Variation in the vocal behavior of nonhuman vertebrates includes graded transitions and more dramatic changes.Wapiti males produce a reproductive bugle that has a fundamental frequency that surpasses 2,000 Hz with evi...Variation in the vocal behavior of nonhuman vertebrates includes graded transitions and more dramatic changes.Wapiti males produce a reproductive bugle that has a fundamental frequency that surpasses 2,000 Hz with evidence of biphonation and other nonlinear phenomena.Here,we analyze the acoustic structure of captive wapiti vocalizations to compare the male bugle with 3 categories of distress vocalizations:neonate distress(capture)calls,calf isolation calls,and adult female isolation calls.These 4 high-arousal call categories serve a common general function in recruiting conspecifics but occur in different behavioral contexts(capture,isolation,reproduction).Our goal was to distinguish characteristics that vary in graded steps that may correspond to an animal’s age or size from characteristics that are unique to the bugle.Characteristics of the high and loud fundamental(G0)varied in an age/size-graded manner with a decrease in minimum G0,an increase in the maximum and range of G0,with no evidence of sex differences.The nonlinear phenomena of deterministic chaos,biphonation,and frequency jumps were present in all 4 call categories and became more common from the distress vocalizations of neonates to calves to adult females to the male bugle.Two temporal characteristics sharply distinguished the bugle from the 3 categories of distress vocalizations:these included a prolonged call duration and a maximum G0 that occurred much later in the call for the bugle than for distress vocalizations.Our results suggest that distress vocalizations of different age groups and the reproductive bugle of wapiti share a high G0,with age/size-graded changes in G0 and nonlinear phenomena,but differ sharply in temporal characteristics.展开更多
With the development of new media technology and the popularity of the TikTok platform in China,a large number of popular vocal music teachers have flocked to online platforms for teaching.Online vocal music education...With the development of new media technology and the popularity of the TikTok platform in China,a large number of popular vocal music teachers have flocked to online platforms for teaching.Online vocal music education in China is undergoing a transformation and facing challenges.This study adopts an exploratory research approach,interviewing students learning pop vocal music,and observing popular pop teachers on TikTok.The advantages,disadvantages,techniques,and methods of domestic TikTok pop vocal music teaching were investigated and studied,and a series of experiences and suggestions for optimizing TikTok teaching were put forward.The results of this study are helpful for understanding the advantages and disadvantages of TikTok pop vocal music teaching and grasping the correct development direction.These guidance and suggestions can stimulate teachers’creativity and improve their vocal music teaching level.展开更多
Amyotrophic lateral sclerosis(ALS)is a neuromuscular condition resulting from the progressive degeneration of motor neurons in the cortex,brainstem,and spinal cord.While the typical clinical phenotype of ALS involves ...Amyotrophic lateral sclerosis(ALS)is a neuromuscular condition resulting from the progressive degeneration of motor neurons in the cortex,brainstem,and spinal cord.While the typical clinical phenotype of ALS involves both upper and lower motor neurons,human and animal studies over the years have highlighted the potential spread to other motor and non-motor regions,expanding the phenotype of ALS.Although superoxide dismutase 1(SOD1)mutations represent a minority of ALS cases,the SOD1 gene remains a milestone in ALS research as it represents the first genetic target for personalized therapies.Despite numerous single case reports or case series exhibiting extramotor symptoms in patients with ALS mutations in SOD1(SOD1-ALS),no studies have comprehensively explored the full spectrum of extramotor neurological manifestations in this subpopulation.In this narrative review,we analyze and discuss the available literature on extrapyramidal and non-motor features during SOD1-ALS.The multifaceted expression of SOD1 could deepen our understanding of the pathogenic mechanisms,pointing towards a multidisciplinary approach for affected patients in light of new therapeutic strategies for SOD1-ALS.展开更多
Vocal individuality is essential for social discrimination but has been poorly studied in animals that produce communal signals(duets or choruses).Song overlapping and temporal coordination make the assessment of indi...Vocal individuality is essential for social discrimination but has been poorly studied in animals that produce communal signals(duets or choruses).Song overlapping and temporal coordination make the assessment of individuality in communal signals more complex.In addition,selection may favor the accurate identifcation of pairs over individuals by receivers in year-round territorial species with duetting and long-term pair bonding.Here,we studied pair and individual vocal signatures in the polyphonal duets of rufous horneros Furnarius rufus,a Neotropical bird known for its long-term pair bonds.Hornero partners engage in duets to deter territorial intruders and protect their partnership year-round and can discern duets from neighbors versus strangers.Using a dataset of 471 duets from 43 pairs in 2 populations,we measured fne-scale acoustic features across different duet levels(e.g.,complete duets to non-overlapping syllable parts)and analysis levels(pair or individual).Permuted linear discriminant function analyses classifed pairs and individuals more accurately than expected by chance(means:45%and 47%vs.4 and 2%).Pair identity explained more variance in the multivariate acoustic features of duets than individual or population identities.The initial frequency of the duet showed strong potential for encoding pair identity.The acoustic traits contributing most to individual vocal signatures varied between sexes,which might facilitate the simultaneous assessment of duetters’identities by receivers.Our study indicates that vocal individuality may exist even in species with intricate and innate communal signals and elucidates the mechanisms employed by horneros in their social discrimination ability.展开更多
Passerine mimics often imitate various vocalizations from other bird species and incorporate these sounds into their song repertoires.While a few anecdotes reported that wild songbirds imitated human-associated sounds...Passerine mimics often imitate various vocalizations from other bird species and incorporate these sounds into their song repertoires.While a few anecdotes reported that wild songbirds imitated human-associated sounds,besides captive parrots and songbirds,systemic and quantitative studies on human-made sound mimicry in wild birds remain scarce.In this study,we investigated the mimetic accuracy and consistency of electric moped sounds imitated by an urban bird,the Chinese Blackbird(Turdus mandarinus).We found that:(1)Only one type of electric moped sound was imitated,i.e.,13 of 26 males mimicked the first part of the antitheft alarm,a phrase containing a series of identical notes.(2)The mimicry produced by male Chinese Blackbirds had fewer notes and lower consistency within phrases compared to the model alarms.(3)The mimicry of male Chinese Blackbirds was imperfect,i.e.,most of the acoustic parameters differed from the model alarms.Additionally,mimetic notes were lower in frequency than the models.Mimetic notes from two areas were also different in acoustic structures,suggesting Chinese Blackbirds might learn mimicry mainly from conspecific neighbors within each area respectively rather than electric mopeds,namely the secondary mimicry.Imperfect mimicry of human-made sounds could result from cost and physical constraints,associated with high consistency,frequency,and repetitions.Consequently,Chinese Blackbirds copied a simplified version of electric moped alarms.We recommend further attention to mimic species inhabiting urban ecosystems to better understand vocal mimicry's adaptation to ongoing urbanization.展开更多
Avian vocal communication represents one of the most intricate forms of animal language,playing a critical role in behavioral interactions.Both peripheral and central auditory-vocal pathways are essential for precisel...Avian vocal communication represents one of the most intricate forms of animal language,playing a critical role in behavioral interactions.Both peripheral and central auditory-vocal pathways are essential for precisely integrating acoustic signals,ensuring effective communication.Like humans,songbirds exhibit vocal learning behaviors supported by complex neural mechanisms.However,unlike most mammals,songbirds possess the remarkable ability to regenerate damaged auditory cells.These capabilities offer unique opportunities to explore how birds adjust their vocal behavior and auditory processing in response to dynamic environmental conditions.Recent studies have advanced our understanding of the plasticity of avian vocal communication system,yet the vocal diversity and neurophysiological mechanisms underlying vocalization and hearing have often been examined independently.A comprehensive overview of how these systems interact and adapt in birds remains lacking.To address this gap,this review synthesizes the peripheral and central features of avian vocalization and hearing,while also exploring the mechanisms that drive the remarkable plasticity of these systems.Furthermore,it explores seasonal variations in bird vocalization and hearing and adaptations to environmental noise,focusing on how hormonal,neural,and ecological factors together shape vocal behavior and auditory sensitivity.Avian vocal communication systems present an exceptional model for studying the integration of peripheral and central vocal-auditory pathways and their adaptive responses to ever-changing environments.This review underscores the dynamic interactions between avian vocal communication systems and environmental stimuli,offering new insights into broader principles of sensory processing,and neuroplasticity.展开更多
The proposed mass model of vocal fold vibration holds a significant importance in the auxiliary diagnosis and treatment of human vocal fold disorders.Mathematical models are proposed in aerodynamics and acoustics to s...The proposed mass model of vocal fold vibration holds a significant importance in the auxiliary diagnosis and treatment of human vocal fold disorders.Mathematical models are proposed in aerodynamics and acoustics to simulate vocal fold vibration during phonation.This has always been a hot topic in pathological linguistics research.Over the past few decades,researchers have designed various types of mass models of vocal fold vibration based on experiments.These models differ in principles,computational complexity,and degrees of freedom.Therefore,we classify and describe the mass models according to modeling methods.We summarize the research status and characteristics of different models,and based on this,we look forward to future research directions for vocal fold mass models.展开更多
Voice, motion, and mimicry are naturalistic control modalities that have replaced text or display-driven control in human-computer communication (HCC). Specifically, the vocals contain a lot of knowledge, revealing de...Voice, motion, and mimicry are naturalistic control modalities that have replaced text or display-driven control in human-computer communication (HCC). Specifically, the vocals contain a lot of knowledge, revealing details about the speaker’s goals and desires, as well as their internal condition. Certain vocal characteristics reveal the speaker’s mood, intention, and motivation, while word study assists the speaker’s demand to be understood. Voice emotion recognition has become an essential component of modern HCC networks. Integrating findings from the various disciplines involved in identifying vocal emotions is also challenging. Many sound analysis techniques were developed in the past. Learning about the development of artificial intelligence (AI), and especially Deep Learning (DL) technology, research incorporating real data is becoming increasingly common these days. Thus, this research presents a novel selfish herd optimization-tuned long/short-term memory (SHO-LSTM) strategy to identify vocal emotions in human communication. The RAVDESS public dataset is used to train the suggested SHO-LSTM technique. Mel-frequency cepstral coefficient (MFCC) and wiener filter (WF) techniques are used, respectively, to remove noise and extract features from the data. LSTM and SHO are applied to the extracted data to optimize the LSTM network’s parameters for effective emotion recognition. Python Software was used to execute our proposed framework. In the finding assessment phase, Numerous metrics are used to evaluate the proposed model’s detection capability, Such as F1-score (95%), precision (95%), recall (96%), and accuracy (97%). The suggested approach is tested on a Python platform, and the SHO-LSTM’s outcomes are contrasted with those of other previously conducted research. Based on comparative assessments, our suggested approach outperforms the current approaches in vocal emotion recognition.展开更多
Animals living in syntopy share acoustic space.Asian horned frogs are well known for their sympatric distribution,but little is known about their strategies to avoid acoustic niche competition.This study focused on th...Animals living in syntopy share acoustic space.Asian horned frogs are well known for their sympatric distribution,but little is known about their strategies to avoid acoustic niche competition.This study focused on three sympatric Boulenophrys frog species from southern China—B.nanlingensis,B.ombrophila,and B.shimentaina,with the former two species call in similar frequencies but breed in different seasons.First,we checked the call variation during the change of individual body size and the ambient air temperature in three species.We have found call frequencies were the most static parameters in each species that were associated with body size and contributed most to species identifcation.Temporal call parameters shift with temperature but are mostly infuenced by low temperatures.Second,we checked the interactions between the environment and call properties.The calling site preferences of each species corresponded well with the prediction of the acoustic adaptation hypothesis(in view of higher frequency better transmission in open habitat),and species with similar call frequencies have some aspects of common calling sites.Third,we checked the species–species interaction by using playback tests with male B.nanlingensis.Results from playback experiments showed species that call at similar frequencies could hardly share the same habitat during the same season.These fndings expanded the knowledge of acoustic coexistence in closely related anuran species and provided insights into the vocal behavior of Asian horned frogs.展开更多
In brood-parasitic Cuculus cuckoos,male vocalizations are species-specific and easily distinguishable,whereas female calls are remarkably similar across species,making species identification challenging.In this study,...In brood-parasitic Cuculus cuckoos,male vocalizations are species-specific and easily distinguishable,whereas female calls are remarkably similar across species,making species identification challenging.In this study,we examined the structural characteristics and variability of female bubbling calls among four Cuculus species(Common Cuckoo C.canorus,Oriental Cuckoo C.optatus,Indian Cuckoo C.micropterus,and Lesser Cuckoo C.poliocephalus)breeding in South Korea.Comprehensive acoustic analyses of seven call parameters,using recordings from 2021 to 2023,were conducted to quantify the characteristics of their calls and compare withinand between-individual variability across species.Significant differences were found across all call parameters,with the Common Cuckoo producing the highest number of notes and the Oriental Cuckoo the lowest-frequency calls.Despite these differences,the overall structure of the calls remained acoustically similar,with overlapping characteristics across species.Furthermore,female Common Cuckoos exhibited greater within-individual variability in their calls,while the other species showed higher between-individual variability,which may further complicate species identification based vocalization alone.These findings highlight the complexities of female vocalizations in Cuculus cuckoos and suggest that ecological,social,and evolutionary factors may contribute to this vocal variability.展开更多
The nonlinearity and fear hypothesis predicts that highly aroused vocal mammals and birds produce vocalizations(notably alarm calls and screams)which contain a variety of nonlinear phenomena(NLP).Such vocalizations of...The nonlinearity and fear hypothesis predicts that highly aroused vocal mammals and birds produce vocalizations(notably alarm calls and screams)which contain a variety of nonlinear phenomena(NLP).Such vocalizations often sound“noisy”because vocal production systems are over-blown when animals are highly aroused.While much is known about the conditions under which animals produce vocalizations containing NLP and how species respond to them,there is little research about the heritability of such behavioral traits.Using the quantitative genetic animal model,we estimated the genetic basis of“noise”in alarm calls produced by females and found significant heritability in call entropy-our measure of the noisiness.About 9%of the variance in noisiness can be accounted for by genetic differences.Taken together,these findings suggest that the degree to which marmots produce noisy calls is modestly heritable and can be thus subject to further evolution via natural selection.展开更多
With the rapid development of information technology and the advancement of educational modernization,the teaching mode of vocal music in colleges and universities is undergoing a new transformation,which complies wit...With the rapid development of information technology and the advancement of educational modernization,the teaching mode of vocal music in colleges and universities is undergoing a new transformation,which complies with the trend of digital age and brings new challenges.This paper explores the specific implementation path of artificial intelligence technology,virtual reality technology,big data technology and intelligent interaction technology in vocal music teaching in colleges and universities,aiming to inject new vitality into the traditional teaching mode and improve teaching quality and efficiency.展开更多
Bird vocalizations are pivotal for ecological monitoring,providing insights into biodiversity and ecosystem health.Traditional recognition methods often neglect phase information,resulting in incomplete feature repres...Bird vocalizations are pivotal for ecological monitoring,providing insights into biodiversity and ecosystem health.Traditional recognition methods often neglect phase information,resulting in incomplete feature representation.In this paper,we introduce a novel approach to bird vocalization recognition(BVR)that integrates both amplitude and phase information,leading to enhanced species identification.We propose MHARes Net,a deep learning(DL)model that employs residual blocks and a multi-head attention mechanism to capture salient features from logarithmic power(POW),Instantaneous Frequency(IF),and Group Delay(GD)extracted from bird vocalizations.Experiments on three bird vocalization datasets demonstrate our method's superior performance,achieving accuracy rates of 94%,98.9%,and 87.1%respectively.These results indicate that our approach provides a more effective representation of bird vocalizations,outperforming existing methods.This integration of phase information in BVR is innovative and significantly advances the field of automatic bird monitoring technology,offering valuable tools for ecological research and conservation efforts.展开更多
KHOOMEI is a traditional throat-singing art created by the Mongolian ethnic group and is regarded as one of the oldest forms of this low rumbling vocal technique in the world.In 2006,Khoomei was included in China’s f...KHOOMEI is a traditional throat-singing art created by the Mongolian ethnic group and is regarded as one of the oldest forms of this low rumbling vocal technique in the world.In 2006,Khoomei was included in China’s first national list of intangible cultural heritage items,followed in 2009 by its inclusion on UNESCO’s Representative List of the Intangible Cultural Heritage of Humanity.展开更多
目的:探讨三维超声VOCAL技术评估胰岛素抵抗不孕患者子宫内膜容受性的临床价值。方法:纳入2023年2月至2024年6月我院收治的胰岛素抵抗不孕患者50例(研究组)及同期正常孕龄妇女50例(对照组),均行三维超声VOCAL检查,比较两组内膜容积、VI/...目的:探讨三维超声VOCAL技术评估胰岛素抵抗不孕患者子宫内膜容受性的临床价值。方法:纳入2023年2月至2024年6月我院收治的胰岛素抵抗不孕患者50例(研究组)及同期正常孕龄妇女50例(对照组),均行三维超声VOCAL检查,比较两组内膜容积、VI/FI/VFI参数及血清SHBG、HOMA-IR等指标。结果:研究组内膜容积([2.45±0.31)cm^(3)]、VI(7.74±1.36)、FI(20.46±3.67)、VFI(158.14±10.20)均显著低于对照组(P<0.05),血清SHBG([45.69±5.78)nmol/L]、HDL-C([1.36±0.35)mmol/L]水平亦低于对照组(P<0.05)。研究组血清T([8.58±2.58)ng/mL]、TG([2.11±0.36)mmol/L]、FPG([7.69±1.13)mmol/L]、2 h PG([10.24±1.69)mmol/L]、FINS([27.41±3.16)μIU/mL]、HOMA-IR(2.24±0.35)水平高于对照组(P<0.05)。Pearson相关性分析显示,内膜容积与血清SHBG(r=0.536,P<0.001)、HDL-C(r=0.574,P<0.001)水平呈正相关,与血清T(r=-0.584,P<0.001)、TG(r=-0.496,P<0.001)、FPG(r=-0.547,P<0.001)、2 h PG(r=-0.558,P<0.001)、FINS(r=-0.569,P<0.001)、HOMA-IR(r=-0.585,P<0.001)均呈负相关。VI与血清SHBG(r=0.587,P<0.001)、HDL-C(r=0.604,P<0.001)水平呈正相关,与血清T(r=-0.512,P<0.001)、TG(r=-0.536,P<0.001)、FPG(r=-0.523,P<0.001)、2 h PG(r=-0.514,P<0.001)、FINS(r=-0.525,P<0.001)、HOMA-IR(r=-0.496,P<0.001)均呈负相关。FI与血清SHBG(r=0.601,P<0.001)、HDL-C(r=0.551,P<0.001)水平呈正相关,与血清T(r=-0.555,P<0.001)、TG(r=-0.587,P<0.001)、FPG(r=-0.546,P<0.001)、2 h PG(r=-0.567,P<0.001)、FINS(r=-0.516,P<0.001)、HOMA-IR(r=-0.478,P<0.001)均呈负相关。VFI与血清SHBG(r=0.598,P<0.001)、HDL-C(r=0.527,P<0.001)水平呈正相关,与血清T(r=-0.511,P<0.001)、TG(r=-0.571,P<0.001)、FPG(r=-0.532,P<0.001)、2 h PG(r=-0.510,P<0.001)、FINS(r=-0.536,P<0.001)、HOMA-IR(r=-0.546,P<0.001)均呈负相关。结论:三维超声VOCAL技术可有效评估胰岛素抵抗不孕患者的子宫内膜容受性,为个体化治疗提供影像学依据。展开更多
Acoustic signals are widely used as courtship signals in the animal kingdom.It has long been known that male mice emit ultrasonic vocalizations(USVs)in the presence of female mice or in response to female secretions.T...Acoustic signals are widely used as courtship signals in the animal kingdom.It has long been known that male mice emit ultrasonic vocalizations(USVs)in the presence of female mice or in response to female secretions.This observation led to the hypothesis that male USVs play a role in courtship behavior.Although previous studies showed that female mice have a social partner preference for vocalizing males,it is not known if they exhibit a sexual partner preference when given a choice.To address this issue,we examined the copulatory behaviors of female mice with either devocalized males(with or without the playback of the USVs)or sham-operated males in 2 different behavioral paradigms:the no-choice paradigm in the home cage of a male mouse(without choice of mating partners)or the mate-choice paradigm in a 3-chambered apparatus(with choice of mating partners).In the no-choice paradigm,female mice exhibited comparable sexual receptivity with sham-operated and devocalized males.In addition,we found that female mice showed more approach behavior to-wards devocalized males when male USVs were played back.In the mate-choice paradigm,female mice visited more frequently and stayed longer with sham-operated than devocalized males.Furthermore,we showed that female mice received more intromissions from sham-operated males than devocalized males.In summary,our results suggested that,although female mice can copulate equally with both devocalized and vocalizing males when given no choice of mating partner,female mice exhibit both sexual and social partner preferences for vocalizing males in the mate-choice paradigm.展开更多
目的:评估二维超声(2D-US)、三维超声VOCAL技术(3D-VOCAL)对子宫肌瘤体积(UMV)测量的精确性。方法:选取2022年10月~2023年4月于福建医科大学附属龙岩第一医院行子宫肌瘤外科手术治疗的患者45例,术前运用2D-US、3D-VOCAL对UMV进行测量,...目的:评估二维超声(2D-US)、三维超声VOCAL技术(3D-VOCAL)对子宫肌瘤体积(UMV)测量的精确性。方法:选取2022年10月~2023年4月于福建医科大学附属龙岩第一医院行子宫肌瘤外科手术治疗的患者45例,术前运用2D-US、3D-VOCAL对UMV进行测量,与手术切除后的实际肌瘤体积进行比较,评估两种超声技术测量UMV的准确性及重复性。结果:3D-VOCAL测量肌瘤体积的一致性(ICC=0.992)高于2D-US(ICC=0.976),且3D-VOCAL在不同大小肌瘤中的ICC均高于2D-US(均P<0.001)。2D-US、3D-VOCAL、手术术后3组间UMV测值的体积在最大径<8 cm差异无统计学意义(P>0.05),而3组间在最大径≥8 cm差异有统计学意义(P<0.05);进一步两两分析显示,在最大径≥8 cm UMV中,2D-US与手术术后的UMV测值差异有统计学意义(P<0.05),3D-VOCAL与手术术后的UMV测值差异无统计学意义(P>0.05)。3D-VOCAL在不同观察者间及观察者内的一致性均优于2D-US。结论:3D-VOCAL对于术前UMV的测量优于2D-US,是一种简便、高效的可靠方法,为临床随访提供理论依据。展开更多
Vocal communication plays an important role in survival,reproduction,and animal social association.Birds and mammals produce com-plex vocal sequence to convey context-dependent information.Vocalizations are conspicuou...Vocal communication plays an important role in survival,reproduction,and animal social association.Birds and mammals produce com-plex vocal sequence to convey context-dependent information.Vocalizations are conspicuous features of the behavior of most anuran species(frogs and toads),and males usually alter their calling strategies according to ecological context to improve the attractiveness/competitiveness.However,very few studies have focused on the variation of vocal sequence in anurans.In the present study,we used both conventional method and network analysis to investigate the context-dependent vocal repertoire,vocal sequence,and call network structure in serrate-legged small treefrogs Kurixalus odontotarsus.We found that male K.odontotarsus modified their vocal sequence by switching to different call types and increasing repertoire size in the presence of a competitive rival.Specifically,compared with before and after the playback of advertisement calls,males emited fewer advertisement calls,but more aggressive calls,encounter calls,and compound calls during the playback period.Network analysis revealed that the mean degree,mean closeness,and mean betweenness of the call networks significantly decreased during the playback period,which resulted in lower connectivity.in addition,the increased proportion of one-way motifs and average path length also indicated that the connectivity of the call network decreased in competitive context.However,the vocal sequence of K.odontotarsus did not display a clear small-world network structure,regardless of context.Our study presents a paradigm to apply network analysis to vocal sequence in anurans and has important implications for understanding the evolution and function of sequence patterns.展开更多
Juveniles of interspecific avian brood parasites need to locate and recognize conspecifics to continue their life cycle after being reared by individuals of another species.However,little is known about the recognitio...Juveniles of interspecific avian brood parasites need to locate and recognize conspecifics to continue their life cycle after being reared by individuals of another species.However,little is known about the recognition mechanisms and cues involved in this critical stage of their lives.It has been proposed that adult parasites could show some kind of parental behavior by actively searching and interacting with conspecific young,which in turn could serve the juveniles to learn and/or reinforce the learning of conspecific characteristics.Since acoustic communication is one of the main channels used by birds,if such form of parental behavior by adult avian brood parasites does exist,adult cowbirds should recognize and respond positively to vocalizations of conspecific juveniles.We experimentally tested whether adult shiny Molothrus bonariensis and screaming M.rufoaxillaris cowbirds respond positively towards acoustic signals of conspecific juveniles using two playback experiments,one conducted in semi-captivity and the other in the field.In both cases,we presented 3 types of playbacks to adults of both cowbird species:vocalizations of shiny cowbird juveniles,vocalizations of screaming cowbird juveniles,and white noise as a control.In the experiment in semi-captivity,no significant differences were found between treatments.In the field experiment,no conspecifics approached the playback area,but hosts of the species whose playback was played were attracted to the loudspeaker.In conclusion,our results do not support the predictions we tested from the parental behavior hypothesis and indicate that adult shiny and screaming cowbirds do not respond positively to acoustic signals of conspecific juveniles,at least not to the type of signals used in our experiments.展开更多
基金The University of Winnipeg and The University of Winnipeg Foundation contributed funding to this research.
文摘Variation in the vocal behavior of nonhuman vertebrates includes graded transitions and more dramatic changes.Wapiti males produce a reproductive bugle that has a fundamental frequency that surpasses 2,000 Hz with evidence of biphonation and other nonlinear phenomena.Here,we analyze the acoustic structure of captive wapiti vocalizations to compare the male bugle with 3 categories of distress vocalizations:neonate distress(capture)calls,calf isolation calls,and adult female isolation calls.These 4 high-arousal call categories serve a common general function in recruiting conspecifics but occur in different behavioral contexts(capture,isolation,reproduction).Our goal was to distinguish characteristics that vary in graded steps that may correspond to an animal’s age or size from characteristics that are unique to the bugle.Characteristics of the high and loud fundamental(G0)varied in an age/size-graded manner with a decrease in minimum G0,an increase in the maximum and range of G0,with no evidence of sex differences.The nonlinear phenomena of deterministic chaos,biphonation,and frequency jumps were present in all 4 call categories and became more common from the distress vocalizations of neonates to calves to adult females to the male bugle.Two temporal characteristics sharply distinguished the bugle from the 3 categories of distress vocalizations:these included a prolonged call duration and a maximum G0 that occurred much later in the call for the bugle than for distress vocalizations.Our results suggest that distress vocalizations of different age groups and the reproductive bugle of wapiti share a high G0,with age/size-graded changes in G0 and nonlinear phenomena,but differ sharply in temporal characteristics.
文摘With the development of new media technology and the popularity of the TikTok platform in China,a large number of popular vocal music teachers have flocked to online platforms for teaching.Online vocal music education in China is undergoing a transformation and facing challenges.This study adopts an exploratory research approach,interviewing students learning pop vocal music,and observing popular pop teachers on TikTok.The advantages,disadvantages,techniques,and methods of domestic TikTok pop vocal music teaching were investigated and studied,and a series of experiences and suggestions for optimizing TikTok teaching were put forward.The results of this study are helpful for understanding the advantages and disadvantages of TikTok pop vocal music teaching and grasping the correct development direction.These guidance and suggestions can stimulate teachers’creativity and improve their vocal music teaching level.
文摘Amyotrophic lateral sclerosis(ALS)is a neuromuscular condition resulting from the progressive degeneration of motor neurons in the cortex,brainstem,and spinal cord.While the typical clinical phenotype of ALS involves both upper and lower motor neurons,human and animal studies over the years have highlighted the potential spread to other motor and non-motor regions,expanding the phenotype of ALS.Although superoxide dismutase 1(SOD1)mutations represent a minority of ALS cases,the SOD1 gene remains a milestone in ALS research as it represents the first genetic target for personalized therapies.Despite numerous single case reports or case series exhibiting extramotor symptoms in patients with ALS mutations in SOD1(SOD1-ALS),no studies have comprehensively explored the full spectrum of extramotor neurological manifestations in this subpopulation.In this narrative review,we analyze and discuss the available literature on extrapyramidal and non-motor features during SOD1-ALS.The multifaceted expression of SOD1 could deepen our understanding of the pathogenic mechanisms,pointing towards a multidisciplinary approach for affected patients in light of new therapeutic strategies for SOD1-ALS.
基金P.D.and P.S.A.received Ph.D.scholarships from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES)(Finance Code 001)P.D.received a Postdoctoral fellowship from CAPES(grant number:88887.469218/2019-00)+4 种基金R.H.M.received a fellowship from Conselho Nacional de Desenvolvimento Científco e Tecnológico(CNPq)for the duration of the study.Funding was also provided by Animal Behavior Society[ABS Student Research Grant to P.S.A.]Association of Field Ornithologists[E.Alexander Bergstrom Memorial Research Award to P.S.A.]American Ornithological Society[Postdoctoral Research Award to P.D.]the logistic and fnancial support provided by Programa de Pós-Graduação em Ecologia from Universidade de Brasília in association with Programa de Excelência Acadêmica PROEX/CAPES(1789/2015)the fnancial support provided by CNPq(471945/2013-7).
文摘Vocal individuality is essential for social discrimination but has been poorly studied in animals that produce communal signals(duets or choruses).Song overlapping and temporal coordination make the assessment of individuality in communal signals more complex.In addition,selection may favor the accurate identifcation of pairs over individuals by receivers in year-round territorial species with duetting and long-term pair bonding.Here,we studied pair and individual vocal signatures in the polyphonal duets of rufous horneros Furnarius rufus,a Neotropical bird known for its long-term pair bonds.Hornero partners engage in duets to deter territorial intruders and protect their partnership year-round and can discern duets from neighbors versus strangers.Using a dataset of 471 duets from 43 pairs in 2 populations,we measured fne-scale acoustic features across different duet levels(e.g.,complete duets to non-overlapping syllable parts)and analysis levels(pair or individual).Permuted linear discriminant function analyses classifed pairs and individuals more accurately than expected by chance(means:45%and 47%vs.4 and 2%).Pair identity explained more variance in the multivariate acoustic features of duets than individual or population identities.The initial frequency of the duet showed strong potential for encoding pair identity.The acoustic traits contributing most to individual vocal signatures varied between sexes,which might facilitate the simultaneous assessment of duetters’identities by receivers.Our study indicates that vocal individuality may exist even in species with intricate and innate communal signals and elucidates the mechanisms employed by horneros in their social discrimination ability.
基金supported by the National Key Research and Development Program of China(2022YFC3202104)the Western LightKey Laboratory Cooperative Research Cross-Team Project of Chinese Academy of Sciences(xbzg-zdsys-202207)。
文摘Passerine mimics often imitate various vocalizations from other bird species and incorporate these sounds into their song repertoires.While a few anecdotes reported that wild songbirds imitated human-associated sounds,besides captive parrots and songbirds,systemic and quantitative studies on human-made sound mimicry in wild birds remain scarce.In this study,we investigated the mimetic accuracy and consistency of electric moped sounds imitated by an urban bird,the Chinese Blackbird(Turdus mandarinus).We found that:(1)Only one type of electric moped sound was imitated,i.e.,13 of 26 males mimicked the first part of the antitheft alarm,a phrase containing a series of identical notes.(2)The mimicry produced by male Chinese Blackbirds had fewer notes and lower consistency within phrases compared to the model alarms.(3)The mimicry of male Chinese Blackbirds was imperfect,i.e.,most of the acoustic parameters differed from the model alarms.Additionally,mimetic notes were lower in frequency than the models.Mimetic notes from two areas were also different in acoustic structures,suggesting Chinese Blackbirds might learn mimicry mainly from conspecific neighbors within each area respectively rather than electric mopeds,namely the secondary mimicry.Imperfect mimicry of human-made sounds could result from cost and physical constraints,associated with high consistency,frequency,and repetitions.Consequently,Chinese Blackbirds copied a simplified version of electric moped alarms.We recommend further attention to mimic species inhabiting urban ecosystems to better understand vocal mimicry's adaptation to ongoing urbanization.
基金supported by the National Natural Science Foundation of China(NSFC,32471572)to D.L.the NSFC(32401298)the Hebei Natural Science Foundation(C2023205016)to L.W。
文摘Avian vocal communication represents one of the most intricate forms of animal language,playing a critical role in behavioral interactions.Both peripheral and central auditory-vocal pathways are essential for precisely integrating acoustic signals,ensuring effective communication.Like humans,songbirds exhibit vocal learning behaviors supported by complex neural mechanisms.However,unlike most mammals,songbirds possess the remarkable ability to regenerate damaged auditory cells.These capabilities offer unique opportunities to explore how birds adjust their vocal behavior and auditory processing in response to dynamic environmental conditions.Recent studies have advanced our understanding of the plasticity of avian vocal communication system,yet the vocal diversity and neurophysiological mechanisms underlying vocalization and hearing have often been examined independently.A comprehensive overview of how these systems interact and adapt in birds remains lacking.To address this gap,this review synthesizes the peripheral and central features of avian vocalization and hearing,while also exploring the mechanisms that drive the remarkable plasticity of these systems.Furthermore,it explores seasonal variations in bird vocalization and hearing and adaptations to environmental noise,focusing on how hormonal,neural,and ecological factors together shape vocal behavior and auditory sensitivity.Avian vocal communication systems present an exceptional model for studying the integration of peripheral and central vocal-auditory pathways and their adaptive responses to ever-changing environments.This review underscores the dynamic interactions between avian vocal communication systems and environmental stimuli,offering new insights into broader principles of sensory processing,and neuroplasticity.
基金the Shanghai Educational Sciences Research Program(No.C2021016)。
文摘The proposed mass model of vocal fold vibration holds a significant importance in the auxiliary diagnosis and treatment of human vocal fold disorders.Mathematical models are proposed in aerodynamics and acoustics to simulate vocal fold vibration during phonation.This has always been a hot topic in pathological linguistics research.Over the past few decades,researchers have designed various types of mass models of vocal fold vibration based on experiments.These models differ in principles,computational complexity,and degrees of freedom.Therefore,we classify and describe the mass models according to modeling methods.We summarize the research status and characteristics of different models,and based on this,we look forward to future research directions for vocal fold mass models.
基金The author Dr.Arshiya S.Ansari extends the appreciation to the Deanship of Postgraduate Studies and Scientific Research at Majmaah University for funding this research work through the project number(R-2025-1538).
文摘Voice, motion, and mimicry are naturalistic control modalities that have replaced text or display-driven control in human-computer communication (HCC). Specifically, the vocals contain a lot of knowledge, revealing details about the speaker’s goals and desires, as well as their internal condition. Certain vocal characteristics reveal the speaker’s mood, intention, and motivation, while word study assists the speaker’s demand to be understood. Voice emotion recognition has become an essential component of modern HCC networks. Integrating findings from the various disciplines involved in identifying vocal emotions is also challenging. Many sound analysis techniques were developed in the past. Learning about the development of artificial intelligence (AI), and especially Deep Learning (DL) technology, research incorporating real data is becoming increasingly common these days. Thus, this research presents a novel selfish herd optimization-tuned long/short-term memory (SHO-LSTM) strategy to identify vocal emotions in human communication. The RAVDESS public dataset is used to train the suggested SHO-LSTM technique. Mel-frequency cepstral coefficient (MFCC) and wiener filter (WF) techniques are used, respectively, to remove noise and extract features from the data. LSTM and SHO are applied to the extracted data to optimize the LSTM network’s parameters for effective emotion recognition. Python Software was used to execute our proposed framework. In the finding assessment phase, Numerous metrics are used to evaluate the proposed model’s detection capability, Such as F1-score (95%), precision (95%), recall (96%), and accuracy (97%). The suggested approach is tested on a Python platform, and the SHO-LSTM’s outcomes are contrasted with those of other previously conducted research. Based on comparative assessments, our suggested approach outperforms the current approaches in vocal emotion recognition.
基金supported by the Project for Endangered Wildlife Investigation,Supervision and Industry Regulation of the National Forestry and Grassland Bureau of China(202407-HN-001)the Project for Endangered Wildlife Protection of Hunan Forestry Bureau of China(HNYB-2024001).
文摘Animals living in syntopy share acoustic space.Asian horned frogs are well known for their sympatric distribution,but little is known about their strategies to avoid acoustic niche competition.This study focused on three sympatric Boulenophrys frog species from southern China—B.nanlingensis,B.ombrophila,and B.shimentaina,with the former two species call in similar frequencies but breed in different seasons.First,we checked the call variation during the change of individual body size and the ambient air temperature in three species.We have found call frequencies were the most static parameters in each species that were associated with body size and contributed most to species identifcation.Temporal call parameters shift with temperature but are mostly infuenced by low temperatures.Second,we checked the interactions between the environment and call properties.The calling site preferences of each species corresponded well with the prediction of the acoustic adaptation hypothesis(in view of higher frequency better transmission in open habitat),and species with similar call frequencies have some aspects of common calling sites.Third,we checked the species–species interaction by using playback tests with male B.nanlingensis.Results from playback experiments showed species that call at similar frequencies could hardly share the same habitat during the same season.These fndings expanded the knowledge of acoustic coexistence in closely related anuran species and provided insights into the vocal behavior of Asian horned frogs.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by The Ministry of Education(NRF-2020R1I1A2063567)。
文摘In brood-parasitic Cuculus cuckoos,male vocalizations are species-specific and easily distinguishable,whereas female calls are remarkably similar across species,making species identification challenging.In this study,we examined the structural characteristics and variability of female bubbling calls among four Cuculus species(Common Cuckoo C.canorus,Oriental Cuckoo C.optatus,Indian Cuckoo C.micropterus,and Lesser Cuckoo C.poliocephalus)breeding in South Korea.Comprehensive acoustic analyses of seven call parameters,using recordings from 2021 to 2023,were conducted to quantify the characteristics of their calls and compare withinand between-individual variability across species.Significant differences were found across all call parameters,with the Common Cuckoo producing the highest number of notes and the Oriental Cuckoo the lowest-frequency calls.Despite these differences,the overall structure of the calls remained acoustically similar,with overlapping characteristics across species.Furthermore,female Common Cuckoos exhibited greater within-individual variability in their calls,while the other species showed higher between-individual variability,which may further complicate species identification based vocalization alone.These findings highlight the complexities of female vocalizations in Cuculus cuckoos and suggest that ecological,social,and evolutionary factors may contribute to this vocal variability.
基金supported by the National Geographic Society,the University of California Los Angeles(Faculty Senate and Division of Life Sciences)an RMBL research fellowship and the U.S.National Science Foundation(NSF IDBR-0754247 and DEB-1119660 and 1557130 to D.T.B.,as well as DBI 0242960,07211346 and 1226713 to RMBL).
文摘The nonlinearity and fear hypothesis predicts that highly aroused vocal mammals and birds produce vocalizations(notably alarm calls and screams)which contain a variety of nonlinear phenomena(NLP).Such vocalizations often sound“noisy”because vocal production systems are over-blown when animals are highly aroused.While much is known about the conditions under which animals produce vocalizations containing NLP and how species respond to them,there is little research about the heritability of such behavioral traits.Using the quantitative genetic animal model,we estimated the genetic basis of“noise”in alarm calls produced by females and found significant heritability in call entropy-our measure of the noisiness.About 9%of the variance in noisiness can be accounted for by genetic differences.Taken together,these findings suggest that the degree to which marmots produce noisy calls is modestly heritable and can be thus subject to further evolution via natural selection.
基金Education Department of Hainan Province(Project No.:Hnjg2024-112&Hnjg2025ZC-80)。
文摘With the rapid development of information technology and the advancement of educational modernization,the teaching mode of vocal music in colleges and universities is undergoing a new transformation,which complies with the trend of digital age and brings new challenges.This paper explores the specific implementation path of artificial intelligence technology,virtual reality technology,big data technology and intelligent interaction technology in vocal music teaching in colleges and universities,aiming to inject new vitality into the traditional teaching mode and improve teaching quality and efficiency.
基金supported by the Beijing Natural Science Foundation (5252014)the National Natural Science Foundation of China (62303063)。
文摘Bird vocalizations are pivotal for ecological monitoring,providing insights into biodiversity and ecosystem health.Traditional recognition methods often neglect phase information,resulting in incomplete feature representation.In this paper,we introduce a novel approach to bird vocalization recognition(BVR)that integrates both amplitude and phase information,leading to enhanced species identification.We propose MHARes Net,a deep learning(DL)model that employs residual blocks and a multi-head attention mechanism to capture salient features from logarithmic power(POW),Instantaneous Frequency(IF),and Group Delay(GD)extracted from bird vocalizations.Experiments on three bird vocalization datasets demonstrate our method's superior performance,achieving accuracy rates of 94%,98.9%,and 87.1%respectively.These results indicate that our approach provides a more effective representation of bird vocalizations,outperforming existing methods.This integration of phase information in BVR is innovative and significantly advances the field of automatic bird monitoring technology,offering valuable tools for ecological research and conservation efforts.
文摘KHOOMEI is a traditional throat-singing art created by the Mongolian ethnic group and is regarded as one of the oldest forms of this low rumbling vocal technique in the world.In 2006,Khoomei was included in China’s first national list of intangible cultural heritage items,followed in 2009 by its inclusion on UNESCO’s Representative List of the Intangible Cultural Heritage of Humanity.
文摘目的:探讨三维超声VOCAL技术评估胰岛素抵抗不孕患者子宫内膜容受性的临床价值。方法:纳入2023年2月至2024年6月我院收治的胰岛素抵抗不孕患者50例(研究组)及同期正常孕龄妇女50例(对照组),均行三维超声VOCAL检查,比较两组内膜容积、VI/FI/VFI参数及血清SHBG、HOMA-IR等指标。结果:研究组内膜容积([2.45±0.31)cm^(3)]、VI(7.74±1.36)、FI(20.46±3.67)、VFI(158.14±10.20)均显著低于对照组(P<0.05),血清SHBG([45.69±5.78)nmol/L]、HDL-C([1.36±0.35)mmol/L]水平亦低于对照组(P<0.05)。研究组血清T([8.58±2.58)ng/mL]、TG([2.11±0.36)mmol/L]、FPG([7.69±1.13)mmol/L]、2 h PG([10.24±1.69)mmol/L]、FINS([27.41±3.16)μIU/mL]、HOMA-IR(2.24±0.35)水平高于对照组(P<0.05)。Pearson相关性分析显示,内膜容积与血清SHBG(r=0.536,P<0.001)、HDL-C(r=0.574,P<0.001)水平呈正相关,与血清T(r=-0.584,P<0.001)、TG(r=-0.496,P<0.001)、FPG(r=-0.547,P<0.001)、2 h PG(r=-0.558,P<0.001)、FINS(r=-0.569,P<0.001)、HOMA-IR(r=-0.585,P<0.001)均呈负相关。VI与血清SHBG(r=0.587,P<0.001)、HDL-C(r=0.604,P<0.001)水平呈正相关,与血清T(r=-0.512,P<0.001)、TG(r=-0.536,P<0.001)、FPG(r=-0.523,P<0.001)、2 h PG(r=-0.514,P<0.001)、FINS(r=-0.525,P<0.001)、HOMA-IR(r=-0.496,P<0.001)均呈负相关。FI与血清SHBG(r=0.601,P<0.001)、HDL-C(r=0.551,P<0.001)水平呈正相关,与血清T(r=-0.555,P<0.001)、TG(r=-0.587,P<0.001)、FPG(r=-0.546,P<0.001)、2 h PG(r=-0.567,P<0.001)、FINS(r=-0.516,P<0.001)、HOMA-IR(r=-0.478,P<0.001)均呈负相关。VFI与血清SHBG(r=0.598,P<0.001)、HDL-C(r=0.527,P<0.001)水平呈正相关,与血清T(r=-0.511,P<0.001)、TG(r=-0.571,P<0.001)、FPG(r=-0.532,P<0.001)、2 h PG(r=-0.510,P<0.001)、FINS(r=-0.536,P<0.001)、HOMA-IR(r=-0.546,P<0.001)均呈负相关。结论:三维超声VOCAL技术可有效评估胰岛素抵抗不孕患者的子宫内膜容受性,为个体化治疗提供影像学依据。
基金This work was supported by JSPS KAKENHI grant numbers 17K19408,15K14881,25118007(TK)and 13J08901(AA).
文摘Acoustic signals are widely used as courtship signals in the animal kingdom.It has long been known that male mice emit ultrasonic vocalizations(USVs)in the presence of female mice or in response to female secretions.This observation led to the hypothesis that male USVs play a role in courtship behavior.Although previous studies showed that female mice have a social partner preference for vocalizing males,it is not known if they exhibit a sexual partner preference when given a choice.To address this issue,we examined the copulatory behaviors of female mice with either devocalized males(with or without the playback of the USVs)or sham-operated males in 2 different behavioral paradigms:the no-choice paradigm in the home cage of a male mouse(without choice of mating partners)or the mate-choice paradigm in a 3-chambered apparatus(with choice of mating partners).In the no-choice paradigm,female mice exhibited comparable sexual receptivity with sham-operated and devocalized males.In addition,we found that female mice showed more approach behavior to-wards devocalized males when male USVs were played back.In the mate-choice paradigm,female mice visited more frequently and stayed longer with sham-operated than devocalized males.Furthermore,we showed that female mice received more intromissions from sham-operated males than devocalized males.In summary,our results suggested that,although female mice can copulate equally with both devocalized and vocalizing males when given no choice of mating partner,female mice exhibit both sexual and social partner preferences for vocalizing males in the mate-choice paradigm.
文摘目的:评估二维超声(2D-US)、三维超声VOCAL技术(3D-VOCAL)对子宫肌瘤体积(UMV)测量的精确性。方法:选取2022年10月~2023年4月于福建医科大学附属龙岩第一医院行子宫肌瘤外科手术治疗的患者45例,术前运用2D-US、3D-VOCAL对UMV进行测量,与手术切除后的实际肌瘤体积进行比较,评估两种超声技术测量UMV的准确性及重复性。结果:3D-VOCAL测量肌瘤体积的一致性(ICC=0.992)高于2D-US(ICC=0.976),且3D-VOCAL在不同大小肌瘤中的ICC均高于2D-US(均P<0.001)。2D-US、3D-VOCAL、手术术后3组间UMV测值的体积在最大径<8 cm差异无统计学意义(P>0.05),而3组间在最大径≥8 cm差异有统计学意义(P<0.05);进一步两两分析显示,在最大径≥8 cm UMV中,2D-US与手术术后的UMV测值差异有统计学意义(P<0.05),3D-VOCAL与手术术后的UMV测值差异无统计学意义(P>0.05)。3D-VOCAL在不同观察者间及观察者内的一致性均优于2D-US。结论:3D-VOCAL对于术前UMV的测量优于2D-US,是一种简便、高效的可靠方法,为临床随访提供理论依据。
基金supported by the National Natural Science Foundation of China(31772464,32000313)Youth Innovation Promotion Association CAS(2012274)+2 种基金Sichuan ScienceandTechnology Program1(2022JDTD0026)NaturalScience Foundation of Sichuan Province(2022NSFSC1736)Open Research Program in Ministry of Education Key Laboratory for Ecology of Tropical Islands(HNSF-OP-202002).
文摘Vocal communication plays an important role in survival,reproduction,and animal social association.Birds and mammals produce com-plex vocal sequence to convey context-dependent information.Vocalizations are conspicuous features of the behavior of most anuran species(frogs and toads),and males usually alter their calling strategies according to ecological context to improve the attractiveness/competitiveness.However,very few studies have focused on the variation of vocal sequence in anurans.In the present study,we used both conventional method and network analysis to investigate the context-dependent vocal repertoire,vocal sequence,and call network structure in serrate-legged small treefrogs Kurixalus odontotarsus.We found that male K.odontotarsus modified their vocal sequence by switching to different call types and increasing repertoire size in the presence of a competitive rival.Specifically,compared with before and after the playback of advertisement calls,males emited fewer advertisement calls,but more aggressive calls,encounter calls,and compound calls during the playback period.Network analysis revealed that the mean degree,mean closeness,and mean betweenness of the call networks significantly decreased during the playback period,which resulted in lower connectivity.in addition,the increased proportion of one-way motifs and average path length also indicated that the connectivity of the call network decreased in competitive context.However,the vocal sequence of K.odontotarsus did not display a clear small-world network structure,regardless of context.Our study presents a paradigm to apply network analysis to vocal sequence in anurans and has important implications for understanding the evolution and function of sequence patterns.
基金supported by grants PICT 2015-1628 from Agencia Nacional de Promoción Científica y Tecnológica and UBACYT 20020170100521BA from Universidad de Buenos Aires to J.C.R.
文摘Juveniles of interspecific avian brood parasites need to locate and recognize conspecifics to continue their life cycle after being reared by individuals of another species.However,little is known about the recognition mechanisms and cues involved in this critical stage of their lives.It has been proposed that adult parasites could show some kind of parental behavior by actively searching and interacting with conspecific young,which in turn could serve the juveniles to learn and/or reinforce the learning of conspecific characteristics.Since acoustic communication is one of the main channels used by birds,if such form of parental behavior by adult avian brood parasites does exist,adult cowbirds should recognize and respond positively to vocalizations of conspecific juveniles.We experimentally tested whether adult shiny Molothrus bonariensis and screaming M.rufoaxillaris cowbirds respond positively towards acoustic signals of conspecific juveniles using two playback experiments,one conducted in semi-captivity and the other in the field.In both cases,we presented 3 types of playbacks to adults of both cowbird species:vocalizations of shiny cowbird juveniles,vocalizations of screaming cowbird juveniles,and white noise as a control.In the experiment in semi-captivity,no significant differences were found between treatments.In the field experiment,no conspecifics approached the playback area,but hosts of the species whose playback was played were attracted to the loudspeaker.In conclusion,our results do not support the predictions we tested from the parental behavior hypothesis and indicate that adult shiny and screaming cowbirds do not respond positively to acoustic signals of conspecific juveniles,at least not to the type of signals used in our experiments.
