Jasper Copping, Telegraph (London), April 20, 2014
Some say they first appeared in the British skies after escaping from the set of the Humphrey Bogart film The African Queen.
Others argue they have bred from a pair released in Carnaby Street in the 1960s by the rock star Jimi Hendrix. Still others suggest they were first liberated from a private collection during the Great Storm of 1987.
But whatever the truth–one thing has now been established about Britain’s booming ring necked parakeet population: they are pushing out the country’s other wildlife and threatening their numbers.
A new study into the birds, which are spreading across south east England and beyond, found they are having a “significant” impact on the foraging habits of native birds, which it compares to calamitous effect that grey squirrels have had on populations of reds since they were introduced into Britain. The researchers said that their findings could have long-term implications for the populations of some native species.
The research, by academics from Imperial College London, the Zoological Society of London and the Natural History Museum, involved monitoring the feeding habits of garden birds, and found they ate less in the presence of the large, dominant, gregarious parakeets, and stayed away from spots where they saw them. Although they are not aggressive, their noisy, squawky behaviour and large size, makes the smaller birds wary and keen to avoid them.
Hannah Peck, who was part of the team, said: “No one really knows what the impact of the birds has been. We found they put off other birds from feeding. We don’t know what the long term impact of that will be, but there is a negative effect going on. It could be that the other birds are being displaced, or it could be they are not getting much food, full stop.”
The study, published in Behavioral Ecology, involved monitoring bird tables at 41 sites within 30 miles of central London, including some which parakeets did not frequent.
The researchers analysed the behaviour of birds visiting the tables, in a series of experiments.
A cage was placed next to the table and on some occasions, it contained a parakeet, on others it was empty, and on others it contained a Great Spotted Woodpecker–a native bird with a reputation for dominance and aggression when feeding.
The researchers found that the presence of the parakeet meant fewer birds came to feed, and those that did, ate less. A similar effect was noted with the woodpecker, but to a far less degree.
The reluctance to eat in the presence of parakeets was noted even in areas where they are already a common sight, suggesting the birds do not become accustomed to them. The parakeets had an effect on all garden birds observed, though most were Blue and Great Tits.
The researchers say the reduced feeding could lower the fitness of some birds and that the presence of parakeets could gradually deprive them of food sources.
They believe it is the first case of a non-native bird causing such an impact and compare it to the decline in red squirrels caused by the accidental introduction of greys.
Parakeet numbers have soared in London over the last two decades and they can now be found across the wider south east, especially large parts of Kent, Surrey and Sussex. There are also populations in Manchester, Birmingham and Oxford, with reports in Edinburgh too. There are suggestions their numbers are increasing at up to 30 per cent a year, and estimates have put their population at up to 50,000. They originate from the foothills of the Himalayas, and exactly how they came to be released here is genuinely unknown.
The bird (Psittacula krameri) feeds on fruit, berries, nuts and seeds, a similar diet to many other species. Previous studies have found that parakeets spend half their feeding time at artificial bird feeders.
In 2009, Natural England added the species, the UK’s only naturalised parrot–to its “general license”, meaning it can be culled, in certain circumstances–such as if they are causing damage to crops. The change gives them the same legal status as pigeons, crows and magpies.