The Belgian birds look like ringnecks. The Chicago birds are quaker parrots, which are very successful at surviving in northern US cities. The flock in Brooklyn might be the most famous one:
http://brooklynparrots.com/ But there are several others.
They're a major nuisance to the electric company. Unlike most parrots, quakers build large communal nests, and they like to do it on power poles which tends to short out the system and cause power outages. The power companies usually dealt with it by killing the birds, but that made people angry so now many of them have started setting up platforms for the birds to use instead of the utility poles.
Nest on a power pole.

Nest on an "alternative" platform.
