The decision-making process of migrating birds at stopover sites is a complex interplay of the innate migration program and both intrinsic and extrinsic factors. While it is well studied how variation in precipitation, wind and air pressure influence this process, there is less evidence of the effects of temperature changes on the departure decision. Thus, we lack knowledge on how the predicted changes due to global climate change in temperature alone may affect the decision-making process during migration. Aiming to fill parts of this gap, we conducted a proof-of-concept study by manipulating the ambient temperature of temporarily confined wild-caught migrant songbirds under constant feeding conditions. In spring, departure probability increased with a 20°C rise in temperature for both a medium-distance migrant (European robin, Erithacus rubecula) and a long-distance migrant (northern wheatear, Oenanthe oenanthe), and in autumn, departure probabilities of the long-distance migrant both decreased with a 20°C rise and increased with a 20°C drop. Consequently, the temperature is an important departure cue influencing the decision-making process of migrating songbirds. Incorporating causal relationships between changes in temperature and departure probability in migration models could substantially improve our ability to predict the effects of climate change on the phenology of migratory birds.

中文翻译：

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温度变化是夜间迁徙的重要离开线索：概念验证研究中对野生鸟类的对照实验

候鸟在中途停留地的决策过程是先天迁徙计划以及内在和外在因素的复杂相互作用。虽然对降水、风和气压的变化如何影响这一过程进行了充分研究，但关于温度变化对出发决定的影响的证据较少。因此，我们缺乏关于仅因全球气候变化而导致的预测温度变化如何影响迁移过程中的决策过程的知识。为了填补这一空白，我们通过在恒定喂食条件下操纵暂时封闭的野生迁徙鸣禽的环境温度进行了概念验证研究。在春季，中距离迁徙者（欧洲知更鸟、Erithacus rubecula）和远距离迁徙者（北方小麦，Oenanthe oenanthe），在秋季，远距离迁徙者的离开概率均随温度升高 20°C 下降而随着下降 20°C 而增加。因此，温度是影响候鸟迁徙决策过程的重要出发线索。在迁徙模型中纳入温度变化与离开概率之间的因果关系可以大大提高我们预测气候变化对候鸟物候影响的能力。温度是影响候鸟迁徙决策过程的重要出发线索。在迁徙模型中纳入温度变化与离开概率之间的因果关系可以大大提高我们预测气候变化对候鸟物候影响的能力。温度是影响候鸟迁徙决策过程的重要出发线索。在迁徙模型中纳入温度变化与离开概率之间的因果关系可以大大提高我们预测气候变化对候鸟物候影响的能力。