I noticed this morning when my Mom gave our chickens some cheese curls, that the black one was hanging back while the two red ones were eating. I gave them a small amount of scratch as a test, and the same thing happened.
This evening, after they had gone up to roost, but before it was dark, I heard some squawking, so opened the coop up to investigate. The black one was being pecked (hard) by the RIR and was trying to get away from her by getting in the nestboxes. I called the black one to me, took her out and stroked her for a few minutes, and then put her back in again. She started to go to the nestboxes, but changed her mind and pushed her way on the roost by the other hen (so that she wasn't roosting by the aggressive one).
Any ideas on might have started this -
Some things I thought of are -
Maybe the submissive behavior is triggering the bullying, by making the RIR think the other chicken is now lower in the pecking order.
Molting (Red is not molting yet, but the other two are - at least I think they are).
Illness - Maybe Red isn't feeling well? Or maybe Blackie is sick and she senses that?
Maybe its the time of year - Our weather has been good this week (45 to 59), but they have been cooped up more than usual (they are out from dawn to dusk, approximately 7 to 4:45). And when they are not cooped up, it has been raining off and on, which limits their ability to run around.
Please let me know if you have any thoughts on managing their behavior. I don't want to have to isolate one of them, but I will if I have to.