Our 15 week old ducks that I had high hopes would be female are not quacking, they still sound like males. I cant say I am not disappointed. One of them is a beautiful light colouration so he/she will be particularly good as a breeder. The other is more like a Dark Campbell. They are fantastic layers it has to be said. My original 2 Silver Appleyard ducks started laying just after new year and have rarely missed a day. That is a fantastic record and duck eggs are marvelously tasty.
I have two more ducklings at 7 weeks old and they are quacking so at least I have females there I think.