Thanks for your hints. I don't see any red feathers in the tail yet.
I've separated 2 of them (females) to another place... quite small but it will be temporary.
The male was going after them like crazy and one of them had traces of blood in her feathers near the legs (I don't know if it was the male who pulled her feathers or if she did it to herself?!)
So now I have together: 1 male and 2 females (I think). The reason why I didn't put just the pair alone is because I don't have anymore room to the other female.
But anyway, one thing I still don't understand: some people say that button quail should be paired up and some say they should be in trios because "the male may become agressive if paired with single hens".... ( http://www.singing-wings-aviary.com/buttonquail.htm ) I don't really know which theory is the correct one!?!
The truth is that my male was being agressive to all four females when they were together (picking a lot on their feet and running after them like crazy) and he is being agressive now with two females. I am also afraid to remove one more female and leave only the pair alone... what if he redirects all his anger to that single hen?!??
Some more hints please...