I must admit, the first time I was told that a Sparrowhawk was taking them, I was a little sceptical, especially as we have quite a few Goshawks too, but after seeing it with my own eyes I now have no doubt.
i know a trained sparrow-hawk could not kill numerous pheasants safely and this would lead e to believe it is a gos, buzzard etc. but i also know, to take a pigeon with a trained spar is quite a hard task, but wild spars seem to take quite a few. if it is not a mature pheasent then i know of a few sparrowhawks that have taken young pheasents. but in my opinion, a spar could not take a full grown pheasent
Most of the victims have been little heavier than a Woody, and I've watched Sparrowhawks take them on numerous occasions.