Any idea what predator would do this?

[Dogue]

The only predator that I've had to deal with (IOW: killed my poultry) that took off heads and left bodies, when they could have taken the entire carcass are domestic dogs. I've dealt with raccoons (feathers everywhere, no carcasses), cats (took of heads through fencing, but couldn't take the body, but DID take the heads with them), and dogs (they kill just for the joy of it, leave carcasses, and every time this has happened, the poultry has been beheaded).

I would think that a predator such as a big cat would have taken the carcass with them. At least, when they are hunting wild game, they kill and then move their meal to a new location most of the time.

That's just my opinion, take it or leave it

 

[JJSS89]

So not a single distinguishable track out of all that?

That is the only way to be sure.

Otherwise, domestic dog or fox is my guess. I've never had that many birds killed by anything so I don't have much of an opinion but if you can find a track and take a picture next to a VISA card (flipped over) or a quarter, I could help you out.