The Ruddy Duck (Oxyura jamaicensis) is North American and has a wide range over most of the US, Mexico and parts of Canada.  They breed in marshy lakes or posts, with nests of grass hidden in tall vegetation and dive and swim underwater to feed on Arthropods and aquatic plants. Introduced into the UK in 1948, escapees became established there and in Europe, with about 6000 individuals.  Because of their aggressive courting and interbreeding, it was decided to cull them and  the population was reduced to about 20-100.