My daughter brought a library book home the other day and it was about the care and keeping of ducks. Of course, I started reading it and there was a breeding section that said ducks of different species that mate will produce offspring that are sterile. Having experience with horses I know that mules (cross between horse and donkey) are sterile, but I didn't realize there were different species of ducks. I thought there were just different breeds. Does this mean my pekin/mallard cross ducklings will be sterile? I don't mean to sound like a dunce, but could someone explain?