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。

Variation in Communication Vocalization of Adult Greater Tube-Nose Bats, Murina leucogaster

Bats belonging to Microchiroptera have been known one of the most gregarious mammals. They rely mainly on acoustic signals to communicate in darkness and maintain their social structures. Some species demonstrate a diverse repertoire of syllables, but few studies have conducted on their social calls for specific species. We recorded the social vocalizations of captive adult Murina leucogaster and analyzed its spectral characteristics based on the shape of sound wave in the spectrogram. Communication calls were grouped together into preliminary vocalization types based on their visual similarity in sonograms, and then we performed a principal component analysis (PCA) and a discriminant function analysis (DFAs) to confirm the preliminary classification. The results show that M.leucogaster possess a rich repertoire of social vocalizations with sixteen distinct syllable types. These syllables were further categorized into 13 simple syllables and 3 composite syllables, and most of them had multiple harmonics. Simple syllables can be classified into 9 frequency modulation syllables, 2 quasi-constant frequency syllables and 2 noise burst syllables. Composite syllables consist of simple syllables conjoined without any silent interval. Maximum frequency of fundamental frequency, bandwidth of fundamental frequency and duration were highly correlated to the types of frequency modulation syllables. These results provide a basis for future studies not only of the behavioral significance of vocalization, but also of the neural basis of vocal communication in the M. leucogaster.