I made reference to these birds in a picture I posted yesterday (located here: http://www.pbase.com/ccasey/image/150185538)
Today they finally made enough noise that I could locate what part of the wall that they were in. Two were in a nest in the upper half of the wall while a third had fallen down into the depths of the old wall. It was this third one that was making most of the noise as he tried to scratch his way the 10 feet or so back up to the nest. I finally got the wall taken apart enough to get to these guys. Much harder than it sounds. Ordinarily I would not be one to interfere with nature, but in this case I really did not have a choice as at least one of them was trapped inside. I finally got all three of them out of the wall and into a cardboard box which is when I snapped this picture of them. I'm hoping that the mother will come back for them as I placed the box back outside the building near where we believe she gained entrance to the wall. Now that they are outside of the wall and on their own though, I will have to let nature take its course.