Greater Scaup
(Aythya marila)

Overview

Summary

© Ralph Hocken
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Two scaup species occur in Canada, the Greater Scaup and the Lesser Scaup. These two closely related species are nearly identical in appearance, which can cause difficulties in distinguishing them. The population status of scaup (Greater and Lesser Scaup, combined) in North America became a conservation concern due to apparent declines from historic high levels observed in the late 1970s. Their populations have not yet fully recovered, and research to understand the cause of the decline is ongoing. Greater Scaup are the least abundant of the two species and are the only diving duck with a circumpolar breeding distribution. The Greater Scaup is widely distributed across Arctic and Subarctic regions where it mainly nests in coastal tundra habitats. The information below regarding the population estimate and population status is for the two species combined. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.

Designations

Population status

Population estimate

Distribution maps

• BirdLife International / NatureServe

Migration strategy, occurrence

Responsibility for conservation of world population

Conservation and management

Research is ongoing to elucidate why scaup are not more abundant now. However, the difficulty in differentiating between Greater Scaup and Lesser Scaup during aerial surveys is a challenge for managers who require more detailed information on the status of populations. Currently, numbers of both species observed during aerial, and most ground-based, surveys preclude identification of differing population trajectories and species-specific population estimates. Because Lesser Scaup are a dominant component of the combined population, changes in population status of the less abundant Greater Scaup may be undetectable. The harvest of Lesser Scaup and Greater Scaup has declined considerably in Canada over the long term.
 

Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

• conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
• stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
• management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
• other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

References

• Canadian Wildlife Service Waterfowl Committee. 2014. Population Status of Migratory Game Birds in Canada: November 2014. CWS Migratory Birds Regulatory Report Number 44. Canadian Wildlife Service Waterfowl Committee. 2014. Population Status of Migratory Game Birds in Canada: November 2014. CWS Migratory Birds Regulatory Report Number 44. (Link)