Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. https://www.spidertattooz.com/Nora-NEFLINTW-R6MPW-6-E-Series-FLIN-Round-LED-Downlight-27K-30K-35K-40K-50K-Selectable-120V/