One time I hunted someone else's tower blind and heard a commotion as I was climbing the ladder. When I got in the blind, one of the windows was cracked open and there was an owl nest with some eggs inside the blind. I closed the window and sure enough the momma owl came back within a few minutes and tried to come in through the now-closed window. She came back several times and flew around the blind.

When I left the blind I left the window as I had found it. I came back the next day and when I drove up I could see that momma owl was back in the blind with her eggs.

By the way, she was a barn owl with the white breast and face feathers, known for nesting in barns and outbuildings.