We learned they were eastern screech owls because of the owl website that had sound files of their calls. These screech owls have a rippling sort of hoot that is kind of shivery. I hear them even in the daytime out at the farm where I ride.
The parent owl showed up as the sun started to go down. She or he flies back and forth between the trees on the edge of the yard to the owl house on the shed roof. Ben said that this morning she had a dove in her talons. Babies are eating good then.
The bottom photo is of the biggest baby peeking out. They must see the camera lens and the binoculars as owl eyes looking back at them.