I have three, seven week old ducks I hatched from eggs. These are my first ducks. The are either Runners, Khaki Campbells or a cross of the two. I've tried to sex them by quack but they don't sound like either of the examples on the Majestic waterfowl sight. They are louder then the drake but quieter then the duck. The two brown ones make a wak! wak! sound and the grey one says wonk! wonk! None of them has a sign of a curly tail feather. The browns look like Campbells to me and the grey has a more upright stance of a runner. But they all stand up tall when they move. Anyone know what they are? Boys or girls? Runners, Campbells or a cross?