Animals that communicate by acoustic signaling share a common acoustic environment. Birds are particularly vocal examples, using a wide repertoire of broadcast signals for mate attraction and territorial defense. However, interference caused by sounds that overlap in frequency and time can disrupt signal detection and reduce reproductive success. Here, we investigated competition avoidance mechanisms used by the bird community inhabiting a primeval lowland temperate forest in Białowieża, Eastern Poland. We recorded the dawn chorus at 84 locations in early and late spring and calculated dissimilarity indices of the broadcast signals to examine how species with greater song similarities use spatial and temporal partitioning to avoid competition for acoustic space throughout the breeding season. The bird community changed its use of acoustic space throughout the day and season. Birds did not use spatial partitioning of signal space when we looked at recording locations over the whole study period, but they did in a seasonal context, with species more acoustically different than expected by chance recorded at the same point in the same part of the season. Our results also indicate that daily temporal niche partitioning may only occur at certain times before sunrise, with no evidence of large-scale temporal partitioning between species vocalizing during the same 1-min recordings in daytime. These results contribute toward our understanding of the evolution of bird communication and highlight the strategies employed by different species to improve their signal transmission.

中文翻译：

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温带森林鸟类群落声学空间的竞争

通过声音信号进行交流的动物共享一个共同的声音环境。鸟类是特别有声音的例子，它们使用广泛的广播信号来吸引配偶和保卫领地。然而，由频率和时间重叠的声音引起的干扰会扰乱信号检测并降低繁殖成功率。在这里，我们研究了居住在波兰东部比亚沃维扎原始低地温带森林的鸟类群落所使用的避免竞争机制。我们在早春和晚春在 84 个地点记录了黎明合唱，并计算了广播信号的差异指数，以研究歌曲相似性较大的物种如何利用空间和时间分区来避免整个繁殖季节对声学空间的竞争。鸟类群落在白天和季节中改变了声学空间的使用。当我们在整个研究期间查看记录位置时，鸟类并没有使用信号空间的空间分区，但它们在季节背景下这样做了，物种在声学上的差异比预期在季节同一部分的同一点偶然记录的要多。我们的结果还表明，日常时间生态位划分可能只发生在日出前的某些时间，没有证据表明在白天相同的 1 分钟录音中物种之间发声的大规模时间划分。这些结果有助于我们了解鸟类通讯的进化，并强调不同物种为改善信号传输而采用的策略。