Ключевые слова: animal, background, beautiful, bird, birds, calories, chickadees, cold, color, conditions, diet, difficult, fat, fauna, feed, feeding, grease, great tit, grey, human activity, hungry, ice, nutrition, nuts, ornithology, paridae, passerine, peanuts, plenty, plumage, protein, seeds, small, snow, source, survival, tit, titmice, tits, white, winter,