Great stuff Don and I have to confess, your back yard is a whole lot bigger than mine. With the thread I've just taken a couple or more liberties and made it a yard with no boundaries.
Well, kinda the back yard! I have a Kawasaki mule ATV that has storage areas, one being open, no door. A Bewick's Wren decided to create a nest in there. I cleared it out at least 4 times trying to discourage her, but she persisted. 5 eggs and a couple of weeks later, I now have a mobile bird habitat. So, the 'mule' is out of service for a week or so letting these squatters grow up a bit. There really are 5 in there! Move faster than a 2 year old child.