Green flying “aliens” with a raucous call are a long established feature of Thanet’s skies and parks.

Visitors are frequently taken aback when they notice the circling flocks of bright green, exotic rose-ringed parakeets.

But anyone who has lived in Margate, Broadstairs and Ramsgate for any time recognises the invaders as the norm, an everyday part of the scenery.

Now the parrots, native to Africa and India, are the focus of a new research network being launched at the University of Kent at Canterbury.

Parrotnet is based at the Durrell Institute of Conservation and Ecology (DICE), uniting researchers from Kent, Imperial College, London, other UK partners and European scientists.

Parrotnet aims to better understand why species such as parrots are highly successful invaders and will also explore ways to monitor and predict the various impacts, including the economic and ecological ones, and how to mitigate them.

The rose-ringed parakeet, so common in Thanet, has begun to pose problems in both town’s and the countryside. They include disturbance to humans, competition with native wildlife and, increasingly an agricultural pest, already prompting changes in national policies.

They are thought to have originally colonised the UK in the 1970s from a few escaped pet birds. The rose-ringed parakeet is now one of the UK’s fastest growing bird populations, with more than 32,000 individuals.

Parrotnet chairman Dr Jim Groombridge, a DICE reader in biodiversity conservation, said: “The rose-ringed parakeet is listed amongst the top 100 worst alien species in Europe, and since the 1970s has rapidly established itself in more than 100 cities across the continent and beyond, with recent evidence of explosive population growth in some regions of Europe. Given the extent of this problem we expect that our findings will be of interest to both policy-makers and the general public.”

He said: “Its possible these birds were originally pets that escaped or were deliberately released. They have thrived and set up breeding populations in places like Thanet.

“The issues they may cause include noise disturbance with impacts on native bird species, for example in Belgium they have been linked to declines in populations like nuthatches.

"Work is underway at the moment to measure their impact.

“They are fairly loud and quite gregarious and so quite dominant in the bird world with the potential to scare away other birds from breeding sites and nests.”

Parrotnet would be working to find out exactly where and how many birds there were. The plan was to set up a virtual European Monitoring Centre based at the University of Kent to investigate all invasive parrot species and publishing the results.

He said: “When this is up and running we are hoping to use the general public to tell us where the parrots are.

“When a species is introduced it may cause problems, but there are also many people who quite enjoy seeing them. We want to explore what the public perception is of parakeets.”