Job Jacob R, Myers Kyle, Naghshineh Koorosh, Gill Sharon A
Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States of America.
Department of Mechanical and Aerospace Engineering, Western Michigan University, Kalamazoo, MI, United States of America.
PLoS One. 2016 Jul 28;11(7):e0159883. doi: 10.1371/journal.pone.0159883. eCollection 2016.
Animals select and use habitats based on environmental features relevant to their ecology and behavior. For animals that use acoustic communication, the sound environment itself may be a critical feature, yet acoustic characteristics are not commonly measured when describing habitats and as a result, how habitats vary acoustically over space and time is poorly known. Such considerations are timely, given worldwide increases in anthropogenic noise combined with rapidly accumulating evidence that noise hampers the ability of animals to detect and interpret natural sounds. Here, we used microphone arrays to record the sound environment in three terrestrial habitats (forest, prairie, and urban) under ambient conditions and during experimental noise introductions. We mapped sound pressure levels (SPLs) over spatial scales relevant to diverse taxa to explore spatial variation in acoustic habitats and to evaluate the number of microphones needed within arrays to capture this variation under both ambient and noisy conditions. Even at small spatial scales and over relatively short time spans, SPLs varied considerably, especially in forest and urban habitats, suggesting that quantifying and mapping acoustic features could improve habitat descriptions. Subset maps based on input from 4, 8, 12 and 16 microphones differed slightly (< 2 dBA/pixel) from those based on full arrays of 24 microphones under ambient conditions across habitats. Map differences were more pronounced with noise introductions, particularly in forests; maps made from only 4-microphones differed more (> 4 dBA/pixel) from full maps than the remaining subset maps, but maps with input from eight microphones resulted in smaller differences. Thus, acoustic environments varied over small spatial scales and variation could be mapped with input from 4-8 microphones. Mapping sound in different environments will improve understanding of acoustic environments and allow us to explore the influence of spatial variation in sound on animal ecology and behavior.
动物根据与其生态和行为相关的环境特征来选择和利用栖息地。对于使用声学通讯的动物来说，声音环境本身可能是一个关键特征，然而在描述栖息地时，声学特征并不常被测量，因此，人们对栖息地在空间和时间上的声学变化知之甚少。鉴于全球人为噪声的增加，以及迅速积累的证据表明噪声会妨碍动物检测和解读自然声音的能力，这些考虑非常及时。在这里，我们使用麦克风阵列在自然环境条件下以及在引入实验噪声时记录了三种陆地栖息地（森林、草原和城市）的声音环境。我们在与不同分类群相关的空间尺度上绘制了声压级（SPL），以探索声学栖息地的空间变化，并评估在自然环境和噪声条件下阵列中捕获这种变化所需的麦克风数量。即使在小空间尺度和相对短的时间跨度内，声压级也有很大变化，尤其是在森林和城市栖息地，这表明量化和绘制声学特征可以改善对栖息地的描述。在自然环境条件下，基于4个、8个、12个和16个麦克风输入的子集地图与基于24个麦克风的完整阵列的地图在不同栖息地略有差异（<2 dBA/像素）。引入噪声后，地图差异更为明显，尤其是在森林中；仅由4个麦克风绘制的地图与完整地图的差异更大（>4 dBA/像素），比其余子集地图的差异更大，但由8个麦克风输入绘制的地图差异较小。因此，声学环境在小空间尺度上存在变化，并且可以用4 - 8个麦克风的输入来绘制这种变化。绘制不同环境中的声音将增进我们对声学环境的理解，并使我们能够探索声音的空间变化对动物生态和行为的影响。
