Dark down, small headspot, small bars, dark on leg fronts. Barred Rocks can be sexed at hatch by headspot, down color (males are darker than females), and leg color, all traits taken together as a whole.
BA's are a great breed, too; you should be very happy with your flock. Unfortunately, BA's don't have built in early sex clues like BR's do, though I find that within a few weeks my guesses are pretty good just by the combs, thicker legs, stance, and behavior.
The one in the back of the first picture and the one in the second picture both look like pullets to me (not sure if they're the same chick...) The one in the front of the first picture looks like it *could* be a roo because of the thick legs, but I can't see well enough to know for sure.
Quote:
I'll concur - I guess pullet for both then (I just couldn't see enough of the front chick in the first picture to really make an educated guess). My BA roos were already looking decidedly male by that age, too. More comb development, more of a "rooish" stance.