Natural noise affects conspecific signal detection and territorial defense behaviors in songbirds

Recent research suggests that anthropogenic noise can substantially alter animal behavior. Although there are many sources of natural background noise, the relative influence of these sounds on behavior has received much less attention. Using landscape-scale playbacks of rushing rivers and crashing ocean surf, we investigated how habitat appropriate natural noise alters territorial defense behaviors in lazuli buntings (Passerina amoena) occupying riparian areas and spotted towhees (Pipilo maculatus) in riparian and coastal areas when exposed to simulated intruder song. We also incorporated naturally occurring cicada noise as an acoustic source influencing lazuli bunting behavior. Both songbird species possess songs that share substantial spectral overlap with low-frequency, water-generated noise, and lazuli bunting song shares an additional high-frequency overlap with cicada calls. Thus, there is potential for background acoustic conditions to mask conspecific signals. We found that det...最新研究表明，人为噪声（anthropogenic noise）可显著改变动物行为。尽管自然界存在多种自然背景噪声源，但这类声音对动物行为的相对影响却未得到足够关注。本研究通过开展景观尺度的湍急河流与拍岸海浪回放（playback）实验，探究了适配生境的自然噪声，对栖息于河岸带（riparian areas）的琉璃鹀（Passerina amoena）、栖息于河岸带与沿海区域（coastal areas）的斑唧鹀（Pipilo maculatus）在暴露于模拟入侵者鸣唱（simulated intruder song）时的领域防御行为（territorial defense behaviors）的影响。此外，本研究还将自然存在的蝉鸣噪声作为声学声源，纳入对琉璃鹀行为影响的实验设计中。两种鸣禽的鸣唱均与低频水声噪声存在显著的频谱重叠（spectral overlap），而琉璃鹀的鸣唱还额外与蝉鸣存在高频频谱重叠。因此，背景声学环境有可能掩盖同类个体间的信号传递（conspecific signals）。本研究发现，det...