DEADBEAT DUCKS
Several waterfowl—including redheads, canvasbacks, wood ducks, ruddy ducks, hooded mergansers, and snow geese—pursue a breeding strategy known as nest parasitism, where females lay eggs in the nests of other females of the same species. Some wood duck nest boxes have been found with as many as 50 eggs laid by multiple hens. Female redheads regularly lay eggs in the nests of other duck species. In one study conducted on Manitoba's Delta Marsh, more than 90 percent of canvasback nests contained redhead eggs. The unsuspecting foster hens raise the redhead ducklings as their own.