scholarly journals Vocal plasticity in a reptile

2017 ◽  
Vol 284 (1855) ◽  
pp. 20170451 ◽  
Author(s):  
Henrik Brumm ◽  
Sue Anne Zollinger
Keyword(s):  
Signal Detection ◽  
Communication Systems ◽  
Vocal Communication ◽  
Animal Communication ◽  
High Amplitude ◽  
Vocal Plasticity ◽  
Lombard Effect ◽  
Gekko Gecko ◽  
High Degree ◽  
Signalling Systems

Sophisticated vocal communication systems of birds and mammals, including human speech, are characterized by a high degree of plasticity in which signals are individually adjusted in response to changes in the environment. Here, we present, to our knowledge, the first evidence for vocal plasticity in a reptile. Like birds and mammals, tokay geckos ( Gekko gecko ) increased the duration of brief call notes in the presence of broadcast noise compared to quiet conditions, a behaviour that facilitates signal detection by receivers. By contrast, they did not adjust the amplitudes of their call syllables in noise (the Lombard effect), which is in line with the hypothesis that the Lombard effect has evolved independently in birds and mammals. However, the geckos used a different strategy to increase signal-to-noise ratios: instead of increasing the amplitude of a given call type when exposed to noise, the subjects produced more high-amplitude syllable types from their repertoire. Our findings demonstrate that reptile vocalizations are much more flexible than previously thought, including elaborate vocal plasticity that is also important for the complex signalling systems of birds and mammals. We suggest that signal detection constraints are one of the major forces driving the evolution of animal communication systems across different taxa.

scholarly journals The syntax–semantics interface in animal vocal communication

2019 ◽  
Vol 375 (1789) ◽  
pp. 20180405 ◽  
Author(s):  
Toshitaka N. Suzuki ◽  
David Wheatcroft ◽  
Michael Griesser
Keyword(s):  
Cognitive Processes ◽  
Communication Systems ◽  
Vocal Communication ◽  
Animal Communication ◽  
Experimental Studies ◽  
Human Language ◽  
Cognitive Mechanisms ◽  
Evolution Of Language ◽  
Language Research ◽  
Phenomenological Studies

Syntax (rules for combining words or elements) and semantics (meaning of expressions) are two pivotal features of human language, and interaction between them allows us to generate a limitless number of meaningful expressions. While both features were traditionally thought to be unique to human language, research over the past four decades has revealed intriguing parallels in animal communication systems. Many birds and mammals produce specific calls with distinct meanings, and some species combine multiple meaningful calls into syntactically ordered sequences. However, it remains largely unclear whether, like phrases or sentences in human language, the meaning of these call sequences depends on both the meanings of the component calls and their syntactic order. Here, leveraging recently demonstrated examples of meaningful call combinations, we introduce a framework for exploring the interaction between syntax and semantics (i.e. the syntax-semantic interface) in animal vocal sequences. We outline methods to test the cognitive mechanisms underlying the production and perception of animal vocal sequences and suggest potential evolutionary scenarios for syntactic communication. We hope that this review will stimulate phenomenological studies on animal vocal sequences as well as experimental studies on the cognitive processes, which promise to provide further insights into the evolution of language. This article is part of the theme issue ‘What can animal communication teach us about human language?’

scholarly journals Lungs contribute to solving the frog’s cocktail party problem by enhancing the spectral contrast of conspecific vocal signals

2020 ◽  
Author(s):  
N. Lee ◽  
J. Christensen-Dalsgaard ◽  
L. A. White ◽  
K. M. Schrode ◽  
M. A. Bee
Keyword(s):  
Communication Systems ◽  
Vocal Communication ◽  
Animal Communication ◽  
Control Function ◽  
Signal To Noise Ratio ◽  
Calling Behavior ◽  
Cocktail Party ◽  
Science Data ◽  
Cocktail Party Problem ◽  
Spectral Contrast

AbstractNoise impairs signal perception and is a major source of selection on animal communication. Identifying adaptations that enable receivers to cope with noise is critical to discovering how animal sensory and communication systems evolve. We integrated biophysical and bioacoustic measurements with physiological modeling to demonstrate that the lungs of frogs serve a heretofore unknown noise-control function in vocal communication. Lung resonance enhances the signal-to-noise ratio for communication by selectively reducing the tympanum’s sensitivity at critical frequencies where the tuning of two inner ear organs overlaps. Social network analysis of citizen-science data on frog calling behavior indicates the calls of other frog species in multi-species choruses are a prominent source of environmental noise attenuated by the lungs. These data reveal that an ancient adaptation for detecting sound via the lungs has been evolutionarily co-opted to create spectral contrast enhancement that contributes to solving a multi-species cocktail party problem.

scholarly journals Alarm calls evoke a visual search image of a predator in birds

2018 ◽  
Vol 115 (7) ◽  
pp. 1541-1545 ◽  
Author(s):  
Toshitaka N. Suzuki
Keyword(s):  
Visual Search ◽  
Communication Systems ◽  
Vocal Communication ◽  
Animal Communication ◽  
Visual Image ◽  
Alarm Calls ◽  
Mental Images ◽  
Search Image ◽  
In The Wild ◽  
Parus Minor

One of the core features of human speech is that words cause listeners to retrieve corresponding visual mental images. However, whether vocalizations similarly evoke mental images in animal communication systems is surprisingly unknown. Japanese tits (Parus minor) produce specific alarm calls when and only when encountering a predatory snake. Here, I show that simply hearing these calls causes tits to become more visually perceptive to objects resembling snakes. During playback of snake-specific alarm calls, tits approach a wooden stick being moved in a snake-like fashion. However, tits do not respond to the same stick when hearing other call types or if the stick’s movement is dissimilar to that of a snake. Thus, before detecting a real snake, tits retrieve its visual image from snake-specific alarm calls and use this to search out snakes. This study provides evidence for a call-evoked visual search image in a nonhuman animal, offering a paradigm to explore the cognitive basis for animal vocal communication in the wild.

Some general comments on the evolution and design of animal communication systems

1993 ◽  
Vol 340 (1292) ◽  
pp. 215-225 ◽  
Keyword(s):  
Communication Systems ◽  
Animal Communication ◽  
Signal Design ◽  
Geological Time ◽  
Minimum Requirement ◽  
Fitness Consequences ◽  
Evolution Of Signals ◽  
Efficiency And Reliability ◽  
Signalling Systems

Animal communication systems have evolved so that individuals can make decisions based upon the behaviour, physiology or morphology of others. Receiving mechanism s probably evolve to increase the efficiency and reliability of information reception whereas signals probably evolve to increase the efficiency of communication and reliability of manipulation of the receiving individual to the benefit of the emitter. The minimum requirement for clear reception suggests that any study of the evolution and design of communication systems must consider the factors that affect the quality of the received and processed signal. Critical information is needed about how the signal is generated and emitted, how it fares during transmission through air, water or substrate, how it is received and processed by the receiver’s sensory and cognitive systems, and the factors which affect the fitness consequences of alternative ways of reacting to the information contained in the signal. These should allow predictions about the kinds and forms of signals used by animals signalling under known conditions. Phylogenetic history, and the geological time a clade spends in different signalling environments, will also affect signal evolution, and hence the success of predictions about signal design. W e need to use methods of m any different biological fields to understand the design and evolution of signals and signalling systems.

scholarly journals On the evolution of noise-dependent vocal plasticity in birds

2012 ◽  
Vol 8 (6) ◽  
pp. 913-916 ◽  
Author(s):  
Sophie Schuster ◽  
Sue Anne Zollinger ◽  
John A. Lesku ◽  
Henrik Brumm
Keyword(s):  
Background Noise ◽  
Animal Communication ◽  
Signal Transmission ◽  
Bird Species ◽  
Vocal Plasticity ◽  
Lombard Effect ◽  
Signal Plasticity ◽  
Communication Signal ◽  
History Of ◽  
Bird Group

Signal plasticity is considered an important step in the evolution of animal communication. In acoustic communication, signal transmission is often constrained by background noise. One adaptation to evade acoustic signal masking is the Lombard effect, in which an animal increases its vocal amplitude in response to an increase in background noise. This form of signal plasticity has been found in mammals, including humans, and some birds, but not frogs. However, the evolution of the Lombard effect is still unclear. Here we demonstrate for the first time the Lombard effect in a phylogentically basal bird species, the tinamou Eudromia elegans . By doing so, we take a step towards reconstructing the evolutionary history of noise-dependent vocal plasticity in birds. Similar to humans, the tinamous also raised their vocal pitch in noise, irrespective of any release from signal masking. The occurrence of the Lombard effect in a basal bird group suggests that this form of vocal plasticity was present in the common ancestor of all living birds and thus evolved at least as early as 119 Ma.

scholarly journals Individual Differences in the Vocal Communication of Malayan Tapirs (Tapirus indicus) Considering Familiarity and Relatedness

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1026
Author(s):  
Robin Walb ◽  
Lorenzo von Fersen ◽  
Theo Meijer ◽  
Kurt Hammerschmidt
Keyword(s):  
Individual Differences ◽  
Vocal Communication ◽  
Social Role ◽  
Animal Communication ◽  
Solitary Living ◽  
Low Visibility ◽  
Living Species ◽  
The Individual ◽  
Tapirus Indicus

Studies in animal communication have shown that many species have individual distinct calls. These individual distinct vocalizations can play an important role in animal communication because they can carry important information about the age, sex, personality, or social role of the signaler. Although we have good knowledge regarding the importance of individual vocalization in social living mammals, it is less clear to what extent solitary living mammals possess individual distinct vocalizations. We recorded and analyzed the vocalizations of 14 captive adult Malayan tapirs (Tapirus indicus) (six females and eight males) to answer this question. We investigated whether familiarity or relatedness had an influence on call similarity. In addition to sex-related differences, we found significant differences between all subjects, comparable to the individual differences found in highly social living species. Surprisingly, kinship appeared to have no influence on call similarity, whereas familiar subjects exhibited significantly higher similarity in their harmonic calls compared to unfamiliar or related subjects. The results support the view that solitary animals could have individual distinct calls, like highly social animals. Therefore, it is likely that non-social factors, like low visibility, could have an influence on call individuality. The increasing knowledge of their behavior will help to protect this endangered species.

scholarly journals Discrimination of natural acoustic variation in vocal signals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam R. Fishbein ◽  
Nora H. Prior ◽  
Jane A. Brown ◽  
Gregory F. Ball ◽  
Robert J. Dooling
Keyword(s):  
Zebra Finch ◽  
Acoustic Communication ◽  
Communication Systems ◽  
Vocal Communication ◽  
Relevant Information ◽  
Speech Sounds ◽  
Vocal Signals ◽  
Acoustic Variation ◽  
Zebra Finch Song ◽  
Human Listener

AbstractStudies of acoustic communication often focus on the categories and units of vocalizations, but subtle variation also occurs in how these signals are uttered. In human speech, it is not only phonemes and words that carry information but also the timbre, intonation, and stress of how speech sounds are delivered (often referred to as “paralinguistic content”). In non-human animals, variation across utterances of vocal signals also carries behaviorally relevant information across taxa. However, the discriminability of these cues has been rarely tested in a psychophysical paradigm. Here, we focus on acoustic communication in the zebra finch (Taeniopygia guttata), a songbird species in which the male produces a single stereotyped motif repeatedly in song bouts. These motif renditions, like the song repetitions of many birds, sound very similar to the casual human listener. In this study, we show that zebra finches can easily discriminate between the renditions, even at the level of single song syllables, much as humans can discriminate renditions of speech sounds. These results support the notion that sensitivity to fine acoustic details may be a primary channel of information in zebra finch song, as well as a shared, foundational property of vocal communication systems across species.

Spesialisasie binne die bedryfsielkunde

1985 ◽  
Author(s):  
I. Van W Raubenheimer
Keyword(s):  
Signal Detection ◽  
Personnel Selection ◽  
Signal Detection Theory ◽  
Work Performance ◽  
Job Analysis ◽  
Vigilance Task ◽  
Detection Theory ◽  
Industrial Psychology ◽  
High Degree ◽  
Selection Instrument

Personnel selection is carried out by the personnel psychologist/ personnel practitioner responsible for the supply of human resources. Selection models and -technology have been refined to a high degree and are scientifically acceptable. With regards to the identification of critical attributes on which selection is based, it is suggested in the study that job analysis be performed in the light of insights and knowledge gained in other branches of Industrial Psychology. Specifically the study shows that high and low work performance operators (N=25) involved in a a vigilance task, can be differentiated on the basis of signal detection theory. The results of the study (t-test for differences between means) suggest that selection in the situation investigated, should be based on the ability to discriminate between signals and not on the response bias of operators. The results also indicate that the task, based on signal detection theory, which was designed for the study, could be used as a selection instrument. OpsommingPersoneelkeuring setel gewoonlik by die personeelsiel-kundige/ personeelpraktisyn wat vir die voorsiening van menslike hulpbronne verantwoordelik is. Keuringsmodelle en –tegnologie is in 'n hoë mate verfyn en vakkundig verantwoordbaar. Ten opsigte van die identifisering van kritieke attribute op grond waarvan keuring plaasvind, word daar in die studie betoog dat daar aanvullend tot werkontleding ook op die kennis en insig wat in ander vertakkinge van die Bedryfsielkunde gegenereer word, gesteun moet word. In besonder word daar in die studie (N=25) aangetoon dat 'n onderskeid tussen hoë en lae werkprestasie-operateurs, gemoeid met 'n waaksaamheidstaak, op grond van seinbespeuringsteorie gemaak kan word. Uit die resultate van die studie (t-toets vir gemiddeldes) blyk dit dat keuring in die betrokke situasie op diskriminasievermoë en nie op responsievooroordeel nie, afgestem behoort te word en dat die taak, voortspruitend uit seinbespeuringsteorie wat vir die studie ontwerp was, as keuringsinstrument gebruik kan word.

scholarly journals Acoustic cues to individuality in wild male adult African savannah elephants (Loxodonta africana)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10736
Author(s):  
Kaja Wierucka ◽  
Michelle D. Henley ◽  
Hannah S. Mumby
Keyword(s):  
Communication Systems ◽  
Animal Communication ◽  
Current Knowledge ◽  
Individual Recognition ◽  
Social Bonds ◽  
Loxodonta Africana ◽  
Mature Male ◽  
Acoustic Cues ◽  
Acoustic Parameters ◽  
Male Adult

The ability to recognize conspecifics plays a pivotal role in animal communication systems. It is especially important for establishing and maintaining associations among individuals of social, long-lived species, such as elephants. While research on female elephant sociality and communication is prevalent, until recently male elephants have been considered far less social than females. This resulted in a dearth of information about their communication and recognition abilities. With new knowledge about the intricacies of the male elephant social structure come questions regarding the communication basis that allows for social bonds to be established and maintained. By analyzing the acoustic parameters of social rumbles recorded over 1.5 years from wild, mature, male African savanna elephants (Loxodonta africana) we expand current knowledge about the information encoded within these vocalizations and their potential to facilitate individual recognition. We showed that social rumbles are individually distinct and stable over time and therefore provide an acoustic basis for individual recognition. Furthermore, our results revealed that different frequency parameters contribute to individual differences of these vocalizations.

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