aggressive alert Australian bird common gymnorhina tibicen insectivore lookout Magpie protective sharp sharp eyed swoop swooping territorial watchful watching beak black bill black crown bright eyed cinnamon cleaning colored coloring colors coloured colouring colours fauna grooming head plumes Heron long white head plumes long yellow legs Nankeen night heron nocturnal nuptial plumes nycticorax caledonicus omnivore omnivorous plumes preening rufous night heron secretive shy stocky waterbird widespread wildlife black-bill black-crown bright-eyed head-plumes long-yellow-legs Nankeen-night-heron nuptial-plumes nycticorax-caledonicus perched plumage rufous-night-heron sharp-eyed Bird of prey large majestic powerful talons wedge-tailed eagle black-winged blue-black carnivore carnivorous crest crested egretta-picata green long-legged pied-egret Pied-Heron pond reeds reedy reflections sharp-beaked sharp-bill thin wader wading wading-bird water yellow-bill yellow-legged black-and-white gymnorhina-tibicen maggie mottled nesting nesting-material scavenging scrounging