This is an owner's nightmare and one of the most frustrating problems with which a bird lover may have to contend. Exactly why a bird goes into self-destruct mode is a question that bird lovers have wrestled with ever since the first person thought it would be a nifty idea to keep a bird in a cage. Here are a few clues to help you solve the mystery of why your bird is acting abnormally. First, let's define feather plucking as the behavior of a bird that intentionally pulls out or mutilates its own feathers. Do not confuse feather plucking with a molt.
Birds naturally renew their feathers at least once a year.
In the wild, this enables the bird not only to shed its own feathers, but also to rid itself of nasty pests such as feather mites. Although birds are now kept in clean, relatively pest-free environments, they have not lost the need to renew their feathers. With some birds, the molting process is so gradual that you hardly notice it except for the odd feathers on the cage bottom. Having said this, an excessive molt can lead to feather plucking by an overly ambitious preener of incoming feathers. A sure indication of a bird being picked by another is a plucked head, since a bird cannot pluck its own head feathers.