Orientation by untrained pigeons requires the sun.
Untrained homing pigeons released on sunny days oriented homeward regardless of the direction of the release site from the loft. Similar pigeons released under total overcast vanished randomly, whereas experienced birds released on the same days at the same sites oriented homeward. Apparently untrained pigeons require the sun for orientation but experienced pigeons do not.
D000818:Animals; D010856:Columbidae; D003213:Conditioning, Psychological; D006702:Homing Behavior; D009949:Orientation; D013472:Sunlight