Communication often happens in noisy environments where interference from the ambient noise and other signalers may reduce the effectiveness of signals which may lead to more conflict between interacting individuals. Signalers may also evolve behaviors to interfere with signals of opponents, for example, by temporally overlapping them with their own, such as the song overlapping behavior that is seen in some songbirds during aggressive interactions. Song overlapping has been proposed to be a signal of aggressive intent, but few studies directly examined the association between song overlapping and aggressive behaviors of the sender. In the present paper, we examined whether song overlapping and ambient noise are associated positively with aggressive behaviors. We carried out simulated territorial intrusions in a population of great tits (Parus major) living in an urban–rural gradient to assess signaling and aggressive behaviors. Song overlapping was associated negatively with aggressive behaviors males displayed against a simulated intruder. This result is inconsistent with the hypothesis that song overlapping is an aggressive signal in this species. Ambient noise levels were associated positively with aggressive behaviors but did not correlate with song rate, song duration, or song overlapping. Great tits in noisy urban habitats may display higher levels of aggressive behaviors due to either interference of noise in aggressive communication or another indirect effect of noise.

中文翻译：

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大山雀中的歌曲重叠，杂音和领土侵略

通信通常发生在嘈杂的环境中，在这种环境中，来自环境噪声和其他信号器的干扰可能会降低信号的有效性，从而可能导致交互个体之间发生更多冲突。信号器还可能演变行为以干扰对手的信号，例如，通过在时间上将其与自己的信号重叠来进行干预，例如在积极互动期间某些歌曲中看到的歌曲重叠行为。歌曲重叠已被提出是攻击意图的信号，但是很少有研究直接检查歌曲重叠与发送者的攻击行为之间的关联。在本文中，我们检查了歌曲重叠和环境噪声是否与攻击行为呈正相关。我们对一群大山雀（主要（Parus major）居住在城乡之间，以评估信号和攻击行为。歌曲重叠与男性对模拟入侵者的攻击行为负相关。此结果与歌曲重叠是该物种中侵略性信号的假设不一致。环境噪声水平与攻击行为呈正相关，但与歌曲速率，歌曲持续时间或歌曲重叠无关。在嘈杂的城市栖息地中，大山雀可能会表现出较高的攻击行为，这可能是由于噪声干扰了积极交流或产生了间接的噪声影响。