The proper ratio for males and females- if you end up with fenales too-
1-5 females per 1 drake.
You can have 1-3 females per drake if you don't have any other ducks, 4-5 females per drake if you have other ducks.
So....
females quack. Males have a quieter, raspy whaap whaaap.
At 16-24 weeks they will develop the curled drake feather- only AFTER the second molt.
And he head bob happens in either gender. The ONLY ways to successfully and accurately tell gender is:
a) voice sexing at 6-10 weeks
b) Drake...