The first physiological cue for migration will be the improvements from the working day duration. These changes are connected with hormonal alterations inside the birds. While in the interval before migration, numerous birds Show higher activity or Zugunruhe (German: migratory restlessness), very first described by Johann Friedrich Naumann in 1795, https://indoorcatproductsuae83714.aioblogs.com/90364470/5-simple-statements-about-pet-bird-explained