Neotropical forest soundscapes with call identifications for katydids

Insects are an integral part of terrestrial ecosystems, but while they are ubiquitous, they can be difficult to census. Passive acoustic recording can provide detailed information on the spatial and temporal distribution of sound producing insects. We placed recording devices in the forest canopy on Barro Colorado Island in Panamá and identified katydid calls in recordings to assess what species were present, in which seasons they were signaling, and how often they called. The focal recordings were collected at a height of 24 meters in two replicate sites, sampled three times per night across five months, spanning both wet and dry seasons. Katydid calls were commonly detected in recordings, but the call repetition rates of many species were quite low, consistent with findings from individual focal recordings. The recordings contained 6,789 calls with visible pulse structure. Of these, we identified 4,371 to species with the remainder representing calls that could not be identified to species. The identified calls corresponded to 24 species, with 15 of these species detected at both replicate sites. Katydid calls were detected throughout the night. Most species were detected at all three timepoints in the night, although some species called more just after dusk and just before dawn. The annotated dataset provided here serves as an archival sample of the species diversity and number of calls present in the forest canopy of Barro Colorado Island, Panama. These hand-annotated data will also be key for evaluating automated approaches to detecting and classifying insect calls. In changing forests and with potentially declining insect populations, consistent approaches for insect sampling will be key for generating interpretable and actionable data.

昆虫是陆地生态系统不可或缺的组成部分，尽管它们分布广泛，但普查难度颇高。被动声学记录（Passive Acoustic Recording）可提供发声昆虫的时空分布细节信息。我们在巴拿马的巴罗科罗拉多岛（Barro Colorado Island）的林冠层布设了录音设备，对录音中的螽斯（katydid）鸣叫声进行识别，以此分析当地存在的物种、其鸣唱季节以及鸣唱频次。本研究的聚焦录音采集于两处重复样地的24米高度处，在横跨干湿两季的五个月内，每夜采样三次。录音中常可检测到螽斯鸣叫声，但多数物种的鸣唱重复率极低，这与单份聚焦录音的研究结果相符。本次采集的录音共包含6789段具有清晰脉冲结构的鸣叫声，其中4371段被鉴定至物种水平，剩余部分则无法确定具体物种。经鉴定的鸣叫声隶属于24个物种，其中15个物种在两处重复样地中均有检出。螽斯鸣叫声在整夜均可被检测到。多数物种在夜间三个采样时段均有出现，不过部分物种的鸣唱活动集中在黄昏后与黎明前时段。本次公开的标注数据集可作为巴拿马巴罗科罗拉多岛林冠层昆虫物种多样性与鸣叫声数量的档案样本。这些人工标注的数据也将成为评估昆虫鸣叫声自动检测与分类方法的关键基准。在森林环境持续变化、昆虫种群或现下降趋势的背景下，标准化的昆虫采样方法将是获取可解释且可落地数据的核心手段。