While calls are most common at night, the birds do call during the day as well.

A few birds called to each other in the distance, but she heard nothing else; saw no one.

Three times the bird called, but only she took notice of it.

Birds called, and the sun came out from behind a bank of clouds.

Birds are often associated with the sounds and calls that they make.

In the quiet, a few birds calling, she felt someone behind her.

A bird called in the trees, and another answered it from ahead.

Birds often call while perched on top of a rock.

A little wind stirred outside the window, and a bird called.

That being said, one morning on the final day of school, my son heard birds calling outside our dining room window.