The American tree sparrow (Spizelloides arborea), formerly known as the winter sparrow, is a medium-sized sparrow.It previously was classified under the genus Spizella, but multilocus molecular evidence suggested placement in its own genus.Adults have a rusty cap and grey underparts with a small dark spot on the breast. They have a rusty back with lighter stripes, brown wings with white bars and a slim tail. Their face is grey with a rusty line through the eye.