NOT KNOWN FACTUAL STATEMENTS ABOUT FERTILE SWAN EGGS

I'm no pro on swans. I alternatively feel that an evening-time predator filched the eggs. I have heard men and women declare that their birds( chickens, geese, whatever) get rid of infertile or nonviable eggs from their nest. In forty yrs I haven't experienced a chook get rid of their very own egg/s within the nest other than accidentally. Finally