He's in the garage in a cage as of this morning. We're not keeping him. I can't risk losing another of my beautiful sweet ladies. I guess I'm trying to see if it could be anything else. If it was I would think their deaths would be closer together.
I do not know for sure whether the rooster killed the hens, but it does sound like he is very hard on them.
Separating the rooster sounds like a good plan. The hens can get a break, and you can decide what to do with the rooster. (And, if another hen dies while the rooster is separated, you will know he did NOT do it, which might help with finding the actual cause. But I really hope no other hens die!)
Has anyone ever had a rooster kill hens when mating with them? We have a rooster and used to have 10 hens. Most of them were getting bare backs and heads from mating and of course some were worse than others. A few weeks ago we found a hen dead in the large coop. No blood, no wounds. She may have been the one that was having trouble getting up after he was on her the day before. And then last night we found another hen dead in the coop. Is he killing them by jumping on them? He's a jersey giant but isn't any bigger than a normal rooster.
Whether the rooster could have caused those deaths is something I don't know for sure.
I'm going to list other things I can think of, just in case I hit something useful.
Chickens can just drop dead from stress, but that is quite rare. If it did happen, it could be stress caused by the rooster, or stress caused by a dog running around the coop, or stress from any other "scary" thing. This one is hard to check for, but having two dead hens at such different times makes it seem unlikely to be any stress except possibly the rooster.
Chickens can also drop dead from heat, which seems unlikely at this time of year. If they died on days that were extra-hot, this should be seriously considered.
Chickens can drop dead from fatty liver disease, which is caused by them being too fat. You won't know what caused that, unless someone does an autopsy on a dead hen. If one hen is extra fat, the others might be as well, so this is something that could affect multiple hens at different times. It appears to be most common in pet chickens that are fed lots of treats.
Chickens can drop dead from eating something poisonous, but they would often show symptoms first, and it would probably affect more than one at a time. Two hens, several weeks apart, does not sound right for that.
Most diseases cause symptoms before chickens drop dead. Diseases also tend to spread to the whole flock quickly, which apparently has not happened. So I don't really think any disease is causing this.
Chickens could be killed by a predator, but a predator would usually leave some sort of marks on the body. Also, a predator would probably come back more frequently than once every few weeks. And for the dead body to be in the coop, the predator would have to get in too or else reach through the side somehow. I think a predator is unlikely.
Parasite of various kinds can weaken a chicken, so it is more likely to die from other causes. I suggest you check them all for external parasites (mites, lice, etc.) And maybe get their droppings checked for internal parasites. If you do find parasites, they should be treated, no matter what you do with the rooster. So I think parasites could be a contributing cause, but probably not the only cause of death.
Other than possible fatty liver disease, I think mating (or overmating) by the rooster sounds most likely to be the cause of death. This could happen directly (he squishes them or otherwise causes injury), or indirectly (stress makes them susceptible to something else).
