Ruddy Duck, Oxyura jamaicensis
Ruddy Duck, male, 6/11/08, Marble Hot Springs Road, Sierra Valley, Plumas Co
Ruddy Duck, female, 8/8/10, Palo Alto Baylands
Ruddy Duck, male, non-breeding plumage, 10/8/07, Moss Landing, Monterey Co
Ruddies are unusual among ducks in that the males are in non-breeding plumage, above, for about half the year; in most ducks, the bright male breeding plumage is present for the whole year except for the female-like eclipse plumage briefly held after the breeding season. The male non-breeding plumage lacks the dark stripe on the cheek that is found on the female.
 
Ruddy Duck, male, 4/8/07, Palo Alto Baylands
Ruddy Duck, male, 8/8/10, Palo Alto Baylands
6/8/08, Marble Hot Springs Road, Sierra Valley, Plumas Co
Ruddy Duck, male, 4/8/07, Palo Alto Baylands