US Geological Survey


Date of this Version



Published in Bull. Wildlife Disease Assoc. Vol. 5, October, 1969.


Losses among mallards (Anas platyrhynchos ) wintering on a seepage ditch below the Garrison Dam on the Missouri River at Riverdale, North Dakota, were reported on February 24, 1968. In early February, while conducting their annual winter banding operation, personnel of the North Dakota Game and Fish Department observed approximately 1.000 mallards on the ditch. Approximately 200 mallards were banded after being captured in a walk-in trap baited with corn and wheat located on the bank of the ditch. Snow covered the area and caused the ducks to concentrate at the bait site from the time of the banding operation until the reporting of the losses.