Ruddy duck shooting to end this summer.
Despite its extent and expense, critics of the culling programme argue it will not be completely effective as pockets of the birds remain.
The culling programme, scheduled to finish this August, is being undertaken in order to protect the threatened Spanish population of white-headed duck with which the ruddy duck has been known to interbreed.
In Spain, control of ruddy duck is ongoing. Six ruddy duck were seen there in 2008, the most recent year for which figures are available, and all of them were culled.
The culling programme in the UK has seen far larger numbers of ruddy duck eradicated.
At the start of the programme in September 2005, the UK population of the duck was estimated at 4,400.
Since then FERA has culled more than 6,200 birds, with the most recent cull taking place just days ago in Hampshire.
The remaining population is estimated to number only a few hundred birds. Several online birding sites and forums have highlighted the expense of the culling operation and have criticised the ?government marksmen? and ?DEFRA gunships? employed on the UK?s lakes to cull the duck.
The jobs of culling operatives were filled following advertising in the pages of Shooting Times magazine several years ago.
Indeed, the accuracy of the ?marksmen? has countered the argument that the cull would impact on non-target species.
During a three-year trial cull between 1999 and 2002, a total of 15 non-target species were shot, in comparison with 2,651 ruddy duck culled, which equates to a 0.006% rate of errors.
An RSPB spokesman last week affirmed the charity?s support for the cull: ?We have long felt that it would be wrong to stand by, do nothing and allow the whiteheaded duck to become extinct. It is important that eradication from the UK is achieved as soon as possible.?
In contrast, Andrew Tyler, director of the anti-fieldsports organization, Animal Aid, told The Daily Telegraph this weekend the cull amounted to hopeless slaughter.
He said: ?The whole premise is nonsense, as well as the logistics, and it has also been extraordinarily expensive.?
A DEFRA spokesman said: ?Eradicating the ruddy duck in the UK is part of the European Life Project to conserve and protect the whiteheaded duck and is supported by conservation organisations such as the RSPB, BirdLife International and the Wildfowl & Wetlands Trust. Extensive research has shown that culling ruddy duck by shooting is the most humane way of eradicating them and this is carried out by trained expert marksmen.?
Between April 2008 and March last year, a total of 1,284 ruddy duck were shot on 60 sites.
Adult males made up 36% of the total number shot, adult females 27% and immature birds 37%.
The proportion of immature birds was higher than in previous years.
FERA has concluded that this reflects slightly better breeding success now that reduced numbers of the duck have allowed a larger proportion of the UK?s population on to the best breeding sites.