Wu Nicholas C, Villada-Cadavid Tomás, Welbergen Justin A, Turbill Christopher
Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia.
Centre for Terrestrial Ecosystem Science and Sustainability, Harry Butler Institute, Murdoch University, Murdoch, Western Australia, Australia.
Ecol Lett. 2025 Jun;28(6):e70155. doi: 10.1111/ele.70155.
Seasonality is a fundamental challenge for life on Earth and energy storage prior to colder and drier periods by fattening is a common strategy for survival. Fattening should reflect a trade-off between an expected seasonal energy deficit and the costs of increased body mass, which are particularly important to flying endotherms. We examined body mass change (ΔM), a proxy of fat storage, among bat populations over low productivity periods with global variation in yearly average and seasonality of local climates. We found that ΔM increased with decreasing mean annual surface temperature (MAST) but ΔM also increased at higher MAST with higher seasonality of rainfall. Seasonal use of body energy reserves by bats is predicted to be widespread in warm, seasonal climates at low latitudes but is poorly studied compared to cold temperate regions. In colder climates only, females lost less mass than males over winter, supporting the 'thrifty females' hypothesis, and ΔM has increased with year of study in warm climates, possibly linked to effects of global climate change on their energetics. Our quantitative synthesis highlights how intrinsic and environmental factors shape seasonal fattening in bats, and its global importance for survival in this diverse and widespread mammal group.
季节性是地球上生命面临的一项基本挑战，在寒冷干燥时期来临之前通过增肥来储存能量是一种常见的生存策略。增肥应反映出预期的季节性能量赤字与体重增加成本之间的权衡，这对飞行的恒温动物尤为重要。我们研究了在生产力低下时期蝙蝠种群的体重变化（ΔM），它是脂肪储存的一个指标，同时考虑了全球各地年平均气温和当地气候季节性的差异。我们发现，ΔM随着年平均地表温度（MAST）的降低而增加，但在MAST较高且降雨季节性较强的情况下，ΔM也会增加。预计蝙蝠在低纬度温暖的季节性气候中广泛地季节性利用身体能量储备，但与寒冷的温带地区相比，这方面的研究较少。仅在较寒冷的气候中，雌性蝙蝠在冬季体重损失比雄性少，这支持了“节俭雌性”假说，并且在温暖气候中，ΔM随着研究年份的增加而增加，这可能与全球气候变化对它们能量代谢的影响有关。我们的定量综合分析突出了内在因素和环境因素如何塑造蝙蝠的季节性增肥，以及这对这个多样且分布广泛的哺乳动物群体生存的全球重要性。
