The reason why the yellow bird does not hatch eggs

The yellow bird does not hatch eggs because maternal nature is not very good.Its breeding area is wide, and it can be used from Europe to eastern Siberia. my country is mainly concentrated in areas north of Daxing'an Ridge and Aron Mountain.After the male birds reach the breeding area, they will sing, so as to attract the female, then complete the pairing, and camp on the tree.After the nest is made, the female bird will start to produce eggs. Each nest can produce 4-6 pieces.