The reason why Sixi Bird does not hatch eggs

There are many reasons why the four -happy bird does not hatch eggs, such as the poor motherhood of the birds, the quality of the eggs, or being frightened, and so on.This bird will built the nest in the tree hole, and it is mostly composed of dry grass, grass roots and fine branches.Female birds will spawn in the nest. Each nest will produce 4-6 pieces. The eggs are pale green, green brown, yellow or gray, and dense brown or brown spots on it.