古北界啄木鸟属三种啄木鸟基于鸣声的生物地理变异

Biogeographical Variation of Three Species of the Dendrocopos in the Palaearctic Based on Vocalization

为了探究古北界啄木鸟属(Dendrocopos)鸣声的地理变异,我们通过xeno-canto.org网站收集了广泛分布于古北界的啄木鸟属3种啄木鸟和黑啄木鸟(Dryocopus martius)的鸣声数据。利用音频处理软件Audacity与声谱分析软件Wavesurfer对收集到的1353条啄木鸟鸣声数据进行鸣声参数数据的提取。其中大斑啄木鸟(D. major)鸣声数据664条,白背啄木鸟(D. leucotos)鸣声数据178条,叙利亚啄木鸟(D. syriacus)鸣声数据208条和黑啄木鸟鸣声数据303条。利用Kruskal-Wallis检验,对不同地区啄木鸟属3种啄木鸟的鸣声地理差异进行分析,结果显示:古北界大斑啄木鸟、白背啄木鸟、叙利亚啄木鸟的鸣声特征均存在显著的地理差异。分布于亚洲地区的大斑啄木鸟、白背啄木鸟、叙利亚啄木鸟的鸣声音节持续时间最长,最高频率最高。北欧地区白背啄木鸟、叙利亚啄木鸟的鸣声间隔时间最短,即鸣声较其他地区急促。采用系统聚类分析方法,比较古北界啄木鸟属不同地区鸣声的相似性,结果显示:亚洲地区的3种啄木鸟鸣声特征与欧洲地区的鸣声特征均存在着地理差异。西欧地区的和北欧地区的大斑啄木鸟鸣声特征最相近,与亚洲地区和中欧地区的鸣声差异最大。亚洲地区和中欧地区的叙利亚啄木鸟鸣声特征相似,与东欧和南欧地区的鸣声存在着明显地理差异。另选取黑啄木鸟鸣声作为外群,与啄木鸟属鸣声特征比较,结果显示:与黑啄木鸟鸣声特征相比,啄木鸟属内具有强烈的鸣声相似性。在啄木鸟属中,大斑啄木鸟和叙利亚啄木鸟鸣声特征相似,与白背啄木鸟聚成两类。通过对啄木鸟鸣声地理变异一般规律的研究,并与形态学、分子生物学等综合分析,将更有利于对啄木鸟的生物地理变异进行探究与应用。

This systematic survey aimed to explore the geographic variation among the vocalizations of multiple species of woodpeckers that are widely distributed throughout the palearctic. We collected the audio data from three species of woodpeckers of the genus Dendrocopos and the black woodpecker (Dryocopus martius) through xeno-canto.org. We extracted the song parameters of 1353 woodpecker song data sets using the audio processing software Audacity and the sound spectrum analysis software Wavesurfer. These included 664 song data sets about the great spotted woodpecker (D. major), 178 song data sets about the white-backed woodpecker (D. leucotos), 208 song data sets about the Syrian woodpecker (D. syriacus), and 303 song data sets about the outgroup species, the black woodpecker (D. martius). We used the Kruskal-Wallis test to analyze the geographical differences in woodpecker vocalization characteristics. The results showed that there were significant geographical differences among the acoustic characteristics of the great spotted woodpecker, the white-backed woodpecker, and the Syrian woodpecker in the palearctic. The duration of song syllables characterizing the species distributed in Asia, the large spotted woodpecker, the white-backed woodpecker, and the syrian woodpecker, was longer than that of species in other regions, and the highest frequency found in Asian species was higher than that found in species in other regions. In northern Europe, the white-backed woodpecker and the Syrian woodpecker had the shortest syllable interval length, which means their vocalizations were more rapid than those of woodpeckers in the other regions. Furthermore, we compared and analyzed geographic differences in palearctic Dendrocopos vocalizations using a hierarchical clustering method. The results showed that the vocalization characteristics of the three woodpecker species in Asia were significantly different from those of European species. The vocalizations of the western and northern European great woodpeckers were distributed similarly. We found a clear difference when comparing these vocalizations to those of the Asian and Central European great woodpeckers. The Syrian woodpecker’s vocalization characteristics can be divided into two groups based on their similarity, the eastern European and southern European group and the Asian and Central European group. In addition, we selected the vocalization of the black woodpecker as the out-group and compared it with the vocalizations of the Dendrocopos species using hierarchical cluster analysis. The results showed that the three species of Dendrocopos woodpeckers are grouped together and clearly distinguishable from the black woodpecker. This indicates that compared with vocalization characteristics of the black woodpecker, the vocalization characteristics of the Dendrocopos species have strong similarity. At the same time, we found two clusters among the Dendrocopos species, which included one group combining the similar song characteristics of the great spotted woodpecker and the Syrian woodpecker and another group with only the white-backed woodpecker. Through the study of the general rule of geographical variation of woodpecker vocalization, and the comprehensive analysis of morphology and molecular biology, it will be more beneficial to the exploration and application of woodpecker’s biogeographic variation.