Young sp: The post-juvenile moult includes body and (probably always) LC and MC. Most birds also include 1-3 GC, but birds with all GC unmoulted are not rare. A few birds may include a single T, and occasionally also single RR.
Young WC: The pre-breeding moult includes whole plumage. Variation in wear (also between feather groups) in spring is likely to be caused by differing (or prolonged) periods of moult during winter.
Adult sp: The post-breeding moult is higly variable. Most seem to have moulted parts of body, regularly with a few inner GC and single TT moulted. However, a few birds seem to leave Scandinavia with more or less unmoulted worn pre-breeding plumage while, according to Jenni & Winkler (1994), exceptional birds may have conducted a complete moult.
Adult WC: The pre-breeding moult includes whole plumage. Variation in wear (also between feather groups) in spring is likely to be caused by differing (or prolonged) periods of moult during winter.