Greater-Scaup, Aythya marila

Greater Scaups inhabit a range of aquatic habitats, including both freshwater and saltwater environments. They can be found in large lakes, reservoirs, coastal bays, and estuaries. Their world range extends across northern parts of North America, Europe, and Asia. They are known for their ability to tolerate colder temperatures and icy conditions.

The male Greater Scaup has a distinctive appearance with a black head, a white body, and a bluish-gray bill. Females, on the other hand, have a mottled brown plumage with a darker head and a pale bill. Both males and females have yellow eyes, which are a characteristic feature of the species.

Greater Scaups are diving ducks. They are known for their strong flight and diving abilities. They can dive underwater for extended periods and swim with agility beneath the surface. They forage by diving to reach their food. They primarily feed on a variety of aquatic invertebrates, mollusks, crustaceans, and small fish. They have been observed to dive to considerable depths in search of food.

During the breeding season, Greater Scaups form pairs. The female selects the nest site, typically on the ground near water or on a floating platform made of vegetation. They may nest in areas with tall grass or shrubs for concealment. The nest is a shallow depression lined with plant material and down feathers.

Greater Scaup females typically lay around 6-9 eggs, with an average of 7 eggs per clutch. The eggs are pale olive to greenish-buff in color. The female incubates the eggs for approximately 24-28 days. The male usually leaves after mating to molt and regrow his flight feathers.

Once the eggs hatch, the female leads the ducklings to the water within a day or two. The ducklings are precocial and capable of swimming and feeding themselves shortly after hatching. They primarily feed on invertebrates and small aquatic organisms found in the water. The young Greater Scaups fledge at around 45-55 days after hatching. They become independent but may remain in family groups for some time.

During winter, Greater Scaups undertake migrations, with individuals from the Arctic breeding grounds moving to milder climates where they inhabit coastal bays, estuaries, and open waters of lakes and reservoirs. They often form large flocks during the winter.