A Chicken or duck or rooster was found dead in my chicken coop and it,s head was missing

[CluckerFamily]

Cougars won't just eat the head.
Weasels tend to eat the inners and leave the rest.
Raccoons will kill poultry and only eat the head and leave the rest of the body there.

I think you had a raccoon get into your fenced in area.
It will keep returning and possibly bring others with it.
I would work on getting that gate to close all the way so that nothing can get in.

 

[bobbi-j]

the chickens were pecking at the body and it was just so sad to see a dead chicken in the coop

Yes, chickens will do that. They didn’t kill the other one, though. That would have been very bloody and messy.

After you get the gate fixed, make sure the rest of the fence is secure as well. Also check for signs of anything trying to dig into your coop or run. (Just this week we had a mink burrow into the attached run from under the coop - it killed one of my pullets and ate her head.)

 

[cmom]

There are several predators that only take the head. If you have a game camera put it up and you will probably find out what's been lurking and killed your bird. Good luck...