NOT KNOWN FACTUAL STATEMENTS ABOUT SWAN EGGS TO HATCH

I'm no skilled on swans. I rather feel that a night-time predator filched the eggs. I have listened to people today declare that their birds( chickens, geese, whatsoever) clear away infertile or nonviable eggs from their nest. In 40 years I have never experienced a chicken eliminate their particular egg/s within the nest other than accidentally. S