small kestrel?

Out for a quicky yesterday, nothing much about but just as we got back to the car hubby noticed a few birds on a wire.  2 mistle thrushes and a crow, then something else.  He thought it was a bop but it looked really small (he had the binocs), to my naked eye it looked not much bigger than the mistle thrushes.  I could only just see the bird through the camera, but after cropping it looks like a kestrel (although I'm not entirely convinced as its size is bothering me). For those who don't know, we see lots of kestrels when out and about.  I got a pic of it with the crow, which didn't try to mob it, nor did the mistle thrushes seem bothered by it.  Anyway what do you think - is it really small?

Edit - have posted the pic but it seems to have disappeared - here goes again