Measurements
Both Sexes
- Length
- 15.4–22 in
39–56 cm - Wingspan
- 28.3–31.1 in
72–79 cm - Weight
- 25.6–48 oz
726–1360 g
Other Names
- Scaup (British English)
- Fuligule milouinan (French)
- Porron bastardo, Buixot (Spanish)
Cool Facts
- Occasionally an older female Greater Scaup will have male-like head color and male patterning on her back, but she still has the typical white face patch of a female.
- Once incubation begins, the male Greater Scaup leaves the female and goes to molt on some relatively large, isolated lake. These lakes are used year after year during molt, and may be in the immediate vicinity of the breeding wetlands or many miles away. They are relatively shallow and contain abundant food and suitable cover.
- The nest of a Greater Scaup is usually lined with a thick layer of down plucked by the mother from her own breast. Nests of poor-condition females may lack down and instead may contain small, grayish-white feathers plucked from beneath the outer body feathers.
Habitat
Lake/Pond
Found on lakes, ponds, and bays. Mostly marine in winter.
Food
Insects
Clams, snails, crustaceans, aquatic insects, seeds, and aquatic plants.
Nesting
Nesting Facts
- Clutch Size
- 5–13 eggs
- Egg Description
- Brownish olive-buff.
- Condition at Hatching
- Downy and eyes open. Leave nest as soon as they are dry. Feed themselves immediately.
Nest Description
Bowl-shaped depression in ground, usually lined with grasses and a thick layer of down. Placed in tall grass in an area not subject to flooding.
Nest Placement
Ground
Behavior
Surface Dive
Dives under water to capture food.
Conservation
Least Concern
Because of similarities to abundant Lesser Scaup, accurate winter counts difficult to obtain. Populations may be declining.
Credits
- Kessel, B., D. A. Rocque, and J. S. Barclay. 2002. Greater Scaup (Aythya marila). In The Birds of North America, No. 650 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA