They may be cute, colourful and chatty, but South American quaker parrots have taken up residence in Madrid and other Spanish cities, irritating residents with their shrill squawks and destabilising the ecosystem.

The small, bright green and grey-breasted birds - also known as monk parakeets - first arrived in Spain in cages as entertaining pets, but some either escaped or were let loose, getting their first taste of freedom in the green, leafy Spanish capital - and then proliferating.

They build communal nests that weigh up to 50 kilos (110 pounds), mostly in trees - they favour cedars - but also in electric pylons.
In order to do so, the parrots tear thousands of branches off trees, at times leaving them nearly bare.

According to research by the society, there were around 20,000 quaker parrots - called so for their bobbing and shaking - in 2015, many of them in Madrid, Barcelona and Malaga on the southeast coast.

Classified as an invasive species, Spanish authorities are allowed to take measures to cull them, and in 2011 sales of the bird were banned in the country.

~ The Local