Feeding Ecology Waste corn appears to be the dietary staple of most dabbling ducks and geese during the annual stopover in south central Nebraska. The winter diet of mallards consisted principally of foods taken on agricultural lands. Unharvested sorghum became a relatively important item in the diet during the 1978-79 winter when seed stalks were accessible above the snow cover and access to corn was restricted. Birds fed almost exclusively on corn when foraging in grazed corn stubble, whereas aquatic plant seeds and animal matter came principally from riverine habitats. These data suggest that mallards fare well on a diet that is principally corn but small quantities of animal matter are needed to meet nutritional requirements.
Field feeding by white-fronted geese occurs primarily in corn and winter wheat fields.
The birds probably take some animal matter from Basin wetlands to meet calcium and protein requirements but further study is needed to identify the contribution of wetland foods to the diet of white-fronted geese. The study area serves as a major conditioning site for spring staging waterfowl. Fat levels among males and females increased at a daily rate of 12.5 and 17.6 g, respectively. Assuming a 30 day stopover, lipid deposition among males and females averaged 375 and 528 g, respectively.