Evidence for Black Duck Winter Distribution Change

Authors

  • RODNEY W. BROOK,

    Corresponding author
    1. Ministry of Natural Resources, Wildlife Research and Development Section, DNA Building, Trent University, 2140 E Bank Drive, Peterborough, ON K9J 7B8, Canada
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  • R. KENYON ROSS,

    1. Canadian Wildlife Service, Environment Canada, 335 River Road, Ottawa, ON K1A 0H3, Canada
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  • KENNETH F. ABRAHAM,

    1. Ministry of Natural Resources, Wildlife Research and Development Section, DNA Building, Trent University, 2140 E Bank Drive, Peterborough, ON K9J 7B8, Canada
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  • DAVID L. FRONCZAK,

    1. United States Fish and Wildlife Service, Migratory Bird Management, Bishop Henry Whipple Federal Building, 1 Federal Drive, Room 501, Fort Snelling, MN 55111-4058, USA
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  • J. CHRIS DAVIES

    1. Ministry of Natural Resources, Wildlife Research and Development Section DNA Building, Trent University, 2140 E Bank Drive, Peterborough, ON K9J 7B8, USA
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rod.brook@ontario.ca

Abstract

ABSTRACT  The Mississippi Flyway midwinter population survey (MWS) indicates that American black ducks (Anas rubripes) have been rapidly declining for the last 10 years. We found a negative relationship between MWS and Ontario (Canada) midwinter counts for black ducks. Thus, as number of black ducks in the MWS decreased, Ontario midwinter counts increased. A shift in midwinter distribution of black ducks may be partly responsible for the decreasing trend in MWS counts. We recommend that midwinter black duck surveys be expanded to more sites in southern Canada and northeastern United States that currently are not sampled to better assess winter habitat use and improve the midwinter black-duck population index.

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