Waterfowl such as ducks, geese, and swans are among the best known birds, with webbed feet and water-repellent feathers that let them float and swim easily. Often striking in plumage, they live in watery habitats from the arctic to the tropics. Dabbling ducks feed by tipping tail-up in the water and can spring directly into flight, while diving ducks go deep in search of food and must run across the water surface to take flight. Wetlands are a vital link in the natural system that supplies the water sustaining all life, and they lessen the destructive effects of storms and floods, cleanse water of pollutants, recharge groundwater supplies, provide homes for many kinds of wildlife, and offer beautiful places for people to enjoy the outdoors. Yet each year the United States loses another two percent of its remaining wetlands, an astonishing 290,000 acres, to agriculture, development, mining, and other purposes.