Oh how pretty! For someone who keeps chickens (who has even lost chickens to hawks), I am disproportionatly obsessed with raptors. They're so pretty and majestic and dignified looking, not to mention the fact that they serve an important purpose by keeping the rodent population down. Not that I don't run around the yard with a broomstick like a crazy person any time I see a hawk when my chickens are out.... because I totally did that today. I don't know the answer for sure. Owls typically prey on smaller animals, so I definitely wouldn't let any young chicks out. And it depends on the size of the owl- I don't have a good frame of reference, but these guys don't look very big. Keep in mind not all owls hunt at night, some hunt sporadically during the day (and I can't remember what types of owls do, I want to say barn owls). Obviously these owls are awake during the day, have you ever seen them fly when it was light? If not, and you just occasionally see them come out during the day, I would just be super cautious at dawn and dust- don't let your girls out until the sun is well and up, and try to get them shut up before dusk (I know I know, easier said than done- I'm lucky, the tree line to the West tricks my girls into going to bed before dusk, though). Hope all goes well and these birds can coexist with yours!