GESTATION PERIOD FOR SWAN EGGS SECRETS

I am no skilled on swans. I alternatively feel that a night-time predator filched the eggs. I have read persons claim that their birds( chickens, geese, whatsoever) get rid of infertile or nonviable eggs from their nest. In 40 a long time I haven't experienced a chook eliminate their own egg/s in the nest aside from unintentionally. Eggs will not