shared two days ago: Canvasback, Aythya valisineria (synonyms, Aristonetta valisineria, Marila valisineria and Nyroca valisineria ; protonym, Anas valisineria ), Wilson, A., 1814, photographed at Rockport , Texas (USA). Question: This North American mystery bird is often the victim of another species' breeding behaviour. What behaviour is that? What effects does