Quote: The more space they have, the better. And most of the time less fighting because they can all go to their own different spots on the pen to get away from each other. Every group has its own dynamics and even the dynamics of the relationships in the pen can change so you just have to watch behaviors and see how it goes. For our full grown, large fowl chickens we try to keep a minimum of 10 square feet per adult bird that is penned most of the time. Our free-rangers get less coop space per bird only because they are inside only at night and as long as they have the ability to free range during the day, they are comfortable. For youngsters in the grow-out pens, we monitor for behaviors as they grow and if we think that a lack of space is causing undue fights, then we go ahead and rearrange (which can include culling and butchering) everyone to get more space. We have small pens that can house 1 or two full grown cocks comfortably (these are 4x8 ft and 4x10 ft pens that are approx. 3 feet tall, a-frame style) and then we have our mid to large size breeding pens, and our large size grow-out and larger flock pens. We move birds around when we need to if we find that a lack of space is causing a problem for a particular bird or group of birds.
Separating them by gender early on has not diminished any protective or mating instincts when ours are finally allowed to be with the females. We've put cocks into the free-range pen that grew up without girls, and they had not lost any instincts at all. They went from being civil to each other to having bloody fights with each other until they established which cock was going to be the alpha rooster. Then they each took half of the hens in the group as their own harem. One of them died defending the hens from coyotes while his brother led the hens away from the danger.
