You who live in the mountains or plantations will certainly hear the birds chirp in the morning. Scientists call the event as a dawn chorus phenomenon. Birds usually start activities at 4:00 am and end in a few hours later to find food.
Besides chirping in the morning can also produce a consistent sound wave so that other birds can clearly recognize the sound
But why is the chirp more often heard in the morning? There are several theories that say as quoted from the following WIRED.
One theory that allows birds to sing in the morning is because the level of lighting is still dim. The lack of lighting makes it difficult for non-nocturnal birds to search for food. So with the circumstances, chirping is the right way to start the activity.
Another theory reveals that the morning is a good time to signal to other birds. Since chirping is a vital part of birds, a loud chirp can serve as a warning to other males to escape power.