ABSTRACT Acoustic communication in animals relies upon specific contexts and environments for effective signal transmission. Increasing anthropogenic noise pollution and different weather conditions can disrupt acoustic communication. In this study, we investigated call parameter differences in the bladder grasshopper Bullacris unicolor inhabiting two sites in close proximity to each other that differed in their noise levels. Calling activity was monitored via passive acoustic recorders. Weather conditions, including wind speed, temperature and humidity, were also recorded. We found that the interval between successive calls increased with higher noise levels at both sites, and the peak frequency became lower. The total number of calls detected also decreased with anthropogenic noise, but this relationship was only evident at the noisier site. In addition, grasshoppers shifted the timing of their calls to later in the night at the noisier site, possibly to take advantage of relatively lower noise levels. We also found that weather conditions, particularly temperature, had a significant influence on call parameters. Further studies are thus needed to disentangle the effects of anthropogenic noise and environmental variables on calling activity in this species. Our results lend support to the growing concern regarding the effects of noise pollution on animal acoustic signalling systems and also highlight the complexity of factors which affect sound signalling in natural environments.

中文翻译：

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人为噪声和天气条件对膀胱蚱蜢 Bullacris unicolor 雄性叫声的影响

摘要动物的声学通信依赖于特定的环境和环境来进行有效的信号传输。不断增加的人为噪声污染和不同的天气条件会破坏声学通信。在这项研究中，我们调查了栖息在两个彼此靠近但噪音水平不同的地点的膀胱蚱蜢的叫声参数差异。通话活动通过无源录音机进行监控。还记录了天气状况，包括风速、温度和湿度。我们发现两个站点的连续呼叫之间的间隔随着噪声水平的升高而增加，并且峰值频率变得更低。检测到的呼叫总数也随着人为噪音而减少，但这种关系仅在噪音较大的地点才明显。此外，蚱蜢将它们的叫声时间转移到噪音较大的地方的深夜，可能是为了利用相对较低的噪音水平。我们还发现天气条件，尤其是温度，对呼叫参数有显着影响。因此，需要进一步的研究来解开人为噪声和环境变量对这个物种的叫声活动的影响。我们的结果支持对噪声污染对动物声学信号系统影响的日益关注，并强调了影响自然环境中声音信号的因素的复杂性。特别是温度，对调用参数有显着影响。因此，需要进一步的研究来解开人为噪声和环境变量对这个物种的叫声活动的影响。我们的研究结果支持对噪声污染对动物声学信号系统影响的日益关注，并强调了影响自然环境中声音信号的因素的复杂性。特别是温度，对调用参数有显着影响。因此，需要进一步的研究来解开人为噪声和环境变量对这个物种的叫声活动的影响。我们的结果支持对噪声污染对动物声学信号系统影响的日益关注，并强调了影响自然环境中声音信号的因素的复杂性。