BiBio (Biodiversity and Bioindicators Research Group), Natural Sciences Museum of Granollers, Av. Francesc Macia, 51, 08402 Granollers, Catalonia, Spain; CREAF, Universitat Autònoma de Barcelona, Cerdanyola del Valles, 08193, Catalonia, Spain.
BiBio (Biodiversity and Bioindicators Research Group), Natural Sciences Museum of Granollers, Av. Francesc Macia, 51, 08402 Granollers, Catalonia, Spain.
Sci Total Environ. 2022 Jul 1;828:154403. doi: 10.1016/j.scitotenv.2022.154403. Epub 2022 Mar 8.
Bat arousals during hibernation are related to rises in environmental temperature, body water loss and increasing body heat. Therefore, bats either hibernate in cold places or migrate to areas with mild winters to find water and insects to intake. During winter, insects are relatively abundant in wetlands with mild climates when low temperatures hamper insect activity in other places. However, the role of wetlands to sustain winter bat activity has never been fully assessed. To further understand bat behaviour during hibernation, we evaluated how the weather influenced hibernating bats, assessed the temperature threshold that increased bat arousals, and discussed how winter temperatures could affect bat activity under future climate change scenarios. The effects of weather and landscape composition on winter bat activity were assessed by acoustically sampling four different habitats (wetlands, rice paddies, urban areas and salt marshes) in the Ebro Delta (Spain). Our results show one of the highest winter bat foraging activities ever reported, with significantly higher activity in wetlands and urban areas. Most importantly, we found a substantial increase in bat activity triggered when nocturnal temperatures reached ca. 11 °C. By contrasting historical weather datasets, we show that, since the 1940s, there has been an increase by ca. 1.5 °C in winter maximum temperatures and a 180% increase in the number of nights with mean temperatures above 11 °C in the Ebro Delta. Temperature trends suggest that in 60-80 years, winter months will reach average temperatures of 11 °C (except maybe in January), which suggest a potential coming interruption or disappearance of bat hibernation in coastal Mediterranean habitats. This study highlights the significant role of wetlands in bat conservation under a climate change scenario as these humid areas represent one of the few remaining winter foraging habitats.
冬眠期间蝙蝠的觉醒与环境温度升高、身体水分流失和体热增加有关。因此，蝙蝠要么在寒冷的地方冬眠，要么迁徙到冬季温和的地区寻找水和昆虫。在冬季，当低温抑制其他地方昆虫活动时，气候温和的湿地昆虫相对丰富。然而，湿地在维持冬季蝙蝠活动方面的作用从未得到充分评估。为了进一步了解蝙蝠在冬眠期间的行为，我们评估了天气如何影响冬眠的蝙蝠，评估了增加蝙蝠觉醒的温度阈值，并讨论了未来气候变化情景下冬季温度如何影响蝙蝠活动。通过在埃布罗三角洲（西班牙）的四个不同栖息地（湿地、稻田、城市和盐沼）进行声学采样，评估了天气和景观组成对冬季蝙蝠活动的影响。我们的研究结果显示，冬季蝙蝠觅食活动是有记录以来最高的，湿地和城市地区的活动明显更高。最重要的是，我们发现当夜间温度达到约 11°C 时，蝙蝠活动会显著增加。通过对比历史天气数据集，我们表明，自 20 世纪 40 年代以来，埃布罗三角洲冬季最高温度已经升高了约 1.5°C，夜间平均温度高于 11°C 的夜晚数量增加了 180%。温度趋势表明，在 60-80 年内，冬季月份的平均温度将达到 11°C（也许 1 月除外），这表明在地中海沿海栖息地，蝙蝠冬眠可能会中断或消失。本研究强调了湿地在气候变化情景下对蝙蝠保护的重要作用，因为这些潮湿地区是为数不多的冬季觅食栖息地之一。
