Acoustic deterrents influence foraging activity, flight and echolocation behaviour of free-flying bats

Data for Research Article in Journal of Experimental Biology. Including trajectory measurement dataset, acoustic bat call count dataset and echolocation call parameter dataset. Abstract: Acoustic deterrents have shown potential as a viable mitigation measure to reduce human impacts on bats, however, the mechanisms underpinning acoustic deterrence of bats have yet to be explored. Bats avoid ambient ultrasound in their environment and alter their echolocation calls in response to masking noise. Using stereo thermal videogrammetry and acoustic methods, we tested predictions that i) bats would avoid acoustic deterrents and forage and social call less in a ‘treated airspace’; ii) deterrents would cause bats to fly with more direct flight paths akin to commuting behaviour and in line with a reduction in foraging activity, resulting in increased flight speed and decreased flight tortuosity; iii) bats would alter their echolocation call structure in response to the masking deterrent sound. As predicted, overall bat activity was reduced by 30% and we recorded a significant reduction in counts of Pipistrellus pygmaeus (27%), Myotis spp. (probably M. daubentonii) (26%) and Nyctalus and Eptesicus spp. (68%) passes. P. pygmaeus feeding buzzes were also reduced by the deterrent in relation to general activity (by 38%), however social calls were not (only 23% reduction). Bats also increased their flight speed and reduced the tortuosity of their flight paths and P. pygmaeus reduced echolocation call bandwidth and start frequency of calls in response to deterrent playback, probably due to the masking effect of the sound. Deterrence could therefore be used to remove bats from areas where they forage, for example wind turbines and roads, where they may be under threat from direct mortality.

本数据集用于《实验生物学杂志》（Journal of Experimental Biology）的研究论文，包含轨迹测量数据集、蝙蝠声学鸣叫计数数据集以及回声定位鸣叫参数数据集。
摘要：声学威慑手段已被证实为减轻人类活动对蝙蝠负面影响的可行缓解措施，但其介导蝙蝠声学威慑效应的内在机制仍有待深入探究。蝙蝠会规避其生存环境中的环境超声，并会针对掩蔽噪声调整自身的回声定位鸣叫信号。本研究采用立体热成像摄影测量法与声学检测方法，对三项预测进行了验证：其一，蝙蝠会规避声学威慑装置，在施加威慑的"处理空域"内觅食与社交鸣叫行为均会减少；其二，威慑处理会使蝙蝠采取更趋近于通勤飞行的直线路径，伴随觅食活动的减少，进而导致飞行速度提升、飞行路径曲折度降低；其三，蝙蝠会针对掩蔽性威慑声波调整其回声定位鸣叫的结构特征。
研究结果与预测一致：蝙蝠总体活动水平降低了30%，且记录到普通伏翼蝠（Pipistrellus pygmaeus）、鼠耳蝠属（Myotis spp.，大概率为道氏鼠耳蝠M. daubentonii）以及夜蝠属与棕蝠属（Nyctalus and Eptesicus spp.）的过境飞行次数分别显著减少27%、26%与68%。相较于总体活动水平，普通伏翼蝠的觅食蜂鸣信号也因威慑处理减少了38%，但社交鸣叫仅减少23%，未出现显著变化。此外，蝙蝠的飞行速度显著提升，飞行路径曲折度降低；普通伏翼蝠的回声定位鸣叫带宽与鸣叫起始频率也因威慑回放出现下降，这一现象可能源于威慑声波的掩蔽效应。因此，声学威慑手段可用于将蝙蝠从其觅食区域（例如风力涡轮机与道路区域）移除，而这些区域正是蝙蝠可能面临直接致死威胁的场所。