Australia Australian bird black black swan Cygnus atratus emblem emblematic fauna gregarious iconic large life pairs pair protected protected species red beaked red eyed ripples rippling river social swan swans swimming symbol symbolic water bird Western Australian State emblem black-swan curved-neck cygnus-atratus dark elegance elegant long-necked protected-species red-beaked red-eyed water-bird Western-Australian-State-emblem wildlife estate Gateshead Gibside heritage national trust North East park reflections green-water life-pairs pond water