[animal mad]

hi, i have 5 hybrid chicks all 4 and half weeks old. the two black ones and the light sussex are about 1 third bigger than the two   columbian black tail chicks. one of the black ones which i thought was a cuckcoo maran is brown and black, she is getting really bossy around the columbian black tail chicks, is there any thing that i can do or should i just leave them to get their own order. they are in a space of 6foot by 3 foot, with an electric hen, they always have food when they want although they seem to spill most of it over the floor. any ideas :

[SMD66]

I don't think there is anything you can do, they will decide amongst themselves who is going to be the boss and in my experience if you remove her then another bird will take over the role. 
 It may be that the picked on one might want a bit of space to get out of the way, I saw a recommendation in a chook book which said have a bucket on it's side so the hen being chased can get into it and face the attacker, this stops the attacker in their tracks and lets the one being chased have a rest.  they may be a bit small for a bucket to work, but you could use a plant pot or something.