This is a Great Horned Owl which was chased into my yard by a red-tail hawk. It stayed in a freshly-budded cottonwood tree from late afternoon until after dark.
Two crows periodically stopped by to harrass the owl, but it did little other than to flinch and hiss at its tormenters. I think it might have been injured by the hawk, but there was no evidence that I could see, other than its unwillingness to leave the tree until after dark.
Click either of the photos to see the rest in the set over at Flickr. Over on YouTube I also have a couple of videos of the crows and the owl. Video 1. Video 2.