Since the position of the sunset changes with latitude and season, researchers think that these birds must be able to compensate for the changes by means of “a biological clock that tells them the time of year, ” says Science.
लेकिन सूर्यास्त की स्थिति, अक्षांश रेखा (latitude) और ऋतुओं के हिसाब से बदलती रहती है ।