Wetland hydrodynamics and long-term use of spring migration areas by lesser scaup in eastern South Dakota

Great Plains Research
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Abstract

Lesser scaup (Aythya affinis [Eyton]) populations remain below their long-term average despite improved habitat conditions along spring migration routes and at breeding grounds. Scaup are typically associated with large, semipermanent wetlands and exhibit regional preferences along migration routes. Identifying consistently used habitats for conservation and restoration is complicated by irregular wetland availability due to the dynamic climate. We modeled long-term wetland use by lesser scaup in eastern South Dakota based on surveys conducted during below-average (1987-1989) and above-average (1993-2002) water condition years. Wetland permanence, longitude, and physiographic region were all significant determinants of use (P<0.01). Long-term use was best described by a quadratic equation including wetland surface area variability, an index of wetland hydrodynamics that is linked to productivity, biodiversity, and value to waterfowl. Contrary to previous findings, our study shows that over the long term, lesser scaup are more than twice as likely to use permanent wetlands as they are semipermanent wetlands. The northern region of South Dakota's Prairie Coteau, which holds the highest density of hydrologically dynamic permanent wetlands, should be considered an area of conservation concern for lesser scaup. The criteria we identified may be used to identify important lesser scaup habitats in other regions of the Prairie Pothole Region.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Wetland hydrodynamics and long-term use of spring migration areas by lesser scaup in eastern South Dakota
Series title Great Plains Research
Volume 22
Issue 1
Year Published 2012
Language English
Publisher Center for Great Plains Studies
Contributing office(s) Coop Res Unit Leetown
Description 10 p.
First page 69
Last page 78
Country United States
State South Dakota
Other Geospatial Prairie Pothole Region