More wild birds in Oxfordshire are being shot and poisoned than ever before according to a Government agency, but conservationists say the known killings are just the "tip of the iceberg".
There were 11 reports of bird crime in the county last year compared to just one in 2005. Six of the incidents involved birds of prey.
In Didcot, poisoned rabbits were laid out as bait disguised as road-kill, targeting red kites, and in Finstock a barn owl was found shot.
Other incidents reported to the National Wildlife Crime Unit, a so-called 'stand alone' police and Government agency which gathers evidence of wildlife crime and supports the police in its investigations, included a sparrowhawk shot and hidden in a garage, a dead buzzard containing four pieces of shot and three other dead birds of prey which had either been shot or trapped and killed.
In November in Stonor, several dead ravens and crows and a red kite were found stuffed into a hedge.
The previous year's statistics showed the reporting of one crime against a wild bird and none against birds of prey in the county.
RSPB spokesman Andy Waters said: "The reported incidents are the tip of a significant iceberg of wildlife crime and abuse.
"We must maintain the pressure on people who take the law into their own hands and persecute wild birds.
"The county is proud to host the return of birds such as red kites and buzzards - some of the UK's most beautiful animals.
"And future generations must be given the chance to enjoy seeing these amazing creatures spiralling above Oxfordshire's towns, villages and countryside."
Across the UK there were 1,109 reports of wild bird crime, a rise of 50 per cent.
The RSPB believe the increase in the number of reports is partly due to improved procedures for recording wildlife crimes after the creation of the wildlife unit this year.
George Candelin, chairman of the Oxford Ornithological Society, said: "We know there are egg collectors out there and there is also an element of a lack of understanding when people block up eaves where birds nest, and while it is not necessarily a crime, it causes a loss of habitat. We don't see a lot of bird crime ourselves but it definitely goes on."
To report a wildlife crime, contact the National Wildlife Crime Unit on 01620 893607.