Ключевые слова: abstract, animal, ardea, background, beak, bill, biology, bird, blue, china, cinerea, closeup, copulation, ecological, ecology, environment, fauna, feather, forest, gray, great, green, grey, heron, large, love, mating, natural, nature, neck, nest, ornithology, outdoor, park, plumage, protection, stand, tree, white, wild, wildlife, wing,