We tested ability of egg acceptance in two species of diving ducks — Common Pochard and Tufted Duck — by adding experimental parasitic eggs of Mallard Anas platyrhynchos. Individual reactions were compared with control nests, where no parasitic egg(s) were added.
We looked for three different reactions to the parasitic egg(s): (1) abandonment of the clutch, (2) ejection of the eggs from the nest and (3) acceptance of the eggs. In total, experiments with 15 Common Pochard and 24 Tufted Duck nests were carried out.