The key physiological cue for migration will be the improvements within the day length. These alterations are connected with hormonal changes in the birds. During the period right before migration, a lot of birds Screen better activity or Zugunruhe (German: migratory restlessness), initial described by Johann Friedrich Naumann in 1795, https://whypetskystore51716.suomiblog.com/the-smart-trick-of-bird-ownership-checklist-uae-that-no-one-is-discussing-53397124