Black Swans are large waterbirds that measure between 1.1 and 1.4 m (3.5 - 4.5 ft) in length. They have a wingspan between 1.6 and 2 m (5.2 - 6.5 ft) and they weigh between 6 and 9 kgs (13 - 20 lbs).
Their feathers are mainly black in colour but they have a line of white flight feathers on the edges of their wings. These feathers are sometimes on show when they are at rest but they are conspicuous in flight. Their bill is bright red with a pale bar and tip, and their legs and feet are grey/black in colour. They moult once a year after breeding and during this time they cannot fly.
Their neck is long and "S" shaped and while swimming they either hold their neck arched or straight and they often carry their wings raised in an aggressive display.
In flight a group of swans will either fly in a line or in a "V" shape. Each individual will fly strongly making a whistling sound with their wings and a baying, bugling or trumpeting calling sound. As well as a bugling call, Black Swans can also make whistling sounds and softer more crooning notes.
Male Black Swans are slightly larger than females and they have a longer, straighter bill.
Black Swans are found in the wetlands of Australia and New Zealand. They are nomadic birds with no set migratory pattern, they have opportunistic responses to either rainfall or drought.
Black Swans feed on aquatic plants and when on land they graze on grass.
Black Swans pair up for life and they build their nests in the wetter months from February to September. Most swans will not allow other swans into their territory during the breeding season, but Black Swans are the exception to this and they often build nests in colonies. Both the male and female contribute to the nest building and the nest consist of grasses, weeds and reeds. The dimensions of the nest are approximately 1 - 1.5 m (3.3 - 4.9 ft) in diameter and up to 1 m (3.3 ft) in height.
4 - 7 greenish/white eggs are laid and they are incubated for 35 - 40 days by both of the parents. The cygnets are greyish/brown in colour with pale edging on their feathers. After 3 - 4 weeks their new feathers begin to grow and the young swans quickly learn to swim and feed themselves. Sometimes they will ride on their parents back for longer trips into deeper water.
The young swans are tended to by their parents for 6 - 9 months until they fledge and go off and find their own territory.