ABSTRACT Capsule: We document previously undescribed nocturnal flight behaviour by Bearded Vultures Gypaetus barbatus using a combination of accelerometer and global positioning system (GPS) information. Aims: To study the nocturnal flight activity of the Bearded Vulture and determine whether nocturnal flights could be linked to foraging behaviour. Methods: We used both accelerometer and GPS location data of 11 Bearded Vultures in the Spanish Pyrenees along with 88 carcasses monitored with camera traps. Results: Over half (55%, n = 11) of the individuals tracked were recorded flying between 0.7 and 6.1 km on at least 19 different nights, including 37% that occurred when less than 20% of the moon was illuminated. Bearded Vultures displayed feeding activity in only 8.2% of the 146 feeding events existing during the hour after dawn and the hour before dusk. Conclusions: Our findings suggest that foraging benefits do not explain the nocturnal flights. Disturbances or adverse weather conditions may result in the abandonment of an overnight roosting site. This could also explain why individuals recovered in the field showed impact injuries.

中文翻译：

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首次使用 GPS 和加速度计数据检测到胡须秃鹫 Gypaetus barbatus 的夜间飞行

摘要胶囊：我们使用加速度计和全球定位系统 (GPS) 信息的组合记录了胡须秃鹫 Gypaetus barbatus 以前未描述的夜间飞行行为。目的：研究大胡子秃鹰的夜间飞行活动，并确定夜间飞行是否与觅食行为有关。方法：我们使用了西班牙比利牛斯山脉 11 只大胡子秃鹫的加速度计和 GPS 位置数据，以及用相机陷阱监控的 88 具尸体。结果：超过一半（55%，n = 11）的被追踪个体被记录到至少在 19 个不同的夜晚飞行在 0.7 到 6.1 公里之间，其中 37% 发生在不到 20% 的月亮被照亮时。Bearded Vultures 仅在 8 个中表现出进食活动。146 次进食事件中的 2% 发生在黎明后的一小时和黄昏前的一小时。结论：我们的研究结果表明，觅食的好处并不能解释夜间飞行。干扰或恶劣的天气条件可能会导致放弃过夜栖息地。这也可以解释为什么在野外康复的个体会出现撞击伤。