I once found a young robin that was hopping around on the ground beneath some large redwood trees. It didn't quite know how to fly yet, and it was in an area with a large number of cats. It's mother was flying around looking very distraught about the whole thing, but she couldn't do anything about it. I ended up taking the bird to a place called Native Animal Rescue that raises birds and other animals that got into these types of situations, then lets them go when they're big enough to fend for themselves.
Several years after that, I was at work, on the second floor, and there was a very loud chirping bird noise. I thought that a bird must be sitting right outside the open (but with a screen) window and chirping into the building for it to be that loud, but I looked over to the window and there was no bird. A few minutes later I got up from my desk and turned around, and there was a baby mockingbird standing on the floor behind me, chirping at me. He had hopped in the door downstairs and all the way up the stairs to the second floor, and into my office. I took him to Native Animal Rescue as well.