While free ranging my 2 guineas and 4 barred rocks, the 2 guineas decided to beat each other up, lots of head slamming and wattle grabbing (what are those little floppy things on the sides of their heads called?) I'm guessing the winner was the one less bloodied. The other seemed dazed and confused for a while, too. Now they're all happily wandering the yard nibbling at things again. I guess that confirms they're both probably male.