Toshkova Nia, Kolev Maksim, Deleva Stanimira, Simeonov Tzvetan, Popov Vasil
National Museum of Natural History at the Bulgarian Academy of Sciences, Sofia, Bulgaria National Museum of Natural History at the Bulgarian Academy of Sciences Sofia Bulgaria.
Institute of Biodiversity and Ecosystem Research at the Bulgarian Academy of Sciences, Sofia, Bulgaria Institute of Biodiversity and Ecosystem Research at the Bulgarian Academy of Sciences Sofia Bulgaria.
Biodivers Data J. 2025 Jan 24;13:e141801. doi: 10.3897/BDJ.13.e141801. eCollection 2025.
Little is known about the winter bat activity in Bulgaria, which poses challenges in monitoring potential deviations in their behaviour as a consequence of the warming climate. Using passive acoustic monitoring, we investigated the winter activity in some of Europe's largest hibernacula. Our findings reveal cave and species-specific activity patterns. Activity was observed throughout each month of the survey, with distinct peaks on specific days. At one high-elevation site, bat activity was restricted to a single night, while the highest overall activity occurred at the highest elevation site (1325 m). The most active species was (Bonaparte, 1837). While bats were mostly active right after sunset following their usual circadian rhythm, some daytime activity was also observed, including emergence at temperatures as low as -8°C. At sites with sufficient activity data, external temperature emerged as a significant positive predictor of bat activity, with higher temperatures associated with increased activity. Our data also suggest that bats rarely forage near the roost entrances. The observed variability in activity levels between study sites highlights the need for high-resolution, site-specific data rather than broad generalisations.
关于保加利亚蝙蝠冬季活动的情况所知甚少，这给监测它们因气候变暖而可能出现的行为偏差带来了挑战。我们利用被动声学监测技术，对欧洲一些最大的冬眠洞穴中的冬季活动进行了调查。我们的研究结果揭示了洞穴和物种特定的活动模式。在调查的每个月都观察到了蝙蝠活动，在特定日期有明显的高峰。在一个高海拔地点，蝙蝠活动仅限于一个晚上，而总体活动最高的情况出现在海拔最高的地点（1325米）。最活跃的物种是邦氏鼠耳蝠（Bonaparte，1837年）。虽然蝙蝠大多按照其通常的昼夜节律在日落后立即活跃，但也观察到了一些白天活动，包括在低至-8°C的温度下出洞。在有足够活动数据的地点，外部温度成为蝙蝠活动的一个显著正预测因子，温度越高，活动越多。我们的数据还表明，蝙蝠很少在栖息地入口附近觅食。研究地点之间观察到的活动水平差异突出表明，需要高分辨率的、特定地点的数据，而不是宽泛的概括。
