Question

Why do the birds not chirp during daytime?​

Answer 1

Answer:

Birds can sing at any time of day, but during the dawn chorus their songs are often louder, livelier, and more frequent. ... One idea is that in the early morning, light levels are too dim for birds to do much foraging. Since light levels don't affect social interactions as much, it's a great opportunity to sing, instead.

Answer 2

Explanation:

Not all chirping from birds at night are due to light pollution or even normal behavior. Birds general react to threatening stimuli. So in cases where there is distress or think they are in danger, they will start chirping as a form of raising an alarm.