When will rooster (the dad) realize there are cockerels in the pen.

[Mamagirl3]

Our hatchlings are 3 months old. At what age will they be when the rooster (dad) notice them as cockerels and will fight with them? They will need to be separated so as not to be hurt or worse.. not sure what age to be watching for?
Thank you..
If i have posted in wrong forum i apologize... sometimes i am not sure.

 

[Tonyroo]

It's the cockerel that will stir the aggression, the dad will only be defending himself. You'll notice there temperament change around 4 to 7 months of age. This is when you should separate them. When their close to a year old they will fight for territory.

 

[Yardmom]

It will depend on the personalities of the both birds. Some cockerals know Dad is in charge and never challenge, others will as early as 3 months.

 

[Sahraschweiss]

As @Yardmom said, it depends. I have a flock of 50+ with 5 boys. One is 3 years old and the other 4 are a year this February. One of the young ones, a splash wyandotte, displaced the the 3 year old buff orpington. Wasn't too violent and was quickly sorted. They now know who's where in the pecking order so there isn't much fuss. They have loads of space and lots of water and feeder stations. While the boys think they are boss, the ladies pick who the hang and do their business with.

Any rooster that causes undo stress in the flock is rehomed.

 

[SueT]

I had one cockerel raised by a hen within the flock and he was fine. He did not challenge his father. His father rarely corrected him for anything. He was a good understudy, which turned out to be important, as the father was killed by a predator when son was 1 year old. Son took over seamlessly and has always been a gentle leader.
In this pic, son is in the foreground, dad is in the rear.