What's wrong with the pearl bird tail hair?

The pearl bird's tail hair is lost. It means that it is necessary to change the hair. It does not have a clear time for changing hair. It will always change in summer and autumn.When changing hair, you must keep the hygiene in the cage, and you must sweep out anything unclean.And also give it some oily feed to make its feathers brighter.In addition, the birds will lose hair when they get skin disease, so it is necessary to check it. If you get sick, treat it in time.