Asiatic clam (Corbicula manilensis) and other foods used by waterfowl in the James River, Virginia

Corbicula manilensis was found in the gizzards of 24 ducks of 5 species taken from the James River, Virginia, between 1973 and 1976. Percent average volume in these species ranged from trace to 6%. This is the first known occurrence of this exotic clam in the food of duck in Chesapeake Bay. A total of 135 other food items was identified from the 116 gizzards of 9 species that were examined. Food that predominated included Cyperus spp.,Leersia oryzoides, Polygonum spp., and Zea mays. The great diversity of food consumed in this fresh tidal section of the James River indicates the high value of these wetlands to waterfowl.