London, April 22 : Parts of Britain are facing an immigration problem from an India link with a difference - parakeets originally from India have multiplied in such large numbers that they are threatening native birds such as robins and woodpeckers.

The rose-ringed parakeets are native to the Himalayas and are reported to number over 30,000 in Britain. They have colonised parks and gardens in London, Surrey and Kent. Ornithologists are concerned because they compete with native birds for food and nesting space. A recent study found that of all the native British birds, the nuthatch is the most likely to be ousted by the parakeet.

In London last year the parakeet (Psittacula krameri), which gives a sharp and carrying kee-ak kee-ak call, was among the 20 most-sighted birds. The Royal Society for the Protection of Birds (RSPB) estimates their number will rise to 50,000 by 2010.

The Department for Environment, Food and Rural Affairs said it was working with RSPB and other agencies to address the issue. One of the solutions being considered is a purge of the parakeets — by shooting them.

A spokesman for the department said: “We have commissioned the Central Science Laboratory to do a desk study of parakeet data to get a fuller picture. In the meantime landowners can apply to Natural England (the conservation agency) for an individual licence to control the species.”

Tony Drakeford, an ecologist who lives near Bushy Park in southwest London, where the parakeet population has grown by 30 percent in the past year, told the media: “They are very pretty and exotic but are having an impact on our woodland tree-crevice nesters. Something needs to be done but the options are complicated.”

Tim Webb of RSPB said the charity was yet to be convinced that parakeets were a problem for native species but if they were, shooting was the only sensible option.

A parakeet is larger than most garden birds “so should not prove too difficult” to shoot, he said, and added that many people would be distressed to see the birds shot.

A Natural England spokesman said shooting or trapping are the normal methods to cull the birds. Licenses could be granted for one of three reasons, and that individuals or groups could apply. He said: “People have to apply for a licence for a reason. One reason is conservation, another is for agriculture or to protect crops, and a third is for public health and safety.

“There is usually an escalating scale of what people can do. The first is non-lethal scaring, for example using noise or something visual to move the problem away. Then you can move up to lethal scaring, where there is a specific time-frame to shoot a certain number of birds. Then there is population control.”(IANS)