BLACK SWANS OF THE SWAN RIVER
The black swan (Cygnus atratus) is a large water bird species, which breeds mainly in the southeast and southwest regions of Australia. Black swans are mostly black-feathered birds with white flight feathers, the bill is bright red with a pale bar and tip. “Cobs” (males) are slightly larger than the “pens” (females) with a longer and straighter bill. Cygnets (immature birds) are a greyish brown with pale edged feathers.
A mature black swan measures between 110 and 142 centimetres (43 and 56 inches) in length and weighs 3.7 to 9 kilograms (8.2 -19.8 pounds) It’s wing span is between 1.6 and 2 metres (5.2 – 6.6 feet). The neck is long (relatively the longest neck among the swans) and is curves in an “S” – shape.
The black swan is common in the wetlands in South-West Western Australia, its known range is from the North West Cape to Cape Leeuwin and Eucla. Black swans were once thought to be sedentary (stay in one place) but the species is now known to be highly nomadic. The current global population is estimated to be up to 500,000 individuals. No threat to extinction or significant decline in population has been identified with this numerous and wild spread bird. Like other swans, the black swan is largely monogamous pairing for life. They are almost exclusively herbivorous, and while there is some regional and seasonal variation, there diet is generally dominated by aquatic and marshland plants. Black Swans like many other waterfowl lose their flight feathers at once when they moult after breeding and are unable to fly for about a month. During this time they settle on large and open waterways for safety. Both sexes incubate the eggs, with the female incubating at night. They change over between incubation periods is marked by ritualised displays by both sexes. If eggs accidentally roll out of the nest both sexes will retrieve the egg using their neck – in other swan species only the female will perform this feat..
The black swans role in Australian history heraldry and culture extends to the 18th century. It has often been equated with antipodean identity, the contrast to the white swan of the northern hemisphere indicating “Australianness”. The black Swan is featured on the state flag, and is both the state bird and state emblem of Western Australia; it also appears on the coat of arms and other iconography of the state’s institutions.
The state flag of Western Australia was officially adopted in 1870 and modified slightly in 1953