is it not possible it's a BOP?
Falcons do kill by biting the head off their prey; it's one of the ways that you tell that a dead bird has been killed by a falcon. ...
I don't expect you to get close and personal with the dead bird but a cat will play with anything for quite a while before it actually kills it.
It's never immediate even when the cat is hungry.
So if your bird looks knocked around and trashed up, it may very well be a cat.
A Falcon just rips off the head and drops the rest.
Racoons also eat birds but mostly livestock like chickens. They tear off the legs and head.
But they will take small birds. A raccoon typically attacks birds by biting the head or upper neck area. The heads of adult birds are usually bitten off and left some distance from the body. The crop and breast may be torn and chewed and the entrails eaten.
So again, your DB will be totally maimed.
I vote for a Falcon or similar. If the bird is well fed and there is no shortage of food then some BOP will take the head only and leave the rest.
My opinion only, many will disagree with me, but I wanted to add my 2 cents to this discussion.
Meghan