Both our ducks will be 11 weeks tomorrow, and we still have no idea what they are. Neither of them have drake feathers, and they hardly quack at all. When we go out there, they just talk to each other in that low peeping noise. When they do quack, it will either be the low raspy one, or a high normal one, they both will do both when they get separated. We noticed one of them has their back feathers changing. The brown feathers are becoming less defined and are turning more of a gray than anything else. I also heard you can tell a little by beak color, but both of them have completely dark beaks with a little yellow here and there. We still see no green tinting on their heads. Both of their speculums range from blue green, to purple blue, to true blue, it just depends which way we are looking at them. These are our first ducks so we have no clue what we should be looking for and at what age.