Took a stroll down the street to see if the unboxed pair are still around, it would seem they are nesting now, based on activity. Prior to nesting owls are usually quite active right after flyout as was previously noted/blogged. There is lots of calling and they were fairly conspicuous. It seems once nesting is underway they are much quieter, the female would be incubating, and the male busy hunting. Not to mention it would not be ‘wise’ to be advertising their nest site to potential predators. I only saw this one owl. Also I cannot find where they are staying either the roost cavity or hopefully a nest cavity, it will only get more difficult as leaves start appearing on the trees.