Department of Basic Sciences and Foundations, The University of Urbino, Campus Scientifico Enrico Mattei, 61029 Urbino, Italy.
J Acoust Soc Am. 2013 Jul;134(1):891-900. doi: 10.1121/1.4807812.
An altered acoustic environment can have severe consequences for natural communities, especially for species that use acoustic signals to communicate and achieve breeding success. Numerous studies have focused on traffic noise disturbance, but the possible causes of road effects are inter-correlated and the literature on noise qua noise is sometimes contradictory. To provide further empirical data in this regard, the authors investigated the spatio-temporal variability of the singing dynamics of an avian community living in an acoustic context altered by traffic noise. Fieldwork was carried out in a wood of Turkey oaks (central Italy) bordered on one side by a main road. The soundscape was examined by positioning eight digital recorders, distributed in two transects perpendicular to the road, and recording between 6:30 and 8.30 a.m. for 12 continuous sessions. The acoustic complexity index was used to obtain a quantification of singing dynamics, which were positively correlated with traffic noise. This may indicate that birds try to propagate their signals with greater emphasis (e.g., amplified redundancy or loudness of the songs) to override the masking effect of noise. Nevertheless, an ecotonal effect could have influenced the correlation results, with this enhanced dynamic possibly being due to a more densely populated environment.
改变的声环境会对自然群落产生严重的后果，特别是对那些使用声信号进行交流和繁殖成功的物种。许多研究都集中在交通噪声干扰上，但道路影响的可能原因是相互关联的，而且关于噪声本身的文献有时也存在矛盾。为了在这方面提供进一步的经验数据，作者研究了生活在交通噪声改变的声环境中的鸟类群落的歌唱动态的时空可变性。实地工作是在一个由土耳其橡树（意大利中部）组成的树林中进行的，树林的一侧有一条主要道路。通过在两条与道路垂直的横截线上布置八个数字记录器，并在每天早上 6:30 到 8:30 之间连续记录 12 个会话，对声景进行了检查。使用声音复杂性指数来获得歌唱动态的定量，歌唱动态与交通噪声呈正相关。这可能表明鸟类试图通过更强调（例如，歌曲的放大冗余或响度）来传播它们的信号，以克服噪声的掩蔽效应。然而，生态过渡带效应可能影响了相关结果，这种增强的动态可能是由于更密集的环境。
