They are completely resilient to our winters and breed prolifically. They are quite a cheerful addition to the city (I have flocks of hundreds of them flying by each morning and evening; they sometimes come to my balcony to dine on seeds of my plants - I had to remove a thornapple otherwise I might have had dead parakeets there)if it weren't for the fact that they are quite aggressive and squat woodpecker nesting holes (spotted woodpeckers are becoming a rarity in the city). The recent advent of large bird-eating birds of prey (Goshawk and peregrin falcon) as breeding species in Amsterdam may limit their numbers in the future though. If similar things happen in the other cities, who knows, things may turn out to be manageable.
Anyway, someone asked for the scientific name of the European Roller: Coracias garrulus. A picture may be found here: http://www.birdpix.nl/album_page.php?pic_id=6784
Hope this helps, Z.
