North American ducks use a variety of foods and habitats over vast landscapes during their annual cycles to survive and reproduce. Historically, a diversity of natural wetlands and perhaps some uplands provided seasonal forage for breeding, migrating, and wintering ducks. Since the 20th century, human activities have significantly altered or destroyed wetlands that foraging ducks rely on throughout their annual range. Expansion of and technological advances in agriculture contributed to landscape change and simultaneously provided new sources of high-energy forage for some waterfowl species. In recent decades, public and private conservation initiatives have returned some marginal agricultural areas to natural foraging habitats for ducks. Clearly, foraging resources and ducks remain dynamic at spatio-temporal scales. Previous studies suggested or linked availability of forage throughout the annual cycle of ducks with their survival and reproduction. Thus, researchers have endeavored to estimate abundance of plant and animal foods in ecoregions important to North American ducks, and these data have been used to improve conservation planning and management.
In this plenary session will review the status of knowledge regarding abundance, dynamics, and conservation of duck foods in North America. Three invited talks will cover major portions of the annual cycle: 1) breeding; 2) fall migration and wintering, and 3) spring migration. Each seasonal review will provide historical background on food abundance for key foraging-habitat types, report on efforts to monitor distributions and dynamics of ducks and duck foods, and discuss major conservation strategies for providing foods and improving forage abundances. Finally, authors will suggest future challenges and opportunities that researchers and managers may face given potential changes in land use, climate, policy, and human population growth. In addition to the three invited seasonal reviews, other contributed papers will be included that focus on current research on abundance, dynamics, and conservation of foods and foraging habitats.
Plenary 3. Abundance, Dynamics, & Conservation of Duck Foods & Foraging Habitats in North America
Oral Presentations - Wednesday morning, 19 August 2009