#4 is the only suspect on my list of being a cockerel, but as the PP stated, standing would be a better pose. #5 is definitely a pullet. I guess I'm questioning everyone else... a wee bit.
I've had experience with this as well.The roosters form a nice comb and wabbles.See only 4 has nice wabbles.Also the feathering on number3 gives it away.Its tails clearly a curly and it looks like its wetted 1 clue.And its wabbles and combs.