One more! I went back today to check on the chickadees mostly because I wanted to get a photo of the cardinals in their nest (there is a cardinal nest beside one of the chickadee boxes). It was in a situation where the only way to get a decent photo was in overcast light. I thought by the looks of them that they were a few days younger than the chickadees, but I was wrong because today, two days later, they had fledged and were in the surrounding bush being tended to by the parent birds. Also in the same area were two families of Alder Flycatchers that had fledged and were being fed by parent birds. It looks like a number of bird species are fledging all around the same time. The chickadees here are ready to fly. In the other box, which is a day ahead of this box, I wasn't able to open it more than a crack because the chickadees were ready to jump out. So this is it. Possibly tomorrow there will be 15 new chickadees out there!
Meanwhile, in my yard, the duck egg was eaten by a crow. I had covered it with a glass box for a couple of days so the ducks could still see it while crow and coon couldn't get at it, but the ducks showed zero interest in it and I thought I might as well let it go to whoever wanted to eat it.