Birdsong is an important feature that mediates several aspects of bird reproduction, such as mate choice, territory defense, and individual recognition. Any factor that impairs vocal transmission through the environment may also impair conspecific recognition and thus reduce the effectiveness of reproduction. In this scenario, birds inhabiting urban environments might be subject to different selective pressures on their vocal amplitude due to acoustic barriers in the song transmission, such as excessive background noise and abnormal atmospheric absorption of sound. Therefore, we measured the amplitude of the song of the Southern House Wren (Troglodytes aedon musculus), to determine the relationships between the variation in vocal intensity and the environmental features. We expect divergence in vocal amplitude according to the noise levels, with song intensity responding to the increasing noise. We found that birds sang with higher amplitude in areas where traffic noise is elevated. Multiple linear regression showed a positive relationship between song amplitude and background noise and a negative relationship between vocal intensity and atmospheric attenuation. Our findings suggest a direct influence of urban environmental structures on the vocal behavior of wrens, which may challenge the effectiveness of communication between subjects and affect the behavioral ecology of the species.

鸟鸣是一个重要特征，可介导鸟类繁殖的多个方面，例如伴侣选择，领土防御和个人认可。任何影响通过环境的声音传输的因素也可能损害特定的识别，从而降低再现的效率。在这种情况下，居住在城市环境中的鸟类可能会由于歌曲传输过程中的声音障碍（例如过多的背景噪音和异常的声音吸收）而在声音振幅上受到不同的选择压力。因此，我们测量了南屋W（Troglodytes aedon musculus）歌曲的振幅），以确定声音强度变化与环境特征之间的关系。我们期望根据噪声水平在人声幅度上有所差异，而歌曲强度会响应不断增加的噪声。我们发现，在交通噪音较高的地区，鸟类会以较高的幅度唱歌。多元线性回归显示歌曲振幅与背景噪声之间呈正相关，而声音强度与大气衰减之间呈负相关。我们的发现表明，城市环境结构对the的发声行为有直接影响，这可能会挑战主体之间的交流效果并影响物种的行为生态。