The ring-necked parakeet is also known by the alternative name of rose-ringed parakeet.
Only the male sports the distinctive black neck ring with rose-pink collar.
The ring-neck is the most widely distributed of all the parrots, as it is found naturally on two continents: Africa and Asia.
In Africa it occurs across a broad area south of the Sahara, stretching from Senegambia in the west to Somalia in the east. In Asia it can be found from western Pakistan to Burma.
Today this parrot has established itself widely throughout Europe, occurring in many large towns and cities from Lisbon to London.
Feral populations can also be found in South Africa, Mauritius, Singapore, Macao and Hong Kong.
No one knows for certain how it became established in Britain. One of the more fanciful stories is that birds were released from Isleworth Studios, Middlesex, after the filming of The African Queen in 1951.
What is most likely is that the birds became established following either accidental or deliberate escapes from captivity.
The first confirmed breed in Britain was in Kent in 1971. Since then they have increased and spread rapidly, though the centre of population remains Greater London.
In recent years Liverpool, Manchester, Sheffield and Birmingham have all been colonised.
Curiously, these birds prefer urban habitats in the UK, in areas with human habitation. So far they have shown no signs of colonising the wider countryside.
Though sedentary during the breeding season, there is a tendency for birds to disperse more widely during the winter.
Their success is a reflection of the birds’ adaptability. Though mainly fruit eaters, they have been quick to come to bird feeders, where peanuts are their favourite food.
They have the potential to be a major pest on farmland; in both Africa and Asia they are known to inflict considerable damage on fruit crops and maize.
Suspicions that they would be unable to cope with prolonged periods of cold weather have proved unfounded, for they have proved to be remarkably tough.
The preferred nesting site is a hole in a tree, though they have been know to nest in buildings and even rock cavities.
Competition for suitable next sites may well limit their population expansion.
A concern of conservationists is that the parakeets out-compete native birds, such as nuthatches, woodpeckers and starlings, for nest sites.
A typical clutch is three to four eggs, but up to six have been recorded.
Incubation is by the female only, and takes 22 days. The chicks fledge seven weeks after hatching.
These birds are now officially regarded as pests in the UK, and can be shot or destroyed legally by landowners or authorised people.