It’s been a case of pretty polly up to now, but it may not be for much longer. Government scientists are to investigate the activities of the flocks of rose-ringed parakeets breeding in London’s suburbs, amid rising fears that they may be harming native British bird species.
The brilliant green parakeets have hitherto been a popular sight in the parks and gardens where they are to be found, squabbling and dashing from tree to tree, in a broad swath of south London from Croydon in the east to Esher and beyond in the west. But since they first began breeding in the wild more than 40 years ago, their numbers have built up to a point where now some ecologists fear their population is exploding, with potentially damaging results. It is feared that the parakeets, which nest in holes and crevices in trees, may be displacing British tree-nesting species such as woodpeckers, nuthatches and starlings.
There is as yet no hard evidence that this is taking place, says the Royal Society for the Protection of Birds (RSPB). But as a precaution the society has asked the Government to investigate the risk from the parakeets under its recently launched strategy for dealing with invasive non-native species.
The strategy is focusing on troublesome plants such as the rapidly-spreading Japanese knotweed, whose eradication from the Olympics site in east London alone may cost millions of pounds, and invertebrates such as the Chinese mitten crab, which is doing much damage burrowing under the banks of the Thames and other rivers.
The rose-ringed parakeet,Psittacula krameri, which is native to a great belt of land stretching from Africa across to India and the Himalayas, is the most obvious bird which in Britain today could be seen as invasive and non-native.
No one knows how it came to start breeding in London, although it is certain to have been the result of the accidental or deliberate release of captive birds. One persistent theory is that an entire flock escaped from Shepperton Studios in Surrey in 1951, during the filming of the adventure drama The African Queen, starring Humphrey Bogart and Katherine Hepburn.
They are now particulary plentiful in west London, especially in the wooded stretch of the Thames from Kew to Hampton Court; they have become a permanent feature, for example, at the Royal Botanic Gardens, where their sharply-loud screeching call and long flight silhouette are as distinctive as their brilliant emerald plumage.
The ecologist Tony Drakeford thinks their population must be in excess of 30,000, and rapidly expanding. He is convinced they must be displacing native birds. “Recently I went to Bushy Park where there thousands of parakeets and very few native birds,” he said. But he thinks it may be too late to do anything about it. “A major cull would meet with a lot of opposition,” he said.
News reports of the Government inquiry, to be carried out by the Central Science Laboratory, have prompted local paper headlines that a cull is imminent, backed by the RSPB. But an RSPB spokesman, Andre Farrar, denied the society was backing any mass killing. “We have simply asked the Government to study the situation,” he said. “Some people think they are doing harm, but as yet there is no hard evidence that they are.”
If it were proved that the parakeets were causing a reduction in the conservation status of native British bird species, “then a cull might be the right answer”, Mr Farrar saidpointing out that of the 1,200 globally-threatened species of birds, 340 were threatened by introduced non-native species.
But, he said, at the moment the RSPB was not calling for any cull, merely for an inquiry.