GESTATION PERIOD FOR SWAN EGGS SECRETS

I'm no professional on swans. I rather imagine that an evening-time predator filched the eggs. I've heard people today claim that their birds( chickens, geese, regardless of what) take away infertile or nonviable eggs from their nest. In forty a long time I haven't had a chook take away their own personal egg/s in the nest aside from unintentionall