While visiting Mannheim, Germany (near Heidelberg) last May (04) we were surprised to find a large flock of feral Alexandrine Ringneck parrots nesting at the Schwetzingen Castle park.
Our friend in Mannheim says they often visit his walnut trees, and chase little birds away from his feeder. He mentions they wake him up rather frequently as well.
Apparently the cold temperatures are not a problem for this hardy species!
If you go, be sure to take your binoculars!
http://www.freeparrots.net/article.php?story=20050128200321828