Below are some tips to make it as painless as possible to introduce new chickens to your existing flock. With these tips, you may still see some aggression, but hopefully it will be minimal.
Side by Side
Temporarily install a partition in your existing coop or pen so that your new chickens can live right next to your main flock. Use mesh so that the chickens can see, hear, and smell one another without being able to attack one another. If you are only introducing a few birds, a dog crate or small cage will work well. Depending on your flock, the chickens may try to fight some through the wire mesh, but they won’t be able to cause serious harm.
After a week or two of this separation, the chickens will be much more used to each other, and you should be able to tell this from their behavior. Then, using the other tips below, you can remove the partition and let the new chickens into the main flock.
New Coop and Run
If you are not able to use the approach above, then another approach you can take is to move both your existing flock and the new chickens to a new chicken house before introducing the new chickens. The change in housing will cause both the old and the new chickens to feel somewhat unsettled and disoriented, and it will make it easier to add the new chickens.
Introduce them at Night
Wait until nightfall to add the new chickens. You can quietly set the new chickens onto the roost next to the existing chickens. This will give the chickens a chance to be together and get used to each other overnight.
Provide Hiding Places
Have places in your chicken coop and/or the chicken run where less aggressive chickens can hide from those who are more aggressive.
Extra Food and Water
Aggressive chickens can keep newcomers from gaining access to food and water. Provide extra feeders and waterers so that if some chickens block others’ access to one feeder or waterer, there will still be another feeder and waterer for the newcomers to access.
Isolate the Aggressor
If one bird is particularly aggressive toward the newcomers, remove her to a separate area (a dog crate works well for this) then reintroduce her to the flock a few days later. This will usually take her a few notches down in the pecking order. If she continues to be a problem, consider having her for dinner.
Introduce Several Birds at One Time
If you introduce only one bird into a new flock, that bird is likely going to be on the receiving end of most of the aggression and can be seriously injured. It is better to introduce several birds at a time, so that the aggression is spread out rather than being focused on a single bird.
Dim the Lights
If the birds are in a confinement house, dim the lights, so that the birds can’t see each other as well. Over the course of a week or so, gradually restore the original lighting after the birds have gotten used to each other.
Caution about Introducing Roosters
If you have a rooster in your existing flock, then introducing another rooster is asking for trouble. Roosters can be very aggressive toward one another in a mixed flock that contains both hens and roosters. Depending on the breed, the individual chickens, the amount of space available to the chickens, etc., you may or may not be able to introduce a new rooster successfully, so if you need to introduce a new rooster, please proceed carefully.
Keep a Watchful Eye
The first few days after you introduce new birds into your flock, keep a close eye on them. Watch to make sure that no one becomes injured to the point of bloodshed. If you see any chickens that are bleeding, remove them from the flock and isolate them. If you find one particularly aggressive bird, remove it from the flock temporarily. Watch for chickens that are not getting access to waterers or feeders because of more aggressive birds. If everything goes well, the aggression will settle down over the course of a week or more, as the new pecking order is established.
Do You Have Other Questions about Flock Integration?
In the next articles in this series, we would like to answer questions that you may have about introducing chickens. If you have questions, please post them as comments below this article.