同一生境中强脚树莺鸣声的个体差异及多样性

在杭州市郊小和山森林公园内约85 hm ²范围内，用SHARP-CE-15l型录音机(频响30—l4 000 Hz)和强指向麦克风(频响40—14 000 Hz)，对夏季繁殖期连续分布的同一生境中不同个体的强脚树莺(Cettia fortipes)的鸣声进行了记录，并通过计算机声谱分析系统从句型结构、音图结构、时域和频域特征及短时能量等方面进行了分析和比较，发现在同一生境一个小范围内同一种鸟就有6种不同类型的鸣声。这些鸣声的音调各不相同，鸣声的结构差异很大，大多声学参数之间也存在显著或极显著差异。形成这种鸣声多样性的原因可能是繁殖竞争在声行为上的体现。     

圆蟾舌蛙鸣声特征分析

为研究体型较小的蛙类的鸣声特征,2012年7~8月,采用录音机和指向性话筒,在野外录制51只雄性圆蟾舌蛙(Phrynoglossus martensii)鸣声并对应测量了录音个体的体重、体长及头宽等体征数据。雄性圆蟾舌蛙的体重为(1.26±0.55)g,体长为(21.04±2.57)mm,头宽为(6.76±0.75)mm。该种蛙可发出广告鸣声和争斗鸣声。广告鸣声为单音节鸣叫,主频(3 782.25±167.78)Hz,3 100~4 349 Hz;基频(1 519.69±70.60)Hz,1 057~1 765 Hz。广告鸣声主频和基频均与体重、体长、头宽呈显著负相关,而音节间隔与体重和头宽呈正相关(相关性分析)。争斗鸣声主频(3 752.64±174.47)Hz,(3 304~4 081)Hz;基频(1 674.88±79.88)Hz,1 367~1 870 Hz。与广告鸣声相比,争斗鸣声的基频显著增高(t=﹣5.374,df=56,P0.001),音节时长和音节间隔显著降低(P0.05),而主频在两种鸣声类型中无显著差异(t=0.436,df=56,P=0.665)(独立样本T检验)。结果表明,作为体型较小的蛙类,体型影响了圆蟾舌蛙的鸣声结构和类型。     

扬子鳄幼鳄出壳前后的鸣声特征比较

成年扬子鳄(Alligator sinensis)的声信号已经有过深入的研究,然而其声音的个体发育,特别是幼鳄出壳前后鸣声的时空特征至今还不为人所知。为了解扬子鳄声音的发育过程,记录和分析了21只扬子鳄幼鳄的260个叫声,结果表明,幼鳄出壳前后的鸣声具有相似的特征,即开始向上的频率调节和较长的向下的频率调节。出壳前和出壳后的两组叫声均包括持续叠加的多组谐波,并且绝大多数的鸣声都是在第3谐波显示了最强的能量。分析了出壳前后鸣声的9个参数,即总时长、向上调频的时长、向下调频的时长、基频的起始频率、最高频率、结束频率、向上调频的倾斜度、向下调频的倾斜度、主频。除了向上调频的时长,出壳前后鸣声的其他时长参数均没有表现出显著差异。与之相反的是,出壳前后鸣声的频谱参数,特别是基频的最高频率和主频均表现出显著差异(P0.05)。出壳前鸣声基频的最高频率为(573±103)Hz,出壳后的声音最高频率(460±52)Hz,出壳前比出壳后高113 Hz;出壳前的声音主频(1 359±229)Hz,出壳后的声音主频(1 123±216)Hz,前者比后者高236 Hz。幼鳄发出主频较高的鸣叫有利于吸引附近母鳄的注意同时避免天敌的捕食。     

红蹼树蛙繁殖期鸣声特征及鸣叫节律

鸣叫是无尾两栖类声音通讯的重要环节之一。许多蛙类的鸣叫行为具有节律性,且受温度和湿度的影响。为研究红蹼树蛙(Rhacophorus rhodopus)的鸣声特征和鸣叫节律,2016年5—6月,采用录音机和指向性话筒,在野外录制了61只雄性红蹼树蛙的鸣声,并通过悬挂录音笔和自动温湿度记录仪研究其鸣叫节律(22 d)。结果发现:红蹼树蛙的鸣声分为单音节和多音节(音节数2~20;平均6.27±2.94)2种类型。与多音节鸣声的主频(2213.32±106.95 Hz)、音节时长(14.83±1.27 ms)和音节间隔(60.66±8.56 ms)相比,单音节鸣声的主频(2289.87±120.14 Hz)、音节时长(16.93±1.68 ms)和音节间隔(610.99±178.48ms)显著升高(P0.05),而2种鸣声的基频(单音节鸣声:212.51±21.63 Hz;多音节鸣声:225.39±26.80 Hz)无显著差异(P0.05)。红蹼树蛙每晚19:00至次日03:00具有鸣叫行为,22:00为高峰期。结果表明:红蹼树蛙主要通过改变鸣声的主频、音节时长、音节间隔以及音节数提高声音通讯效率。红蹼树蛙的鸣叫行为具有昼夜节律,且在一定程度上受温度和湿度的影响。     

杂色山雀指名亚种繁殖期的鸣声行为

2012年3～7月,对辽宁仙人洞自然保护区9巢18只杂色山雀(Parus varius varius)个体及其雏鸟的鸣声进行了录音,共获取了9种类型鸣叫(呼唤、警戒、报警、恫吓、驱逐、惊叫、喂食、雏鸟乞食、集群)和5种类型鸣唱.通过语图分析得出音节类型18种,频率范围为800 ～18 900 Hz.对杂色山雀不同个体鸣声特征参数的比较发现,鸣声的句子和音节时长在不同个体之间存在显著性差异,而最高频率、最低频率在不同个体间均无显著性差异.本研究实现了对杂色山雀繁殖期鸣声参数的量化,有助于进一步研究其繁殖行为.     

基于鸣声模型的云南柳莺地理种群关系分析

将录自北京、甘肃、四川和陕西7个地区共117段云南柳莺(Phylloscopus yunnanensis)的鸣唱样本分别提取短时特征Mel倒谱系数(MFCC),利用系统聚类方法,构建云南柳莺不同地理种群鸣声特征之间的树状关系图,并对云南柳莺地理鸣声差异产生机制的可能因素(地理距离、海拔等)进行探讨。这是基于鸣声短时特征的物种识别在研究同一物种不同地理种群关系中的首次尝试。结果显示,其鸣声地理差异与距离之间没有显著相关性(Pearson,r=﹣0.036,P=0.762,n=117),但与海拔存在显著的相关性(Pearson,r=﹣0.836,P0.001,n=117)。     

环境噪声对临安和阜阳两地白头鹎鸣声频率的影响

为了解环境噪声对白头鹎(Pycnonotus sinensi)鸣声频率的影响,在浙江临安和安徽阜阳两地分别对白头鹎在高低噪声水平环境中的鸣声做了研究。把用数码录音机记录到的鸣声输入计算机,利用计算机声谱分析系统进行分析,再对每一鸣声的每个音节的主频进行Mann—Whitney U检验。结果显示：高噪声水平区和低噪声水平区相比,在两地白头鹎每一鸣声的各音节主频中,最低和最高主频以及第I、Ⅱ音节的主频都有显著提高;在阜阳第Ⅲ音节的主频也有显著提高。这表明白头鹎可以通过提高声音频率来避免环境噪声对鸣声的影响,从而保证噪声环境中声信息的有效传递;而噪声对各音节的不同影响也表明,同一鸣句的各音节,对于噪声通讯中的信息识别,具有不同的地位。     

黑蚱蝉鸣声的结构和音色特征

本文对北京、河北和福建等地黑蚱蝉(Cryptotympana atrata Fabricius)的三种鸣声进行了分析,并对发声机理进行了讨论。 黑蚱蝉野外的自然鸣声具有基本相同的结构层次,都由重复频率为43—49Hz的节奏组成,每个节奏含有4个单音节,每个单音节含有3个脉冲群,每个脉冲群含有若干个脉冲。但是音色有明显的差异,即分别为单音色、双音色和具有高幅低频声的复合声。黑蚱蝉室内的惊鸣声和自鸣声,虽然音色有一定的变化,但仍保持自然鸣声的结构层次。鸣声的结构层次明显取决于发声膜的结构特征,这表明具有种类的特性。音色的差异性不仅与调音、扩音结构的功能有关,而且可能与发声膜的力学性质和发声的原初过程有关,即可能具有地区性和种下差异。 这些结果可为蝉类发声机制和有害昆虫声引诱的声学模型的研究提供依据。     

饰纹姬蛙求偶鸣声特征分析

2012年5月,用SX950录音笔和Praat声音分析软件对浙江丽水繁殖季节饰纹姬蛙(Microhyla ornata)求偶鸣声进行录制和特征分析.结果表明,饰纹姬蛙发出的求偶鸣声具有单一谐波鸣声结构、多脉冲(7、9～16)及纺锤形振幅等特征;所有鸣声主频率范围为1.22～4.09 kHz (n=233),且由不同脉冲数组成的鸣声主频率平均值几近相等;叫声时程随脉冲数的增加而增大,脉冲时程在不同脉冲数鸣声中的大小几近相等,但最后一个脉冲的时程大小≤其他脉冲;脉冲间隔与叫声时程则刚好相反,即叫声时程越短,脉冲间隔就越大.在7个脉冲的鸣声中,其脉冲间隔最大,脉冲率最小;而在16个脉冲的鸣声中,脉冲间隔则最小,脉冲率最大.除7个脉冲和16个脉冲鸣声的脉冲率分别与其他鸣声存在显著性差异以外,随着叫声时程和脉冲数的增加,脉冲率也出现相应变化.在声强方面,除16个脉冲鸣声与其余所有的脉冲鸣声出现显著性差异以外,其他脉冲鸣声之间的两两比较差异不显著.丽水种群与其他5个地理种群(杭州、宣城、Kamoor、Bajipe和Padil)的鸣声特征比较显示饰纹姬蛙在不同地理种群的鸣声结构相似,而鸣声主频率、叫声时程、脉冲时程及脉冲率等在6个地理种群种均出现不同程度的差异.了解不同物种的声信号特征有助于更好地理解动物通讯行为及其进化特点.     

刺激家鸽中脑丘间复合体背内侧核诱发叫声与其自鸣声的比较

利用计算机声谱分析技术比较了家鸽刺激中脑丘间复合体背内侧核(DM)诱发叫声和其正常自鸣声。家鸽的单次自鸣声“di·Gu—”,包括前奏、高潮声和尾声,其主频率和相对幅值都呈明显的逐步递增、平稳和逐步下降过程。高潮声平稳期的载波主频率(318Hz)所表征的主音调比前奏和尾声的主频率(239Hz)分别平均高4.9个半音,相对幅值分别平均高24.4dB和13.2dB,品质因数(Q6dB)分别增高1.8倍和2.8倍。随着刺激电压的增大和减小,家鸽单次鸣声持续时间呈显著的线性递减和递增。诱发叫声的主频率显著性低于自鸣声,声图中有1-2个陪音。本实验为阐明非鸣禽发声调控提供声学特征上的依据     

Acoustic Features Used in Song Discrimination by the Veery

To investigate which song features are used for discrimination by the veery (Catharus fuscescens), we synthesized songs by computer and manipulated or deleted various features. These songs were then played to territorial males in their natural habitat. Differences in response to these stimuli indicated the relative importance of the manipulated song components. We found that certain features must be maintained in order to elicit a territorial response similar to that elicited by the natural song. These features were the frequency changes between and within syllables, the dominant higher frequency band (or voice), the intra-syllable syntax, and the rapid repetitive amplitude and frequency modulations. Manipulations of inter-syllable syntax independent of frequency changes between syllables, broad changes in amplitude, and the lower frequency band, did not have a significant effect on response. We thus concluded that they are not essential as cues for discrimination or species identification. Re-recordings of songs broadcast along transects indicate that song components used in encoding species identity are those which transmit well across veery territories.     

丹顶鹤性活动的声行为研究

丹顶鹤繁殖期的性活动可分为雄鹤求偶、雌鹤对雄性求偶的应答、两性交配和交配完结4个阶段,其相应的鸣声模式分别为雄性的求偶鸣声、雌性对雄性求偶的应答声和两性的对鸣声、两性对唱的交配声和两性的高声合唱。4个阶段鸣声都是以基本音的主频率(PF)为主音的单音调声,前3个阶段都带数个近似fn=nf0(f0=FP)关系的低幅值谐频成分。第4个阶段带数个近似fn=nf0(f0=FP)关系的高幅值谐频成分;品质因数(Q3dB)多半为4～6,声脉冲重复频率(RFP)一般为150～180Hz,而第2阶段声的RFP一般为180～260Hz。雄性鸣声的每个单次叫声中含有的音节数较少,一般不超过4个;而雌性鸣声比较复杂。每个单次叫声中含有的音节数较多,一般都在7～8个以上;但雌雄鸣声的每个音节都是由3个声脉冲组成。雄鹤鸣唱声频率变化范围较小,而雌鹤鸣唱声频率变化形式是由低到高达到高峰后又开始下降。4个阶段的鸣声都具有较好共鸣。只有第2阶段发声运动较快。而且发现雄鹤鸣唱单次鸣叫声的音节数“增多”。各阶段鸣声特性均存在差异,不同配偶间均存在显著差异,研究结果表明丹顶鹤雌雄都具有不同的鸣声,且其性活动过程中不同的鸣声行为具有较高的个体识别信号潜能。另外,求偶鸣叫声和求偶应答与对鸣声在性活动鸣声中起着决定性的作用。     

Song parameters of the fuscous honeyeater Lichenostomus fuscus correlate with habitat characteristics in fragmented landscapes

Both avian abundance and species richness decline in response to habitat loss and fragmentation. Studying variation in bird song structure across modified landscapes can provide insights into the effects of habitat alterations on coherence of social interactions within populations. Here, we tested whether fragmentation or change of habitat quality within box‐ironbark forest of central Victoria impacted cultural connectivity and song characteristics in fuscous honeyeater, a declining common Australian bird. First, we tested whether geographic distance and/or spatially‐explicit landscape connectivity models can explain patterns of song similarity across fragmented landscapes. We found no evidence that distance or habitat fragmentation impacts the nature and transmission of fuscous honeyeater song, and concluded that acoustic connectivity at the scale of our study is high. Second, we tested whether variation in habitat quality explains variation in song characteristics. In accordance with acoustic adaptation to habitat structure, birds sang longer songs in sites with more large trees and produced longer common song elements in sites with greater tree height. However, the acoustic adaptation hypothesis cannot explain the finding that in less‐disturbed landscapes with higher tree‐cover birds sang songs (and song elements) with higher maximum frequency and wider frequency bandwidth. We also found that birds sing longer and more variable songs of wider frequency bandwidth in less disturbed sites with a greater number of large mature trees, which may represent better feeding resources. Our study suggests that changes in song structure with habitat degradation could signal disturbed population processess, such as changes in the acoustic communication among resident birds.     

Differences in Frequency of Shared Song Types Enables Neighbour‐Stranger Discrimination in a Songbird Species with Small Song Repertoire

Acoustic Neighbour‐Stranger (N‐S) discrimination is widespread in birds and has evolved to settle territorial disputes with low costs. N‐S discrimination was found both in song‐learning oscines and non‐song‐learning bird taxa, irrespective of the repertoire sizes they have. Therefore, it seems that more than just a single mechanism enable N‐S discrimination. Species with larger repertoires, where males have unique phrases or syllables may rely on such interindividual differences. The majority of birds have rather small repertoires, which often are shared among neighbours. In this case, males are facing the problem of individual recognition when rivals produce songs, at least superficially, identical. To better understand the acoustic basis of N‐S discrimination in species with small and shared repertoires, I studied the ortolan bunting (Emberiza hortulana). Males of this small oscine species are able to N‐S discrimination based on a single song rendition when presented in a playback experiment, regardless of song‐type diversity and song‐sharing level within a particular population. It was also found that songs of the same type sung by different males differ in the frequency of the initial song phrases and these differences persist over years. Here, I tested whether males are able to discriminate among the natural songs and the artificially modified songs of their neighbours in which the frequency was experimentally changed by relatively small value in comparison with the variation range found in this population. Subjects responded significantly more aggressively to the songs with an artificially modified frequency, suggesting that males treat such songs as having come from the repertoire of a non‐neighbour. These results confirm an earlier prediction that differences in the frequency of shared song types enable N‐S discrimination. The study presents one of the possible mechanisms enabling N‐S discrimination in songbirds with small repertoires and stress the role of within‐song‐type variation, which is still understudied song characteristic.     

Independent evolution of song structure and note structure in American wood warblers

This study addresses the issue of how evolutionary convergence within shared environments shapes some features of bird song while leaving others unaffected, using as an example the songs of 51 North American wood warblers (Parulinae). I combined published information on breeding habitats and evolutionary relationships to show that the structure of warbler songs is correlated with habitat, whereas the structure of the notes that comprise the songs is relatively unaffected by habitat and more closely related to phylogenetic history. The results confirm known relationships between bird song and habitat, including correlations between song frequency and the type and density of canopy foliage, and between the number and arrangement of notes in the song and foliage density and moisture. More importantly, the results suggest that individual notes and whole songs are to some extent functionally independent, because the configuration of notes shows more evidence of evolutionary constraint than does the way notes are assembled into songs.     

Differentiation of Mating Vocalizations in Birds: Acoustic Features in Mainland and Island Populations and Evidence of Habitat-Dependent Selection on Songs

Local environments can act as selective agents on some characteristics of birds’ songs, whereas other song traits may not reflect local genetic adaptation. Geographic variation in songs of two Australian bird species (red‐capped robins Petroica goodenovii, western gerygones Gerygone fusca) was studied to examine one component of the ‘habitat‐dependent selection’ hypothesis. This hypothesis suggests that: (1) the detailed spectral characteristics of male songs are an evolved response to local habitat conditions affecting signal propagation and detection and (2) parallel evolution of other fitness traits sets up the potential for assortative mating by female choice. To examine the first part of the hypothesis, I made comparisons among widespread mainland populations and an island population using two levels of analysis: a typological analysis of song morphology (phonology: notes, syllables, syntax, temporal pattern, repertoires) and a spectral analysis of acoustic characteristics of songs (mean frequency, Wiener entropy, frequency modulation) using an automated procedure of feature extraction (Sound Analysis Pro). Spectral analysis was also used to extract values of the same acoustic features from the background sound environment of each recorded population. The typological analysis revealed no differences among mainland populations of either species, but large differences between mainland songs and those on the island. In contrast, the spectral analysis revealed acoustic divergence among populations, both mainland and island. For both species, Wiener entropy of songs correlated negatively with that of the ambient sound environment, consistent with predictions of the habitat‐dependent selection hypothesis of environmental selection on signal design.     

A Previously Undescribed Method of Song Matching in a Species with a Single Song “Type”, the Kentucky Warbler (Oporornis formosus)

The song of male Kentucky warblers consists of several repetitions of syllables containing 2 to 7 elements within a frequency range from 1.8 to 6.0 kHz. Each male has a single, individually distinctive song type that spans part or all of this frequency range. Song responses to playbacks of songs artificially elevated or lowered in frequency by 200 Hz show that a bird is able to alter its song in two ways. It may lower or raise the frequency range of the song or put more energy into the lower or higher frequencies within the song's elements to more closely match the energy distribution of the playback song. The syllable or element structure of the song is kept constant with only the song's energy distribution among frequencies changing. Thus, Kentucky warblers are able to alter their single song type to “match countersing” in a way similar to that of species with song repertoires who switch song types to match those of rivals. The Kentucky warbler may have a single songtype because of its ability to change its song's energy distribution. This ability may perform the same functions as song matching does in species with larger repertoires. This finding is discussed in relation to ideas on the evolution of song repertoires in intrasexual competition.     

The effect of isolation,fragmentation, and population bottlenecks on song structure of a Hawaiian honeycreeper

Little is known about how important social behaviors such as song vary within and among populations for any of the endemic Hawaiian honeycreepers. Habitat loss and non‐native diseases (e.g., avian malaria) have resulted in isolation and fragmentation of Hawaiian honeycreepers within primarily high elevation forests. In this study, we examined how isolation of Hawai'i ‘amakihi (Chlorodrepanis virens) populations within a fragmented landscape influences acoustic variability in song. In the last decade, small, isolated populations of disease tolerant ‘amakihi have been found within low elevation forests, allowing us to record ‘amakihi songs across a large elevational gradient (10–1800 m) that parallels disease susceptibility on Hawai'i island. To understand underlying differences among populations, we examined the role of geographic distance, elevation, and habitat structure on acoustic characteristics of ‘amakihi songs. We found that the acoustic characteristics of ‘amakihi songs and song‐type repertoires varied most strongly across an elevational gradient. Differences in ‘amakihi song types were primarily driven by less complex songs (e.g., fewer frequency changes, shorter songs) of individuals recorded at low elevation sites compared to mid and high elevation populations. The reduced complexity of ‘amakihi songs at low elevation sites is most likely shaped by the effects of habitat fragmentation and a disease‐driven population bottleneck associated with avian malaria, and maintained through isolation, localized song learning and sharing, and cultural drift. These results highlight how a non‐native disease through its influence on population demographics may have also indirectly played a role in shaping the acoustic characteristics of a species.     

Songs of Holcostethus strictus (Fabricius): a different repertoire among landbugs (Heteroptera: Pentatomidae)

Songs emitted during mating by male and female Holcostethus strictus were recorded as substrate vibrations. Spectra of the vibrational signals have a dominant frequency peak between 100 and 260 Hz and in this respect reflect the general characteristic of the family Pentatomidae. Songs of H. strictus differ from the song repertoire of the southern green stink bug Nezara viridula (L.) (Pentatomidae) in many respects. The female calling and courtship songs differ in echeme and phrase duration. The male calling song is composed of spectrally different subunits. The male courtship song is characterised by three types of spectrally and temporally different echemes. The male copulatory song is composed of echemes of two types, which constitute a phrase of less regular temporal structure. In H. strictus, males start to sing first and female songs are less complex than in N. viridula. The female calling song is evoked by male calling and does not trigger male response. The female and male courtship song phrases are superimposed on one another and we have not observed any obvious regularity in their exchange. The possible role of different songs in H. strictus is discussed and compared with that in other pentatomide landbug species.     

Community convergence in bird song

Species in similar habitats are often similar in morphology or behaviour, attributed to adaptation to similar environmental selection pressures, sometimes mediated by competitive interactions. For passerine songs, similarity of phenotype in identical habitats and character displacement have been documented, the former due to adaptation to the acoustics of the habitat, and the latter due to competition for acoustic space among species. If these phenomena are widespread, they should lead to community convergence of bird songs. Here, we test if passerine communities in similar habitats converge in song attributes or in acoustic differentiation among species. We compared the songs of European and North American Mediterranean climate passerine communities in open and closed habitats. Song frequency varied across different habitats but not continents. This was independent of both phylogeny and body size, indicating community convergence due to acoustic adaptation, rather than species sorting or similarity as a by-product of another type of ecological convergence. We found little evidence for regular spacing in song features among species, as would be expected if acoustic competition shapes within-community structure. However, for one of five song components, the open habitat communities showed a similar distribution of phenotypes on each continent. The proportion of interspecific variation in song explained by these effects was small. The fact that songs are complex signals that vary in many dimensions may explain why competition for acoustic space seems to be of small importance in structuring songs in these passerine communities.