Influence of experience and migratory distance on the variation of the realised and endogenous migration behaviour

夜间迁徙的鸣禽幼鸟会独立于同种鸟类飞行数千公里到达它们的越冬地区。鸟类天生的迁徙程序决定了鸟类迁徙的时空组织和对环境因素的反应规范。以高时空分辨率跟踪第一次迁徙表明内源性控制的迁徙程序如何引导鸟类穿越空间和时间，而成鸟的迁徙受其经验的影响。随着迁徙距离的增加，稳定（定向）选择的强度应该会增加，以达到精确的繁殖时间，特别是在北极。主要目的是研究自由飞行naïve和有经验的鸟类的实际迁徙行为，表明迁徙的遗传基础，以及先天迁徙行为的变化是否随着迁徙距离的增加而减少，从而增加稳定（定向）选择压力。北麦穗（Oenanthe Oenanthe）是世界上范围最大的鸣禽之一，从加拿大东部开始繁殖，穿过格陵兰岛，欧亚大陆，进入阿拉斯加。由于撒哈拉以南非洲的所有种群都在过冬，迁徙距离因种群而异。它们的运动可以通过光级地理定位器以高时空分辨率进行跟踪。方法的缺点是，由于阿拉斯加种群的大量纵向迁徙成分允许关于中途停留和飞行阶段的精确时间信息，因此没有关于春分前后纬度的信息，这在阿拉斯加种群中被最小化。这使得研究取向表现、时空迁移策略和对不同环境的反应规范可能存在的年龄差异成为可能。除了阿拉斯加鸟类（迁徙距离：14000公里），德国小麦（4000公里）也将通过光照地理定位进行研究。由于使用轻型地理定位器需要重新捕获；只有归来的鸟儿才可以被考虑。为了更连贯地研究先天迁徙程序对迁徙实现的重要性，我们需要结合不同种群naïve鸟类的内源成分（燃料沉积、迁徙不安）的变化，通过普通花园实验来考虑自由飞行个体的迁徙行为。这里我们将额外考虑来自摩洛哥（1500公里）、挪威（5000公里）和冰岛（6000公里）的鸟类。由于迁徙距离可能与迁徙过程中所经历的自然选择压力的强度相当，本研究将揭示自然选择如何影响先天迁徙性状的变化。在不久的将来，icarus项目可以对小生物进行遥感，这将克服只考虑返回鸟类的问题。未来的观点是研究个体迁移行为的可重复性和最初naïve个体多年来的一致性。

Juvenile nocturnally migrating songbirds travel thousands of kilometres to their wintering areas independently of conspecifics. To arrive at the spot and in time, their innate migration program defines birds spatiotemporal organisation of migration and their reaction norm to environmental factors. Tracking the first migration at a high spatiotemporal resolution indicates how the endogenously controlled migration program guides birds through space and time, whereas adults migration is influenced by their experience. With an increasing migration distance the strength of stabilizing (directional) selection is supposed to increase towards an accurate timing for reproduction especially in the Arctic. The main aims are to investigate the realised migration behaviour of free-flying naïve and experienced birds indicating the genetic basis of migration and whether the variation of the innate migration behaviour decreases with increasing migration distance and consequently increased stabilizing (directional) selection pressure.The Northern Wheatear (Oenanthe oenanthe) has one of the largest ranges of any songbird in the world, breeding from eastern Canada across Greenland, Eurasia and into Alaska. As all populations winter in sub-Saharan Africa, migration distance varies between populations. Their movements can be tracked in a high spatiotemporal resolution by light-level geolocators. Methods drawback, i.e., no information about latitude around equinoxes, is minimized in the Alaskan population due to its large longitudinal migratory component allowing precise temporal information about stopover and flight stages. This enables studying possible age differences in the orientation performance, spatiotemporal migration strategy and reaction norms to varying environments. In addition to Alaskan birds (migration distance: 14000 km), German wheatears (4000 km) will be studied also by light-level geolocation. As the usage of light-level geolocators requires re-trapping; only returning birds can be considered. To study coherently the importance of the innate migration program on the realization of migration, we need considering migration behaviour of free-flying individuals in combination with the variation of the endogenous components (fuel deposition, migratory restlessness) in naïve birds of different populations by common-garden experiments. Here we will consider additionally birds from Morocco (1500 km), Norway (5000 km) and Island (6000 km). As migration distance might be equivalent with strength of the natural selection pressure experienced during travelling, this study will show how natural selection affected the variation of the innate migratory traits. The problem of considering only returning birds will be overcome with the ICARUS-Project in the near future allowing remote sensing of small organisms. A future perspective is studying the individual repeatability and consistency of the migration behaviour of initially naïve individuals over years.