Ключевые слова: animal, bank, beautiful, bird, brown, closeup, colony, color, conservation, cute, fauna, flight, flying, habitat, hole, holes, material, migrant, migratory, mud, natural, nature, nest, nesting, nice, ornithology, parents, riparia riparia, sand martin, small, songbird, spring, swallow, swallows, tunnel, wild, wilderness, wildlife,