An impossible bird

MountGrace explored a walk in Saratoga and found more black swans.
 
Black swans are found in all parts of Australia except Cape York. They make big, untidy nests which float or are placed on small islands in calm, foreshore water. Their plumage is all black, except for the white feathers on their wing tips.
 
Black swans are monogamous and pairs share parenting responsibilities. About a quarter of pairings are male - male. How do they acquire eggs? Apparently they steal them from hetero pairs or form temporary threesomes and drive the female away once she has produced eggs.
 
The black swan is the emblem of Western Australia. Black swans have spiritual significance for some First Nations people. They are often invoked in philosophical discourse as an example of an impossibility, since early settlers ‘knew’ from European experience that swans are white. One white black swan has been found, in Tasmania. Not an albino apparently but a rare genetic condition.