Ключевые слова: behind, bird, birdie, black, build, chicks, collecting, common, common house martin, cute, delichon, delichon urbicum, europe, european, family, fauna, feathers, feeding, flight, fly, glass, house, house martin, little, looks, martin, migration, migration birds, migratory, migratory bird, mud, nest, nestling, northern, one, ornithology, pellets, ringing, season, small, swallow, swallow bird, tail, town, tracking, urban, urbicum, white, window, wings,