I observed a couple of Mute Swans, Cygnus olor, at London's St. James Park.
Brief description of what you observed
Observed them hanging out with the Canada geese. These are resident. The one with the brown mixed in, was born all brown this spring.
The Mute Swan (Cygnus olor) is a species of swan, and thus a member of the waterfowl family Anatidae. It is native to much of Europe and Asia, and (as a rare winter visitor) the far north of Africa. It is also an introduced species in North America, Australasia and southern Africa. The name 'mute' derives from it being less vocal than other swan species. Measuring 125 to 170 centimetres (49 to 67 in) in length, this large swan...