Sea Duck Research

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At the USGS Alaska Science Center, research on sea ducks has been designed to anticipate and address priority information needs of management agencies.  Until recently, very little was known about sea ducks in Alaska in terms of migration patterns and general biology.  Therefore, much of our past work focused on individual species, their migration, population demography, and ecology to fill these information gaps.  The USGS has also incorporated sea ducks into Nearshore Marine Ecology Research as an indicator of marine and nearshore ecosystem health.  USGS research has also focused on delineation of population segments so that management plans can be the most effective.  USGS was involved in the recent publication of a book (Edited by: Savard, Derksen, Esler and Eadie 2015) that provides a significant update to our understanding of sea duck biology.

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The group of waterfowl called sea ducks has 15 species that nest in North America including eiders, scoters, mergansers, goldeneyes, buffleheads, long-tailed ducks, and harlequin ducks.  Sea ducks have unique adaptations for life in high latitude and marine environments, including glands which excrete salt after the consumption of sea water, dense plumage, and extensive fat reserves.  Historically, sea ducks have been an important resource for indigenous communities in the arctic, providing rich food, and down and densely feathered material for clothing.  Elaborate plumages and remote distributions also attract bird enthusiasts and waterfowl hunters.

Common Eider

Common eiders are circumpolar in their distribution and remain at high latitudes for both breeding and winter, making them a model species for testing the influence of changing Arctic conditions to a sea duck species.  Common eiders are also a model species for understanding the influence of disease, contaminants, and predation on sea ducks in general because common eiders occur at larger densities during nesting that many other sea ducks.  Lastly, Common eiders are unique in that they are one of the few species of waterfowl to have substantial genetic, plumage and morphological differences among different regions of the world.  Much of the USGS Alaska Science Center research on Common eiders has focused on effects of sea ice, breeding biology, migration, contaminants and disease, and behaviors that drive the observed differences between populations.

King Eider

Image: King Eider Tagging

(Credit: USGS Alaska Cooperative Fish and Wildlife Research Unit. Public domain.)

King eiders are susceptible to at-sea oil spills because of their broad distribution throughout coastal and off-shore areas of Alaska during all months of the year.  USGS Alaska Science Center research on King eiders began after the 1996 M/V Citrus oil spill in the Pribilof Islands, Alaska.  Nothing was known about which breeding populations were impacted by the spill, so genetic analyses were conducted to determine if origins of the oil birds could be determined.  However, genetic analyses suggested limited differentiation among breeding and wintering populations of King eiders that resulted from their highly migratory nature. 

Spectacled Eider

Spectacled Eiders are large sea ducks that spend 9 to 12 months of the year in marine habitat (Petersen et al. 1999). At sea, eiders forage on clams, polychaete worms, and other organisms on the sea floor. In winter, the world population of Spectacled Eiders group at a single site south of St. Lawrence Island, Alaska, in the northern Bering Sea. In the summer, the species is divided into three breeding populations; western and northern Alaska and northern Russia. A majority (> 90%) of adults nest in Russia.

In 1993, the Spectacled Eider was listed as threatened under the Endangered Species Act and critical habitat was later designated throughout the species’ North American range. USGS research on Spectacled Eiders has focused on migration, wintering and breeding ecology, and factors involved in population status and trends.  In 1993 -1997, biologists at the USGS Alaska Science Center marked Spectacled Eiders with implantable satellite transmitters, which led to the discovery of critical molting and wintering areas.  Current research is providing important location and habitat information for Spectacled eiders migrating through northwest Alaska that is informing oil and gas development activities.

Steller's Eider

In 1999, the Alaska population of Steller’s Eider was listed as threatened under the Endangered Species Act.  In winter, much of the Russian and Alaskan breeding populations congregate in coastal areas of south-central and western Alaska, mostly along the Alaska Peninsula and into the Aleutian Islands.  In the summer, the Pacific portion of species is divided into three breeding populations; western and northern Alaska and northern Russia. The majority (> 90%) of adults nest in Russia.  USGS Alaska Science Center research on this species has focused on determining population connectivity between populations in Alaska and Russia, migration, molt and winter ecology, health assessments, and providing information for recovery efforts by the U.S. Fish and Wildlife Service.

Harlequin duck

The Harlequin duck is a common species in marine coastal areas of North America during most of the year.  In summer, the species nests along river and creek banks.  Because of the difficulty in finding large numbers of Harlequin ducks to study during the breeding season, most of our understanding of Harlequin duck biology comes from the post-breeding and wintering seasons when birds are more easily observed.  Harlequin ducks in Prince William Sound were harmed by the 1989 Exxon Valdez oil spill in Alaska and research on impacts and recovery form the spill has spanned the past 2 decades.  The Harlequin duck is a key component of USGS Nearshore Marine Ecosystem Research.

Long-tailed duck

Male Long-tailed Duck in the water

Male Long-tailed Duck floating in the water in Northern Alaska.
(Credit: Ryan Askren, USGS. Public domain.)

The long-tailed duck is a ubiquitous sea duck species in northern latitudes through the Arctic and sub-arctic.  While common in ocean and coastal areas during fall, winter and spring, in summer, birds nest in low densities making them difficult to study.  To fill gaps in our knowledge about the general biology of this species, USGS Alaska Science Center research on long-tailed ducks has focused mainly on molting birds in the Arctic, where they congregate in larger numbers, and pooling scant data from multiple years of nesting studies to understand drivers of population change.


Scoters are a common species in coastal marine areas of western, south-central, and south-eastern Alaska during winter and spring.  All three species (black, white-winged, and surf) breed in coastal and interior parts of Alaska during the summer.  USGS Alaska Science Center research on scoters has focused on migration, wintering and breeding ecology, population delineation, and use of marine resources during winter and the flightless molt period in late summer to fill gaps in our knowledge about these species.

Common Goldeneye, Barrow’s Goldeneye, and Bufflehead

Goldeneyes and buffleheads are cavity nesting species of the boreal and coastal forests of North America.  They are a common species in coastal marine areas of western, south-central, and south-eastern Alaska during winter and spring.  USGS Alaska Science Center research on these species has focused on filling gaps in our knowledge about population delineation, disease and contamination, and migration.

Red-breasted Merganser pair

Red-breasted Merganser pair in North Slope of Alaska.(Credit: Brian Uher-Koch, USGS. Public domain.)


Mergansers are the only sea duck species that forage nearly entirely on fish.  The three species (red-breasted, common, and hooded) are found across North America but in slightly different habitats.  Both common and hooded mergansers are some of the few duck species that nest in tree cavities, whereas red-breasted mergansers nest on the ground and at much higher latitudes than other mergansers.  USGS Alaska Science Center research on mergansers focused on filling knowledge gaps on population delineation, migration, and survival rates of populations.