I pointed out to the young man that there was lots of evidence of "owl" in this tree. If you enlarge the picture below, you can clearly see the "whitewash" which is the owls poo, and to the right of this are the pellets that they regurgitate all the fur and bones of the tiny creatures that make up their diet.
We have owls sit on our TV ariel at work, and I love to bring home the pellets to see what's in them - I find them fascinating!! The kids are not so enthusiastic - I put it down to the lack of decent nature tables in infant and junior schools these days. (I was a very avid provider for my class nature table back in the 60's!!).
Hope you weren't eating!!!