雄性凹耳蛙不同合唱期鸣声特征的变化

声音通讯在凹耳蛙(Odorrana tormota)的繁殖过程中起到关键作用,雄性凹耳蛙个体处于不同性选择压力下会采取不同的发声策略,然而相关研究仍缺乏。本实验采用个体标记法,基于2021年3-5月的野外实验,对雄性凹耳蛙个体(n=12)处于合唱高潮期和低潮期鸣声中的非线性发声现象(nonlinear vocal phenomena,以下简称NLP)总含量及其各组分(混音、半谐波、频率跳跃)含量、鸣声时长以及鸣叫频次之间的差异进行Wilcoxon符号秩检验。结果显示,雄蛙处于合唱高潮期和低潮期鸣声中的部分NLP组分(混音、半谐波)含量以及鸣声时长均没有显著性差异,合唱低潮期的NLP总含量、部分NLP组分(频率跳跃频次)显著大于高潮期,合唱高潮期的发声率显著大于低潮期。实验结果表明,雄性凹耳蛙不同合唱期会采取不同的发声策略,即性选择压力较小的低潮期通过提高鸣声中的NLP含量、扩大声音传播距离、增大声音的不可预测性来更好吸引雌性;高潮期性选择压力大时,雄蛙通过提高鸣叫频次使得个体鸣声更加突出,从而提高抱对成功率。     

雄性凹耳蛙的争斗鸣声及其打斗行为

2017年4月17日,在黄山浮溪完整地记录了2只雄性凹耳蛙（Odorrana tormotus）之间争夺领地的打斗过程、争斗鸣声以及其中一只蛙打斗后的鸣声,并用摄像机记录了此行为的过程。争斗大约持续了8 min,并产生了一个胜利者和一个失败者。实验共录了胜利蛙的争斗鸣声17声,打斗后鸣声7声,失败蛙的争斗鸣声6声,其中两只蛙同时鸣叫了1声。随后通过Praat语音软件获取鸣声的时域参数和频谱参数,并利用T检验来判断两只蛙争斗鸣声参数是否具有显著差异,以及胜利蛙打斗时与打斗后的鸣声参数是否具有显著差异。对两只蛙争斗鸣声的时域和频谱参数分析发现,胜利蛙以多音节鸣叫为主,其平均基频（8 150 ± 1 305）Hz、最大基频（9 741 ± 1 283）Hz、最小基频（5 809 ± 1 139）Hz以及最大最小基频差（3 932 ± 1 122）Hz都高于失败蛙,尤其是平均基频和最大基频（P < 0.05）,而最小基频以及最大最小基频差二者差异并不显著（P > 0.05）,但是胜利蛙的主频却要略低于失败蛙（P > 0.05）;失败蛙的鸣声中非线性片段时长占总时长的百分比更大,甚至超过50%。将胜利蛙的争斗鸣声与打斗后鸣声进行比较,发现总时长、非线性片段时长和平均基频在争斗后都有明显减小（P < 0.05）,最大基频、最小基频有略微减小（P > 0.05）,而音节间隔时间占总时间的百分比和大小基频差都有所增大（P > 0.05）,这可能是为了在争斗过程中更快地击退对手。因此,推测胜利蛙获取胜利的原因可能是因为其具有较高的鸣叫率以及较低的主频。本文描述了雄性凹耳蛙争斗过程中的鸣声特征,可对凹耳蛙雄性之间的竞争过程有更进一步的了解。     

不同物种雄性鸣声刺激下雌性凹耳蛙脑组织中ZENK的表达

通过免疫组化SABC法,研究在背景噪音刺激、雄性凹耳蛙(Odorrana tormota)声音刺激以及雄性大绿臭蛙(O. graminea)声音刺激下ZENK蛋白在雌性凹耳蛙脑部的表达。结果显示,上述三种声音刺激下雌性凹耳蛙的端脑、间脑和小脑区域均未发现ZENK蛋白的阳性细胞。在雄性凹耳蛙声音刺激下,雌性凹耳蛙中脑的视顶盖、脚间核、中脑深部核、被盖、半环隆枕以及延脑的孤束核、中缝核、网状核、网状结构、上橄榄核部位均有阳性细胞分布,在大绿臭蛙声音刺激下,这些部位的阳性细胞数量明显减少。本实验中ZENK蛋白阳性细胞表达部位的一部分是位于与两栖类处理听觉信息有关的中脑半环隆枕、被盖以及延脑的上橄榄核,由此可推断,在雌性凹耳蛙ZENK蛋白与听觉信息处理有着密不可分的联系。     

同一噪音环境下武夷湍蛙与凹耳蛙的求偶鸣声特征比较及其适应策略

为了解同域分布的两种无尾两栖类动物武夷湍蛙(Amolops wuyiensis)和凹耳蛙(Odorrana tormotus)在高噪音环境下的求偶鸣声特征及其适应策略,该研究利用超声录音设备录制并分析了繁殖季节武夷湍蛙和凹耳蛙雄性个体在同一噪音环境下的求偶鸣声。结果显示,繁殖期武夷湍蛙在不同时段均能发出3~6个音节数不等的单一鸣声,每个音节由2~10个声脉冲组成,鸣声平均持续时间为2198.20ms,主频为2231.90Hz,信噪声强差为33.00dB,且鸣声不含超声组分,不具备超声通讯的基础。凹耳蛙在每天的18:00—21:00有集中鸣叫行为,鸣声平均持续时间为331.80ms,主频为6665.50Hz,信噪声强差为37.00dB,且鸣声谐波包含超声组分,与前人描述一致。经进一步分析发现,武夷湍蛙和凹耳蛙的鸣声主频和声强均高于背景噪音,噪音不会对其鸣声产生掩蔽作用。通过比较分析得知,武夷湍蛙鸣声主频率<凹耳蛙,推测其声信号传播距离相对后者更远,该蛙在噪音环境下有可能通过调整自身的发声策略(即采用多音节鸣叫声、增加鸣叫时长和鸣叫频次等)来完成种内通讯,并通过改变鸣声时长来体现雄性自身的品质,以便提高对雌性的吸引力。而相同噪音环境下的凹耳蛙则可能采用较为节约能量的方式提高声信号频率的通讯策略,完成种内竞争和交流。     

噪音环境下花臭蛙求偶鸣声特征分析

2012年7月份,在黄山浮溪地区利用超声录音设备录制并分析了繁殖季节雄性花臭蛙(Odorrana schmackeri)个体的求偶鸣声。观察发现花臭蛙繁殖活动主要集中在7月中旬,繁殖高峰期活动无昼夜规律,全天均可见求偶鸣叫及抱对产卵等行为,并且多在浅水滩处活动。花臭蛙鸣声根据音节数和声谱特征可分为4种类型:即单音节音、婴儿音、双音节音和多音节断奏音,其中,单音节音、双音节音和婴儿音较为常见。利用Selena软件给出4种声音的语图以及各自对应的能谱图,利用Sound Analysis pro v1.2对单音节音、双音节音和婴儿音的鸣声特征参数进行定量分析,分析的声音参数包括鸣叫持续时间、音节数、音节持续时间、音节间隔、主频、脉冲率等。结果表明,花臭蛙鸣声的主频范围为1.8~4.5 k Hz(n=65)。鸣声不包括超声组分,主频峰值(3.1±0.7)k Hz,与前人电生理实验所得花臭蛙听觉敏感峰值一致,说明花臭蛙主要在这一频段进行通讯。对3种常见鸣叫音声音参数的单因素方差分析结果表明,双音节音与单音节音和婴儿音在声音持续时间上存在显著性差异(P0.01),双音节音和单音节音在第二谐波声强上也具有显著性差异(P=0.01)。花臭蛙的双音节音在3种常见鸣叫音中具有最长的持续时间,为(99.5±8.4)ms,故推测,双音节音为花臭蛙繁殖期主要求偶鸣声,并通过其鸣声时长的变化来体现自身品质的好坏。     

近距离交流信号对雌性凹耳蛙 抱对成功率的影响

繁殖期雌性凹耳蛙（Odorrana tormota）的声信号已有过深入的研究,但目前国内对其交配行为研究较少,近距离时,雌性凹耳蛙如何与雄蛙交流并完成抱对尚不清楚。为探究繁殖期雌性凹耳蛙与雄蛙近距离交流、交配过程,采用焦点动物取样法和全事件取样法对雌性凹耳蛙交配前行为进行记录。2013至2016年及2018年记录并分析了49组雌雄蛙抱对过程和42组未抱对个体的视频数据。结果表明,凹耳蛙雌蛙与雄蛙近距离交流过程涉及多种信号,包括视觉信号（眨眼、低头、腹部膨胀、脚趾震动、背转向雄蛙）与声信号两类;在每组雌蛙发出信号且抱对成功的实验中,各视觉信号出现1或2次较多,声信号出现1至3次较多,眨眼、鸣声、腹部膨胀三种信号的总次数较多;5个繁殖期所记录的雌蛙交流信号中视觉信号所占的比例均高于声信号。统计分析结果显示,同一只雌蛙在抱对成功与失败时所发出的眨眼、低头和腹部膨胀三种视觉信号的次数存在显著性差异（P < 0.05）,声信号、腹部膨胀、脚趾震动和背转向雄蛙这四种信号仅在抱对成功时出现。因此,推测这些信号在抱对前出现时,有助于提高雌雄凹耳蛙抱对成功率。     

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。     

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。     

凹耳蛙的两性异形

测量和比较采自黄山的凹耳蛙成体标本(雌雄各20个),统计结果表明成年雌雄蛙的体长、头宽、吻长、鼻间距、眼间距、眼径、鼓膜宽、前臂及指长、前臂宽等两性形态学指标存在显著性差异。对与体长显著相关的形态特征,以体长为协变量的协方差分析表明凹耳蛙雌雄两性在头宽、眼间距、眼径、鼓膜宽存在显著差异。凹耳蛙两性异形比达到0.418,雌性平均体长对雄性平均体长的比达到1.716。头宽、眼间距、眼径、鼓膜宽等局部形态特征与体长的线性回归分析表明,雌性斜率大于雄性斜率,说明雌性凹耳蛙上述局部特征随体长的生长速率明显大于雄性。雌性体长的繁殖力选择能够很好地解释凹耳蛙的两性异形。     

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。     

Diversity of the Vocal Signals of Concave-Eared Torrent Frogs (Odorrana tormota): Evidence for Individual Signatures

Male concave-eared torrent frogs ( Odorrana tormota ) have an unusually large call repertoire and have been shown to communicate ultrasonically. We investigated the individual specificity of male advertisement calls in order to explore the acoustic bases of individual recognition, which was demonstrated in an accompanying study. Vocalizations of 15 marked males were recorded in the field. A quantitative analysis of the signals revealed eight basic call-types. Two of them (the single- and multi-note long-calls) were investigated in more detail. Long-calls were characterized by pronounced and varying frequency modulation patterns, and abundant occurrence of nonlinear phenomena (NLP), i.e., frequency jumps, subharmonics, biphonations and deterministic chaos. The occurrence of NLP was predictable from the contour of the fundamental frequency in the harmonic segment preceding the onset of the NLP, and this prediction showed individual-specific patterns. Fifteen acoustic variables of the long calls were measured, all of which were significantly different among individuals, except biphonic segment duration. Discriminant function analysis (DFA) showed that 54.6% of the calls could be correctly assigned to individual frogs. The correct classification was above chance level, suggesting that individual specificity of calls underlie the ability of males to behaviorally discriminate the vocal signals of their neighbors from those of strangers, a remarkable feat for a frog species with a diverse vocal repertoire. The DFA classification results were lower than those for other anurans, however. We hypothesize that there is a tradeoff between an increase in the fundamental frequency of vocalizations to avoid masking by low-frequency ambient background noise, and a decrease in individual-specific vocal tract information extractable from the signal.     

Neighbor–Stranger Discrimination in Concave-Eared Torrent Frogs, Odorrana tormota

The dear enemy phenomenon in which animals discriminate familiar neighbors from unknown strangers, and respond more aggressively to strangers is well established in various social animals, especially in songbirds and mammals. So far, very few studies of neighbor–stranger discrimination have been carried out in amphibians and the results have been mixed. Thus, it is unclear whether this phenomenon exists commonly in frogs and toads, and whether it is exhibited by species with large vocal repertoires. We conducted acoustic playback experiments with male concave-eared torrent frogs ( Odorrana tormota , a species with an unusually large vocal repertoire) kept in a tank in a quiet room to investigate whether or not they can discriminate strangers from neighbors acoustically. Nine of the 14 males tested showed evoked vocal responses to the calls from strangers, but none to calls from neighbors; vocal response to the calls from strangers was accompanied by aggressive motor activity. These results demonstrate that male O. tormota possess the ability to discriminate neighbors from strangers acoustically. Odorrana tormota therefore joins three ranid species ( Rana catesbiana , Rana clamitans , Rana dalmatina , all known to have a comparatively small and stereotyped vocal repertoires) as the only anurans demonstrated to have this ability. Given the difference in signaling complexity between these frog species, the salient acoustic features used for discriminating neighbors and strangers are likely to be quite distinct.     

Ultrasonic communication in concave-eared torrent frogs (Amolops tormotus)

The concave-eared torrent frogs (Amolops tormotus) have highly unusual ear morphology--in males the eardrums are embedded deep inside ear cavities. In collaboration with our colleagues we investigated the functional significance of this morphological feature in hearing. Sound recordings in the field showed that males of A. tormotus produce diverse bird-like melodic calls with pronounced frequency modulations and non-linear phenomena (e.g., frequency jumps, different orders of subharmonics, and chaos) that often contain spectral energy in the ultrasonic range. The audible as well as the ultrasonic components of the species call could effectively evoke males' vocal responses, demonstrating that they can hear and respond to ultrasound. Electrophysiological recordings from the auditory midbrain confirmed the ultrasonic hearing capacity of these frogs. The recessed tympana and extremely thin tympanic membranes are adaptations for hearing ultrasound--this sensitivity may have evolved in response to the intense, predominately low-frequency ambient noise from local streams. Finally, results from the isolated laryngeal preparation in euthanized frogs revealed that the origin of call complexity and diversity lies with having a vocal system with nonlinear properties.     

Subharmonics increase the auditory impact of female koala rejection calls

Although non‐linear phenomena are common in human and non‐human animal vocalisations, their functional relevance remains poorly understood. One theory posits that non‐linear phenomena generate unpredictability in vocalisations, which increases the auditory impact of vocal signals, and makes animals less likely to habituate to call repetition. Female koalas (Phascolarctos cinereus) produce vocal signals when they reject male copulation attempts that contain relatively high levels of non‐linear phenomena, and thus may function as attention grabbing vocal signals during the breeding season. To test this hypothesis, we used playback experiments: firstly, to determine whether female rejection calls induce heightened behavioural responses in free‐ranging male koalas during the breeding season, and secondly, to examine how the relative amount of non‐linear phenomena in rejection calls influences male behavioural response. The results show that male koalas look for longer towards speakers broadcasting playback sequences of male bellows followed by a series of female rejection calls than those broadcasting only male bellows. In addition, female rejection call sequences with more subharmonics, higher harmonics‐to‐noise ratios, and less biphonation produced the greatest male looking responses. Our findings support the hypothesis that female koala rejection calls function to grab male attention during the breeding season, and indicate that subharmonics are the main acoustic feature that increases the auditory impact of these vocal signals.     

Behavioral and Neurogenomic Responses to Acoustic and Visual Sexual Cues are Correlated in Female Torrent Frogs

Diverse a nimal species use multimodal communica tion signals to coordina te reproductive behavior.Despite active research in this field,the brain mechanisms underlying multimodal communication remain poorly understood.Similar to humans and many mammalian species,anurans often produce auditory signals accompanied by conspicuous visual cues(e.g.,vocal sac inflation).In this study,we used video playbacks to determine the role of vocal-sac inflation in little torrent frogs(Amolops torrentis).Then we exposed females to blank,visual,auditory,and audiovisual stimuli and analyzed whole brain tissue gene expression changes using RNAseq.The results showed that both auditory cues(i.e.,male advertisement calls)and visual cues were attractive to female frogs,although auditory cues were more attractive than visual cues.Females preferred simultaneous bimodal cues to unimodal cues.The hierarchical clustering of differentially expressed genes showed a close relationship between neurogenomic states and momentarily expressed sexual signals.We also found that the Gene Ontology terms and KEGG pathways involved in energy metabolism were mostly increased in blank contrast versus visual,acoustic,or audiovisual stimuli,indicating that brain energy use may play an important role in response to these stimuli.In sum,behavioral and neurogenomic responses to acoustic and visual cues are correlated in female little torrent frogs.     

Correlation between auditory evoked responses in the thalamus and species-specific call characteristics

This evoked potential study of the bullfrog's auditory thalamic area (an auditory responsive region in the posterior dorsal thalamus) shows that complex processing, distinct from that reported in lower auditory regions, occurs in this center. An acoustic stimulus consisting of two tones, one which stimulates either the low-frequency or the mid-frequency sensitive population of auditory nerve fibers from the amphibian papilla and the other the high-frequency sensitive population of fibers from the basilar papilla, evoked a maximal response. The amplitude of the response to the simultaneous stimulation of the two auditory organs was, in some locations, much larger than the linear sum of the responses to the individual tones presented separately. Bimodal spectral stimuli that had relatively long rise-times (greater than or equal to 100 ms) evoked much larger responses than similar sounds with short rise-times. The optimal rise-times were close to those occurring in the bullfrog's mating call. The response was dependent on the waveform periodicity and harmonic content, with a fundamental frequency of 200 Hz producing a larger response than those with fundamentals of 50, 100 or 300 Hz. Six of the natural calls in the bullfrog's vocal repertoire were tested and the mating call and warning call were found to evoke the best responses. Each of these calls stimulate the two auditory organs simultaneously. The evoked response had a long refractory period which could not be altered by lesioning the efferent telencephalic pathways. The type of spectral and temporal information extracted by the auditory thalamic area suggests that this center is involved in processing complex sounds and likely plays an important role in the bullfrog's detection of some of its vocal signals.     

凹耳臭蛙胚胎发育及其分类学意义(英文)

通过人工受精的方法获得的凹耳臭蛙(Odorrana tormota)的早期胚胎及胚后幼体的发育过程,根据胚胎发育过程中的形态及生理特征变化规律进行分期。把凹耳臭蛙的发育过程分成两个阶段:1)早期胚胎发育阶段,即从蛙卵受精到鳃盖完成期,在18～23℃水温下,凹耳臭蛙早期胚胎发育阶段历时324h;2)蝌蚪发育阶段,即从鳃盖完成期结束到尾部被完全吸收,本阶段在20～24℃水温条件下历时1207h。凹耳臭蛙蝌蚪未发现腹吸盘特征,从形态特征上支持了分子系统分类学将之从湍蛙属划出的观点。实验中发现,多数胚胎在8细胞期为纬裂,16细胞期为经裂,同时有小部分胚胎(1.5%)在8细胞期为经裂,16细胞期为纬裂。该文进一步讨论了影响卵裂率、孵化率、发育速度,以及生态适应的因素。     

Flexibility as a Strategy for Avoiding Call Overlap in Male Anhui Treefrogs

Male-male vocal competition is critical for mating success in anuran species; however, it remains unknown that how males regulate their competitive strategies dynamically during competition because calling is highly time-consuming, energetically demanding and likely to increase predation risks. Since different parts of calls will encode different information for vocal communication, we hypothesized that competitive strategies of male frogs may be modulated by the temporal and spectral features of different call notes. To test this hypothesis, the natural advertisement calls(OC), its modified versions with the first call note replaced by white noise(WN) or other notes and with the fifth call note replaced by WN, were played back to the Anhui tree frogs(Rhacophorus zhoukaiyae). Results showed that 1) males produced more competitive calls in response to acoustic stimuli compared to their baseline calling during silence; and 2) males emitted more non-overlapping calls compared to overlapping calls in response to the acoustic stimuli. These results are consistent with the idea that males are flexible to acoustic signals and their competition strategies are modulated dynamically by social contexts.