Moulting of feathers in birds is a normal process. Feathers cannot be repaired once they have grown, so the bird has a system of replacement called Moulting. During moulting, old and damaged feathers are gradually replaced by new feathers.
TIMING OF MOULT: Some birds moult twice a year, while some large parrots moult once every two years.
FEATHER GROWTH: The first step in the moult process is for the existing feather to be shed. The follicle then produces a new feather. Plucking of a feather will stimulate the follicle to produce another feather, but cutting or damage to the mature feather (with the shaft still in the follicle) will not cause a new feather to grow.
MOULTING PATTERN: Moulting takes place gradually so that the bird can still fly. Generally the wing feathers are replaced first, then the body feathers and then the tail feathers. Powder down feathers are replaced continuously.
ABNORMAL MOULTS: A prolonged moult or the growth of abnormal feathers is not normal. Abnormal feathers may be miscoloured, malformed, have retained sheaths or stress lines. Abnormal feathers are a reflection of a problem within the bird and occur during the formation of the feather.
