Threatened species of water fowl

Water fowl have suffered greatly from habitat encroachment throughout the world; populations in the USA may be as little as one tenth of what they were before the coming of European civilization. For instance, the Redhead, a once popular and fairly common duck species, decreased in numbers from about 100,000 to fewer than 3,000 in the period from 1955 to 1974, a reduction in the population of 97.6%.

Examples of critically endangered species of Anseriformes (ducks, swans and geese) classified in 1993 by the IUCN as having a 50% probability of extinction within 5 years or 2 generations, whichever is longer, are: the Brazilian merganser Mergus octosetaceus with a known population of ca.20; Madagascar pochard Aythya innotata (one bird seen in the last 20 years); Madagascar teal Anas bernieri (only one breeding site known with 10 pairs in 1992); Campbell Island flightless teal Anas aucklandica nesiotis (population of 30-100); and the crested shelduck Tadorna cristata (last recorded in 1971).