Black swans are a rare sight in London, indeed, anywhere in the UK. They’re not native here. It evokes excitement, whenever I see one precisely because they are so exotic.
It’s an exotic bird over in North America too. In Europe, it never established a large population in the wild. Apparently, they’ve also been introduced in New Zealand, Japan, and China.
They are actually native to Australia and are known as Australian black swans. In fact, the black swan (Cygnus atratus) is the official emblem of Western Australia.