What's wrong with the Belled Bird without breeding?

There are many reasons for the non -reproduction of the Belled Bird. For example, the birds may not be mature enough.This kind of bird will start pairing since the end of March, usually the nest is built in the grass, and the shape is cup.Female birds can produce 4-5 eggs each, and the color is brown or white. After 15 days, the chicks can break the shell.In the summer, with the increase of insects, this bird will also usher in the second breeding.