Greater scaup is fairly shallow and has an abundance of food sources and cover. The female lays six to nine olive-buff-colored eggs, which she incubates for 24–28 days. A larger clutch could indicate brood parasitism by other greater scaups or even ducks of other species. Newly hatched chicks are covered with down and are soon able to walk, swim, and feed themselves; however, they are not able to fly until 40–45 days after hatching. The vulnerable small chicks follow their mother, who protects them from predators. The greater scaup dive to obtain food, which they eat on the surface. They mainly eat
Greater scaup zinc, manganese, copper, lead, cadmium, cobalt and nickel in their tissue samples with varying concentrations of metals in different types of tissues. Further analysis revealed that the kidneys had the highest levels of cadmium, the liver had the highest levels of copper and manganese, the liver and the stomach had the highest levels of zinc, and the lungs and liver had the highest levels of iron. There was no difference in concentration when comparing genders. Greater scaup are rated as a species of least concern by the IUCN Redlist. During aerial population surveys greater and lesser scaup are counted together,