What's wrong with the white -faced sparrow tail hair?

The white -faced sparrow tail hairy is going to the feather change period.This bird's feather change period is from April to July every year. During this period, we must pay attention to the hygiene in the cage, and clean up the hair that fades off in time.There is no need to change the feed before hairy. After the hair is completely faded and starts the new feathers, you need to add some nutritious foods to promote the growth of the new feathers. At the same time, do not take a bath frequently.