The behavior of most animals is influenced by the periods of daylight and darkness in the environment. fiddler crabs' courtship behaviors are instead synchronized by the 29 1/2-day cycle of the moon. what is the adaptive significance of using lunar cues? the behavior of most animals is influenced by the periods of daylight and darkness in the environment. fiddler crabs' courtship behaviors are instead synchronized by the 29 1/2-day cycle of the moon. what is the adaptive significance of using lunar cues?