i have yet to tell the sex of my RIR and Black Astralorp chickens.
i tried to get some good full body shots but was attacked in the
coop....lol.
edited to add RIR are 10.5 weeks and BA are 8 weeks
I would say all roos except in the picture of the 3 together the far left one looks like a pullet to me, Possibly the middle one as well. But that one is harder to tell.
The Australorps look girly to me. My BA roo was still poorly feathered at that age and shortly after (10-12 weeks) had bright red comb and wattles. At 16 weeks my Australorp hen still has only the faintest pink in her comb.