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The Anatidae, is a group or family of birds among which include ducks, geese and swans, they are distributed by the 5 continents of the world. In the following article we will know a little more about this group of birds called the Anatidae, what is their diet, how is their habitat, what are the different species that exist and which are the ones that ceased to exist, discover this and much more.

Definition of Anatidae

The Anatidae or Anatidae are the biological family of birds that tend to include ducks, geese and swans. The family has a cosmopolitan distribution, occurring on all continents of the world. These birds are adapted to be able to swim, floating on the surface of the water and, in some cases, also diving at least in waters that are shallow.

The Anatidae or Anatidae family has approximately 146 species distributed in 43 genera. The magpie goose is no longer considered part of the Anatidae, but is placed in its own family of the Anseranatidae.

They are generally herbivorous birds and are also known to be monogamous breeders. Several of the species undertake annual migrations. Some of the species have been domesticated for agriculture, and many of the species are hunted for food and recreation. Only 5 of the species have become extinct since 1600 and many more are endangered.

Description

Ducks, geese and swans are small to large birds with a broad, elongated overall body plan. Diving species tend to vary from this in being more rounded. Existing species vary in size from the cotton pygmy goose, which is only 26.5 cm long and weighs about 164 grams, to the trumpeter swan, which is about 183 cm long and weighs 17.2 kg.

The wings of these birds are short and pointed, and are supported by strong wing muscles that generate rapid flapping in flight. They usually have long necks, although this also varies in degree between species. The legs are short, strong and set far back from the body, more so in species that are aquatic, and have a leathery feel with a scaly texture.

Combined with their body shape, this can make some of the species more awkward on land, but they are more walkable than other seabird species and also waterfowl species such as grebes or petrels. They usually have webbed feet, although in some species such as the Nenehan they secondarily lose their webbing.

The beads are made of soft keratin with a very thin, sensitive layer of skin on top that has a sort of leathery feel when touched. For most species, the shape of the bill is usually to more flattened to a greater or lesser extent. These contain serrated lamellae that are particularly well defined in filter-feeding species.

Reproduction

Anatidae or Anatidae are generally seasonal breeders and are called monogamous. The level of monogamy tends to vary within the family; many of the smaller ducks only hold the bond for a single season and find a new mate the next year, whereas in the case of the larger swans, geese and some of the more territorial ducks maintain pair bonds for several years, and even for life in some species.

However, forced extra-pair copulation among the Anatidae is very common, occurring in 55 of the species in all 17 genera.

The Anatidae or Anatidae is a large proportion of the 3% of male bird species that possess a penis, although they vary significantly in size, shape and surface elaboration. Most species are adapted for copulation in water only. They usually build nests simply and of whatever material is at hand, often lined with a layer of down that is plucked from the mother’s breast.

In most species, only the female is responsible for incubating the eggs. The young are precocious and can feed themselves from birth. One aberrant species, the black-headed duck, is an obligate brood parasite, laying its eggs in the nests of gulls and coots.

Egg Incubation

Eggs are usually incubated for about 22 to 40 days and hatching is synchronous within 24 hours. Several days before hatching, the young chicks begin to call from inside the eggs. The chicks are precocial, called nidifugous, and they tend to hatch with their eyes open. The chicks can walk and swim within hours after hatching. Females feed themselves as long as they stay close to the mother.

Breeding

Fledging of the chicks occurs at 5 to 10 weeks. In some of the species, the young of the year will return to the breeding sites with the parents for at least 1 to 2 years. Acquisition of adult plumage may take as long as 1 to 3 years. Most ducks are sexually mature when they reach the age of 1 to 2 years, while geese and swans may reach maturity at 5 years. The life expectancy in the wild for these individuals that survive to their 1st year may be 1 or 2 years longer for ducks and 4 or more for geese and swans.

Relationship with Humans

Duck, eider, goose feathers have long been very popular for quilts, pillows, sleeping bags and also for coats. Members of this family have also long been used for food.

Humans have had a long relationship with ducks, geese and swans; they are very important economically and also culturally to humans, and several of the duck species have benefited from an association with people. However, some of the Anatidae are harmful to agricultural pests and have acted as vectors of zoonoses such as avian influenza.

Since the 1600s, 5 of the duck species have become extinct due to human activities and subfossil remains have come to show that humans caused numerous extinctions in prehistoric times. Today, many more are considered threatened.

Most of the historical and prehistoric extinctions of these species were island species, all vulnerable due to small populations that were often endemic to an island, and island tameness. Having evolved on islands that lacked predators, these species lost their anti-predator behaviors, as well as the ability to fly, and were vulnerable to pressure from human hunting and introduced species.

Systematics

The Anatidae family was introduced by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1820. While the status of the Anatidae as a family is straightforward, and to which species they properly belong. It is little debated, the relationships of the different tribes and subfamilies within it which are little known.

The systematics of the Anatidae is in a state of flux.Previously divided into 6 subfamilies, a study of anatomical characters by Livezey suggests that the Anatidae are best treated in 9 subfamilies. This classification was popular in the late 1980s to 1990s. However, mtDNA sequence analyses have shown, for example, that diving and diving ducks do not belong to the same subfamily.

Although deficiencies certainly occur in Livezey’s analysis, mtDNA is an unreliable source of phylogenetic information in many waterfowl especially ducks because of its ability to produce fertile hybrids, in those cases that are rare possibly even beyond the genus level. Because the sample size of many of the molecular studies available to date was very small, mt DNA results should be viewed with great caution.

Prehistoric Species

From the subfossil bones that have been found on Kaua’ i in the Hawaiian Islands, 2 enigmatic waterfowl are known. The living and assignable prehistoric avifauna of the archipelago contains as Anseriformes the Branta geese and their descendants, and the moa-nalos as mentioned above. ( see article: White Swan ).

The following taxa, while certainly new species, cannot even be assigned to the subfamily; because Kaua ‘ i is the oldest of the large Hawaiian Islands, which means that the species may have been evolving in isolation for nearly 10 million years i.e. may have been from the upper Miocene, and because of this helps us determine their affinities:

In much the same way, the Branta rhuax from the Big Island of Hawaii , and a giant goose anatid from O ‘ ahu these 2 are known only from certain bone fragments which are very incomplete, and in the former case badly damaged. The former has been alleged to be a shelduck, however this was generally discounted because of the great damage to material and biogeographical considerations. The long-legged Kaua ‘ i bird, however, hints at the possibility of an ancient Tadornine presence in the archipelago.

Anatidae or Anatidae fossil

The fossil record of the Anatidae or Anatidae is somewhat extensive, but many of the prehistoric genera cannot be unequivocally assigned to present-day subfamilies for reasons that are stated above. For the most prehistoric species of extant genera, see the respective genus accounts.

Dendrocheninae

A relative that is either a more advanced relative of the whistling ducks or an ancestral relative of the hairy ducks in parallel to the whistling ducks; if not found extinct, possibly belonging to the Oxyurinae including Malacorhynchus.

Anatidae that are putative or disputed prehistoric are as follows:

The middle Oligocene Limicorallus which is from Chelkar – Teniz of Kazakhstan regions is sometimes considered anserine.

However, it is a primitive cormorant. It was believed that this bird that the middle Eonessa Eonessa belonged to the Anatidae, however, the reexamination of the holotype in 1978 resulted in the genus being placed as the Aves incertae sedis.

The Genres

The Anatidae or Anatidae are comprised of 49 genera and also 5 subfamilies which are:

• The Anatinae
• The Anserinae
• The Dendrocygninae
• The Stictonettinae
• The Tadorninae

The largest subfamily of all is the Anatinae, which includes about 8 groups, namely:

• The Tadornini (shelducks and allies: 5 genera, 14 species)
• The Tachyerini (steamer ducks: one genus, 4 species)
• The Cairini (perching ducks and allies: 9 genera, 13 species)
• The Merganettini (Torrent Duck (Merganetta armata)
• The Anatini (dabbling ducks: 4 genera, 40 species)
• The Aythyini (pochards: 2 genera, 15 species)
• The Mergini (mergansers and allies: 7 genera, 18 species)
• The Oxyurini (stifftails: 3 genera, 8 species)

Subfamily of the Dendrocygninae

A pantropical genus of distinctive, long-legged, goose-like birds.

The Anserinae subfamily

They are the swans and geese which correspond to 3 to 7 existing genera with more than 25 to 30 living species, mainly in the cold temperate northern hemisphere, but also some of the species in the southern hemisphere, with the swans in one genus 2 genera in some treatments, and the geese in 3 genera 2 genera in some treatments. Some of the other species are sometimes placed here, but appear somewhat more distinct.

The Subfamily of Stictonettinae

A genus from regions of Australia, formerly included in the Oxyurinae, but with an anatomy suggesting a distinct ancient lineage, perhaps closest to the Anserinae, especially the Cape Sterile Goose.

The Plectropterinae Subfamily

It is of a genus in Africa, formerly included in the “perching ducks”, but closer to the Tadorninae.

The Tadorninae Subfamily – Shelducks and Sheldgeese

This is a group of larger, often semi-terrestrial, waterfowl that can be seen as intermediate between the Anserinae and the Anatinae. Revision in 1986 has resulted in the inclusion of 10 extant genera with approximately 2 dozen living species of which 1 is probably extinct.

In this subfamily, mainly from the Southern Hemisphere, but some also in the Northern Hemisphere, but the affiliations of several putative tadornine genera have later been questioned and the group in the traditional alignment is likely to be paraphyletic.

Subfamily of the Aythyinae

They are the diving ducks about 15 species of diving ducks, from worldwide distribution, from 2 to 4 genera; Morphological analysis in the year 1986 suggested that probably the extinct pink-headed duck from India, previously treated separately in Rhodonessa, should be placed in the Netta, but this has been questioned.

Also, although morphologically close to ducks, mtDNA data usually indicate that a treatment as a distinct subfamily is actually correct, with the Tadorninae actually closer to the diving ducks.

• Aythya, pochards, scaups, etc. are 12 species.

The Anatinae Subfamily

What are ducks and moa – nalos. The globally distributed group of diving ducks was formerly limited to 1 or 2 genera, but had been further extended to include about 8 extant genera and about 55 living species, including several genera formerly known as the “perching ducks”; mtDNA, on the other hand, confirms that the Anas genus is overexploited and calls into question the affiliations of the diving ducks of several genera.

The moa – nalos, of which 4 of the species themselves only 3 genera are known to the present day, are a peculiar group of flightless anatidae and are extinct from the Hawaiian Islands. Gigantic in size and with huge bills, they were thought to be geese, but have been shown to be closely related to mallards. They evolved to fill the ecological niche of turtles, ungulates and other megaherbivores.

• Anas, ducks, mallards, etc. are 40 to 50 living species, of which 3 are extinct

The Tribe of Mergini, Eiders, Scoters, Sawbills and other Sea Ducks

There are about 9 extant genera and about 20 living species, most of them of this group occur in the northern hemisphere, but a few of the mergansers are mostly extinct in the southern hemisphere.

The Oxyurini Tribe, Stiff-tailed Ducks

A small group of 3 or 4 genera, 2 or 3 of which are monotypic, with 7 or 8 species that are living.

The Irresolute

The greatest degree of uncertainty that exists among scientists concerning whether a number of genera found closer to sheds or ducks.

• Cereopsis, Cape Barren Goose – Anserinae, Tadorninae, or subfamily proper

• Malacorhynchus, pink-eared ducks 1 living species – Tadorninae, Oxyurinae or Dendrocheninae
• Pteronetta, Hartlaub’s duck: ducks that traditionally dabble, but may be closer to Cyanochen
• Cairina, Muscovy duck and white-winged duck 2 species, ducks that traditionally dive, but may become paraphyletic, with one species in Tadorninae and the other closer to the diving ducks
• Marmaronetta, marbled duck, formerly ducks actually a diving duck or a distinct subfamily

Distribution and Habitat

Anatidae tend to be distributed throughout the world, with the exception of the Antarctic region. Anatidae inhabit aquatic habitats such as lakes, ponds, streams, rivers and marshes. Some of the taxa inhabit marine environments outside the breeding season.

Feeding

Anatidae taxa are mostly herbivorous, however in some cases they may also forage on aquatic invertebrates. Many of the Anatidae feed on seeds, roots, stems, leaves and flowers of aquatic vegetation. Some of them also have a diet of plankton or algae. Other foods that can be included are: mollusks, aquatic insects, crustaceans and also small fish.

Predators

Predatory mammals of the Anatidae or Anatidae can be mentioned the:

Predatory birds of the Anatidae include the:

Behavior

Some of the Anatidae species are aggressively territorial, while others are peaceful and make colonial nests. Colonies are usually small in size ranging from several dozen to more than 100 pairs. Anatidae usually breed seasonally although some species maintain territories year-round.

Nest sites usually vary from shallow scrapes in the ground, mounds of plant material on land or in water, to nests in trees. Material that is used for nesting includes vegetation as well as feathers. Clutch size tends to range from 4 to 13 eggs with an egg-laying interval of 24 hours. Females of some species will lay eggs in the nests of other females. Some species are parasitic and will lay eggs in the nests of other species.

Anatidae of Spain

The Anatini group. Also known as Surface Ducks. They are small to large birds, which feed on the surface of the water. They live in shallow waters. To grasp food when the water is a little deeper, they submerge the front of the body, leaving only the tail out. The following species are found in the regions of Spain: