The first Ruddy Ducks of the winter season, a quartet of one male and three females, paddled around the Open Circle viewpoint around midday.
They are likely the advance guard of larger numbers, such as appeared on the North Basin last winter a bit later in November. More information about this bird appears in that post.
They are native to North America, all the way into the Caribbean; hence the species name “jamaicensis” — from Jamaica. They have not been welcomed to Europe. Wikipedia relates:
Ruddy ducks were imported into the UK in 1948 by conservationist Sir Peter Scott. As a result of escapes from wildfowl collections in the late 1950s, they became established in Great Britain, from where they spread into Europe. By the year 2000, the population had increased to around 6,000 individuals. This duck’s aggressive courting behavior and willingness to interbreed with the endangered native white-headed duck (Oxyura leucocephala), of southern Europe, caused concern amongst Spanish conservationists. Due to this, a controversial scheme to extirpate the ruddy duck as a British breeding species started; there have also been culling attempts in other European countries. By early 2014, the cull had reduced the British population to about 20–100, down from a peak of about 5500 in 2000.