I also have Cayuga ducklings, one has a white dot on its back, visible only when the wings are spread. When calling a breeder about getting more, he asked me "are those the ones with the white dot?" Do all Cayugas have a white dot? That would be news to me! Not sure he knew much about them, and I'm new to this, too.
So do white dots in young birds indicate females?
I bought 4 more black ducks from him. This was out of a crowd of about 100 different ducklings, all different colors. Separated from the parents, I have no idea which ones were the corresponding adults. For all I know I just bought 4 ordinary Black Ducks.
This same seller also had a pair of swans. "Oooh, do you have any cygnets?" I asked He was puzzled, "hmm? you mean BABIES?" This is no bird expert.
the two older ducks are feathering out with green heads and blue wings. Any suggestions as to how to tell the girls from the boys?