The number of ring necked parakeets in the central urban part of the Netherlands has almost doubled to some 22,000 in 10 years, according to a count by volunteers on behalf of bird research group Sovon Vogelonderzoek Nederland.

The birds were counted at known roosting places, where they live in groups outside the breeding season.

The bright green birds are moving to more and more places in the Netherlands, with almost 10,000 observations reported to bird monitoring website Waarneming.nl last year.

The birds are common in the big cities, particularly Amsterdam, Utrecht and Leiden but have now been spotted in parts of Noord-Brabant, Flevoland and Zeeland.

The bird, which originates in central Africa and India, is classified as an ‘exotic invader’. The parakeet, the researchers say, competes for nesting space with other birds which live in hollow trees, such as owls.

In addition, they have been known to plunder orchards and eat the fruit. Attracted to bird feeders in urban gardens, they are particularly fond of raw peanuts and generate complaints about the noise they make when flying in groups or settling in trees.