The Australian black swan (cygnus atratus) is, as its name implies, a native of Australia. It is very rarely found in the wild in Europe.
Eric Dempsey of Birds Ireland said: "Yes, it seems that your Black Swan is quite at home in County Down. No doubt an escapee from a collection somewhere. Collectors keep their birds from flying by clipping their flight feathers but of course these grow again and so many birds can then fly. Black Swans are non-migratory so would never ever occur naturally in Europe. Still, they are very beautiful additions to a lake."
Richard James, Wildlife Advisor of Royal Society for the Protection of Birds, told us: "There are many black swans that have escaped from captivity. There have been reports of a few pairs breeding in the UK. There doesn't seem to be a problem with black swans and our native wildfowl but, as with all introduced species, it is worth monitoring."
Photographs of the black swan in Dromantine lake in 2005