A Crow from Below or An Odd Look at a Rook!!

Decided to spend some time in my classroomtoday as there are always odd jobs that need doing and can't be done when the kids are in. Schools are always nicer places without the kids!!

Part of my classroom has a flat roof with plastic domed rooflights. There I was minding my own business when there was a sudden clattering and shadows flickered. Looking up I got this unusual view. I know I should be able to tell from the tail whether it's a Crow or a Rook!!