Photos: 11
Forms: 7 (F/Breeding, F/Non-breeding, Juvenile, M/Breeding, M/Molting, M/Non-Breeding, M/Non-breeding)
CA-BCUS-DCUS-IAUS-ILUS-INUS-MDUS-TNUS-VA
0ISSF.
Plumage varies, breeding (MAR-SEP) and non-breeding (SEP-MAR).
M/F differ, especially in breeding plumage. May be mistaken in wintering plumage.