Distribution and habitat use of waterfowl wintering in Oklahoma

The distribution and habitats of waterfowl were studied in Oklahoma during winters 1978-79 and 1979-80. A stratified random sample of quarter sections of land area was used to sample wetland habitats and waterfowl wintering on small scattered wetlands in Oklahoma. Aerial and ground counts of waterfowl on large reservoirs and national wildlife refuges provided a perspective of the statewide role of smaller water basins in maintaining wintering waterfowl populations. Dabbling ducks preferred natural wetlands over man-made impoundments. Most common mergansers (Mergus merganser) wintered on reservoirs and most geese (Chen caerulescens, Branta canadensis) wintered on national wildlife refuges associated with large reservoirs. Numbers of dabbling ducks decreased on reservoirs during late winter and simultaneously increased on small natural wetlands. Small wetlands were differentially selected by paired and female mallards (Anas platyrhynchos) and were used primarily as feeding habitats. Dabbling ducks used palustrine wetlands more in 1979-80 than in 1978-79, apparently because of increased wetland numbers, hectares of surface water, diversity of wetland types, and emergent vegetation-open water interspersion of palustrine basins during 1979-80. Protection of natural wetlands and unaltered rivers appears more ecologically beneficial to dabbling ducks wintering in Oklahoma than enhancing areas associated with large reservoirs and/or construction of farm ponds.