Raising chickens has taught me a lot about animals and human behavior, and the etymology of words.
Birds and people get stressed from being all cooped up because of cold weather. Like humans, birds take it out on whomever is most convenient. They target weaker birds and pick on them to relieve the stress and establish a pecking order.
Witness "Negro Dos" (Blackie Two) above. The other five birds have pecked off her tail feathers out of frustration, boredom and instinct.
Did you know that state law requires that chickens can only be sold in groups of six because chickens are social creatures. They need a group of at least three to be happy. The law also prevents one or two birds being sold at Easter as a living toy that may be neglected and abused.
Chickens know how to abuse each other. I'm not sure that it's good. It is natural instinct to establish a social order. Someone has to be in charge. And unfortunately, someone has to be on the bottom. Bullying is an unfortunate fact of the animal kingdom.
We humans have the intellect to be aware of bullying, educate each other and make different decisions. We can learn from "being all cooped up" and "the pecking order." I wish my chickens could.