Thanks joepyeweed! As far as the entrance hole being enlarged, I think that's a problem in terms of predators entering the box. I'm not certain, but it's my guess based on the premise there's a recommended entrance hole size to being with. I didn't do anything to keep squirrels out. Both squirrels and birds had put quite a bit of nesting material in the box, which we cleaned out after the owl exited one night. Besides Chris' Eastern Screech owl web site, the best info. I've gotten on E S owls has been from Frederick R. Gelbach's book, The Eastern Screech Owl. Here is a link that might be useful: owl box info.

Elly, is the term 'witches broom' a new one to you? I'm sure you've seen them, but didn't know what they were. They don't qualify for barred owl housing. (See image in the attached link.) Spinster, I heard barred owls many times last year. One would even land on the peaks of our roof and call away. THAT'S something that will make you jump right out of bed! Anyway, a witches' broom is a dense cluster of branches, seeming to rise from a central point. It is a mutation found on a wide number of woody plant species, and is caused by a genetic mutation, or by a mutative response different kinds of insects. They can be huge or very small. Some witches' brooms result in some interesting new plant cultivars. The ones found in conifers are often hunted and collected. Here is a link that might be useful:

I've had a pair of Barred Owls nesting in my backyard for eight years now. I used to have lots of pictures on here from previous years nests but they have been removed over time. However, here is a picture of mama owl sitting in the nest this year while there were eggs or tiny young in there. Now she sits on a limb of another tree guarding her nest of young. (I saw a little one peeking out at me yesterday while I was in the yard). As you can see, the nest site is in a large tree that lost a limb many years ago and this resulted in a large cavity in that spot. What you are describing of the owl sitting in one spot tells me that her nest is nearby and that young ones are in the nest. Check all the big trees you have closely near where she is sitting and maybe you will find what she is guarding. Good luck and keep us posted if you find the nest!!

Yes, given by the size of the entrance cavity, the cavity was probably originally made by a Northern Flicker. BN