A week and a half ago I found my Jersey Giant hen cowering in the nesting box. The whole back of her head was a bloody mess. Since then I've had her in my screened porch and she has healed up nicely. She even started to lay eggs a few days ago. I've always thought she was the Alpha hen. This morning she ran out the door when I went out to feed the chickens and geese. Immediately the cockerel was on her, attacking. She got away and hid away from him. I'd bring her back in the porch but she won't let me get near enough to pick her up. As to the cockerel. He hatched mid August from a hen who hid her nest from me. His father was put down for being people aggressive. He was the only cockerel of the batch of 10 chicks. I do not plan on keeping him. I had a Salmon Faverolles rooster that I loved but he got taken by a fox one evening when I was too ill to lock the chickens up and the roommate was late getting home to do it for me. I have 3 Salmon Faverolles male chicks coming in April. Will keep one and share the other 2 with neighbors who want one. This aggression to just one hen seems strange to me. He wasn't trying to breed with her or at least it didn't look that way. I guess my question is whether a cockerel or rooster can take a big dislike to a hen or not.