As a result, increased protection and restoration of wetlands in key spring migration corridors may be warranted to achieve continental population objectives for scaup and other waterfowl species. But until recently, little information on the nutritional requirements and feeding habits of spring migrating waterfowl was available to direct wetland conservation and management efforts in these areas. Waterfowl biologists have assumed that increased foraging habitat will benefit waterfowl survival and body condition, and the quality of wetland habitat for migrating waterfowl in spring is determined by how much food this habitat provides the birds. Food availability, in turn, is associated with the type of wetland habitat and management actions that are applied to this habitat.
To address these important questions, Ducks Unlimited and many conservation partners recently conducted a multi-year, landscape-level study on the habitat needs of waterfowl during spring migration in the Great Lakes and Upper Mississippi River watersheds. Specifically, this study examined waterfowl food availability, diet, feeding habits, body condition, and nutrient acquisition during spring migration. Findings from this research will be used to direct future wetland management and protection work in these important waterfowl migration corridors.
Spring migration research was conducted on six sites throughout the upper Mississippi Flyway.
To help ensure the findings would be relevant to the full spectrum of spring migrating waterfowl, researchers focused on five duck species with different body sizes, feeding regimes, migration habits, and breeding chronology. These ducks included mallards, scaup, gadwalls, blue-winged teal, and ring-necked ducks. We also chose six study sites that were representative of important spring staging areas (see map) across the Upper Mississippi and Great Lakes regions. At each site, food samples were taken in all wetland types, hens were collected and examined to determine their diet and body condition, and birds were observed in the wild to determine their feeding activity and use of different habitats.
Prior to this study, most waterfowl research focused on the birds' diet during the breeding season or winter. In general, ducks consume invertebrates high in protein during the breeding season, as protein acquisition is important for egg laying. During the fall and winter, ducks primarily focus on carbohydrates available in seeds, grain, and other plant foods to meet the energetic demands of harsh winter weather and fuel spring migration. The diet of spring migrating ducks has not been well documented, and it wasn't clear when ducks shift from a diet high in carbohydrates to protein as hens move north toward their breeding grounds. An understanding of diet and the factors that influence diet is important so managers can maximize production of preferred waterfowl foods in managed habitats.
Continue Reading >>