South Asian and sub-Saharan African species, introduced or escaped in the British and European region (though still "wild birds" for listing purposes). I don't mind them now they're here, though they're not everyone's favourite.
Wiki says: "Concerns have been raised over the impact of the growing numbers of parakeets in south-east England. Scientific research programmes have analysed the behaviour of parakeets and found that they compete with native bird species and bats for food and nesting sites. Although not aggressive, parakeets deter smaller birds with noisy gregarious behaviour. The detrimental effect of competitive exclusion has been likened to the impact of the introduction of grey squirrel on the red squirrel. However, British parakeets are not without natural predators; ornithologists have observed an increase in the population of birds of prey in London, and have reported sparrowhawks, peregrine falcons and hobbies preying on parakeets".
Thank you for your kind comments on my pictures, and good birding!
John
