attempts to implement the recognition of emotional prosody into artificial applications and interfaces have perhaps been met with greater success, but the ultimate test of synthetic emotional prosody will be to critically compare how people react to synthetic emotional prosody vs. natural emotional prosody, at the behavioral, socio-cognitive and neural levels.
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Affiliation(s)
- Rachel L C Mitchell
- Centre for Affective Disorders, Institute of Psychiatry Psychology and Neuroscience , King's College London, London, UK
| | - Yi Xu
- Speech Hearing and Phonetic Sciences, Division of Psychology and Language Sciences, University College London , London, UK
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Ziegler L, Arim M, Bozinovic F. Intraspecific scaling in frog calls: the interplay of temperature, body size and metabolic condition. Oecologia 2015; 181:673-81. [DOI: 10.1007/s00442-015-3499-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 10/27/2015] [Indexed: 11/30/2022]
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Dunn JC, Halenar LB, Davies TG, Cristobal-Azkarate J, Reby D, Sykes D, Dengg S, Fitch WT, Knapp LA. Evolutionary trade-off between vocal tract and testes dimensions in howler monkeys. Curr Biol 2015; 25:2839-2844. [PMID: 26592343 PMCID: PMC4635310 DOI: 10.1016/j.cub.2015.09.029] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/17/2015] [Accepted: 09/11/2015] [Indexed: 01/02/2023]
Abstract
Males often face a trade-off between investments in precopulatory and postcopulatory traits [1], particularly when male-male contest competition determines access to mates [2]. To date, studies of precopulatory strategies have largely focused on visual ornaments (e.g., coloration) or weapon morphology (e.g., antlers, horns, and canines). However, vocalizations can also play an important role in both male competition and female choice [3, 4, 5]. We investigated variation in vocal tract dimensions among male howler monkeys (Alouatta spp.), which produce loud roars using a highly specialized and greatly enlarged hyoid bone and larynx [6]. We examined the relative male investment in hyoids and testes among howler monkey species in relation to the level of male-male competition and analyzed the acoustic consequences of variation in hyoid morphology. Species characterized by single-male groups have large hyoids and small testes, suggesting high levels of vocally mediated competition. Larger hyoids lower formant frequencies, probably increasing the acoustic impression of male body size and playing a role analogous to investment in large body size or weaponry. Across species, as the number of males per group increases, testes volume also increases, indicating higher levels of postcopulatory sperm competition, while hyoid volume decreases. These results provide the first evidence of an evolutionary trade-off between investment in precopulatory vocal characteristics and postcopulatory sperm production. Howler monkey hyoid volume varies significantly between sexes and among species Hyoid volume negatively correlates with number of males per group and testes volume Larger hyoids lower formant spacing, increasing the acoustic impression of body size Results provide the first evidence of a trade-off between vocal investment and testes
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Affiliation(s)
- Jacob C Dunn
- Division of Biological Anthropology, University of Cambridge, Pembroke Street, Cambridge CB2 3QG, UK.
| | - Lauren B Halenar
- Department of Biology, Farmingdale State College, State University of New York, 2350 Broadhollow Road, Farmingdale, NY 11735-1021, USA; New York Consortium in Evolutionary Primatology, American Museum of Natural History, Central Park West and 79(th) Street, New York, NY 10024, USA
| | - Thomas G Davies
- Division of Biological Anthropology, University of Cambridge, Pembroke Street, Cambridge CB2 3QG, UK
| | - Jurgi Cristobal-Azkarate
- Division of Biological Anthropology, University of Cambridge, Pembroke Street, Cambridge CB2 3QG, UK
| | - David Reby
- Mammal Vocal Communication and Cognition Research Group, School of Psychology, University of Sussex, Falmer, Brighton BN1 9QH, UK
| | - Dan Sykes
- Imaging and Analysis Centre, Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Sabine Dengg
- Clinic of Diagnostic Imaging, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | - W Tecumseh Fitch
- Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria; Haidlhof Research Station, University of Vienna/University of Veterinary Medicine Vienna/Messerli Research Institute, Haidlhofer Strasse, 2540 Bad Vöslau, Austria.
| | - Leslie A Knapp
- Department of Anthropology, University of Utah, 270 1400 E, Salt Lake City, UT 84112, USA
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Charlton BD. The Acoustic Structure and Information Content of Female Koala Vocal Signals. PLoS One 2015; 10:e0138670. [PMID: 26465340 PMCID: PMC4605621 DOI: 10.1371/journal.pone.0138670] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 09/02/2015] [Indexed: 11/28/2022] Open
Abstract
Determining the information content of animal vocalisations can give valuable insights into the potential functions of vocal signals. The source-filter theory of vocal production allows researchers to examine the information content of mammal vocalisations by linking variation in acoustic features with variation in relevant physical characteristics of the caller. Here I used a source-filter theory approach to classify female koala vocalisations into different call-types, and determine which acoustic features have the potential to convey important information about the caller to other conspecifics. A two-step cluster analysis classified female calls into bellows, snarls and tonal rejection calls. Additional results revealed that female koala vocalisations differed in their potential to provide information about a given caller’s phenotype that may be of importance to receivers. Female snarls did not contain reliable acoustic cues to the caller’s identity and age. In contrast, female bellows and tonal rejection calls were individually distinctive, and the tonal rejection calls of older female koalas had consistently lower mean, minimum and maximum fundamental frequency. In addition, female bellows were significantly shorter in duration and had higher fundamental frequency, formant frequencies, and formant frequency spacing than male bellows. These results indicate that female koala vocalisations have the potential to signal the caller’s identity, age and sex. I go on to discuss the anatomical basis for these findings, and consider the possible functional relevance of signalling this type of information in the koala’s natural habitat.
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Affiliation(s)
- Benjamin D. Charlton
- School of Biology and Environmental Science, University College Dublin (UCD), Belfield, Dublin, Ireland
- * E-mail:
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Charlton BD, Keating JL, Rengui L, Huang Y, Swaisgood RR. The acoustic structure of male giant panda bleats varies according to intersexual context. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:1305-1312. [PMID: 26428769 DOI: 10.1121/1.4928606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Although the acoustic structure of mammal vocal signals often varies according to the social context of emission, relatively few mammal studies have examined acoustic variation during intersexual advertisement. In the current study male giant panda bleats were recorded during the breeding season in three behavioural contexts: vocalising alone, during vocal interactions with females outside of peak oestrus, and during vocal interactions with peak-oestrous females. Male bleats produced during vocal interactions with peak-oestrous females were longer in duration and had higher mean fundamental frequency than those produced when males were either involved in a vocal interaction with a female outside of peak oestrus or vocalising alone. In addition, males produced bleats with higher rates of fundamental frequency modulation when they were vocalising alone than when they were interacting with females. These results show that acoustic features of male giant panda bleats have the potential to signal the caller's motivational state, and suggest that males increase the rate of fundamental frequency modulation in bleats when they are alone to maximally broadcast their quality and promote close-range contact with receptive females during the breeding season.
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Affiliation(s)
- Benjamin D Charlton
- School of Biology and Environmental Science, University College Dublin (UCD), Belfield, Dublin 4, Ireland
| | - Jennifer L Keating
- Applied Animal Ecology, San Diego Zoo's Institute for Conservation Research, San Diego, California 92027-7000, USA
| | - Li Rengui
- China Research and Conservation Centre for the Giant Panda, Sichuan, People's Republic of China
| | - Yan Huang
- China Research and Conservation Centre for the Giant Panda, Sichuan, People's Republic of China
| | - Ronald R Swaisgood
- Applied Animal Ecology, San Diego Zoo's Institute for Conservation Research, San Diego, California 92027-7000, USA
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Moreno-Gómez FN, León A, Velásquez NA, Penna M, Delano PH. Individual and sex distinctiveness in bark calls of domestic chinchillas elicited in a distress context. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:1614-1622. [PMID: 26428799 DOI: 10.1121/1.4929750] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Animals obtain information about their social environment by means of communication signals, which provide relevant subtle cues for individual recognition. An important requisite for this process is the existence of larger between- than within-emitter signal variation. Acoustic signals are complex traits susceptible of variation in their spectral and temporal components, implying that signal distinctiveness can result from differences in single or various acoustic components. In this study, domestic chinchillas were induced to vocalize in a distress context to describe the acoustic characteristics of the bark calls, and to determine features that denote the potential value of this vocalization for individual and/or sexual recognition. The results demonstrate that the variation in spectral and temporal components of the bark calls of chinchillas elicited under a distress context is larger between than within individuals, suggesting the potential of these signals for distinctiveness between individual signalers, although the potential of this call type for sex distinctiveness is quite limited. These results combined with previous studies on auditory capabilities of chinchillas contribute to position this rodent as a valuable model species for studying auditory-vocal interactions.
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Affiliation(s)
- Felipe N Moreno-Gómez
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Casilla 70005, Correo 7, Santiago, Chile
| | - Alex León
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Casilla 70005, Correo 7, Santiago, Chile
| | - Nelson A Velásquez
- Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Casilla 617, Talca, Chile
| | - Mario Penna
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Casilla 70005, Correo 7, Santiago, Chile
| | - Paul H Delano
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Casilla 70005, Correo 7, Santiago, Chile
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Intrasexual selection drives sensitivity to pitch, formants and duration in the competitive calls of fallow bucks. BMC Evol Biol 2015; 15:149. [PMID: 26279584 PMCID: PMC4538740 DOI: 10.1186/s12862-015-0429-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/16/2015] [Indexed: 11/10/2022] Open
Abstract
Background Mammal vocal parameters such as fundamental frequency (or pitch; fo) and formant dispersion often provide information about quality traits of the producer (e.g. dominance and body size), suggesting that they are sexually selected. However, little experimental evidence exists demonstrating the importance of these cues in intrasexual competition, particularly fo. Male Fallow deer (bucks) produce an extremely low pitched groan. Bucks have a descended larynx and generate fo well below what is expected for animals of their size. Groan parameters are linked to caller dominance, body size and condition, suggesting that groans are the product of sexual selection. Using a playback experiment, we presented bucks with groans that had been manipulated to alter vocal cues to these male characteristics and compared the response to the same, non-modified (natural) groans. Results We experimentally examined the ability of bucks to utilise putative cues to dominance (fo), body size (formant frequencies) and condition (groan duration), when assessing competitors. We found that bucks treated groans with lowered fo (more dominant), and lowered formant frequencies (larger caller) as more threatening. By contrast, groans with raised formant frequencies (smaller caller), and shorter durations (more fatigued caller) were treated as less threatening. Conclusions Our results indicate that intrasexual selection is driving groans to concurrently convey caller dominance, body size and condition. They represent the first experimental demonstration of the importance of fo in male competition in non-human mammals, and show that bucks have advanced perception abilities that allow them to extract information based on relatively small changes in key parameters. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0429-7) contains supplementary material, which is available to authorized users.
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Ellis W, FitzGibbon S, Pye G, Whipple B, Barth B, Johnston S, Seddon J, Melzer A, Higgins D, Bercovitch F. The Role of Bioacoustic Signals in Koala Sexual Selection: Insights from Seasonal Patterns of Associations Revealed with GPS-Proximity Units. PLoS One 2015; 10:e0130657. [PMID: 26154295 PMCID: PMC4496073 DOI: 10.1371/journal.pone.0130657] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 05/25/2015] [Indexed: 11/18/2022] Open
Abstract
Despite being a charismatic and well-known species, the social system of the koala (Phascolarctos cinereus--the only extant member of the family Phascolarctidae) is poorly known and much of the koala's sociality and mating behaviors remain un-quantified. We evaluated these using proximity logging-GPS enabled tracking collars on wild koalas and discuss their implications for the mating system of this species. The frequency and duration of male-female encounters increased during the breeding season, with male-male encounters quite uncommon, suggesting little direct mating competition. By comparison, female-female interactions were very common across both seasons. Body mass of males was not correlated with their interactions with females during the breeding season, although male size is associated with a variety of acoustic parameters indicating individuality. We hypothesise that vocal advertising reduces the likelihood of male-male encounters in the breeding season while increasing the rate of male-female encounters. We suggest that male mating-season bellows function to reduce physical confrontations with other males allowing them to space themselves apart, while, at the same time, attracting females. We conclude that indirect male-male competition, female mate choice, and possibly female competition, mediate sexual selection in koalas.
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Affiliation(s)
- William Ellis
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia
- * E-mail:
| | - Sean FitzGibbon
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Geoff Pye
- San Diego Zoo Global, P.O. Box 120551, San Diego, California 92112–0551, United States of America
| | - Bill Whipple
- San Diego Zoo Global, P.O. Box 120551, San Diego, California 92112–0551, United States of America
| | - Ben Barth
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Stephen Johnston
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Jenny Seddon
- Faculty of Veterinary Science, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Alistair Melzer
- CQUniversity, Koala Research Centre of Central Queensland, School of Medical and Applied Sciences, Rockhampton, Queensland, 4702, Australia
| | - Damien Higgins
- Faculty of Veterinary Science, The University of Sydney, Sydney, Australia
| | - Fred Bercovitch
- Kyoto University Primate Research Institute & Wildlife Research Center, 41–2 Kanrin, Aichi, Inuyama, 484–8506 Japan
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Gustison ML, Townsend SW. A survey of the context and structure of high- and low-amplitude calls in mammals. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.04.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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