Parakeets have colonised parts of Britain so successfully that they may have to be culled to prevent them from driving away native birds such as robins and woodpeckers.

Ringnecked parakeets are native to the Himalayas but an estimated 30,000 now live in Britain, mainly in the South East.

Whitehall officials are so concerned that they have ordered a study to identify where parakeets are concentrated and what effects they are having on native birds. Among the issues to be considered is whether their numbers are sufficiently large to warrant a cull.

It is not known when ringnecked parakeets, Psittacula krameri, first escaped into the wild in Britain. They may even have been released deliberately. One theory is that they escaped from the set of The African Queen, filmed in Ealing, West London, in 1951. Other suggestions are that they escaped from an aviary during the storm of 1987, and even that the release of a pair by Jimi Hendrix in Carnaby Street, Central London, in the 1960s, may be partly to blame.

Tiny populations have been spotted in Britain since 1855, but only in recent years has the number started to increase sharply. Colonies of the birds, also known as rose-ringed parakeets, have become established across the South East, including, for years, a large roost of about 6,000 around Esher Rugby Club in Surrey. Parakeets have been seen as far north as Manchester, but only in small groups that are thought to die out because of inbreeding. In time, however, they are expected to spread more widely.

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

Yesterday the Department for Environment, Food and Rural Affairs said it was working with the RSPB and other agencies to address the issue.

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 of the issues. In the meantime, landowners can apply to Natural England [the conservation agency] for an individual licence to control the species.”

Natural England said that birds would usually be culled by shooting or trapping. A spokesman said that licences 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 nonlethal 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 amount of birds. Then there is population control.”

Tim Webb, a spokesman for the RSPB, said: “People are starting to have concerns about the numbers. We want to make sure that this is looked at before it becomes a major issue and suddenly we are all caught unawares. We do see a cull as a last resort, something only to be considered if a native species were to be under threat.” Andre Farrar, a colleague at the society, said that there was no evidence that native bird populations were in decline because of competition from parakeets, but the situation was being monitored.

A recent study found that of all native British birds the nuthatch is the most likely to be ousted by the parakeet. Researchers found “a suggestion” that when parakeets move into a wood, the nut-hatches move out.

The starling, which has suffered an unexplained slump of more than 60 per cent in 25 years, is also feared by some bird enthusiasts to be affected by the parakeet. Graham Apple-ton, of the British Trust for Ornithology, said: “One of the concerns expressed is that they might be outcompeting starlings by taking over nesting holes in trees.”

The birds are roughly the size of a collared dove and get their name from the rose-col-oured ring around the throat. They have a bright red beak and distinctive pointed wings.

Some farmers in the South East have complained that the exotic species eats crops. However, with milder winters and no natural predators, parakeet numbers have grown rapidly.

The birds became so prevalent in the tall poplar trees at Esher Rugby Club that the under17 girls team was named the Parakeets and players wear a picture of a parakeet on their shirts.

Last year the RSPB said that the birds could now be found in every London borough.

Clever – and tough like Bogart

* Records suggest that parakeets have been living in the wild in Britain since 1855, but in recent years the numbers have risen sharply

* They starred as escaping extras in The African Queen, with Humphrey Bogart and Katharine Hepburn, partly filmed at Ealing

* One of the chief complaints made against them is that with their tough beaks they peel open garden feeders

* “People love them or hate them,” according to the British Trust for Ornithology. “They are either colourful or noisy, depending on your view”

* They lay three or four eggs in a hole in a tree and can live for up to 34 years. They outnumber barn owls, nightingales and kingfishers

* An invasive species, the parakeet is present in several European cities as well as Iran, Florida, South Africa and Japan

* A cull might not work. They are intelligent birds and would quickly learn to avoid guns. Poison would wipe out other animals. Gassing or netting would be costly and difficult

* In India, parakeets are believed to have been kept in captivity for 3,000 years

* They join Chinese mitten crabs, Japanese knotweed, goldfish and grey squirrels as some of the nonnative invasive creatures giving cause for concern in Britain

Sources: BTO, RSPB, Times database

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