The pre-migratory flight behaviour in a songbird migrant – spatiotemporal characteristics and potential delayed fitness consequences

候鸟在它们的繁殖区和越冬地之间穿梭，以利用这些环境中资源的季节性波动。鸟类特定的年度周期事件，例如繁殖和迁徙，在时间上进行了很好的调整，并适应了它们所居住的生态系统。如果鸟类偏离这一时间模式，它们可能会经历不利的条件，例如食物短缺或恶劣的环境迁徙。这些情况可能会产生直接的适合性后果，即直接导致死亡的时间偏差，以及延迟的适合性后果，即，时间偏差导致繁殖成功率降低。研究鸟类何时偏离预期的时间模式，对于认识到偏离的原因(S)并预测相应的后果是重要的。大多数鸣鸟迁徙的研究都集中在越冬地的变化如何影响后来的年度周期事件。只有几项研究调查了繁殖区域的变化是否以及如何导致延迟的健康后果。这在一定程度上是因为，数据记录器和遥感可以识别越冬地的关键特征，即位置和栖息地质量，但繁殖期的关键特征，如繁殖的时机、父母的投资和迁徙准备，则无法确定。后者代表从静止繁殖期向流动迁移期的过渡。在这一过渡期间，发生了重大的行为和生理变化，为迁徙做准备。一项对候鸟的研究表明，鸟类在夜间飞行几个小时，然后再次降落在繁殖区。讨论了这些“迁徙前飞行”的四个潜在原因：i)实行夜间飞行，ii)发展定向技能，iii)制作磁力/地形图，以及iv)实践评估气象条件。人们对这些迁徙前飞行的时空特征知之甚少。我们不知道它们是否会影响秋季迁徙的开始和繁殖区的返回，从而推迟适应结果。迁徙前飞行的遗传基础尚未得到研究。这项研究提案将部分填补这些空白。我们将研究诺德尼地区北方小麦(Oenanthe Oenanthe)的繁殖种群。北海的无线电接收站阵列和运行一年的无线电发射机相结合，将使我们能够记录迁徙前飞行的时空特征、秋季迁徙的开始以及随后繁殖区的到达时间。这些行为特征的遗传基础将在实验室条件下用来自诺德尼的手工饲养的北方小麦进行研究。该项目的实施将提供关于在自然和实验室条件下的迁徙前飞行的详细知识，这对于全面了解鸟类迁徙是至关重要的。

Bird migrants travel between their breeding areas and wintering grounds to make use of the seasonal fluctuation of resources in these environments. Birds’ specific annual cycle events, e.g., breeding and migrating, are chronologically well-adjusted and adapted to the ecosystems they inhabit. If birds deviate from this temporal pattern, they may experience unfavourable conditions, e.g., food shortage or harsh environments migration. These conditions may have immediate fitness consequences, i.e., temporal deviation directly causing death, and delayed fitness consequences, i.e., temporal deviation causing decreased reproductive success. Studying when birds deviate from the expected temporal pattern is important to recognize the causes(s) of the deviation and to predict the corresponding consequences. Most songbird migration studies have focused on how variation in the wintering ground affects later annual cycle events. Only a few studies investigated whether and how changes in the breeding area result in delayed fitness consequences. This is partly so because, the key features of the wintering grounds, i.e., location and habitat quality, can be identified by data loggers and remote sensing, but the key features of the breeding period, e.g., the timing of breeding, parental investment and preparation for migration, cannot. The latter represents the transition from the stationary breeding period to the mobile migratory period. During this transition, significant behavioural and physiological changes occur to prepare for migration. A study of migrant songbirds showed that birds flew around for several hours at night and then landed again in the breeding area. Four potential reasons for these “pre-migratory flights” are discussed: i) Practising nocturnal flights, ii) developing orientation skills, iii) generating a magnetic/landscape map and iv) practising evaluating meteorological conditions. Little is known about the spatiotemporal characteristic of these pre-migratory flights. We do not know if they influence the start of autumn migration and the return to the breeding area and thus have delayed fitness consequences. The genetic basis of the pre-migratory flights has not been studied. This research proposal will fill parts of these gaps. We will study the breeding population of northern wheatears (Oenanthe oenanthe) on Norderney. The combination of the array of radio receiving stations in the North Sea and radio-transmitters running for > 1 year would enable us to record the spatiotemporal characteristics of the pre-migratory flights, the start of autumn migration and subsequent breeding area arrival timing. The genetic basis of these behavioural traits will be studied with hand-raised northern wheatears from Norderney under laboratory conditions. The realization of this project would provide detailed knowledge about the pre-migratory flights under natural and laboratory conditions that are essential for a holistic understanding of bird migration.