Blue Jays harass the female Eastern Screech Owl nesting in the nest box every morning - this attempted intimidation may make the Blue Jays - the Backyard micro managers - feel better, but I'm not sure what purpose it serves as the owls rule the night and the male owl is quietly watching all this activity from his hidden perch in the deep cover of Palmetto trees nearby. Screech Owls readily hunt and eat songbirds sleeping in trees at night. Birds that are late to turn in like Cardinals and Dove can sometimes be taken by the male owl right at dusk. If the Blue Jays were to discover the male owls daytime roost in the heavy brush they would attack him mercilessly and he would retreat. It is unlikely such pressure would stop the owls from using the nest box, but if one were to put a perch on the front of the nest box it could very well lead to failure of nesting as such a perch could be used to more seriously harass and fight with the female owl and get at the eggs. Such are the ways of Nature.
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