ajohn

Your first unidentified bird (ID1) is a male Wood Duck in eclipse plumage. The second (ID2) is a male Mallard in eclipse plumage.

Ho-fai, you are right that many of the ducks, geese and swans in the first post are captive. The London Wetland Centre is a WWT reserve with a captive waterfowl collection but also a well-managed area for wild birds.