Data and code for: River noise alters orb-weaving spider abundance, web size, and prey capture

Novel anthropogenic noise has received considerable attention in behavioral ecology, but natural acoustic environments have largely been ignored as ecological niche axes. In riparian sites, within an arid sagebrush steppe ecosystem, we use a natural range of acoustic environments along with experimentally broadcasted whitewater river noise to test our hypothesis that river noise is an important niche axis. We show that orb-weaving spiders (Araneidae and Tetragnathidae) are more abundant in high sound level environments, but do not seem to be affected by the background noise spectrum. We explore multiple hypotheses for these patterns, such as loss of vertebrate predators and increased prey capture, and then assess how web-building behavior and body condition may be altered. Here, we demonstrate that river noise has the potential to alter spider abundance and behavior.

人为新增噪声在行为生态学领域已受到广泛关注，但自然声学环境作为生态位轴（ecological niche axes）却在很大程度上被忽视。本研究选取干旱山艾灌丛草原生态系统中的河岸生境，借助声学环境的自然梯度与实验播放的急流河噪声，验证“河流水声是重要生态位轴”这一假说。研究结果显示，结圆网蜘蛛（orb-weaving spiders），涵盖园蛛科（Araneidae）与长脚蛛科（Tetragnathidae），在高声学环境中的种群丰度更高，但其丰度似乎不受背景噪声频谱的影响。针对上述观测结果，我们探讨了多种潜在解释假说，包括脊椎动物捕食者流失、猎物捕获率提升等，并进一步评估了结网行为与身体状况可能发生的变化。本研究证实，河流水声具备改变蜘蛛种群丰度与行为的潜力。