The most common theory on how rose-ringed parakeets started breeding in the wild in the UK is that an entire flock escaped from Shepperton studios, Surrey, during the filming of The African Queen in 1951.
The film, which starred Humphrey Bogart and Katharine Hepburn, right, used a variety of exotic birds and animals shipped in to recreate the jungle. It is thought around 20 birds vanished from an aviary on set.
Other suggestions are that a pair were released by Jimi Hendrix in Carnaby Street in the Sixties as a symbol of peace, or that they are the descendants of domestic pets which escaped their owners' cages.