What a tabloid title!
Apparently the Black Swan is spreading so fast it may be added to the British List (for those who don't that means its wild population in the UK is thought to be self sustaining).
The Swans, who originate from Australia, have escaped from collections and now breed at dozens of sites across the UK.
Black Swans are more agressive than native Mute Swans and there are concerns that they may out compete them.
A BTO survey in 2004 found birds at only 73 sites, of which only 11 were breeding sites. The current survey found 500 reports of birds at 170 locations with 37 sites being breeding.
There are currently no proposals to control the numbers. There are controls on species such as ruddy ducks, to keep numbes down. I'd have thought if such action was to take place it would be best to do it now.