Conservationists have condemned plans that would allow buzzard nests to be destroyed and the birds of prey taken into captivity to protect pheasant shoots.

DEFRA is looking at plans to destroy nests to prevent birds breeding. It is also considering catching buzzards and moving them to falconry centres to keep them from targeting captive-reared young pheasants.

The RSPB said the idea of taking wild buzzards into captivity or destroying their nests was "totally unacceptable", and criticised Defra for spending hundreds of thousands of pounds on the project when money was tight for conservation measures.

In a document setting out plans for the research project, Defra said the 2011 National Gamekeepers Organisation survey found that three quarters of gamekeepers believed buzzards had a harmful effect on pheasant shoots.

Buzzards are naturally carrion eaters but are thought to target pheasant release pens if they find there is a readily available source of food.

Natural England has received a number of requests to license the killing of the bird of prey, which is a protected species.

Buzzard numbers have increased by 146% between 1995 and 2009, although the increase appears to have levelled off between 2009 and 2010, according to the British Breeding Bird Survey.

But the RSPB said buzzards were eradicated from swathes of Britain by persecution and were only now recovering, as a result of legal protection and the warming of attitudes by many lowland land managers towards birds of prey.

Buzzards usually scavenge on animals which are already dead, but will sometimes take young pheasants released for sports shooting, the wildlife charity said.

Around 40 million pheasants, which are not native to the UK, are released for shooting each year and buzzards play only a small role in game bird losses compared to other factors such as collisions with cars, the RSPB said.

One study found just 1% to 2% of pheasants were taken on average by birds of prey.

The Government's document says the impact of buzzards on pheasant shoots has not been investigated and the extent of the issue was unclear.

But it said there were a number of sites where buzzards could be contributing to losses, and that there was an urgent need for management measures to reduce the impact on pheasant shoots.

The RSPB's conservation director Martin Harper said: "We are shocked by Defra's plans to destroy buzzard nests and to take buzzards into captivity to protect a non-native game bird released in its millions.

"Destroying nests is completely unjustified and catching and removing buzzards is unlikely to reduce predation levels, as another buzzard will quickly take its place.

"Both techniques would be illegal under current wildlife laws, and I think most people will agree with us that reaching for primitive measures such as imprisoning buzzards or destroying their nests, when wildlife and economic interests collide, is totally unacceptable."

A Defra spokeswoman said: "The buzzard population in this country has been protected for over 30 years, and as the RSPB says, has resulted in a fantastic conservation story.

"At the same time we have cases of buzzards preying on young pheasants. We are looking at funding research to find ways of protecting these young birds while making sure the buzzard population continues to thrive.

"This research is about maintaining the balance between captive and wild birds."

Shadow environment secretary Mary Creagh called for the Government to drop the project.

She said: "The restoration of the buzzard population has been a real success in recent years.

"It is astounding that Defra are wasting hundreds of thousands of pounds of taxpayers' money disrupting this protected species.

"This out-of-touch Government's priority is protecting the interests of large commercial shooting estates and non-native pheasants, rather than protecting our country's native species.

"The Government should drop this plan now. This has all the hallmarks of another Defra shambles."

But David Taylor, shooting campaign manager for country sports group the Countryside Alliance, welcomed Defra's decision to commission the study.

"Since the early 1980s, successive governments have had the ability to issue licences for buzzard control, but have been reluctant to do so because of their fear of coming under pressure from groups who have a narrow interest in birds of prey, often to the detriment of other species in Britain."