I'm stumped at what is doing this.

[Ole rooster]

I lost 2 white rock setters to a possom, They were killed the same way. Through the rear end, but the rest of the hen was untouched.

 

[CupOJoe42]

You can try dusting the area with flour and keep an eye out for tracks.

 

[Lbrad7]

Quote:
Possums will feed that way.

Hawks strip the meat off the bones and pluck the feathers

I'm betting there's a gap in your fencing somewhere near the top

I agree with Bear. I am sorry for your losses!

Put me down for a possum vote as well.