Swans feed in the water and on land. They are almost entirely herbivorous, although they may eat small amounts of aquatic animals.
What is a swan?
Although swans only reach sexual maturity between 4 and 7 years of age, they can form socially monogamous pair bonds from as early as 20 months that last for many years, and in some cases these can last for life. The lifespan of the mute swan is often over 10 years, and sometimes over 20, whereas the black-necked swan survives for less than a decade in captivity. These bonds are maintained year-round, even in gregarious and migratory species like the tundra swan, which congregate in large flocks in the wintering grounds.
Their nest is on the ground near water and about a metre across. Unlike many other ducks and geese, the male helps with the nest construction. With the exception of the whistling ducks they are the only anatids where the males aid in incubating the eggs. Swans are known to aggressively protect their nests. One man was suspected to have drowned in such an attack.
Distribution and movements
They are generally found in temperate environments, rarely occurring in the tropics. A group of swans is called a bevy or a wedge in flight. Four (or five) species occur in the Northern Hemisphere, one species is found in Australia and New Zealand and one species is distributed in southern South America. They are absent from tropical Asia, Central America, northern South America and the entirety of Africa. One species, the mute swan, has been introduced to North America, Australia and New Zealand.
Several species are migratory, either wholly or partly so. The mute swan is a partial migrant, being resident over areas of Western Europe but wholly migratory in Eastern Europe and Asia. The whooper swan and tundra swan are wholly migratory, and the trumpeter swans are almost entirely migratory. There is some evidence that the black-necked swan is migratory over part of its range, but detailed studies have not established whether these movements are long or short range migration.
Image: Matthew Wiebe
Text: Wikipedia contributors. “Swan.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 11 Jun. 2016. Web. 17 Jun. 2016.