Ключевые слова: animal, animalia, ardea, ardeidae, austria, aves, avian, beak, bill, bird, birdwatching, chordata, chordate, cinerea, color, danube, europe, eye, fauna, feathers, fish, great, grey, heron, horizontal, landscape, large, legs, long, natural, nature, neck, one, ornithology, outdoor, pelecaniformes, river, single, standing, vienna, watchful, water, waterbird, white, wild, wild life, wilderness, wildlife, wings,