Swan

Swans are winged creatures of the family Anatidae inside the variety Cygnus. The swans' nearest family members incorporate the geese and ducks. Swans are gathered with the firmly related geese in the subfamily Anserinae where they structure the clan Cygnini. Here and there, they are viewed as a particular subfamily, Cygninae. There are six living (and numerous wiped out) types of swan; likewise, there is an animal categories known as the coscoroba swan which is not, at this point thought about one of the genuine swans. Swans as a rule mate forever, in spite of the fact that "separate" in some cases happens, especially following settling disappointment, and if a mate passes on, the rest of the swan will take up with another. The quantity of eggs in each grip ranges from three to eight.

The English word 'swan', much the same as the German Schwan, Dutch zwaan and Swedish svan, is gotten from Indo-European root * swen (to sound, to sing). Youthful swans are referred to as swanlings or as cygnets; the last infers through Old French cigne or cisne (minute postfix - and "little") from the Latin word cygnus, a variation type of cycnus "swan", itself from the Greek κύκνος kýknos, an expression of a similar significance. A grown-up male is a cob, from Middle English cobbe (pioneer of a gathering); a grown-up female is a pen.

Swans are the largest extant members of the waterfowl family Anatidae, and are among the largest flying birds. The largest species, including the mute swan, trumpeter swan, and whooper swan, can reach a length of over 1.5 m (59 in) and weigh over 15 kg (33 lb). Their wingspans can be over 3.1 m (10 ft). Compared to the closely related geese, they are much larger and have proportionally larger feet and necks. Quite unusual for birds, swans have "teeth" - jagged parts of their bill that are used for catching and eating fish. Adults also have a patch of unfeathered skin between the eyes and bill. The sexes are alike in plumage, but males are generally bigger and heavier than females.

The Northern Hemisphere species of swan have pure white plumage but the Southern Hemisphere species are mixed black and white. The Australian black swan (Cygnus atratus) is completely black except for the white flight feathers on its wings; the chicks of black swans are light grey. The South American black-necked swan has a white body with a black neck.

Swans' legs are normally a dark blackish grey colour, except for the two South American species, which have pink legs. Bill colour varies: the four subarctic species have black bills with varying amounts of yellow, and all the others are patterned red and black. Although birds do not have teeth, swans have beaks with serrated edges that look like small jagged 'teeth' as part of their beaks used for catching and eating aquatic plants and algae, but also molluscs, small fish, frogs, and worms. The mute swan and black-necked swan have lumps at the base of their bills on the upper mandible.