The mayor of London's quest to clear Trafalgar Square of pigeons has cost at least £226,000, figures have revealed.
Pigeons numbers in the square have dropped
Ken Livingstone hired a pair of Harris Hawks to fly over the popular tourist spot and scare the pigeons away.
Figures released by the London Assembly Liberal Democrats show since November 2003, 121 of the birds have been killed - an average of £90 each.
The mayor's spokesman said the scheme had greatly improved the area and would continue "for as long as necessary".
Mr Livingstone brought in the hawks to control what he branded as "rats with wings".
The hawks were introduced in 2002 and cost £44,343 in their first year rising to £78,241 in 2003/2004. For the current year they cost £38,160.
Mike Tuffrey, of the London Liberal Democrat's said: "The pigeons in Trafalgar Square are both a nuisance and a health hazard that most Londoners would be happy to see gone all together.
"But at a cost of £90 per pigeon removed, serious doubts should be raised about the effectiveness of the scheme as well as its value for money."
The pigeon population in the square has dropped since the introduction of the hawks and a by-law, in 2003, which bans the feeding of pigeons in some parts of the square.
5,000 in 2000
3,500 in 2002
3,200 in 2003
1,400 in 2005
A spokeswoman for the mayor said the pigeon control scheme had had a number of positive results.
"The measures mean the square is more hygienic, improving the space for events.. throughout the year and helping to reduce the cost required to clean listed architecture," she said.
She said the hawks would now be jointly used by the mayor's office and Westminster Council to tackle the problem of feeding on the north terrace.
Westminster Council is also applying for a byelaw to prevent people feeding the pigeons on the north terrace.