Moult
The shedding ('ecdysis') of old, worn feathers for replacement ('endysis') by newly grown ones. Most birds have one complete moult per year at the end of the breeding season ('postnuptial moult'), but partial moults are commonplace, such as the 'prenuptial moult' before the breeding season. Most birds have the type called descendant moult.From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver