降雨噪声对菲菊头蝠出飞行为的影响

降雨噪声属于常见的自然噪声，由雨滴撞击物体表面产生。目前，有关降雨噪声对动物的潜在影响被普遍忽视。回声定位蝙蝠主要利用声信号在黑暗环境导航空间、探测猎物及社群交流，是开展降雨噪声影响研究的理想类群。本研究选择菲菊头蝠 (Rhinolophus pusillus)作为研究对象，检验降雨噪声是否影响蝙蝠出飞行为。我们在集群栖息地外，播放强降雨噪声、空白对照和种内回声定位声波，开展野外回放实验。利用单因素方差分析及其事后检验，评价菲菊头蝠对不同回放刺激的反应差异。研究发现，相比空白对照，强降雨噪声导致菲菊头蝠的通勤数量百分比平均降低2.82倍，回声定位脉冲数量平均减少4.86倍，集群出飞时间延长3.75 min。相比空白对照，同种回声定位声波对菲菊头蝠出飞行为的影响并不显著。研究结果证实强降雨噪声抑制菲菊头蝠的出飞行为。本研究表明，降雨引起的噪声干扰可能是导致蝙蝠躲避降雨的重要因素，为野生蝙蝠物种保育与管理提供启示。

The effect of rain noise on emergence behavior in least horseshoe bats

The sound of rain is a common natural noise generated by raindrops striking the surface of objects. To date，the potential effect of rain noise on animals has been widely neglected. Echolocating bats rely on acoustic signals for spatial navigation，prey detection，and social communication in a dark environment，making them an ideal taxon to study the aversive impact of rain noise. Here，we used least horseshoe bats，Rhinolophus pusillus，as a model to assess whether rain noise affects emergence behavior. Field playbacks，consisting of the noise of heavy rain，silence，and intraspecific echolocation calls，were presented to bats outside the colony roost. One-way ANOVA and post-hoc tests were applied to determine differential responses of bats to different playback stimuli. Analyses revealed that the percentage of bat passes decreased 2.82-fold on average in the presence of heavy rain noise compared to the silent control. The average number of bat echolocation pulses declined 4.86-fold during playback of heavy rain noise compared to playback of silence. The duration of the colony-wide emergence was delayed 3.75 min when heavy rain noise was presented. There were no marked differences in emergence activity in the presence of intraspecific echolocation calls versus the silent control. These results indicate that the sound of heavy rain could suppress emergence behavior in leasthorseshoe bats. Our findings highlight that noise disturbance imposed by rainfall may be an important determinant of rain avoidance in bats，and provides implications for the conservation and management of wild bat species.