The Black Swan are one of the largest flying birds and waterfowls in the Anatidae family, which includes ducks and geese. They are cousins to the White mute swan, and both belong to the Cygnus genus. Although their coloring are different, their behavior is quite similar such as their nomadic tendencies, caring of their young and their diet. The Black Swan possesses white flight feathers that can be only visible during flight, and they also make a variety of noises such as tooting, whistling, hissing, grunting (when they are caring for their young) sometimes bark like dogs. They are also known for 'mating for life' bonds or monogamous breeding, where both male and female parents share responsibility during incubation period.
An adult usually weight from 8 to 20 pounds, its wingspan stretching from 110 to 142 cm.


Black swans are native to Australia and Tasmania, they are found in south western and eastern of Australia, although uncommon in central and northern Australia. They are also found on New Zealand, although they are hunted to extinction, they are still found on some parts of New Guinea.
Figure 1: Black Swan population

Black Swans are highly nomadic; their settlement patterns depends on migration path and climate conditions. They are typically found in wetlands. Black Swans prefer fresh water or brackish water, swamps, fresh waterways and permanent wetlands; it must have at least 40m or more water to take off. Most importantly, the environment must have underwater/developing vegetation and reeds or any material suitable for nest building.

The Black Swan does not have any natural predators, as its size is larger than an average waterfowl. Main predators of Black Swans are humans, owls (stealing their eggs) and coyotes (preying on the swan). Black swans are mainly herbivores; they feed on algae and aquatic and marshland plants, it is obtained by plunging its neck up to 1 meter deep


The Black swan developed fine grooves along their bills to help their grip on underwater plant. This enabled black swans to pull aquatic plants off easier, as this is their main diet; this is crucial to their survival. It also helped them grab more plants off the riverbed.
It swims with one leg, the other tucked above its tail. This allows the swan to change direction more smoothly when it’s swimming on surface of water (spotting food or predator).
Black Swans possess long necks and swims with one leg, the other tucked away

It has also developed 20 to 25 vertebrates in their necks to provide great flexibility in neck (in result neck is by far the longest out of all waterfowls). This allowed the swan to just dip in the water and feed on underwater plants (ease and comfort)
Developed at least 20 to 25 vertebrates in the neck

Aside from that, the black swan also have bigger bills to snatch up more water, filter-feeding mechanism developed from pre-historic animal (Presbyronis). These gave the black swan more of a chance at feeding plants, and avoid competition with smaller ducks or other waterfowls
Fine groves along developed bill to ease clutch of vegetation

The black swans are very protective of eggs (or clutch). During incubation, the pen (female swan) begins to molt (change ‘skin’ of fur) during clutch protection and cannot fly until cob (male swan) begin to molt. This ensures the clutch is protected with one ground parent at all times. Also, there is not a time where both parents can take flight.
Always a parent guarding the nest

Environmental Pressure:

1. Adapted to live on water
The black swan is equipped with a streamline body shape, long neck, and webbed feet. This enables survival in aquatic environment. It also developed a new technique of swimming with one leg which enabled them to change directions while on water, instead of stopping and turning the whole torso around.

2. Nest building. Black swans developed finer bills for the ability to carry more reeds and grasses for their nests in anticipation for incubation.

3. Rise of predators previously unknown to Australia e.g. the fox and the dog leads to fiercer temperament to defend clutch in result, they have become family-orientated birds as black swans build nests and raise young in colonies (this behavior is not common among other swans)
* Note, they are nomadic birds although they nest together as a colony for the protection of their young. This characteristic was passed down from ancient ancestors.

4. Unknown Predators (due to nomadic trait)
This lead to the Black Swan growing larger (gigantism), this is to scare away other animals and because of this, swans don’t have any natural predators.

5. Competition for food
The black swan developed a long neck that helped them ‘dive’ for food in deeper water with ease. Ducks or other similar fowls would have to fully submerge themselves to reach such a height.

For your entertainment :)

a.) Presbyornis
b.) Future Black Swan


Wikipedia . (2010, May 4). Black Swan. Retrieved June 24, 2011, from Wikipedia:
Australian Museum. (2010, September 16). Black Swan. Retrieved June 25, 2011, from Animal Species :
A-Z of Animals 2011. (2007). Swan. Retrieved June 24, 2011, from A-Z of Animals 2011:
Blank Zoo Park 2011. (n.d.). Black Swan. Retrieved June 24, 2011, from
Honolulu Zoo. (2008). Black Swan. Retrieved June 25, 2011, from
Japan Science and Technology Agency. (2011, March 10). The Future of Animal Behavior Research . Retrieved June 26, 2011, from Science Links :
Johnson, C. (2007). Climate Change. Retrieved June 26, 2011, from Future Climate Australia:
Manhattan, Kansas . (n.d.). Black Swans. Retrieved June 23, 2011, from