|Let's Celebrate Pet Birds!|
T.J. Lafeber D.V.M.
For purposes of insulation and warmth, feathers grow to the edge of the vent (opening for the passage of waste material). Thus, in the act of defecation, the feathers must be effectively parted. The bird raises his tail and combined with the increased tension of the abdominal muscles, the feathers divide. The action of the muscles of the cloaca, combined with the flicking of the tail, causes a temporary eversion and prevents any part of the elimination from adhering to the vent. This action is very rapid and the tail drops immediately.
Any time feathers are missing from around the vent or if the feathers in this area are soiled with feces, it can be concluded that the bird currently has or has had diarrhea.