anas superciliosa aquatic bird Australian bird black eye-stripe brown duck common dark-brown duck fauna fowl grey duck omnivore omnivorous Pacific black duck waterbird waterfowl widespread wild duck grey orange swimming water ripples rippling anas-superciliosa aquatic-bird black-eye-stripe brown-duck grey-duck Pacific-black-duck pond wild-duck beautiful Dendrocygna eytoni eyes Eyton's Plumed feathers grass Grass Whistle Duck Grey or Red-legged Whistler Monkey Duck native nature ornithology plumed pretty Red-legged or Whistling Tree-duck resting standing Tree Duck wandering webbed feet whistling wild light paddling reflecting reflections sunlight sunshine surface surfaces wild-life chick direction ducklings follow follow-the-leader following guidance guiding lead leading mother protection protective shade shadows birds mates one leg pair walking