please can someone tell me what this bird is - seen flying above sea cliffs, dark grey plumage (but then saw another one with brown/red plumage) and wings which taper to a point making half moon shape together
I would say Sparrowhawk has broad wings and doesn't really belong above sea cliffs (more of a forest bird).
But if you really want to see crescent-shaped wings (or sickle I would say), take a look at the Common Swift.
I'm not sure they are still around, but it's worth considering.
I hope this helps.
I would suggest you check out Hobby,they often stay around coastal cliffs for a few days before returning to Africa in order to catch migrating Hirundines. They have slate grey backs and from the underneath have red/brown trousers. The timing would also be correct they were all leaving around the end of Sept. Hope this helps.