Ontogeny of the star compass in birds: pied flycatchers (<i>Ficedula hypoleuca</i>) can establish the star compass in spring

ABSTRACT The star compass of birds, like the sun compass, is not innate. To possess either them, birds have to observe rotating sky and determine its centre rotation (in case compass) or sun's movement (for compass). Young are believed learn how use before their first migration, even though evidence this lacking. Here, we tested whether hand-raised Pied flycatchers (Ficedula hypoleuca) that had established prior autumn migration can gain it later in ontogeny, spring. We also attempted examine observation diurnal celestial cues (the polarized light) would affect process learning When vertical magnetic field under natural starry sky, group observed stars spring as were able choose migratory direction. In contrast, never seen nightly field. However, daytime till at disoriented, although might be due small sample size. Our data suggest possibility may learned emphasize necessity for further research into interaction compasses.