United States Department of the Interior - Fish and Wildlife Service
Waterfowl are the most prominent and economically important group of migratory birds in North America. They are highly prized as gamebirds by millions of hunters in Canada, the United States and Mexico, and attract the attention of even alrger numbers of people who enjoy observing them. Waterfowl generate a direct expenditure in excess of several billions of dollars annually. North America is blessed with an abundance and diversity of wetland ecosystems. Wetland complexes and associated uplands are an integral part of the landscape and provide immeasurable ecological, social and economic benefits. Wetland basins collect and store runoff, thus replenishing aquifers and ground-water supplies needed to sustain natural vegetation, crops and wildlife. Wetlands play a role in purification of water supplies, prevent soil erosion, and moderate regional impacts of drought and flooding. The wetlands of North America provide habitat for 37 species of waterfowl which together constitute an important component of the continent's natural heritage.
United States Department of the Interior - Fish and Wildlife Service, Environment Canada - Canadian Wildlife Service. 1986. North American Waterfowl Management Plan