By Danny Wood
BBC correspondent in Madrid
A plague of Quaker parrots is causing alarm in the Spanish city Barcelona.
Quaker parrots munched through over 50,000 tomatoes
Also known as the South American Monk parakeet and originally from Latin America, the bird has a prodigious appetite and its mushrooming population in the city is driving the citizens to distraction.
The Quaker parrot is an aggressive bird and eats just about everything green it can find - flowers, grass, even tree branches.
With a high rate of reproduction, the Quaker is threatening the survival of local bird species.
Citizens of Barcelona are growing increasingly worried as more and more of these grey-green parrots occupy their city.
The first birds arrived as pets in the 1970s.
Owners, tired of their chirping, released them. Now a population of 50 has grown to well over 2,000.
There are even more in the Catalonian countryside. Farmers say last year Quaker parrots munched through over 50,000 tomatoes.
Experts from Barcelona's Museum of Natural Sciences are now trying to control the bird.
They will have to act quickly - Quaker parrots' breeding season has just started and continues until November.