体征对灰眉岩鹀鸣唱频率特征的影响

Lack of Body Size and Beak Length Constraints on the Frequency of Emberiza godlewskii's Song

声信号是鸟类交流的重要方式。鸟类的鸣声特征受到生境的塑造和性选择,也受到发声器官的影响,如种间的比较研究发现,体重大的鸟类鸣声频率低,喙短的鸟类鸣声频宽大。在种内是否也存在类似的规律,目前的结论还不一致。2012年6月,在北京小龙门地区(40°00'N,115°26'E)测量了17只灰眉岩鹀(Emberiza godlewskii)的形态参数以及鸣声的频率特征,未发现体重或喙长与鸣声的最高频率、最低频率、峰频或频宽存在显著的相关性。本研究的结果支持在小型雀形目鸟类中,体型对繁殖期鸣唱频率特征的影响不显著。

Acoustic signal is important for bird communication. Differences in vocal characteristics are usually explained by habitat-dependent selection on signal transmission and/or sexual selection by female preference. The organ to produce signals can also be influence on signal features, for example, the negative relationship between frequency and body size, between frequency bandwidth and beak length. These negative relationships usually stand between species, but it is unclear whether such relationships exist within species. In this study we trapped 17 individuals of Emberiza godlewskii by mist nets using acoustic playback of the species＇song in Beijing Xiaolongmen forest Park （40°00′N,115°26′E） in breeding season from June 2^nd to 12^th in 2012. We recorded the sound from 122 to 542 s for each individuals with mean 300 s in WAV format （44. 1 kHz, 16 bit） using a Tascam HD-P2 portable digital recorder （Tascam Co. Japan ） and a Sennheiser MKH416 P48 external directional microphone （Sennheiser Electronic Co., Germany ）. We measured the maximum frequency, minimum frequency, peak frequency, and frequency range from the sound （ Fig. 1 ）. In the meantime we took their morphological characteristics, including weight, wing length, tail length, total length, and beak length. We used a principal component analysis to compress the original morphological characteristics into comprehensive body size measurement （Table 1 ） , described the frequency traits of sounds and morphological characteristics （Table 2）, and tested their relationship using Pearson correlation analysis. We didn＇t find any significant correlation between the sound frequency traits and body size/beak length （Table 3 ）. Our resultssupport that the relationship between sound frequency and body size/beak length may not significant in small size Passeriformes birds.