Common Name
GREATER SCAUP

Scientific Name
AYTHYA MARILA

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Photo by Bruce Bonebrake
Photo Copyright Bruce Bonebrake

The greater scaup, Aythya marila, is a diving duck that occurs in both Eurasia and North America. It spends the summers on ponds and lakes in tundra habitat, in protected coastal bays, and on large island lakes. North American populations breed in northern Canada and Alaska, and then migrate in flocks to wintering grounds in the Great Lakes region and along the eastern and western coasts of North America. The greater scaup is an uncommon transient to Utah, representing just a minute fraction of the scaup that migrate through the state.

The greater scaup dives from the surface of the water and then swims to capture prey items, such as mollusks and crustaceans. It can dive as deep as 20 feet, and can stay underwater for as long as one minute. Although diving ducks generally consume more animal matter than surface-feeding ducks consume, the greater scaup will also eat aquatic vegetation.

Males engage in a complex courtship behavior with the females, and monogamous pair bonds are formed. The female builds a depression nest concealed in tall grasses, and lines it with fine material. She incubates her large clutch of seven to ten eggs for almost a month; the male deserts the female after incubation begins. The young are born with down and are able to follow their mother and find their own food just after birth. Often females will join together to cooperatively tend and defend their young.

Sources:

  • Ehrlich, P. R., D. S. Dobkin, and D. Wheye. 1988. The birderís handbook[:] a field guide to the natural history of North American birds. Simon & Schuster, New York. xxx + 785 pp.

  • Robbins, C. S., Bruun, B. and H. S. Zim. 1966. Birds of North America. Golden Press, New York.

  • Behle, W. H., Sorensen, E. D. and C. M. White. 1985. Utah birds: a revised checklist. Utah Museum of Natural History, Occasional Publication No. 4. Salt Lake City, UT.

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