Birds usually pluck their feathers to preen and groom themselves. Feather plucking becomes a serious behavioral disorder, when it the birds moderately overpreen, or even self-mutilates itself.
There many causes for feather plucking disorder; they include:
Birds that are overactive and overstimulated frequently pluck their feathers, as do birds that are bored. Such birds also show anxiety and aggressive behaviors. Anxiety can be caused by a lack of fresh air, light and a disturbance in the bird's circadian rhythm (a physiological 24-hour cycle). Another stressful situation occurs when the bird is moved from one place to another, or when there is a change in its habitual environment. Nevertheless, stress in any form can cause the bird to indulge in feather plucking.
Insufficient diet also leads to skin and feather problems, which the bird tries to solve by feather plucking. Similarly, birds affected by internal or external parasites can resort to feather plucking, due to discomfort.