I've got pet ducks (3 of) and we've had them from day old and were told that they *should* all be female, which is what we wanted.
However, we're only getting about 4-5 eggs per week, when we should be getting between 10 and 15 apparently.
They're Cherry Valley ducks and allegedly supposed to lay approximately 5 per week per duck.

My problem is that I don't particularly want to be eating eggs that could potentially be fertile, so is there a foolproof way(that's me) that i can tell whether i have a male duck in my batch or not.

I know I can candle the eggs, but being a noob to duck eggs I wouldn't be able to tell if they're fertile or not until about 7 days after incubation has started, and if they're not then i've lost a couple of omelettes, as cooking up a few eggs that have been at 30c for a week isn't to my liking.

Apols if this is posted in the wrong place as well.

I'm just trying to find out a easy way to sex my ducks. Google has brought up nothing concrete, except for forcing their cloacal opening to look at internal genitalia and I don't really want to be doing that either.