1 Leibniz Institute for Zoo and Wildlife Research , Alfred-Kowalke-Str. 17, Berlin 10315 , Germany.
2 Department of Ecology, Technische Universität Berlin , Rothenburgstr. 12, Berlin 12165 , Germany.
Proc Biol Sci. 2018 Dec 19;285(1893):20182174. doi: 10.1098/rspb.2018.2174.
Each year, large numbers of bats move across Europe between their summer and winter areas, yet even though many of them are endangered and legally protected, we are unaware about many aspects of their migratory behaviour. Here, taking Nyctalus noctula as a model species, we used stable hydrogen isotopic values in fur ( δH) as an endogenous marker to shed light on the migratory behaviour of more than 1000 bats from hibernacula across Central Europe. Specifically, we asked the following questions: how flexible is migration in temperate zone bats? Which general migration pattern do noctule bats follow? How repeatable and thus predictable is the migratory behaviour of individuals? Do morphological correlates of migration occur in bats? Our study confirmed that noctule bats engage in partial and female-biased migration across Europe, suggesting the strongest migration pressures for northern populations. Further, we revealed a combination of partial and differential migration patterns with highly variable migration distances which lead to a pronounced mixing of different source populations in hibernacula where mating occurs. Most individuals were consistent in their migration strategy over time, i.e. 86% could be repeatedly assigned to either long-distance or regional origin across years. This is consistent with our finding that the between-individual component explained 84% of the variation in δH values, suggesting specialized individual migratory behaviours and a strong natal philopatry. We discovered a positive correlation between forearm length and migration distance and support for sex-specific effects of migration on body condition. Our study elucidated migration patterns over large geographical scales, demonstrating that considerable numbers of migratory bats originating from distant populations depend on hibernacula across Central Europe, calling for international conservation management.
每年，大量蝙蝠在夏季和冬季栖息地之间跨越欧洲迁徙，但尽管其中许多蝙蝠濒临灭绝并受到法律保护，我们对它们的许多迁徙行为仍一无所知。在这里，我们以 Nyctalus noctula 为模型物种，利用皮毛中的稳定氢同位素值 (δH) 作为内源性标记，来揭示来自中欧多个冬眠地的 1000 多只蝙蝠的迁徙行为。具体而言，我们提出了以下问题：温带蝙蝠的迁徙行为有多灵活？褐林蝠遵循什么样的一般迁徙模式？个体的迁徙行为有多可重复和可预测？迁徙行为是否与蝙蝠的形态相关？我们的研究证实，褐林蝠在欧洲进行部分和雌性偏倚的迁徙，表明北部种群面临最强的迁徙压力。此外，我们揭示了部分和差异迁徙模式的组合，迁徙距离变化很大，导致在冬眠地发生交配时，不同来源的种群明显混合。大多数个体随着时间的推移保持一致的迁徙策略，即 86%的个体可以在多年间反复被分配到长距离或区域起源。这与我们的发现一致，即个体间成分解释了 84%的 δH 值变化，表明存在专门的个体迁徙行为和强烈的出生地亲缘关系。我们发现前臂长度与迁徙距离之间存在正相关关系，并支持迁徙对身体状况的性别特异性影响。我们的研究阐明了跨越大地理范围的迁徙模式，表明来自遥远种群的大量迁徙蝙蝠依赖于中欧的冬眠地，这需要国际保护管理。
