The reason why the bird does not hatch eggs

Persons do not hatch eggs because it was frightened when it hatched.This bird will build the nest in the main branches of the birch, fir or pine tree, about 3-5 meters high from the ground.The nest is composed of withered and bark, with moss outside, and beasts or feathers are covered with inside.After the nest is built, the female birds begin to lay their eggs. Each nest will produce 5-7 pieces. The eggs are green, and there are red-purple spots on it.