Swans are the largest extant individuals of the waterfowl own family Anatidae, and are among the most important flying birds. the largest species, consisting of the mute swan, trumpeter swan, and whooper swan, can reach a length of over 1.5 m (fifty nine in) and weigh over 15 kg (33 lb). Their wingspans can be over 3.1 m (10 toes). in comparison to the closely related geese, they are lots large and have proportionally larger toes and necks. Adults also have a patch of unfeathered pores and skin among the eyes and bill. The sexes are alike in plumage, but adult males are generally larger and heavier than female.
The Northern Hemisphere species of swan have pure white plumage however the Southern Hemisphere species are mixed black and white. The Australian black swan (Cygnus atratus) is completely black besides for the white flight feathers on its wings; the chicks of black swans are light gray. The South American black-necked swan has a white frame with a black neck.
Swans' legs are usually a darkish blackish gray colour, besides for the 2 South American species, that have pink legs. invoice coloration varies: the 4 subarctic species have black bills with various amounts of yellow, and all the others are patterned purple and black. despite the fact that birds do no longer have tooth, swans have beaks with serrated edges that appear like small jagged 'teeth' as a part of their beaks used for catching and eating aquatic vegetation and algae, however also molluscs, small fish, frogs and worms. The mute swan and black-necked swan have lumps at the bottom of their bills on the higher mandible
Swans feed in water and on land. they are nearly totally herbivorous, even though they'll consume small amounts of aquatic animals. inside the water, meals is acquired with the aid of up-ending or dabbling, and their diet is composed of the roots, tubers, stems and leaves of aquatic and submerged plant life.
Even though swans only reach sexual maturity between 4 and 7 years of age, they are able to shape socially monogamous pair bonds from as early as 20 months that ultimate for many years, and in some cases these can ultimate for existence. The lifespan of the mute swan is regularly over 10 years, and every now and then over 20, while the black-necked swan survives for less than a decade in captivity. these bonds are maintained yr-spherical, even in gregarious and migratory species just like the tundra swan, which congregate in huge flocks in the wintering grounds. Their nest is on the floor close to water and about a metre throughout. not like many different ducks and geese, the male helps with the nest creation. common egg size (for the mute swan) is 113×seventy four mm, weighing 340 g, in a take hold of length of four to 7, and an incubation duration of 34–45 days.with the exception of the whistling ducks they are the best anatids wherein the men resource in incubating the eggs.
Swans are recognised to aggressively shield their nests. One man turned into suspected to have drowned in such an assault.