I think you have two drakes and possibly a third. The ones to the left could be this years hatch. They are all old enough to sex. I would say the one at the back and one far right are drakes then possibly the one far left. You might find some of the others are too. How many "quackers" have you got?
OK, The one furthest right is definitely a drake and the one at the back with the grey head and olive beak might also be. The problem is, when I picked them up to worm them last night, they all decided to remain silent "don't squeak Bill, or they'll put you in a rice pancake!".
I'm still really hoping we have one drake and six ducks though. I mean, if we had hatched them, it would undoubtably be the other way around..... so both genetics and karma therefore dictate that other people must be hatching predominantly females, right?