You can pretty much tell with their quack by now. The males, as you know, will be low and sexy, the females LOL will be loud and mouthy...don't know, looks like 3-4 drakes to me, but I'm no expert by any means.
At their age, it's in the quack, and the drakes definitely stand much taller and almost dwarf the girls. Will be easy to tell real soon! Even at 5 weeks could tell them apart, much easier than other breeds. Ours are almost 12 weeks now, and the drake is very obvious, very tall in stature and has that deep soulful voice. However, the pair tends to be timid and submissive to the Pekins, they won't even come out of their cage unless the Pekins are out first., no matter what. BUT they are fairly intelligent and trainable with a little coaxing, peas work well, lettuce, sliced grapes or cherries are great training tools for ours, duck candy! Can do a lot of tricks with my Sweet Pea Pekin, up donwn this way and that. She loves her candy at 16 weeks, and altho she is dropping some eggs, she is still fairly obedient going through puberty. She really has no idea what is happening to her, and wish I could have that mother-daughter talk. Qvack!!! Be a good girl!!
Good luck with them, you will soon be able to tell, if you haven't already. They are funny creatures, cross between the Pekin and Runners, very upright posture as opposed to Pekin, but seem very hardy and robust, my first experience with them this year, but will try to breed my pair and keep this threatened breed going. And you should as well. They should produce many fertile eggs for you and the babies, as you know, are absolutely precious! Have fun!