Instructions
Put all the chickens in a new enclosure to eliminate established territories. If possible, keep a pen empty at all times so you can move the flock whenever you introduce new chickens. This should limit fighting to about 24 hours, during which they will establish pecking order and territories.
Introduce new birds gradually by dividing the pen with chicken wire to keep the new chickens separate from the established flock. This will allow both sides to become acquainted with each other.
Introduce birds that are about the same size and age as the established flock. Mixing mature and immature birds is not a wise idea, particularly if they are undersized or oversized.
Never combine roosters. While hens will fight to establish pecking order, roosters will fight to the death.
Combine the flocks in the dark. The established flock might not notice the new birds if they wake up with them in the enclosure. This also helps ensure that the hens find unclaimed spots rather than risk stealing a spot already claimed by a hen from the established flock.
Feed the flock while adding new birds to keep them distracted. Scatter the ground with fruit, greens and chicken scratch to keep them pecking at the ground rather than at their new bunkmates.
How to Introduce Chickens
A flock of chickens provides companionship and plenty of eggs, but it can be a real nuisance to introduce new chickens. The established flock is often not welcoming to newcomers and the new chickens might also throw the flock's pecking order out of whack. However, you can implement a few specific methods to get the flock acquainted with the new chickens and make the transition as smooth as possible.