Skip to main content


Anatidae (ducks, geese, mergansers, pochards, sawbills, swans; class Aves, order Anseriformes) A family of mainly aquatic birds that have flat, lamellate bills, except for the six species of Mergus, the mergansers or sawbills, which feed on fish and have long, narrow, serrated bills, and shelducks (seven species of Tadorna), which are fairly large birds that resemble geese, and have short, slightly upturned bills. The front toes are webbed (the more terrestrial and non-migratory Branta sandvicensis, the Hawaiian goose or ne-ne, has reduced webbing and short wings). Many Anatidae show sexual dimorphism. They have thick feathers with insulating down. (Stifftails (six species of Oxyura) have long, stiff tail feathers and the males have long, blue bills.) The flight feathers are moulted simultaneously after breeding. They feed on vegetable and animal foods and nest on the ground or in holes in trees, among rocks, or in the earth, and the nest is usually lined with down. Eiders (three species of Somateria) are sea ducks, found in estuaries and coastal areas, as are scoters (three species of Melanitta) although these breed inland. Whistling ducks (eight species of Dendrocygna) are partially nocturnal. The largest genus, with 36 species, is Anas (dabbling ducks); A. platyrhynchos (mallard) is the ancestor of most domestic ducks. There are nine or 10 species of Anser (geese); A. anser (greylag goose), A. cygnoides (swan goose), and Cygnus olor (mute swan) are also extensively domesticated. C. atratus (black swan) has been introduced to New Zealand. Branta canadensis (Canada goose) has been introduced into Europe. There are 12 species of Aythya (pochards), some of which feed in sea water. Anseranas semipalmatis (magpie goose) occurs on the floodplains of northern Australia. There are 43 species, with cosmopolitan distribution.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Anatidae." A Dictionary of Zoology. . 17 Apr. 2019 <>.

"Anatidae." A Dictionary of Zoology. . (April 17, 2019).

"Anatidae." A Dictionary of Zoology. . Retrieved April 17, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.