Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
Horm Behav. 2018 Mar;99:9-13. doi: 10.1016/j.yhbeh.2018.01.008. Epub 2018 Feb 3.
Most migrating birds make stopovers to replenish fuel stores. The decision to resume migration from stopover to a large extent shapes the temporal organization of migration. This decision is known to be shaped by a suite of intrinsic and extrinsic factors such as the bird's fuel stores and current weather conditions. However, how departures from stopover are physiologically regulated is largely unknown. We here present data that strongly indicate that corticosterone, a hormone with a stimulatory effect on locomotion, acts as a mediator between fuel stores and departure from stopover. In migrating northern wheatears (Oenanthe oenanthe) temporarily caged at stopover, we observed a positive relationship between the change in fuel stores and the concurrent change in glucocorticoid metabolite (GCM) levels measured in the birds' droppings. We also found a positive relationship between the change in GCM levels and the change in the intensity of nocturnal migratory restlessness. As in northern wheatears nocturnal migratory restlessness is an accurate proxy for stopover departure likelihood, our results indicate that corticosterone mediates between fuel stores and the decision to resume migration. Our unique longitudinal study represents a considerable advance in our understanding of the endocrine regulation of avian migration.
大多数候鸟在中途停留地补充燃料。从中途停留地恢复迁徙的决定在很大程度上塑造了迁徙的时间组织。据了解，这一决定是由一系列内在和外在因素决定的，如鸟类的燃料储备和当前的天气条件。然而，离开中途停留地是如何在生理上调节的，在很大程度上尚不清楚。我们在这里提供的数据强烈表明，皮质酮是一种对运动有刺激作用的激素，它在燃料储备和离开中途停留地之间起着中介作用。在中途停留地被临时关在笼子里的北灰鹟（Oenanthe oenanthe）中，我们观察到，在鸟类粪便中测量的燃料储备变化与同时发生的糖皮质激素代谢物（GCM）水平变化之间存在正相关关系。我们还发现，GCM 水平的变化与夜间迁徙不安的强度变化之间存在正相关关系。就像在北灰鹟中一样，夜间迁徙不安是离开中途停留地可能性的准确代理指标，因此我们的结果表明，皮质酮在燃料储备和恢复迁徙的决定之间起着中介作用。我们独特的纵向研究代表了我们对鸟类迁徙内分泌调节理解的重大进展。
