Great Horned Owl
For scale, the water container is 14" wide, so we believe this is a Great Horned Owl.
Over the years, we've heard plenty of hooting around the house at night and one evening a pygmy owl attacked our hummingbird feeder. But this is the first visit by a Great Horned Owl. Came two nights in the row, at the same time. 5:30 AM is apparently "The Owl Hour".