American tree sparrow, Animalia, Aves, Chordata, Emberizidae, North America, Passeriformes, Pine, S. arborea, Spizella, Spizella arborea, US, USA, Wisconsin, adult, animal, bill, bird, black, brown, cold, cute, early spring, fauna, feathers, grey underparts, lower bill yellow, march, natural, nature, north american, north woods, northern, northwoods, outdoors, outside, perch, perched, pine tree, red pine, red pine tree, rusty cap, small bird, snow, snowing, song bird, songbird, sparrow, spring, spring time, tree, tree branch, tree sparrow, two white wing bars, under bill dark, white, wild, wildlife, winter