In 1994 a Habitat Rehabilitation and Enhancement Project (HREP) was completed on Swan Lake. A major goal of the project was enhancing habitat for migratory waterfowl. A pre-HREP evaluation of Swan Lake determined that relatively few waterfowl were using the lake, and behavior data indicated that time spent feeding was very low compared to published data for other migration habitat. Our study compares pre- and post-HREP abundance and behavior data to determine if Swan Lake is providing high quality habitat for migratory waterfowl. Management regimes initiated on Swan Lake produce large amounts of moist soil plants and seeds for migrating waterfowl. These seeds are high in carbohydrates, providing energy for migration and thermoregulation during fall and winter. Most waterfowl demonstrate a switch to high protein food sources near the end of winter or early spring. It is unknown if this switch is caused by physiological need, or depletion of other food sources. To address this question we collected feeding female mallards (Anas platyrhynchos) (n = 57) and lesser scaup (Aythya affinis) (n = 70) during spring migration 2004 and 2005, while simultaneously collecting food availability data. This information should provide insight into waterfowl food selection during spring migration, the cause and general timing of the dietary shift, and whether current wetland management regimes adequately provide for the nutritional needs of waterfowl during all periods that they use these wetlands.
