I was out the other day enjoying the sunshine as you do, and I noticed two birds quite high in the sky displaying. After watching for a short while I realised that one was a Kestrel and the other was a Jackdaw. They were playing quite happily, each having a go at chasing the other, getting very close without showing any signs of aggression and generally having a great time. It went on for quite a while till they flew out of view, then I saw them again ten minutes or so later still at it. I took some photos just to get a better look at what I was seeing, but as I say they were quite high in the sky and I was shooting towards bright sunshine so they are not good quality.
I'm not sure I wouldn't see it as unusual, but neither would I say its commonplace, if that doesn't seem contradictory. They may have a common goal, or perhaps it was a bit of gentle masterful 'I am boss here' scenario without the fisticuffs.
I'll be interested to see what replies follow.
Mike
Flickr: Peak Rambler
Most likely it was the Jackdaw harassing the Kestrel, all Corvids seem to have an inbuilt dislike of Raptors even when they are no threat to them
Pete
Birding is for everyone no matter how good or bad we are at it,enjoy it while you can