One Chicken Attacking Another at Night-Causes, Dangerous to Add A Pullet(s)?

[bobbi-j]

I mean I don't know why they wouldn't be, they have a large lush yard to roam around every day and treats everyday!

While you don't know "why" they might be unhappy, their behavior tells you that something is wrong. One is being beat up. How could she be happy? The other one is agitated enough to attack. Something wrong there....

 

[centrarchid]

How could I just send them off to be slaughtered?? There's nothing wrong with them

Above potential causes for discord are valid.

Post a picture of bird being attacked. Feel her breast and describe how it feels. Sometimes poor health or odd behavior of victim can cause attacks.

Feathers being dislodged especially from multiple attacks means something very seriously wrong but do not rule out early onset of molt or victim trying to go broody. Ages of some not entirely clear to me because of omission of units.

 

[ChickCrazed]

I could never get rid of my girls!
No we let them free range and leave the door of the run open. The coop itself is supposed to hold up to 5 birds.
The only predator it could have been was a small rat. The run is racoon proof.
But I know it wasn't one... because a) it didn't stop until I separated the two and b) everytime I went out there it was the wyandotte's feathers strewn everywhere, her huddling in the corner, the welsummer standing over her.
I was thinking if we were to add a chicken might want to add to because I heard adding two makes it less lonely for the newbies

Coop manufacturers seem to follow the space requirements documented by the large poultry farms and say their coops can house more than most people would put in them. In my opinion that is a horrible injustice to the birds. Most experienced chicken keepers recommend 4 square feet per bird. I think that you can get away with a smaller coop if the birds have been raised together and you have docile birds but it is really hard to put unfamiliar birds on top of each other with no room to flee. I agree with the others that you need to temporarily or permanently remove the aggressive bird to let the new bird adjust. A kennel in your garage for a few days should suffice for the aggressor. You might seriously consider adding a slightly larger coop though!!! In the long run your birds will be a lot happier!!!

 

[Danniro]

I would hate to give one of them away though... my babies...
They were better behaved when there were more chickens/they were lower on the pecking order because of other chickens. They were a lotttt less noisy.