Sounds like you may have been "given" a canabalistic chicken. There can be many different reasons for this including tight quarters or protein deficiency. There's lots of info on this site if you search it out, regarding this topic. It it were me, I would separate the problem hen from the...
Though fencing can be expensive, the peace of mind is worth it. I have my chickens in a "controlled free range" pasture and it's a good compromise. I don't have to worry about 'em and they seem happy. Their area is fenced (down in the ground a foot) and also is covered with a netting to keep...
Sorry to hear of your loss. Hawkes are the most common chicken predatory problem in my area. I have 4 flying around my property, eyeballin' my babies. They fly "just" overhead, staring down my girls, those bleepin' beasts! I haven't lost any yet, thank goodness, but everywhere my girls are...
I think my 14 week old cockerel heard through the grapevine what his potential outcome may be if he crows. He's silent these days, tries to just fit in with the girls.