When we arrived home yesterday afternoon, we found a wood pigeon casualty on the back lawn, with a scattering of small downy feathers around it. A few moments later, Barbara spotted a bird of prey, probably a sparrowhawk, flying over the houses on the other side of the road, so perhaps we had disturbed it as we returned.
In a sparrowhawk kill, there should be marks on the quills where the sparrowhawk has grasped the feather with its bill. Most of the feathers were too flimsy for this to show but on two of the larger feathers there were traces of marks.
It’s not conclusive but I think that sparrowhawk is most likely. We’ve had a cat visiting the garden that lurks in the flower border then pounces on the birds that have gathered around the feeding pole. We’ve yet to see it catch a bird but two days ago it chased a grey squirrel up the crab apple.