Habitat selection and activities of dabbling ducks during non-breeding periods

Western Tennessee is an important region for waterfowl during non-breeding periods, supporting >40% of the Mississippi Flyway population of American black ducks (Anas rubripes). Understanding habitat selection and activities of waterfowl during the non-breeding period is important for directed habitat management on national wildlife refuges and in other wetlands important in meeting regional waterfowl conservation objectives. During November–February 2011–2013, we investigated diurnal habitat selection and activities of dabbling ducks (Anatini) among 5 common wetland types relative to emergent cover, water depth, and energetic carrying capacity (i.e., duck energy days [DEDs]) in western Tennessee, USA. We observed waterfowl daily and sampled food resources monthly at Tennessee and Cross Creeks National Wildlife Refuges. Mallard (Anas platyrhynchos), gadwall (A. strepera), northern pintail (A. acuta), and American green-winged teal (A. carolinensis) selected moist-soil wetlands over wooded, aquatic bed, and open water wetland types. Gadwall also selected deeper wetlands containing submersed aquatic vegetation. Foraging was the dominant activity of all dabbling ducks in mudflats and moist-soil wetlands, and it was also dominant in wooded wetlands for green-winged teal and gadwall. Deep, open water was avoided by dabbling ducks. Selection of wetland types was negatively correlated with increasing water depth and positively correlated with increasing emergent cover and DEDs. Shallowly flooded moist-soil and wooded wetlands provide high-energy foods and dense emergent cover, and are important to a diversity of dabbling ducks during winter. © 2017 The Wildlife Society.