Rouen X Runner Duck

[JLS77]

I got some eggs last year was suppose to be runners and a couple bonus rouens. Well the all look mixed me. Well the females are setting now. Will their eggs hatch or are the mules and will not have fertile eggs

 

[DurhamDuck]

The eggs will hatch.

There is one type of cross that will not be fertile, but it is different. Look at it this way.

ALL domestic duck breeds except for one are all or almost all the way descended from wild mallards. The birds can all cross with each other infinitely.

Then there is a type of duck called the muscovy. They are big and ugly with turkey-like faces. They are not like mallards.

If you cross a muscovy with a mallard-derived breed, you get mulard "mule muscovy/malard" ducks. These ducks will be the mules, and they will be unable to have babies.

Basically, you can cross almost anything and it will hatch, as long as the male managed to sucessfully mate with the female and fertilize her eggs.