Ключевые слова: animal, animals, avian, biodiversity, bird, birds, cold, eat, eating, eurasian tree sparrow, eurasian tree sparrows, fauna, feed, feeding, food, freeze, freezing, frost, frosted, frozen, german sparrow, german sparrows, ground, hokkaido, ice, icy, japan, kushiro, kushiro japanese crane reserve, natural, nature, one, ornithology, passer montanus saturatus, passerine, passerines, snow, species, subspecies, tree sparrow, tree sparrows, wild, wildlife, winter, zoology,