About ten years ago I was driving along a residential street. I glanced up and saw a bird on a wire. The colouring was nothing like I'd seen in the wild. I stopped the car and realized it was a cockatiel. Knowing that it had escaped from someone's house and didn't stand a chance in the wild, I tried coaxing it down by calling and whistling to it. After a few minutes it flew down and landed on my head. I tried to get it to jump onto my hand, but it flew back to the wire. I went through the calling process again, this time it landed on my arm. This was obviously a very tame bird. I was able to to get it into car and drove it over to my then mother in law's house. THe cockatiel that she had for years had died a few weeks earlier, so I knew that she had a cage large enough to house it while I tried to find the owner. I put up some notices in the area where I'd found it, watched the lost pets section of the paper and generally put the word out. I didn't get one reply.
I'm pretty sure that the ex Mother in Law still has the bird to this day.