Here's the story - a long time ago, a local pet shop let some parrots loose near Fullerton. They multiplied and thrived, and now there is a flock of about 100 of them that fly around downtown Fullerton. When they come around, you can hear them a few blocks away.
I once watched a documentary about similar parrots in San Francisco - it was called The Wild Parrots of Telegraph Hill. Jessica and I watch plenty strange, obscure documentaries from Netflix.