scholarly journals A cross-species framework to identify vocal learning abilities in mammals

2021 ◽  
Vol 377 (1841) ◽  
Author(s):  
Andrea Ravignani ◽  
Maxime Garcia
Keyword(s):  
Sexual Selection ◽  
Social Impact ◽  
Regression Line ◽  
Vocal Learning ◽  
Intermediate Step ◽  
Learning Abilities ◽  
Correlational Approach ◽  
Potential Link ◽  
Multiple Species ◽  
Voice Modulation

Vocal production learning (VPL) is the experience-driven ability to produce novel vocal signals through imitation or modification of existing vocalizations. A parallel strand of research investigates acoustic allometry, namely how information about body size is conveyed by acoustic signals. Recently, we proposed that deviation from acoustic allometry principles as a result of sexual selection may have been an intermediate step towards the evolution of vocal learning abilities in mammals. Adopting a more hypothesis-neutral stance, here we perform phylogenetic regressions and other analyses further testing a potential link between VPL and being an allometric outlier. We find that multiple species belonging to VPL clades deviate from allometric scaling but in the opposite direction to that expected from size exaggeration mechanisms. In other words, our correlational approach finds an association between VPL and being an allometric outlier. However, the direction of this association, contra our original hypothesis, may indicate that VPL did not necessarily emerge via sexual selection for size exaggeration: VPL clades show higher vocalization frequencies than expected. In addition, our approach allows us to identify species with potential for VPL abilities: we hypothesize that those outliers from acoustic allometry lying above the regression line may be VPL species. Our results may help better understand the cross-species diversity, variability and aetiology of VPL, which among other things is a key underpinning of speech in our species. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part II)’.

scholarly journals Vocal plasticity in harbour seal pups

2021 ◽  
Vol 376 (1840) ◽  
Author(s):  
Laura Torres Borda ◽  
Yannick Jadoul ◽  
Heikki Rasilo ◽  
Anna Salazar Casals ◽  
Andrea Ravignani
Keyword(s):  
Social Impact ◽  
Vocal Learning ◽  
Experimental Manipulation ◽  
Low Noise ◽  
Noise Condition ◽  
Learning Abilities ◽  
Vocal Plasticity ◽  
Lombard Effect ◽  
Exposed Individual ◽  
Filtered Noise

Vocal plasticity can occur in response to environmental and biological factors, including conspecifics' vocalizations and noise. Pinnipeds are one of the few mammalian groups capable of vocal learning, and are therefore relevant to understanding the evolution of vocal plasticity in humans and other animals. Here, we investigate the vocal plasticity of harbour seals ( Phoca vitulina ), a species with vocal learning abilities observed in adulthood but not puppyhood. To evaluate early mammalian vocal development, we tested 1–3 weeks-old seal pups. We tailored noise playbacks to this species and age to induce seal pups to shift their fundamental frequency ( f 0 ), rather than adapt call amplitude or temporal characteristics. We exposed individual pups to low- and high-intensity bandpass-filtered noise, which spanned—and masked—their typical range of f 0 ; simultaneously, we recorded pups' spontaneous calls. Unlike most mammals, pups modified their vocalizations by lowering their f 0 in response to increased noise. This modulation was precise and adapted to the particular experimental manipulation of the noise condition. In addition, higher levels of noise induced less dispersion around the mean f 0 , suggesting that pups may have actively focused their phonatory efforts to target lower frequencies. Noise did not seem to affect call amplitude. However, one seal showed two characteristics of the Lombard effect known for human speech in noise: significant increase in call amplitude and flattening of spectral tilt. Our relatively low noise levels may have favoured f 0 modulation while inhibiting amplitude adjustments. This lowering of f 0 is unusual, as most animals commonly display no such f 0 shift. Our data represent a relatively rare case in mammalian neonates, and have implications for the evolution of vocal plasticity and vocal learning across species, including humans. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part I)’.

scholarly journals Chromosomal Evolution in Psittaciformes. Revisited

2016 ◽  
Vol 8 (4) ◽  
pp. 34
Author(s):  
A. Villa Rus ◽  
J. C. Cigudosa ◽  
J. L. Carrasco Juan ◽  
A. Otero Gomez ◽  
T. Acosta Almeida ◽  
...  
Keyword(s):  
Chromosome Rearrangement ◽  
Vocal Learning ◽  
Chromosomal Evolution ◽  
Learning Abilities ◽  
Biogeographic History ◽  
Human Attention ◽  
Evolutionary Radiation ◽  
History Of ◽  
Parrot Species ◽  
Evolutionary Comparisons

<p class="1Body">With colourful plumage, charismatic character and vocal learning abilities, parrots are one of the most striking and recognizable bird groups. Their attractiveness has drawn human attention for centuries, and members of the Psittaciformes order were, also, among the first avian species to be subject to cytogenetic studies which have contributed to understand their taxonomic and evolutionary relationships.</p><p class="1Body">We present here the karyological results collected by the study of thirteen parrot species new to karyology. These results are additionally supported by G banded preparations obtained in five species.</p><p class="1Body">The order Psittaciformes is an interesting example of a, typically, non migratory avian lineage with Gondwanaland origin, whose evolutionary radiation has been shaped by the Cenozoic geographic and climatic events that affected the land masses derived from the Gondwanaland continental split.</p><p class="1Body">We discuss the results of our studies, in conjunction with the previously compiled Psittaciformes cytogenetic data to delineate a picture of the chromosomal evolution of the order, concurrently with the biogeographic history of the lands in the southern Hemisphere.</p><p class="1Body">Considering the available data on parrot cytogenetics, a "standard parrot karyotype pattern" is proposed for evolutionary comparisons.</p><p class="1Body">Several biogeographic, and phylogenetically related "karyogram patterns" are also identified, and mechanisms of chromosome rearrangement that associate this patterns among them, and with the standard parrot karyotype pattern are proposed. These schemes on parrot chromosomal variation are discussed in relation to the general avian chromosome evolutionary theses proposed by cytogenetic and molecular genomic researchers.</p>

scholarly journals Vocal modulation in human mating and competition

2021 ◽  
Vol 376 (1840) ◽  
Author(s):  
Susan M. Hughes ◽  
David A. Puts
Keyword(s):  
Social Interactions ◽  
Social Impact ◽  
Social Contexts ◽  
Future Studies ◽  
Human Voice ◽  
Vocal Behaviour ◽  
Courtship Success ◽  
Human Mating ◽  
Voice Modulation ◽  
Romantic Interest

The human voice is dynamic, and people modulate their voices across different social interactions. This article presents a review of the literature examining natural vocal modulation in social contexts relevant to human mating and intrasexual competition. Altering acoustic parameters during speech, particularly pitch, in response to mating and competitive contexts can influence social perception and indicate certain qualities of the speaker. For instance, a lowered voice pitch is often used to exert dominance, display status and compete with rivals. Changes in voice can also serve as a salient medium for signalling a person's attraction to another, and there is evidence to support the notion that attraction and/or romantic interest can be distinguished through vocal tones alone. Individuals can purposely change their vocal behaviour in attempt to sound more attractive and to facilitate courtship success. Several findings also point to the effectiveness of vocal change as a mechanism for communicating relationship status. As future studies continue to explore vocal modulation in the arena of human mating, we will gain a better understanding of how and why vocal modulation varies across social contexts and its impact on receiver psychology. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part I)’.

scholarly journals Operant control and call usage learning in African elephants

2021 ◽  
Vol 376 (1836) ◽  
pp. 20200254
Author(s):  
Angela S. Stoeger ◽  
Anton Baotic
Keyword(s):  
Low Frequency ◽  
Vocal Learning ◽  
Social Contexts ◽  
Cognitive Mechanisms ◽  
African Elephants ◽  
Verbal Cues ◽  
Learning Abilities ◽  
Vocal Plasticity ◽  
Call Usage ◽  
Usage Learning

Elephants exhibit remarkable vocal plasticity, and case studies reveal that individuals of African savannah ( Loxodonta africana ) and Asian ( Elephas maximus ) elephants are capable of vocal production learning. Surprisingly, however, little is known about contextual learning (usage and comprehension learning) in elephant communication. Usage learning can be demonstrated by training animals to vocalize in an arbitrary (cue-triggered) context. Here we show that adult African savannah elephants ( n = 13) can vocalize in response to verbal cues, reliably producing social call types such as the low-frequency rumble, trumpets and snorts as well as atypical sounds using various mechanisms, thus displaying compound vocal control. We further show that rumbles emitted upon trainer cues differ significantly in structure from rumbles triggered by social contexts of the same individuals ( n = 6). Every form of social learning increases the complexity of a communication system. In elephants, we only poorly understand their vocal learning abilities and the underlying cognitive mechanisms. Among other research, this calls for controlled learning experiments in which the prerequisite is operant/volitional control of vocalizations. This article is part of the theme issue ‘Vocal learning in animals and humans’.

scholarly journals Acoustic allometry and vocal learning in mammals

2020 ◽  
Vol 16 (7) ◽  
pp. 20200081 ◽  
Author(s):  
Maxime Garcia ◽  
Andrea Ravignani
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Empirical Research ◽  
Evolutionary Biology ◽  
Vocal Learning ◽  
Evolutionary Origins ◽  
Vocal Signals ◽  
Animal Vocalizations ◽  
Selection For ◽  
Preliminary Support

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.

scholarly journals Vocal plasticity in harbour seal pups

2021 ◽  
Author(s):  
Laura Torres Borda ◽  
Yannick Jadoul ◽  
Heikki Rasilo ◽  
Anna Salazar Casals ◽  
Andrea Ravignani
Keyword(s):  
Vocal Learning ◽  
Low Noise ◽  
Noise Condition ◽  
Learning Abilities ◽  
Noise Masking ◽  
Vocal Plasticity ◽  
Lombard Effect ◽  
Harbour Seals ◽  
Exposed Individual ◽  
Filtered Noise

ABSTRACTVocal plasticity can occur in response to environmental and biological factors, including conspecifics’ vocalisations and noise. Pinnipeds are one of the few mammalian groups capable of vocal learning, and are therefore relevant to understanding the evolution of vocal plasticity in humans and other animals. Here, we investigate the vocal plasticity of harbour seals (Phoca vitulina), a species with vocal learning abilities attested in adulthood but not puppyhood. To zoom into early mammalian vocal development, we tested 1-3 weeks old seal pups. We tailored noise playbacks to this species and age to induce seal pups to shift their fundamental frequency (F0), rather than adapt call amplitude or temporal characteristics. We exposed individual pups to bandpass-filtered noise, which purposely spanned – and masked – their typical range of F0s, and simultaneously recorded pups’ spontaneous calls. Seals were able to modify their vocalisations quite unlike most mammals: They lowered their F0 in response to increased noise. This modulation was punctual and adapted to the particular noise condition. In addition, higher noise induced less dispersion around the mean F0, suggesting that pups may have been actively focusing their phonatory efforts to target lower frequencies. Noise masking did not seem to affect call amplitude. However, one seal showed two characteristics of the Lombard effect known for human speech in noise: significant increase in call amplitude and flattening of spectral tilt. Our relatively low noise levels may have favoured F0 shifts while inhibiting amplitude adjustments. This lowering of F0 is quite unusual, as other animals commonly display no F0 shift independently of noise amplitude. Our data represents a relatively rare case in mammalian neonates, and may have implications for the evolution of vocal plasticity across species, including humans.

scholarly journals Vocal size exaggeration may have contributed to the origins of vocalic complexity

2021 ◽  
Vol 377 (1841) ◽  
Author(s):  
Katarzyna Pisanski ◽  
Andrey Anikin ◽  
David Reby
Keyword(s):  
Body Size ◽  
Social Impact ◽  
Vocal Communication ◽  
Vocal Tract ◽  
Similar Extent ◽  
Theme Issue ◽  
Articulatory Movements ◽  
Animal Vocalizations ◽  
Second Formant ◽  
Voice Modulation

Vocal tract elongation, which uniformly lowers vocal tract resonances (formant frequencies) in animal vocalizations, has evolved independently in several vertebrate groups as a means for vocalizers to exaggerate their apparent body size. Here, we propose that smaller speech-like articulatory movements that alter only individual formants can serve a similar yet less energetically costly size-exaggerating function. To test this, we examine whether uneven formant spacing alters the perceived body size of vocalizers in synthesized human vowels and animal calls. Among six synthetic vowel patterns, those characterized by the lowest first and second formant (the vowel /u/ as in ‘boot’) are consistently perceived as produced by the largest vocalizer. Crucially, lowering only one or two formants in animal-like calls also conveys the impression of a larger body size, and lowering the second and third formants simultaneously exaggerates perceived size to a similar extent as rescaling all formants. As the articulatory movements required for individual formant shifts are minor compared to full vocal tract extension, they represent a rapid and energetically efficient mechanism for acoustic size exaggeration. We suggest that, by favouring the evolution of uneven formant patterns in vocal communication, this deceptive strategy may have contributed to the origins of the phonemic diversification required for articulated speech. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part II)’.

scholarly journals Rapid tissue-specific screening ofWolbachia,CardiniumandRickettsiain Flies (Diptera: Sepsidae; Drosophilidae)

2021 ◽  
Author(s):  
Cher Wei Yuan ◽  
Ding Huicong ◽  
Nalini Puniamoorthy
Keyword(s):  
Sexual Selection ◽  
Reproductive Tract ◽  
Cytoplasmic Incompatibility ◽  
Horizontal Transmission ◽  
Dual Infection ◽  
Single Infection ◽  
Tissue Specific ◽  
Screening Protocol ◽  
Triple Infection ◽  
Multiple Species

AbstractMaternally transmitted endosymbionts can negatively influence the reproduction of their arthropod hosts (e.g. male-killing, cytoplasmic incompatibility). However, such infections are rarely assessed in insect models such as Sepsidae or Drosophilidae that are routinely used in sexual selection studies. To detect infection and bacterial localisation in the host, we developed and optimised a tissue-specific multiplex screening protocol forWolbachia,CardiniumandRickettsiathat can be completed in a day. The robustness of the protocol was tested with the screening of multiple species and populations of flies commonly used in reproductive studies (N=147 flies; n=426 tissues). With triplex PCRs and more effective duplex PCRs, we detected both single and co-infections in most individuals from both families (Drosophilidae | Sepsidae; Single infection: 51.4% | 62.7%; Dual infection: 29.2% | 9.3%; Triple infection: 4.2% | 0%). Surprisingly, we documented the presence of all three reproductive bacteria in 32 wild-caught drosophilids from Singapore. Also, we note that most sepsid populations (19 out of 22) tested positive forCardinium. We found that theRickettsiainfection was overall low, but it was predominantly detected in the gastrointestinal tract instead of the reproductive tract, suggesting a potential horizontal transmission. Finally, we found that amplicon sequences of equivalent sizes between the three tissues from the same individuals share at least 98.8% identity, which suggests that the same endosymbiont strain inhabits within the whole arthropod. Overall, we believe this protocol is effective in detecting co-infections and understanding the transmission of various reproductive endosymbionts. It can also be used to assess endosymbiont infections in other insects.

scholarly journals Across demographics and recent history, most parents sing to their infants and toddlers daily

2021 ◽  
Vol 376 (1840) ◽  
Author(s):  
Ran Yan ◽  
Ghazal Jessani ◽  
Elizabeth S. Spelke ◽  
Peter de Villiers ◽  
Jill de Villiers ◽  
...  
Keyword(s):  
Social Impact ◽  
Daily Basis ◽  
Human Society ◽  
Theme Issue ◽  
Technological Environment ◽  
Older Parents ◽  
The Past ◽  
Recorded Music ◽  
The Everyday ◽  
Voice Modulation

Music is universally prevalent in human society and is a salient component of the lives of young families. Here, we studied the frequency of singing and playing recorded music in the home using surveys of parents with infants ( N = 945). We found that most parents sing to their infant on a daily basis and the frequency of infant-directed singing is unrelated to parents’ income or ethnicity. Two reliable individual differences emerged, however: (i) fathers sing less than mothers and (ii) as infants grow older, parents sing less. Moreover, the latter effect of child age was specific to singing and was not reflected in reports of the frequency of playing recorded music. Last, we meta-analysed reports of the frequency of infant-directed singing and found little change in its frequency over the past 30 years, despite substantial changes in the technological environment in the home. These findings, consistent with theories of the psychological functions of music, in general, and infant-directed singing, in particular, demonstrate the everyday nature of music in infancy. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part I)’.

Sign in / Sign up

Export Citation Format

Share Document