Sudden aggression-- at a loss.

[Dona Worry]

I have a small flock of 16 pullets, and 2 young cockerels. The pullets are a mix of 3 months, 4 months, and 5 months, and one cockeral is 4 months, and the other is 7 months.
Over the last couple of days, the older birds have ALL (except the older cockeral) been ganging up on the 6 three month babies. They free range, (temporarily) have multiple feeders of 20% all flock feed, and have been getting along fine before this, although the little babies are relatively new to the flock, they were only introduced 3 weeks ago. Before that, they were in 'see but don't touch' for a while, I don't remember exactly anymore but it was well over a week.
The only thing that is new is one of the older pullets has started laying. Her first egg appeared the same day I caught them all chasing the little babies.
I temporarily separated the 3 oldest pullets, but caught the rest chasing and pinning one of larger babies again today! I *think* the problem MAY be the 4 month old cockeral (he is now in jail with the other pullets) but I am just not sure. I haven't seen any signs he has found his hormones yet, he has just barely started crowing, and only occasionally. I only suspect him because he seemed to be pinning the little one down the most.
I am in the process of setting up my winter runs, when they can be separated and confined, but what is causing this to pop up out of the blue? And is there a way to fix it? I have see the entire flock (minus my older cockerel) run across the lawn and hunt these little guys out of the grass! It's 100% NOT the little guys challenging for space, or competition for resources. They will literally chase them down when little babies are minding their own business well away from the big flock.
The only one who will not chase them is the older cockeral, the polish crested. He'll visit with them and show them where some good food is. They roost next to him at night, and pluck his feather out because ??????????

 

[aart]

I *think* the problem MAY be the 4 month old cockeral (he is now in jail with the other pullets) but I am just not sure.

Agrees....I would remove only the younger cockerel, see what happens.

Not sure what your long term plans are for these birds...and why you need two males...or how many enclosures you have...so hard to make suggestions regarding the 'big picture'.

Pullets starting to lay can change the pecking order.
The younger pullets voices may be changing from peep to cluck...
...another change in maturity and possible pecking order status.
Were they being bullied prior, after the integration?

Just some thoughts..chicken society can be complex and ever evolving.

 

[Dona Worry]

Agrees....I would remove only the younger cockerel, see what happens.

Not sure what your long term plans are for these birds...and why you need two males...or how many enclosures you have...so hard to make suggestions regarding the 'big picture'.

Pullets starting to lay can change the pecking order.
The younger pullets voices may be changing from peep to cluck...
...another change in maturity and possible pecking order status.
Were they being bullied prior, after the integration?

Just some thoughts..chicken society can be complex and ever evolving.

I have 2 coops, accidentally ended up with two roos, and long term plans are to enjoy my pet chickens for as long as possible.
I will let the older pullets back out again later, one at a time IF I don't catch any bullying today. Poor babies, I feel so bad for them.

 

[Dona Worry]

All was quiet every time I was able to check in, so the older pullets are back out again, and young cockeral still in jail. If this keeps the peace, than he will find himself dinner very shortly. That attacking was NOT anything like a precursor to mating, just a vicious and unprovoked attack.
But I'll see how the older girls behave before sending him down the road.

 

[Soy Milano]

Sudden aggression in a bird who was usually not, is usually a sign that there is something wrong. Perhaps you might consider taking them to see a vet who treats chickens? - http://www.poultrydvm.com/poultry-vets.php

 

[aart]

All was quiet every time I was able to check in, so the older pullets are back out again, and young cockeral still in jail. If this keeps the peace, than he will find himself dinner very shortly. That attacking was NOT anything like a precursor to mating, just a vicious and unprovoked attack.
But I'll see how the older girls behave before sending him down the road.

Well, it can look that way..before they know what they are doing, or are just buttheads.

 

[Dona Worry]

Well, it can look that way..before they know what they are doing, or are just buttheads.

Maybe. But I don't think I've ever seen pullets gang up with a cockerel like that before. He wasn't the only one targeting her.
Regardless, there hasn't been another dog pile since he's been in jail, so I'll leave him there for a few days to cool his heels a bit. If he starts up the nonsense again when I let him out, it is game over for him.

 

[Dona Worry]

Sudden aggression in a bird who was usually not, is usually a sign that there is something wrong. Perhaps you might consider taking them to see a vet who treats chickens? - http://www.poultrydvm.com/poultry-vets.php

The only vet on that list even in my state is almost 2 hours from me. That's a no.
My large animal vet will help out with things like wounds and dosages of medication, that's good enough for me as far as vet services.

 

[aart]

Maybe. But I don't think I've ever seen pullets gang up with a cockerel like that before. He wasn't the only one targeting her.

Yeah, that part was odd...are they behaving since the cockerel has been segregated? Or wait, they are with him?

 

[Dona Worry]

Yeah, that part was odd...are they behaving since the cockerel has been segregated? Or wait, they are with him?

I let the 3 oldest back out, and all seem to be behaving so far.
The 6 littles are keeping to themselves on one end of the yard, everyone else is minding their own business on the other.
I am trying to remember for SURE if the BO had any part of the bullying. Her and the older cockerel were foraging with the littles earlier, very peacefully, and now that I am thinking, I don't remember if she was involved, or just the other two.
The other 5 seem much more subdued without the younger cockerel-- he was their hatchmate, and they are unsure what to do with themselves.