This is, of course, because the bird cannot reach its head feathers. The one notable exception to this is the bird whose feathers are picked by a cage mate. As mentioned, birds caged together often engage in mutual preening. This behavior can become obsessive and destructive, resulting in feather picking. Causes of Feather Picking There are both medical and non-medical causes for feather picking.
Feather picking is generally a problem of birds in captivity.
Wild birds do not feather pick because they are too preoccupied with their own survival and with reproduction. This stress often results in obsessive, introverted behavior, manifested by feather picking. In the middle of this continuum is normal feather care and maintenance, represented by normal preening. To the left is the complete absence of feather care and maintenance, most commonly seen with domestic, hand-raised birds. To the right of the middle is overzealous preening or outright damage to, or destruction of, the plumage represented by feather picking.