Australia Australian bird black black-swan cygnus-atratus dark emblem emblematic fauna green-water gregarious iconic large life-pairs pond protected protected-species red-beaked red-eyed reflections ripples rippling social swan swans swimming symbol symbolic water water-bird Western-Australian-State-emblem breeding burrows control damage damaging danger destructive devastating digging ecosystem environmental erosion feral invasive mammal mammalian pest pest pest control populated prolific rabbits reproductive spread threat uncontrollable widespread wild wildlife beaks birds blue branches Cockatoos corellas demonstrative docile eucalyptus-tree flock garden pest grazing gum-tree native Noisy pet root eater show-off talker tree vocal white anas superciliosa aquatic bird black eye-stripe brown duck common dark-brown duck fowl grey duck omnivore omnivorous Pacific black duck waterbird waterfowl wild duck Australian-sleepy-lizard blue-tongue blue-tongued-skink bobtail bobtail-goanna bogeyes crawling creature eyes goanna heavily-armored-body lizard mottled pinecone reptile scaly scaly-skin shingleback short-tailed Skink slow-moving stump-tailed-skink stumpy-tail tiliqua-rugosa tough-hide viviparous-skink