斑背大尾莺繁殖期鸣声行为分析

2009年5-7月,在辽宁双台河口保护区录制了20只繁殖期斑背大尾莺雄性个体的鸣声.根据行为特征,该鸟鸣声定义为3种鸣声类型:求偶炫耀鸣唱、报警声和联络声.利用Wavesurfer软件对20只斑背大尾莺雄性个体543个鸣声的句子持续时间、句子音节个数、音节持续时间、音节间隔时间等4个参数进行分析测量,发现求偶炫耀鸣唱由节奏逐渐加快的前部句子和音节组成复杂的主体部两个句子组成; 报警声和联络声的句子均由单音节组成.音节类型总数为38种,其中包括前部句子的音节类型6种.采用单因素方差分析(one-way ANOVA)对求偶炫耀鸣唱的4个参数进行差异性检验发现,不同个体的各个参数均呈极显著差异(P<0.01).     

Vocal communication in adult greater horseshoe bats, Rhinolophus ferrumequinum

Whereas echolocation in horseshoe bats is well studied, virtually nothing is known about characteristics and function of their communication calls. Therefore, the communication calls produced by a group of captive adult greater horseshoe bats were recorded during various social interactions in a free-flight facility. Analysis revealed that this species exhibited an amazingly rich repertoire of vocalizations varying in numerous spectro-temporal aspects. Calls were classified into 17 syllable types (ten simple syllables and seven composites). Syllables were combined into six types of simple phrases and four combination phrases. The majority of syllables had durations of more than 100 ms with multiple harmonics and fundamental frequencies usually above 20 kHz, although some of them were also audible to humans. Preliminary behavioral observations indicated that many calls were emitted during direct interaction with and in response to social calls from conspecifics without requiring physical contact. Some echolocation-like vocalizations also appeared to clearly serve a communication role. These results not only shed light upon a so far widely neglected aspect of horseshoe bat vocalizations, but also provide the basis for future studies on the neural control of the production of communicative vocalizations in contrast to the production of echolocation pulse sequences.     

大足鼠耳蝠交流声波非线性现象

非线性发声现象在动物的发声中普遍存在,因其具有进化上的意义而广受关注。非线性现象一般在动物激进状态下发出,可能具有一定的功能,然而国内外对蝙蝠非线性现象的研究集中于描述性的报道,缺乏进化功能上的探究。大足鼠耳蝠(Myotis pilosus)激进叫声包含2种音节类型,拱形调频音节(AFM)和噪音-短下调调频音节(NB-s DFM),能够组成3种叫声组合,只包含AFM的叫声组合(A)、只包含NB-s DFM的叫声组合(B)、既包含AFM又包含NB-s DFM的叫声组合(C),分别对应着没有非线性现象、具有非线性现象及一种过渡类型。通过回放3种叫声组合,记录7种具有代表性的行为反应(抬头、前臂移动、耳动、发出回声定位脉冲、震颤、张嘴、爬行)次数,其中,前臂移动和发出回声定位脉冲两种行为反应的结果显示,大足鼠耳蝠对上述3种叫声组合的反应程度有显著差异,即具有非线性现象的叫声组合(B)能够提高同种蝙蝠的反应程度。实验结果表明,蝙蝠发声中的非线性现象能够增强叫声的不可预测性,说明非线性现象在蝙蝠发声中可能具有功能上的适应性。     

Social vocalizations of big brown bats vary with behavioral context

Bats are among the most gregarious and vocal mammals, with some species demonstrating a diverse repertoire of syllables under a variety of behavioral contexts. Despite extensive characterization of big brown bat (Eptesicus fuscus) biosonar signals, there have been no detailed studies of adult social vocalizations. We recorded and analyzed social vocalizations and associated behaviors of captive big brown bats under four behavioral contexts: low aggression, medium aggression, high aggression, and appeasement. Even limited to these contexts, big brown bats possess a rich repertoire of social vocalizations, with 18 distinct syllable types automatically classified using a spectrogram cross-correlation procedure. For each behavioral context, we describe vocalizations in terms of syllable acoustics, temporal emission patterns, and typical syllable sequences. Emotion-related acoustic cues are evident within the call structure by context-specific syllable types or variations in the temporal emission pattern. We designed a paradigm that could evoke aggressive vocalizations while monitoring heart rate as an objective measure of internal physiological state. Changes in the magnitude and duration of elevated heart rate scaled to the level of evoked aggression, confirming the behavioral state classifications assessed by vocalizations and behavioral displays. These results reveal a complex acoustic communication system among big brown bats in which acoustic cues and call structure signal the emotional state of a caller.     

Social and vocal behavior in adult greater tube-nosed bats (Murina leucogaster)

Many studies have revealed the significant influence of the social nature and ecological niche of a species on the design and complexity of their communication sounds. The knowledge of communication sounds and particularly of the flexibility in their use among mammals, however, remains patchy. Being highly vocal and social, bats are well suited for investigating vocal plasticity as well as vocal diversity. Thus, the overall aim of this study was to test the presence of structural overlap between calls used in social communication and echolocation pulses emitted during foraging in greater tube-nosed bats (Murina leucogaster). Acoustic analysis and spectrotemporal decomposition of calls revealed a rich communication repertoire comprising 12 simple syllables and 5 composites with harmonics in the ultrasonic range. Simultaneous recording of vocal and social behavior in the same species yielded a strong correspondence between distinct behaviors and specific call types in support of Morton's motivation-structure hypothesis. Spectrographic analysis of call types also revealed the presence of modified components of echolocation pulses embedded within social calls. Altogether, the data suggest that bats can parse complex sounds into structurally simpler components that are recombined within behaviorally meaningful and multifunctional contexts.     

Acoustic identification of eight species of bat (mammalia: chiroptera) inhabiting forests of southern hokkaido, Japan: potential for conservation monitoring

Assessing the impact of forest management on bat communities requires a reliable method for measuring patterns of habitat use by individual species. A measure of activity can be obtained by monitoring echolocation calls, but identification of species is not always straightforward. We assess the feasibility of using analysis of time-expanded echolocation calls to identify free-flying bats in the Tomakomai Experimental Forest of Hokkaido University, Hokkaido, northern Japan. Echolocation calls of eight bat species were recorded in one or more of three conditions: from hand-released individuals, from bats flying in a confined space and from bats emerging from their roost. Sonograms of 171 calls from 8 bat species were analyzed. These calls could be categorized into 3 types according to their structure: FM/CF/FM type (Rhinolophus ferrumequinum), FM types (Murina leucogaster, Murina ussuriensis, Myotis macrodactylus and Myotis ikonnikovi) and FM/QCF types (Eptesicus nilssonii, Vespertilio superans and Nyctalus aviator). Sonograms of the calls of R. ferrumequinum could easily be distinguished from those of all other species by eye. For the remaining calls, seven parameters (measures of frequency, duration and inter-call interval) were examined using discriminant function analysis, and 92% of calls were correctly classified to species. For each species, at least 80% of calls were correctly classified. We conclude that analysis of echolocation calls is a viable method for distinguishing between species of bats in the Tomakomai Experimental Forest, and that this approach could be applied to examine species differences in patterns of habitat-use within the forest.     

白腹管鼻蝠成体交流声波多样性

小蝙蝠亚目即通常所说的蝙蝠,是哺乳动物中群居程度最高的类群之一,主要依靠声学信号在黑暗环境中进行交流并维持社群结构,很多蝙蝠种类的交流声波具有极高的多样性,但是目前关于特定种类蝙蝠交流声波的研究还比较缺乏。我们通过录制白腹管鼻蝠(Murina leucogaster)成体的声波,深入研究其交流声波声谱特征,根据交流声波在声谱图上的形状对声波类型进行初步划分,并利用主成分分析(PCA)和判别分析(DFAs)进行验证。结果表明,其交流声波在声谱结构上具有较高多样性,分为16种不同的音节类型,其中包括13种简单音节和3种组合音节,大多数音节都具有多谐波结构。简单音节可分为9种调频音节、2种准恒频音节和2种噪音,组合音节由简单音节无间隔地组合而成。第一谐波最大频率、第一谐波带宽、持续时间为与调频音节类型相关的主要参数。本研究结果为今后进一步开展研究蝙蝠发声行为的行为学意义和声波交流的神经生理学机制方面的研究奠定了基础。     

Development of social vocalizations in mice

Adult mice are highly vocal animals, with both males and females vocalizing in same sex and cross sex social encounters. Mouse pups are also highly vocal, producing isolation vocalizations when they are cold or removed from the nest. This study examined patterns in the development of pup isolation vocalizations, and compared these to adult vocalizations. In three litters of CBA/CaJ mice, we recorded isolation vocalizations at ages postnatal day 5 (p5), p7, p9, p11, and p13. Adult vocalizations were obtained in a variety of social situations. Altogether, 28,384 discrete vocal signals were recorded using high-frequency-sensitive equipment and analyzed for syllable type, spectral and temporal features, and the temporal sequencing within bouts. We found that pups produced all but one of the 11 syllable types recorded from adults. The proportions of syllable types changed developmentally, but even the youngest pups produced complex syllables with frequency-time variations. When all syllable types were pooled together for analysis, changes in the peak frequency or the duration of syllables were small, although significant, from p5 through p13. However, individual syllable types showed different, large patterns of change over development, requiring analysis of each syllable type separately. Most adult syllables were substantially lower in frequency and shorter in duration. As pups aged, the complexity of vocal bouts increased, with a greater tendency to switch between syllable types. Vocal bouts from older animals, p13 and adult, had significantly more sequential structure than those from younger mice. Overall, these results demonstrate substantial changes in social vocalizations with age. Future studies are required to identify whether these changes result from developmental processes affecting the vocal tract or control of vocalization, or from vocal learning. To provide a tool for further research, we developed a MATLAB program that generates bouts of vocalizations that correspond to mice of different ages.     

Female presence and estrous state influence mouse ultrasonic courtship vocalizations

The laboratory mouse is an emerging model for context-dependent vocal signaling and reception. Mouse ultrasonic vocalizations are robustly produced in social contexts. In adults, male vocalization during courtship has become a model of interest for signal-receiver interactions. These vocalizations can be grouped into syllable types that are consistently produced by different subspecies and strains of mice. Vocalizations are unique to individuals, vary across development, and depend on social housing conditions. The behavioral significance of different syllable types, including the contexts in which different vocalizations are made and the responses listeners have to different types of vocalizations, is not well understood. We examined the effect of female presence and estrous state on male vocalizations by exploring the use of syllable types and the parameters of syllables during courtship. We also explored correlations between vocalizations and other behaviors. These experimental manipulations produced four main findings: 1) vocalizations varied among males, 2) the production of USVs and an increase in the use of a specific syllable type were temporally related to mounting behavior, 3) the frequency (kHz), bandwidth, and duration of syllables produced by males were influenced by the estrous phase of female partners, and 4) syllable types changed when females were removed. These findings show that mouse ultrasonic courtship vocalizations are sensitive to changes in female phase and presence, further demonstrating the context-sensitivity of these calls.     

Microgeographic Variation and Sharing of the Gargle Vocalization and Its Component Syllables in Black-Capped Chickadee (Aves, Paridae, Poecile atricapillus) Populations

Throughout the year during agonistic encounters, black‐capped chickadees (Poecile atricapillus) emit a vocal signal known as the gargle call. Each bird has a repertoire of structurally differing gargle calls; some are shared with others in the local area. As a basis for understanding the cultural evolution of this social signal, we initiated a study of gargle call repertoires of birds living in a narrow belt of continuous riparian habitat occupied throughout by a resident population of chickadees. During two consecutive winter seasons, we sampled repertoires at three locations over a distance of 8.4 km to quantify micro‐geographical variation. Analyses of vocal sharing and population differentiation were carried out on whole gargle calls and on the individual acoustic units (syllables) from which the whole calls are constructed. We analysed 28 380 calls of 46 subjects in the two seasons of study. Birds averaged 7.6 different calls in their gargle repertoires. Calls were composed of about 10 syllables on average. Fifty‐six different syllables were used to construct the calls of all birds. Each study site had some gargle calls unique to the local birds and some that were shared with one or both of the other two sites. There was significantly greater sharing of both calls and syllables among birds within sample sites than between sample sites. The frequencies of the different kinds of gargles and syllables were significantly correlated across the 2 yr of the study, but the correlation was stronger (r² = 0.93) for syllables than for whole gargle calls (r² = 0.61).     

Individual Signature in Canary Songs: Contribution of Multiple Levels of Song Structure

Through variations in features, both within and between individuals, songs of male passerines provide information on the identity of the singer. In domesticated canaries (Serinus canaria), these variations remain, for a large part, to be investigated. This led us to question whether individual identity might be coded at one or more hierarchical levels of song organization, i.e. in acoustic parameters, in the syllable repertoire and in the delivery order of syllables. A song as a whole had numerous individual distinctive acoustic features. However, the structure of its individual signature appeared to be complex. A repertoire combined syllables never sung by other individuals with those shared by other birds. But, most of the individual‐specific syllables that accounted for 16% of a repertoire did not recur frequently. Variation in sequences of multiple syllable types appeared to reflect the individual identity of a male canary. Nearly all sequences larger than three syllable types were specific to the individual that produced them. Some of these occurred recurrently in songs and differed in their acoustic structure between individuals. Focusing upon recurrent sequences might allow vocal recognition of an individual without requiring the knowledge of its full repertoire. However, acoustic parameters and repertoire composition might also serve as additional cues to limit confusion between individuals.     

Discrimination of Infant Isolation Calls by Female Greater Spear-Nosed Bats, Phyllostomus hastatus

In colonial species, recognition of offspring should be under strong selection. For accurate identification to occur offspring must emit individually distinctive signals and parents must be able to discriminate between signals. Female greater spear-nosed bats (Phyllostomus hastatus) roost in stable social groups and use infant vocalizations, termed isolation calls, to locate and identify their young. In this study, we investigate both the production and perception of isolation calls in P. hastatus. First, we measured acoustic features and found that after controlling for ontogenetic effects, sufficient variation exists between pups for isolation calls to function as individual signatures. Moreover, pups from the same social group emit calls with more similar spectral and spectro-temporal features than pups from different social groups, indicating that these features are likely heritable. We used psychoacoustic experiments in the laboratory to determine if adult females could discriminate between calls from pups in the same or different social group. Females discriminated between pups when faced with a template-matching task and their performance was correlated with the salience of spectral and spectro-temporal features. We found no difference in performance when females had to discriminate between pups from the same and different social groups. These results indicate that females should be able to accurately identify their young using isolation calls.     

Song Learning in the Anna Hummingbird (Calypte anna)

Songs of wild male Anna hummingbirds (Calypte anna) consist of syllables grouped into phrases. Nearest neighbors tend to share similar syllable types, rhythms and syntax. Songs from different localities contain different syllable types, syntax and repetition indices. A male raised by hand in isolation produced a song consisting of highly variable syllable types of a wide frequency range. The song was simple in structure, and syllables were not grouped into phrases. Three males raised by hand as a group sang songs containing two stereotyped syllable types sung in alternating sequence and without phrase structure. These three males shared syllable types and syntax. The data from our study indicate that despite its relatively simple syrinx the Anna hummingbird learns syllable types, frequency, rhythm and syntax (as do oscines with their more complex syringes) during the song development process.     

红嘴相思鸟鸣声的初步探讨

2005年4～10月,在四川省屏山县老君山自然保护区通过计算机声谱分析技术对红嘴相思鸟的鸣声进行了初步研究。结果表明：红嘴相思鸟具有报警、联络、警戒和惊叫4种鸣声;其中最常见的鸣声为联络鸣声,报警、警戒和惊叫3种鸣声是一个先后连续的鸣叫过程。通过红嘴相思鸟鸣声特点探讨了与其相应行为的关系。     

Duet structure provides information about pair identity in the red-crowned crane (Grus japonensis)

We studied the acoustic features of the endangered red-crowned crane (Grus japonensis), and, specifically, whether or not the duets carry information about a mating pair identity. The population of this species in the wild is only approximately 2,000 individuals. In 2003–2006, we recorded 343 duets from eight captive and two wild pairs. All of the duets contained an introduction, an unordered alternation of pair mate calls, followed by the main part, representing the regular sequence of syllables, containing 1–2 male and 1–4 female calls per syllable. We subdivided the syllables into five types, by the number of male and female calls per syllable, and analyzed the occurrence of the different syllable types in the duets of the ten pairs. The analysis showed the sustainable pair-specific use of particular syllable types through the years. The discriminant analysis standard procedure, based on seven frequency and temporal parameters of male and female calls, showed 97.7% correct assignment to the pair, which is significantly higher than random values. The high pair specificity of the duet acoustic structures provides the basis for call-based censuses. This would enable the monitoring of the red-crowned crane mating pairs in their natural habitat.     

Versatility and Stereotypy of Free-Tailed Bat Songs

In mammals, complex songs are uncommon and few studies have examined song composition or the order of elements in songs, particularly with respect to regional and individual variation. In this study we examine how syllables and phrases are ordered and combined, ie “syntax”, of the song of Tadarida brasiliensis, the Brazilian free-tailed bat. Specifically, we test whether phrase and song composition differ among individuals and between two regions, we determine variability across renditions within individuals, and test whether phrases are randomly ordered and combined. We report three major findings. First, song phrases were highly stereotyped across two regions, so much so that some songs from the two colonies were almost indistinguishable. All males produced songs with the same four types of syllables and the same three types of phrases. Second, we found that although song construction was similar across regions, the number of syllables within phrases, and the number and order of phrases in songs varied greatly within and among individuals. Last, we determined that phrase order, although diverse, deviated from random models. We found broad scale phrase-order rules and certain higher order combinations that were highly preferred. We conclude that free-tailed bat songs are composed of highly stereotyped phrases hierarchically organized by a common set of syntactical rules. However, within global species-specific patterns, songs male free-tailed bats dynamically vary syllable number, phrase order, and phrase repetitions across song renditions.     

Mechanisms of song differentiation in introduced populations of Chaffinches Fringilla coelebs in New Zealand

Chaffinches Fringilla coelebs were introduced to New Zealand from Great Britain over 100 years ago, and since then their songs have diverged from British ones in both syllable structure and basic organization of syllable sequences. The New Zealand populations seem to be unique in that their songs have undergone differentiation of trill segments by progressive elaboration of syllable morphology and hp ascending and descending changes of pitch. Published sonagrams of British song types have significantly more trill phrases and significantly fewer syllables in the end phrase than do Yew Zealand ones. Many New Zealand song types have much elaborated end phrases and concomitantly simpler trill segments, with songs quite commonly having only one trill phrase. This reversal of complexity between the trill and end phrase in New Zealand seems to have been derived by progressive reduction of the ultimate trill phrase to one syllable, and by recombination of end phrase syllables from different song types into one compound end phrase. The significance of the increased complexity in the end phrases of many song types may relate to the sound transmission properties of dense pine forests in New Zealand, in which Chaffinches are ubiquitous. Elaborate end phrases degrade much less from reverberation in pine forests because individual syllables have more dispersed temporal patterning.
Recombination of syllables to form new song types is a major mechanism of song differentiation in New Zealand. Although whole song copying is the predominant mode of replication, very few song types in a locality sample are composed of a unique set of syllables. Rather, song types in an area are interconnected by different combinations of shared syllables, suggesting that the incorporation of some local syllables in a bird's repertoire is sufficient to signal its status as a member of a neighbourhood and also allows the evolution of broadcast complexity.     

Song convergence in multiple urban populations of silvereyes (Zosterops lateralis)

Recent studies have revealed differences between urban and rural vocalizations of numerous bird species. These differences include frequency shifts, amplitude shifts, altered song speed, and selective meme use. If particular memes sung by urban populations are adapted to the urban soundscape, "urban-typical" calls, memes, or repertoires should be consistently used in multiple urban populations of the same species, regardless of geographic location. We tested whether songs or contact calls of silvereyes (Zosterops lateralis) might be subject to such convergent cultural evolution by comparing syllable repertoires of geographically dispersed urban and rural population pairs throughout southeastern Australia. Despite frequency and tempo differences between urban and rural calls, call repertoires were similar between habitat types. However, certain song syllables were used more frequently by birds from urban than rural populations. Partial redundancy analysis revealed that both geographic location and habitat characteristics were important predictors of syllable repertoire composition. These findings suggest convergent cultural evolution: urban populations modify both song and call syllables from their local repertoire in response to noise.     

Alarm call discrimination in a social rodent: adult but not juvenile degu calls induce high vigilance

Many social animals develop vocal communications to send and receive information efficiently in a group. In alarm communication, call recipients in a social group evaluate alarm calls, enhancing their probability of survival in the face of predatory threats. Calls from naïve and younger group members might be less evocative, in terms of rendering group members vigilant, than calls from more experienced adults because adults are generally more reliable. It remains uncertain, however, what acoustic characteristics render an alarm call reliable. Here, we report that adult degus, Octodon degus (Rodentia, Octodontidae), produced an alarm with a frequency-modulated (FM) syllable, accompanied by low bandwidth and entropy, to evoke a high-vigilance response amongst receivers. Unlike adults, subadult degus did not emit the FM syllable in the warning context, and their call without the FM syllable evoked less vigilance than the adult alarm. We suggest that the FM structure of the adult-produced syllable serves as the primary feature characterizing a reliable alarm call. Our results are consistent with those found in other social rodents, e.g., ground squirrels and gerbils, also produce FM alarm calls in high-urgency situations supports the importance of the FM syllable in alarm communication.