Ключевые слова: america, animal, avian, beak, bird, birding, birdwatching, black, blackbirds, cloud, cloudy, cluster, dense, enormous, fauna, feather, flight, flock, flying, group, habitat, huge, massive, migration, movement, moving, murmuration, native, natural, nature, on the wing, ornithology, outdoor, outdoors, outside, overhead, park, pattern, pennsylvania, sky, swarm, united states, usa, white, wild, wildlife, wing,