The key physiological cue for migration is definitely the modifications from the day size. These adjustments are connected to hormonal modifications from the birds. Inside the time period prior to migration, quite a few birds Screen better action or Zugunruhe (German: migratory restlessness), first described by Johann Friedrich Naumann in https://lorenzoiklfh.blogdiloz.com/36500669/5-easy-facts-about-getting-a-pet-bird-advice-described