Spoke to an RSPB person about kites. He said that they wouldn't take live prey and explained that they weren't strong birds and would find it difficult to rip open an intact carcass, even. Also too weak to carry off a carcass.

Sure other people will have different opinions.
I have been told by several people locally that buzzards will take chickens if they are hungry enough and that they have actually seen them do this.
As yet, the buzzards, kites, kestrel or sparrowhawks have not taken any of my poultry. The cockerels make their special call and all the hens run for the hedges. We look up and you can guarantee there's a bird of prey overhead.