Great-horned Owl came in 3 times, large Opossum came in only once. Negative on small Opossum and Red Fox. Large Opossum came in much later than usual. Re-configuring of cameras and installation of light made observations of owl much more detailed. It spends a lot of time on ground walking up to within a foot or so of immature chickens that could now see it clearly. Owl invested a lot of time trying to get into very same pen the Red Fox breached yesterday morning. Neither owl nor Opossum seemed to have trouble approaching new light source. It has a heat lamp bulb.
Accessing barn by larger Opossum and Red Fox is via same route. I will close that off later today using a framed panel of 2 x 4 welded wire. Then I will start work on a panel system for other side of barn that will be much tougher. Cameras will be re-configured to track how visitors compensate. I want to stop visitors without making navigation for me impractical.