Biological Station Rybachy, Zoological Institute, Russian Academy of Sciences, Rybachy 238535, Kaliningrad Region, Russia
Moscow State Pedagogical University, 1/1 M. Pirogovskaya St., Moscow 119991, Russia.
J Exp Biol. 2021 Feb 9;224(Pt 3):jeb237875. doi: 10.1242/jeb.237875.
The star compass of birds, like the sun compass, is not innate. To possess either of them, birds have to observe the rotating sky and determine its centre of rotation (in the case of the star compass) or the sun's movement (for the sun compass). Young birds are believed to learn how to use the star compass before their first migration, even though the evidence of this is lacking. Here, we tested whether hand-raised Pied flycatchers () that had not established the star compass prior to their first autumn migration can gain it later in their ontogeny, in spring. We also attempted to examine whether the observation of diurnal celestial cues (the sun and polarized light) prior to autumn migration would affect the process of star compass learning in spring. When tested in the vertical magnetic field under the natural starry sky, the group of birds that observed the stars in spring as the first celestial cues were able to choose the migratory direction. In contrast, the birds that had never seen the stars were not able to use the nightly celestial cues in the vertical magnetic field. However, birds that had seen the daytime celestial cues till autumn and the stars at spring were disoriented, although this might be due to the small sample size. Our data suggest the possibility that the star compass may be learned in spring and emphasize the necessity for further research into the interaction of celestial compasses.
鸟类的“星罗盘”和“太阳罗盘”一样，并非与生俱来。鸟类要想拥有这两种罗盘，必须观察旋转的天空并确定其旋转中心（对于“星罗盘”而言）或太阳的运动（对于“太阳罗盘”而言）。尽管缺乏证据，但人们认为幼鸟在第一次迁徙之前就已经学会了如何使用“星罗盘”。在这里，我们测试了在它们第一次秋季迁徙之前没有建立“星罗盘”的笼养白腰文鸟能否在其发育过程中在春季获得“星罗盘”。我们还试图研究在秋季迁徙之前观察昼夜天体线索（太阳和偏振光）是否会影响春季“星罗盘”学习的过程。当在自然星空下的垂直磁场中进行测试时，那些在春季将观察星星作为第一个天体线索的鸟类能够选择迁徙方向。相比之下，从未见过星星的鸟类在垂直磁场中无法利用夜间的天体线索。然而，尽管可能是由于样本量较小，那些在秋季观察过昼夜天体线索并且在春季观察过星星的鸟类迷失了方向。我们的数据表明鸟类可能在春季学习“星罗盘”的可能性，并强调需要进一步研究天体罗盘的相互作用。
