To their detractors, they're dirty alien invaders whose incessant chatter ruins Sunday morning lie-ins. To their supporters, they're beautiful, cheerful reminders of warmer climes amid the winter chill.
Love 'em or hate 'em, thousands of rose-ringed parakeets, close relatives of parrots, have made their home in the Netherlands over the past five decades, and their growing presence has become a source of noisy debate.
Like in other European cities such as London and Paris, the colourful green birds with distinctive red beaks have proliferated over the years.
They gather in garden trees and around schools; they even roost outside the Dutch parliament in The Hague, with urban legend telling how one debate was drowned out by the birds' constant calls.
Imported from Pakistan in the 1960s to brighten the aviaries of wealthy Europeans -- especially the Dutch and British -- over the years many escaped and have now successfully adapted to life in the city.
Indeed, the rose-ringed, or ring-necked parakeet was listed among Europe's top 100 most invasive species in the scientific journal "Biological Invasions" in December.
While their fans claim they are victims of a knee-jerk fear of anything new, some groups actively lobby for their numbers to be culled.
In Amsterdam, where one of the largest colonies of parakeets lives, the town hall has banned residents from putting out food in some areas or risk a 70 euro ($86) fine.
Critics argue the flying flocks undermine the natural order, pinching the resting spaces of owls and bats, leaving behind piles of bird droppings and ravaging trees and plants.
"Some residents are even thinking of moving house because of their infernal noise," said Wilfred Reinhold, president of an association fighting against the birds' presence in the country.
- 'Charming, but destructive' -
With plentiful food, few predators and lots of water, the living is easy in the Netherlands, where the flocks have grown unchecked.
In Leiden, biologist Roelant Jonker has taken the country's oldest colony of the birds under his wing, despite being allergic to their feathers and even though his passion was sorely tested six years ago.
While studying a group of yellow-eared parrots in the jungles of Colombia, Jonker was taken hostage by FARC rebels, a "traumatising experience" which lasted eight months.
But he remains determined to protect the estimated 15,000 parakeets which now call the Netherlands home. By comparison, France is 15 times bigger but counts only some 10,000 parakeets.
"Of course they are charming... but they also cause a lot of damage," said Reinhold, keeping a watchful eye on some budding chestnut trees outside the Dutch parliament.
A recently published picture of an embassy-lined street near the royal palace sullied with parrot droppings has only added grist to his mill.
- 'Here to stay' -
Reinhold insists that measures should be taken to stop the flocks.
"Nets could be dropped on the trees at night to catch hundreds of them," he suggested, accepting however that using guns to shoot them down "would not be a very good idea in the city".
But removing them would be too costly, argued Jonker, declaring: "There is nothing to do. They are here, they are going to stay."
He pointed to some birch trees, saying they had once been imported by the Romans and were now an integral part of the Dutch landscape.
The next generation will see the parakeets "as ordinary birds... and they will be as ordinary as all the different colours of people and birds in Europe," he added.