On the way back today in a tree in front of me was a bird of prey, each time I got close it would swoop down onto the track a few feet off the ground then go back up into another tree, this happened 4 or 5 times, before flying off over the trees. As I was behind it I never got a really good look at it, but the wingspan must have been at least 4 feet. This is on the North Notts/South Yorks border what's it likely to be?