Roosters fighting

[bloomnbeauty]

Today two of my roosters went at each other. They are in separate pens but can see each other and have never fought until today. Neither have hens with them as yet. By the time I heard them my White Leghorn was bloody and his wattle torn. The Black Australorp rooster didn't have a scratch on him. I grabbed the water hose to try and separate them but they didn't even slow down. I finally had to put up a board they can't see over to stop it. What could have caused them to go at it today?

 

[rooster-red]

Roosters will be Roosters.

Out of the 12 roo's I have, a couple would try to fight each other through the fence, I put up metal panels to keep them from seeing each other and all is well.

You've actually already solved the problem when you put the boards up.

As to what triggered this behavior, are these young roo's that are just maturing? Basically they've just found out they really don't like each other.