Ive got two Mallard hens and one Runner duck that free range 24/7. Ive found a nest that one of them has made in the corner of the fence and has been laying an egg a day there. I havent seen any of them sitting there but all three hang out in the area. The eggs are white and look like perfect ovals. Its almost impossible to tell which end is the big end because they are so similar. The two mallards are over a year old and the runner is probably 6 months old. I figured that it was one of the mallard because of the age (I just had the mallards given to me last week). However, ive never had mallards before, but the wild ones lay green eggs. So Are these eggs from my runner? Do they lay at 6 months old?