Right, so, for about three weeks after I took the last photo, the nest remained empty. Then, one day, I noticed a robin which I'd startled fly up to where the nest was, on the log arch just outside our back door (we call our front door our back door, it's really kind of weird that way). Over the next week, various members of my family noticed a robin apparently sitting in or near the nest. Turns out, they were patching it up, and prepping it for Hatching Season Round Two, because yesterday, when the robin was away from the nest, I took the opportunity to use my iPhone to see what was inside the nest (it's the best way for me to look into the nest, since I can see what the camera sees on the screen), and I took this picture. So, looks like two new little ones on the way!