J. T. Lokemoen Harold F. Duebbert 1976 <p>A study of dabbling duck (<i>Anatinae</i>) nesting was conducted during 1971-73 on nine 12- to 54-ha Cropland Adjustment Program fields in the prairie pothole region of north-central South Dakota. The tall, dense vegetation was comprised of introduced cool-season grasses and legumes, primarily smooth bromegrass (<i>Bromus inermis</i>), intermediate wheatgrass (<i>Agropyron intermedium</i>), and alfalfa. Complexes of temporary, seasonal, and semipermanent wetlands surrounded the fields at densities of 1.5-8.1 basins/km2 and areas of 9.4-17.2 ha/km2. Of the 620 nests studied, 38 percent were of blue-winged teal (<i>Anas discors</i>), 24 percent were of mallards (<i>A. platyrhynchos</i>), and 24 percent were of gadwalls (<i>A. strepera</i>). Densities of nests of all species averaged 67, 114, and 47 nests/km2 (3-yr av 77/km2). Calculated hatching rates were 69, 58, and 32 percent (av 56) for the 3 years. Hatchability of eggs in successful nests averaged 97.1 percent. Averages of 4.0, 6.2, and 1.2 ducklings were hatched per hectare in 1971, 1972, and 1973, respectively (3-yr av 3.7/ha).</p> application/pdf 10.2307/3800154 en Wiley Duck nesting in fields of undisturbed grass-legume cover article