Biological Station Rybachy of Zoological Institute RAS, 238535, Rybachy, Kaliningrad reg., Russia.
Department Molecular Physiology and Biophysics, Immanuel Kant Baltic Federal University, Kaliningrad, Russia.
Sci Rep. 2018 Apr 3;8(1):5520. doi: 10.1038/s41598-018-23834-0.
Long-distance avian migrants, e.g. Eurasian reed warblers (Acrocephalus scirpaceus), can precisely schedule events of their annual cycle. However, the proximate mechanisms controlling annual cycle and their interplay with environmental factors are poorly understood. We artificially interrupted breeding in reed warblers by bringing them into captivity and recording birds' locomotor activity for 5-7 days. Over this time, most of the captive birds gradually developed nocturnal locomotor activity not observed in breeding birds. When the birds were later released and radio-tracked, the individuals with highly developed caged activity performed nocturnal flights. We also found that reed warblers kept indoors without access to local cues developed a higher level of nocturnal activity compared to the birds kept outdoors with an access to the familiar environment. Also, birds translocated from a distant site (21 km) had a higher motivation to fly at night-time after release compared to the birds captured within 1 km of a study site. Our study suggests that an interrupted breeding triggers development of nocturnal locomotor activity in cages, and the level of activity is correlated with motivation to perform nocturnal flights in the wild, which can be restrained by familiar environment.
长距离迁徙的鸟类，例如芦苇莺（Acrocephalus scirpaceus），可以精确地安排其年度周期的事件。然而，控制年度周期的近似机制及其与环境因素的相互作用还知之甚少。我们通过将芦苇莺囚禁起来，并记录它们的运动活动 5-7 天，人为地打断了它们的繁殖。在此期间，大多数被囚禁的鸟类逐渐发展出了在繁殖鸟类中没有观察到的夜间运动活动。当这些鸟类后来被释放并进行无线电跟踪时，那些具有高度发展的笼中活动的个体进行了夜间飞行。我们还发现，与在熟悉的环境中饲养的鸟类相比，室内饲养且无法获得当地线索的鸟类会发展出更高水平的夜间活动。此外，与在研究地点 1 公里范围内捕获的鸟类相比，从远距离（21 公里）转移的鸟类在释放后更有夜间飞行的动力。我们的研究表明，繁殖中断会触发笼中夜间运动活动的发展，而活动水平与在野外进行夜间飞行的动机相关，这种动机可以被熟悉的环境所抑制。
