Help--Who/What Did This??

[kycn]

So I need some help. We have been losing quite a few chickens (15-20 maybe). I have a mobile coop with electric poultry netting around it, inside a fenced in pasture that has a few calves and goats. We have added an adult male pyr in the past few weeks, but it hasn't helped. It has all happened in the middle of the day. They have all lost a head and that is about it. A few have been left right by the coop, a few have been drug up to the fence and the predator couldn't drag them through the fence. I don't know what is doing this and how to stop it. It has been happening for a month or longer, not every day.
Does anyone know what type of animal would do this and how to stop it?
Thanks in advance for any tips

 

[muddychicken2]

It could be a animal from the weasel family or even a coon with rabies

 

[leadwolf1]

That looks like every hawk attack that I have ever experienced! Something, maybe the pyrenese is scaring the hawk off but, not before the damage is done.