Seasonal animal migration is a widespread phenomenon. At the species level, it has been shown that many migratory animal species track similar climatic conditions throughout the year. However, it remains unclear whether such a niche tracking pattern is a direct consequence of individual behaviour or emerges at the population or species level through behavioural variability. Here, we estimated seasonal niche overlap and seasonal niche tracking at the individual and population level of central European white storks (Ciconia ciconia). We quantified niche tracking for both weather and climate conditions to control for the different spatio-temporal scales over which ecological processes may operate. Our results indicate that niche tracking is a bottom-up process. Individuals mainly track weather conditions while climatic niche tracking mainly emerges at the population level. This result may be partially explained by a high degree of intra- and inter-individual variation in niche overlap between seasons. Understanding how migratory individuals, populations and species respond to seasonal environments is key for anticipating the impacts of global environmental changes.

中文翻译：

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在候鸟的种群水平上出现了对气候的季节性生态位跟踪

季节性动物迁徙是一种普遍现象。在物种层面，已经表明许多迁徙动物物种全年都在追踪类似的气候条件。然而，目前尚不清楚这种生态位跟踪模式是个体行为的直接结果，还是通过行为可变性在种群或物种水平上出现。在这里，我们估计了中欧白鹳 (Ciconia ciconia) 个体和种群水平的季节性生态位重叠和季节性生态位跟踪。我们量化了天气和气候条件的生态位跟踪，以控制生态过程可能运行的不同时空尺度。我们的结果表明，利基跟踪是一个自下而上的过程。个体主要追踪天气状况，而气候生态位追踪主要出现在人口层面。这一结果可能部分解释为季节之间生态位重叠的个体内部和个体间高度差异。了解迁徙个体、种群和物种对季节性环境的反应是预测全球环境变化影响的关键。