Oxfordshire is home to one of the 20th century's greatest conservation success stories, according to the Royal Society for the Protection of Birds.

A total of 93 red kites were taken to the Chilterns, from Spain, between 1989 and 1993. There are now more than 500 in the area with more than 100 breeding pairs nesting each year.

There were concerns from farmers, landowners and gamekeepers that because they were birds of prey, the red kites would pose a threat to smaller game birds, livestock and wildlife.

Andy Waters, spokesman for the RSPB, said: "Now local people are very supportive of the birds.

"It was an education exercise making sure people learned about the birds and they're now a flagship species of the Chilterns, attracting a lot of tourists to the area.

"They're one of the 20th century's greatest conservation success stories."

The success of the re-introduction of red kites in Oxfordshire area is in sharp contrast to Scotland.

The RSPB said 36 per cent of the birds released there under special programmes, and similar to those in the Chilterns, had been lost because of illegal poisoning.

This is compared with six cases since 1989 in the Chilterns. Mr Waters said: "The birds are vulnerable to poisoning, whether it be deliberate or accidental. Poisoning is a complicated issue because red kites are very quick to swoop on carrion. If they see a dead rat they will get it very quickly. If the rat has been poisoned, the birds can easily take the poison in and die.

"We're thankful that local people in the Chilterns are aware and thoughtful of the red kites in their area."

Red kites have distinctive, forked tails and a five-feet wing span. Human persecution made the bird extinct in England and Scotland in the 19th century.

The success in the Chilterns has allowed young kites from the area to be moved to new sites around the country.