1. U.S. Fish and Wildlife Service, 2014,Waterfowl Population Status, 2014(Washington, DC: U.S. Department of the Interior), pp. 1–81.
2. North American Bird Conservation Initiative, U.S. Committee, 2009,The State of the Birds, United States of America, 2009(Washington, DC: U.S. Department of Interior), pp. 1–36.
3. North American Bird Conservation Initiative Canada, 2012,The State of Canada’s Birds, 2012(Ottawa: Environment Canada), pp. 1–36.
4. Canada Ministry of the Environment, U.S. Department of the Interior, and Mexico Secretariat of Environment and Natural Resources, 2012,North American Waterfowl Management Plan 2012: People Conserving Waterfowl and Wetlands(Washington, DC: U.S. Fish and Wildlife Service), pp. 1–48.