Chicken pecking at another chicken after 4 years?

[bunnybarnes]

Good morning!
I have three chickens that have lived in peace for 4 years in a coop. The dominant hen of the group is picking the vent feathers of the lowest ranked hen. They have had this hierarchy for years. I've checked for mites and the other chicken has no feathers lost. This morning I watched them and confirmed. The dominant hen is a rhode island red and the next in line is a red rock cross and the one being picked on is a columbian rock.
I've been adding lots of enrichment (branches and hay with treats underneath and plastic furniture to roost on and will be picking up a cabbage to hang, mealworms and a parrot string toy today.
I've read to remove the bully and also read to remove the one being picked on. Not sure what to do. These chickens have lived together for years and still go everywhere together.
Has anyone stopped this behaviour with enrichment/toys or is separating my only option?
Also, I'm wondering if adding a few chickens would mix things up or could it add more bullies to my picked on bird?
The picked on area of the bird is about 4 inches by 4 inches and is not red yet nor is their any open wounds. If I do have to separate them can I keep a dog crate/rabbit cage in the coop or completely out of sight?
Thanks for your help!
Christina

 

[Chicken Whisperers]

Separate the bird being picked on for a short while of time. You can use a chicken diaper to protect the area. I have 2 seven year old hens that kind of have a bittersweet relationship. It's just normal

 

[bunnybarnes]

Separate her physically or also visually? Can I keep her in the coop in a cage or put her somewhere else where the others can't see her? For a week? or 3 days?
Thanks...glad to hear its normal.

 

[Chicken Whisperers]

You could use hardware cloth to section off a part of your run to put her in so that they can still see her. The one picking on her might try to get to her through the wiring, so when you notice she's not doing it anymore, bring her back out. If she starts again use a chicken diaper. That's not the actual use for it but it works, so hey why not?