SM4：声学区域工作流程，用于有效比较不同入侵哺乳动物管理制度下的声域
Abstract
One quarter of all terrestrial native bird species have become extinct since human arrival in New Zealand, leading to a pervasive silence in many natural environments due to the decrease in native bird song. Passive acoustic techniques are a potential tool for environmental monitoring, especially for testing whether the control of mammals can reverse the ‘silent forest’ effect. Here we compare soundscapes from two nearby sites within the Waitakere Ranges Regional Park, New Zealand, that have contrasting predator control levels: one with high-level pest mammal control, and the other with low-level pest control. Measurements of twelve acoustic indices extracted from two seasons of passive acoustic recordings are split into 20 acoustic regions to identify which regions best discriminate between the two management regimes. We define the acoustic regions as units of analysis bounded by a specific time period and frequency range chosen to capture the main groups of biologically relevant acoustic events within a soundscape. Analysis of variance and pairwise comparisons indicated the acoustic region bounded from 9 pm to 11:59 pm and a range of 0.988–3.609 kHz in autumn presented the greatest differences between sites. The sounds responsible for these acoustic differences were generated by invasive mammals in the site with no pest control. Results also supports spring season as the most important for bird monitoring in New Zealand. Acoustic indices analysis did not detect a reversal of the ‘silence forest’ effect in the site with high-level predator control.
摘要：
自人类抵达新西兰以来，四分之一的陆地本土鸟类已经灭绝，由于本土鸟类歌声的减少，许多自然环境中普遍沉默。被动声学技术是一种潜在的环境监测工具，特别是用于测试对哺乳动物的控制是否可以扭转“寂静森林”效应。在这里，我们比较了新西兰怀塔克雷山脉区域公园内两个附近地点的音景，这两个地点的捕食者控制水平存在差异：一个是高级害虫哺乳动物控制，另一个是低级害虫控制。从两个季节的被动声学记录中提取的12个声学指标的测量值被分为20个声学区域，以确定哪些区域最能区分两种管理制度。我们将声学区域定义为以特定时间段和频率范围为界的分析单元，这些时间段和范围被选择用于捕捉声景中主要的生物相关声学事件。方差分析和成对比较表明，秋季从晚上9点到晚上11点59分的声学区域和0.988-3.609 kHz的范围在不同地点之间存在最大差异。造成这些声学差异的声音是由该地区没有害虫控制的入侵哺乳动物产生的。研究结果还支持春季是新西兰鸟类监测最重要的季节。声学指标分析没有检测到在捕食者控制水平较高的地点“寂静森林”效应的逆转。
关键词：SM4 声学记录仪，Wildlife野外声学监测，鸟鸣声监测，野生动物声学记录，Wildlife Acoustics 野生动物声学
