Grand Lake originally was constructed for hydropower generation but also is used for flood control, water supply, recreation, and fisheries and wildlife conservation. Each aerial survey was conducted between 0730 and 1200 hr and lasted for about 3.5 hr. We recorded species and abundance of all waterfowl observed. Because of differing census methodologies and effort, it is not possible to compare absolute numbers of ducks observed in our study with the numbers observed in other studies. Stancill et al.
Similar constraints exist relative to the management of Grand Lake for non-dabbling ducks.
Our research was funded by the Grand River Dam Authority through Benham-Holway Power Group, Tulsa, Oklahoma. B. Davenport, S. Haggard, and M. K. Stancill provided valuable assistance with the field work and compiling data, and useful reviews of this manuscript were offered by J. Aldrich and H. Namminga. U.S. Fish and Wildlife Service and Canadian Wildlife Service, North American Waterfowl Plan . U.S. Fish and Wildl. Korte, P.A., and Fredrickson, L.H., Loss of Missouri's Lowland Hardwood Ecosystem.