The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating on the water surface, and in some cases diving in at least shallow water. The family contains around 174 species in 43 genera (the magpie goose is no longer considered to be part of the Anatidae and is now placed in its own family, Anseranatidae).
The ducks, geese, and swans are small- to large-sized birds with a broad and elongated general body plan.
lamellae which are particularly well defined in the filter-feeding species.[2]
Their feathers are excellent at shedding water due to special oils. Many of the ducks display sexual dimorphism, with the males being more brightly coloured than the females (although the situation is reversed in species such as the paradise shelduck). The swans, geese, and whistling-ducks lack sexually dimorphic plumage. Anatids are vocal birds, producing a range of quacks, honks, squeaks, and trumpeting sounds, depending on species; the female often has a deeper voice than the male.[3]
Anatids are generally
mergansers, are primarily piscivorous, and have serrated bills to help them catch fish. In a number of species, the young include a high proportion of invertebrates in their diets, but become purely herbivorous as adults.[3]
Breeding
The anatids are generally seasonal and
extrapair copulation among anatids is common, occurring in 55 species in 17 genera.[4]
Anatidae is a large proportion of the 3% of bird species to possess a
brood parasite, laying its eggs in the nests of gulls and coots
. While this species never raises its own young, a number of other ducks occasionally lay eggs in the nests of conspecifics (members of the same species) in addition to raising their own broods.
Relationship with humans
Duck, eider, and goose feathers and down have long been popular for bedspreads, pillows, sleeping bags, and coats. The members of this family also have long been used for food.
Humans have had a long relationship with ducks, geese, and swans; they are important economically and culturally to humans, and several duck species have benefited from an association with people. However, some anatids are agriculturalpests, and have acted as vectors for zoonoses such as avian influenza.
Since 1600, five species of ducks have become
habitat loss and modification, and hybridisation with introduced ducks (for example the introduced ruddy duck swamping the white-headed duck
in Europe). Numerous governments and conservation and hunting organisations have made considerable progress in protecting ducks and duck populations through habitat protection and creation, laws and protection, and captive-breeding programmes.
The name Anatidae for the family was introduced by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1819.[8][9] While the status of the Anatidae as a family is straightforward, and which species properly belong to it is little debated, the relationships of the different tribes and subfamilies within it are poorly understood. The listing in the box at right should be regarded as simply one of several possible ways of organising the many species within the Anatidae; see discussion in the next section.
The systematics of the Anatidae are in a state of flux. Previously divided into six subfamilies,[
Subfamily: Anserinae, swans and geese (3–7 extant genera with 25–30 living species, mainly cool temperate Northern Hemisphere, but also some Southern Hemisphere species, with the swans in one genus [two genera in some treatments], and the geese in three genera [two genera in some treatments]. Some other species are sometimes placed herein, but seem somewhat more distinct [see below])
Cygnus, true swans (6 species, 4 sometimes separated in Olor)
Subfamily: Stictonettinae (one genus in Australia, formerly included in the Oxyurinae, but with anatomy suggesting a distinct ancient lineage perhaps closest to the Anserinae, especially the Cape Barren goose)
Aythyinae, diving ducks (Some 15 species of diving ducks, of worldwide distribution, in two to four genera; The 1986 morphological analysis[10] suggested the probably extinct pink-headed duck of India, previously treated separately in Rhodonessa, should be placed in Netta, but this has been questioned.[15] Furthermore, while morphologically close to dabbling ducks, the mtDNA data indicate a treatment as distinct subfamily is indeed correct, with the Tadorninae being actually closer to dabbling ducks than the diving ducks[13]
Tribe: Mergini, eiders, scoters, sawbills and other sea-ducks Common goldeneye couple, male on the right. (There are 9 extant genera and some 20 living species; most of this group occur in the Northern Hemisphere, but a few [mostly extinct] mergansers in the Southern Hemisphere)
Sarkidiornis, comb duck – Tadorninae or closer to dabbling ducks?
Tachyeres
, steamer ducks (4 species) – Tadorninae or closer to dabbling ducks?
Cyanochen
, blue-winged goose – Tadorninae or more distant clade?
Nettapus
, pygmy geese (3 species) – Anatinae or part of Southern Hemisphere radiation?
Pteronetta
, Hartlaub's duck – traditionally dabbling ducks, but may be closer to Cyanochen
Asarcornis
, Muscovy duck and white-winged duck, respectively (2 species) – traditionally dabbling ducks, but may be paraphyletic, with one species in Tadorninae and the other closer to diving ducks
Aix
, Mandarin duck and wood duck (2 species) – dabbling ducks or Tadorninae?
Callonetta
, ringed teal – dabbling ducks or Tadorninae?
Chenonetta, maned duck (1 living species) – dabbling ducks or Tadorninae? Includes Euryanas.
Marmaronetta
, marbled duck – formerly dabbling ducks; actually a diving duck or a distinct subfamily
Long-legged "shelduck", Anatidae sp. et gen. indet.
Kaua'i mole duck
, Talpanas lippa
Similarly, Branta rhuax from the Big Island of Hawaiʻi, and a gigantic goose-like anatid from Oʻahu are known only from very incomplete, and in the former case much damaged, bone fragments. The former has been alleged to be a shelduck,[18] but this was generally dismissed because of the damage to the material and biogeographic considerations. The long-legged Kauaʻi bird, however, hints at the possibility of a former tadornine presence on the archipelago.
Fossil Anatidae
The fossil record of anatids is extensive, but many prehistoric genera cannot be unequivocally assigned to present-day subfamilies for the reasons given above. For prehistoric species of extant genera, see the respective genus accounts.
Dendrocheninae – a more advanced relative of the whistling-ducks or an ancestral relative of stifftail ducks paralleling whistling-ducks; if not extinct possibly belong in Oxyurinae (including Malacorhynchus)
Mionetta (Late Oligocene – Middle Miocene of C Europe) – includes "Anas" blanchardi, "A." consobrina, "A." natator, "Aythya" arvernensis
Manuherikia
(Bathans Early/Middle Miocene of Otago, New Zealand)
Aldabranas (Late Pleistocene of Aldabra, Indian Ocean) – anatine or tadornine* "Anas" albae (Late Miocene of Polgárdi, Hungary) – mergine? Formerly in Mergus
"Anas" eppelsheimensis (Early Pliocene of Eppelsheim, Germany) – anatine?
"Anas" isarensis (Late Miocene of Aumeister, Germany) – anatine?
"Anas" luederitzensis (Kalahari Early Miocene of Lüderitzbucht, Namibia) – anatine?
"Anas" meyerii (Middle Miocene of Öhningen, Germany) Described from a single badly crushed tarsometatarsus and phalanges. This species was named in 1867 by Milne-Edwards and then recombined in 1964 by Brodkorb to the genus Aythya. This species is currently regarded as Aves incertae sedis.[19]
"Anser" scaldii (Late Miocene of Antwerp, Belgium) – anserine or tadornine* Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – anatine, oxyurine?
"Anas" velox (Middle–Late? Miocene of C Europe) – anatine? May include "A." meyerii
Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – tadornine?
Anatidae gen. et sp. indet. MNZ S42797 (Bathans Early/Middle Miocene of Otago, New Zealand)
Anatidae gen. et sp. indet. (Middle Miocene of Nördlinger Ries, Germany) – tadornine?
Anatidae gen. et sp. indet. (Sajóvölgyi Middle Miocene of Mátraszõlõs, Hungary)[20]
"Aythya" chauvirae (Middle Miocene of Sansan, France and Credinţa, Romania) – 2 species
Caerulonettion (Early Miocene of France and the Czech Republic, Middle Miocene of Germany)
"Chenopis" nanus (Pleistocene of Australia) – at least 2 taxa, may be living species
The Middle Oligocene Limicorallus (from Chelkar-Teniz (Kazakhstan) was sometimes considered an anserine. It is now recognized as a primitive cormorant. The middle Eocene Eonessa was formerly thought to belong to Anatidae, however reexamination of the holotype in 1978 resulted in the genus being placed as Aves incertae sedis.[1]
^Leach, William Elford (1819). "Eleventh Room". Synopsis of the Contents of the British Museum (15th ed.). London: British Museum. pp. 63–68 [67]. The name of the author is not specified in the document, Leach was the Keeper of Zoology at the time.
Gonzalez, J.; Düttmann, H.; Wink, M. (2009). "Phylogenetic relationships based on two mitochondrial genes and hybridization patterns in Anatidae". Journal of Zoology. 279 (3): 310–318.