beak bird 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 sharp sharp eyed shy stocky waterbird widespread wildlife attract-prey attracted attraction carnivore carnivorous carnivorous-plants clumps clusters cover devour digest digested digesting display distinctive edge edges enzymes flora flowers funnel herbaceous insect-trap insects nectar-like-secretions nutrient-source nutrients operculum passive-trap perennials pitcher-plants pitchers pitfall-traps plants prey proteases rims slippery species trap unusual variations variety vegetation veins