【作者】 江廷磊；

【导师】 冯江；

【作者基本信息】 东北师范大学 ， 环境科学， 2010， 博士

【摘要】 动物的很多社群行为依赖于种内交流和物种与环境的相互作用。无脊椎动物、鸟类和哺乳动物等动物类群的种内声学信号都存在明显的地理变化。然而,对于生态系统中重要的指示生物—蝙蝠而言,尽管研究表明形态、环境和文化漂变等因子影响其回声定位声波的地理变化,但对其原因和意义仍然知之甚少。因此,开展蝙蝠回声定位声波地理变化模式及其影响因素研究,为深入揭示蝙蝠物种形成及其多样性维持机制具有重要意义。另外,环境噪声可能导致蝙蝠回声定位、性选择和交流等行为的非适应性改变,进一步直接影响蝙蝠的繁殖成功和种群增长速率,因此,对其进行研究能为蝙蝠物种多样性保护提供重要的科学依据。本论文通过野外采样、行为实验和室内分析,从形态、生态、文化和遗传的角度,在大地理尺度对中蹄蝠(Hipposideros larvatus)、菲菊头蝠(Rhinolophus pusillus)和大卫鼠耳蝠(Myotis davidii)的回声定位声波地理变化及其影响因素进行研究。另外,在美国加州大学洛杉矶分校神经生理学系首次研究噪声刺激对马铁菊头蝠(Rhinolophus ferrumequinum)回声定位行为的影响,主要内容如下。1.在广阔的地理尺度,数据挖掘技术和克鲁斯凯-沃利斯检验表明中蹄蝠静止频率存在显著的地理变化且具有经度模式,并与地理距离显著相关。同时,蝙蝠个体间静止频率存在显著差异,这支持静止频率的随机文化漂变,并反对猎物探测假说。此外,局域分布的岛屿群体间静止频率的显著差异可能暗示回声定位叫声“方言”的存在。因此,我们认为中蹄蝠每个群体具有一个“私有带宽”以为了群体身份的识别和个体交流,并进一步使其获得更大的生存适合度。2.研究中国广泛分布的菲菊头蝠静止频率的地理变化模式。虽然其分布范围内种群间静止频率显著不同,但与地理距离无显著相关性。广义线性模型和T检验表明菲菊头蝠静止频率存在明显的性别二态性,暗示雌雄性可能保持它们的静止频率在一个狭窄的范围以利于性别识别。Mantel检验和逐步多重线性回归分别表明蝙蝠调节静止频率来适应不同的气候条件和湿度,可能暗示降雨噪声对蝙蝠叫声频率的影响。因此,环境选择可能塑造种群间菲菊头蝠回声定位声波的多样性。同时,我们认为蝙蝠物种保护必须考虑气候变化和环境噪声。3.大卫鼠耳蝠是中国特有种。克鲁斯凯-沃利斯检验和Dunn’s多重比较表明群体间大卫鼠耳蝠的回声定位声波存在显著地理变化,并与群体遗传结构显著相关,但与地理距离和气候条件无显著相关性。然而,群体遗传结构却与地理距离和气候条件显著相关。因此,我们认为气候因子对回声定位叫声分歧的影响可能通过遗传结构级联传递。大卫鼠耳蝠具有高的翼展比和低的翼尖指数,和先前的研究结果类似,表明大卫鼠耳蝠在区域内频繁迁移且一些个体在区域间存在长期的殖民现象。由于蝙蝠回声定位叫声容易受到同种的影响,因此遗传漂变和社会选择可能是导致大卫鼠耳蝠群体间回声定位声波多样性的关键因素。本研究强调迁移行为对塑造回声定位声波地理变化模式的重要作用,并暗示保护管理单元应该包括遗传标记和生态适应特征。4.在静止状态,粉红噪声刺激促使马铁菊头蝠改变静止频率及其幅度和结构。更强的噪声刺激导致更大的叫声改变,而与不同的回声衰减无关。当噪声刺激的中心频率等于蝙蝠的基频时,与其等于静止频率和其他刺激条件相比,静止频率具有最大的变化,表明马铁菊头蝠通过自己的叫声(特别是基频)反馈,而不是其回声来维持叫声频率的稳定。当蝙蝠表现多普勒频移补偿行为时,回声衰减强度对多普勒频移补偿行为产生明显的影响,表明蝙蝠依赖回声的绝对幅度进行多普勒频移补偿行为。我们首次提出窄频带蝙蝠的回声定位声波存在明显的躲避干扰反应,这对深入理解蝙蝠的回声定位行为及其进化具有重要意义。回声定位声波,正如其他行为表现型一样,其地理变化都在漂变和选择的混合效应下进化,并可能最终导致种群分歧、繁殖隔离和物种形成。同时,本研究首次强调噪声对窄频带蝙蝠回声定位行为的影响,对深入理解蝙蝠回声定位行为的适应性进化和物种多样性保护具有重要意义。更多还原

【Abstract】 Most social behaviours are dependent on intraspecific communication and the interaction between species and environment. Geographic variation in animal vocalizations provides a best opportunity to clarify the myriad factors shaping the evolution and divergence of communication signals and test fundamental hypotheses about the evolution of behaviour. Geographic variation in intraspecific acoustic signals has been observed in a range of animal groups, including invertebrates, birds and mammals. However, bats, as a biological indicator in the ecosystem, both the cause and the meaning of geographic variation in echolocation signals remains poorly understood despite some factors have been documented to explain variation in the ultrasonic frequency of bat echolocation within species among geographic isolates or islands. Therefore, study on geographic variation in echolocation calls of bats are very valuable for clarifying the mechanisms of speciation and the maintenance of biodiversity. Additionly, noise pollution may generate potential maladaptive responses of bats’echolocation, sexual selection and communication behaviours, and thus lead to direct bearings on breeding success and ultimately population growth rate. As a results, the study would provide scientific grounds for bats species conservation.The pattern of geographic variation and its impact factors in echolocation calls of the three bats species Hipposideros larvatus, Rhinolophus pusillus and Myotis daivdii were investigated by filed sampling, behavioral research and lab analysis on these aspects: morphology, ecology, culture and genetics from 2007 to 2010. In addition, jamming avoidance response (JAR) in Rhinolophus ferrumequinum with narrow-band echolocation pluses was studied originally at the Department of Integrative Biology and Physiology, University of California, Los Angeles, USA. The details are as followed.1. Variation patterns were examined in the resting frequency (RF) of echolocation calls emitted by the intermediate leaf-nosed bat, Hipposideros larvatus, on a broad geographical scale. Data mining technology and Kruskal–Wallis test both showed substantial variation with a longitudinal pattern in RF in H. larvatus among colonies, and this variation was associated with geographical distance not body size. In addition, we found that a high degree of variability between individuals was hidden under the geographical variation. The results support an effect of random cultural drift, and challenge the prey detection hypothesis. Moreover, acoustic differences among local island colonies may be indicative of a vocal dialect. We found that each colony of H. larvatus seems to maintain a‘private bandwidth’, which could be used for colony identity and individual communication thus helping individuals and colonies to get a number of fitness benefits. 2. We investigated variation patterns in the constant frequency of echolocation calls emitted at rest and when not flying (“resting frequency”RF) of the least horseshoe bat, Rhinolophus pusillus, on a broad geographical scale and in response to local environmental variables. Significant differences in RF were observed among populations throughout the species range in China’s mainland, but this variation was not associated with geographical distance. Sex dimorphism in the RF of R. pusillus may imply that females and males at each site keep their frequencies within a narrow range for sex recognition. The Mantel test and the stepwise multiple regression model showed that bats adjusted resting frequency to local weather conditions and humidity, respectively, which may imply partitioning diet by prey size or the influence of rainfall noise. These results indicated that bats adjust echolocation call frequency to adapt to enviromental selection. Therefore, environmental selection might shape the diversity of echolocation call structure of R. pusillus in geographically separated populations. Simultaneously, we suggested that conservation efforts should focus on change in local climate change and environmental noise.3. Myotis davidii is a Chinese endemic species with wide geographic distribution. Kruskal–Wallis and Dunn’s multiple-comparison test both showed substantial variation in call structure in M. davidii among colonies, and this variation was only associated with genetic structure not geographical distance and climate conditions. However, there were significant correlation between genetic structure and geographical distance, and genetic structure and climate conditions. Therefore, we suspected that the effect of climate conditions on call difference might be translated through genetic structure by a cascade reaction, as a bridge function. In addition, M. davidii, with high aspect ratios and low wing tip indices, and previous study both showed that David’s Myotis migrates frequently within regions and a small quantity of long-distance colonization by individuals among regions. Thus, genetic drift and social selection might be a key factor for the diversification of call structure because echolocation calls can be influenced by conspecifics. Our results highlight the importance of migration in shaping the geographical patterns of echolocation call design, and imply that defining protected management units for conservation efforts should consider both genetic marker and ecologically adaptive traits.4. Pink noise significantly altered the echolocation behavior at rest by shifting the call frequencies, altering call amplitude and call stracture, such as the variation in dCF and frequency modulation (FM) component. Stronger noise stumuli yields a bigger shift in echolocation pulses, but the shift was only associated with noise amplitude instead of different echo attenuation. Interestingly, the strongest frequency shifts were not observed when interfering stimuli were centered on the resting frequency (RF1) but instead on the fundamental frequency (RF0). The result showed that horseshoe bats listen to RF0 in their own calls (rather than in the echoes) to maintain call frequencies at a stable level. In general, pink noise presented during Doppler-shift compensation (DSC) yielded similar effects on call frequency and noise amplitude than for calls emitted at rest. The most significant difference to calls emitted at rest was, however, that different echo attenuations yielded a very pronounced effect on DSC performance, showing an increase in DSC depth with increasing echo intensity. Therefore, Our results suggest, that not the signal-to-noise ratio, but instead the absolute amplitude of the returning echo is necessary and sufficient for the quality of DSC performance. We show for the first time that bats with CF calls have a specific jamming avoidance response (JAR) depending on the frequency band in which the interfering acoustical stimuli were presented. These findings may provide new insights into the complexity of echolocation behaviours and will aid in understanding evolutionary aspects of echolocation and DSC behavior.5. In brief, echolocation calls, like any other phenotype, evolve through the combined effects of drift ans selection. Expanding these scenarios, variability of acoustic signals can facilitate population divergence, reproductive isolation and, ultimately speciation. The constrain of noise will promate the adaptive evolution of echolocation strategies. These results are vary valuable for understanding adaptive evolution of echolocation behaviours and promoting species conservation in bats.更多还原